Dementia

Listening to music and playing an instrument is linked to lower dementia risk. doi.org

Aging Dementia

Cognitive decline and dementia are major challenges in aging societies, and with no treatment that can cure these conditions, prevention plays a central role in public health. In a large Australian cohort, researchers asked whether older people's patterns of listening to music or playing a musical instrument predicted later cognitive performance.

The study followed 10,893 community-dwelling older adults for roughly nine years. Participants were cognitively healthy at enrollment. About three years into follow-up, they completed a one-time questionnaire that asked how often they listened to radio or music and how often they played a musical instrument, including voice. Each activity was later grouped into three frequency levels, and the researchers also created a combined measure that reflected how often participants engaged in both behaviors. These exposure groups were then used to examine later risk of dementia, cognitive impairment without dementia (CIND), and long-term changes in cognitive test scores.

The study identified several links between music engagement and later cognitive measures:

Older adults who reported listening to music on most days had a 39 percent lower incidence of dementia and a 17 percent lower incidence of CIND than those who listened less often. They also showed slower decline in overall cognition and memory, but the study did not find similar differences for word-finding or speed-related tasks.
Participants who often or most days played a musical instrument had about 35 percent lower dementia incidence than those who rarely or never played, although instrument playing alone was not clearly associated with CIND or with changes in cognitive test performance.
People who frequently listened to music and played an instrument had a 33 percent lower dementia incidence and a 22 percent lower incidence of CIND than those who rarely or never did either activity.

These findings fit with the idea that mentally and emotionally stimulating activities can support a more flexible and efficient brain. Music activates several interconnected systems in the brain, among them attention, memory, movement, auditory processing, and emotion, and repeated activation over many years may strengthen the brain's capacity to compensate when certain pathways become less reliable. This capacity, often described as cognitive reserve, helps people maintain everyday thinking skills even when there is some underlying deterioration.

Although the study cannot prove that music itself prevents dementia, the work highlights music engagement as a low cost, widely accessible candidate for dementia risk reduction strategies in healthy older adults. Future trials and longer observational studies will be needed to test whether altering music habits can change cognitive trajectories. My Cognitive Enhancement Blueprint offers a variety of other lifestyle interventions and protocols that have strong potential to improve cognitive performance and slow brain aging.

Higher blood carotenoid levels are linked to slower cognitive decline in older adults carrying the APOE ε4 Alzheimer risk allele. doi.org

Alzheimer's Brain Carotenoids Diet Dementia

Carriers of the apolipoprotein E (APOE) ε4 gene variant face a higher risk of Alzheimer's disease, yet practical ways to reduce that inherited vulnerability are limited. Researchers of the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) trial analyzed whether carotenoids, natural pigments abundant in fruits and vegetables such as carrots, sweet potatoes, and spinach, might be one such lever.

They focused on a group of 442 adults aged 65 and older who were overweight or obese, had a family history of Alzheimer's disease, followed diets that didn't meet the trial's healthy eating guidelines, and had no major cognitive impairment at the start of the study. All contributed APOE genotyping data and were followed with repeated cognitive testing over three years. When the study began, researchers evaluated total plasma carotenoid levels and five carotenoid markers: alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein plus zeaxanthin, and lycopene.

Cognitive trajectories diverged markedly with higher carotenoid levels in APOE ε4 carriers:

For people carrying the APOE ε4 variant, higher total carotenoid levels were modestly but meaningfully linked to better cognitive performance after three years. These associations held up across all six carotenoids.
Comparing APOE ε4 carriers with high and low total carotenoid levels, the difference in cognitive decline was roughly equivalent to being three years younger.
For lycopene and beta-cryptoxanthin, both medium and high carotenoid levels were linked to even larger benefits, equivalent to being about 4 to 6 years younger.
APOE ε4 carriers and noncarriers with high carotenoid levels followed similar cognitive paths, while carriers with low carotenoid levels had the fastest decline.
In contrast, among people without the APOE ε4 gene variant, carotenoid levels were not meaningfully related to changes in cognition.

Carotenoids do not just circulate in the bloodstream, they also make their way into the brain. Several of them, especially lutein and zeaxanthin, are known to accumulate in brain tissue. These compounds settle into areas involved in memory, learning, and executive function, including the cortex and hippocampus. Their presence is important because they can help neutralize oxidative stress, temper inflammation, and stabilize cell membranes, which are stress points in aging brains. APOE ε4 heightens brain oxidative stress and inflammation and weakens antioxidant defenses. So, higher circulating carotenoid levels may help buffer ε4 carriers against this vulnerability.

Although the MIND diet included carotenoid-rich foods, the study was not specifically designed to test their effects. The findings are observational and do not establish cause and effect. Still, the pattern suggests that nutrient status may interact with genetic risk to shape brain aging. In Q&A #55, I discuss the effects of astaxanthin, lutein, and zeaxanthin on cardiovascular and brain health in more detail.

Poor oral health and function are linked to a higher risk of mild cognitive impairment and dementia later in life. doi.org

Dementia

Maintaining oral health may play a more important role in brain aging than previously recognized. A new study from Korea followed middle-aged and older adults to see if oral health could help predict future memory problems.

The study tracked more than 6,700 adults aged 45 and older without a diagnosis of mild cognitive impairment (MCI) or dementia, who answered questions about their oral health at the start of the study. Over the next four years, they took part in regular interviews that recorded any new physician diagnoses of MCI or dementia.

The key measures were:

Overall oral health, assessed using the Geriatric Oral Health Assessment Index (GOHAI), a 12-item survey about oral pain, function, and discomfort, scored from 0 to 60, with higher scores indicating better oral health.
Chewing ability, self-reported as either "good" or "poor".

Here's what the study found:

Each one-point increase in GOHAI score corresponded to about a 2% lower risk of developing MCI or dementia.
Those who reported chewing well had about half the risk of MCI or dementia compared to those with chewing difficulties.
These patterns held up even after accounting for age, education, physical activity, smoking, and other health conditions.
The older group (65 and up) showed the same trends, suggesting the findings also apply well beyond middle age.

The authors note that difficulty chewing may lessen brain stimulation, decrease blood flow to areas involved in memory and thinking, and affect diet quality, while poor oral health can also discourage social interaction, all of which may influence long-term brain health. They also point to research showing that gum disease may trigger inflammation that affects the brain.

The results highlight oral care as a potentially modifiable factor in dementia prevention. However, because both oral health and cognitive status were self-reported rather than clinically assessed, the findings may be subject to reporting errors. The study also cannot establish cause and effect, and further research is needed to determine whether oral health interventions can directly reduce the risk of dementia. Discover other lifestyle interventions that reduce dementia risk in Aliquot #82.

Boosting glycogen breakdown in neurons with tau-related damage improves symptoms of neurodegeneration, a potential strategy for Alzheimer's and related diseases. www.nature.com

Alzheimer's Blood Sugar Brain Dementia Metabolism

Neurodegenerative diseases like Alzheimer's disease and frontotemporal lobar degeneration are characterized by the abnormal buildup of tau, a protein that damages brain cells and drives cognitive decline. A recent study found that tau-related disorders in both fruit flies and humans are closely linked to neuronal accumulation of glycogen—the stored form of glucose—and that breaking down this glycogen substantially reduces tau-related brain damage.

In this study, researchers used fruit flies genetically engineered to produce a harmful form of human tau protein, as well as neurons derived from human stem cells taken from people with frontotemporal lobar degeneration. They tested how diet and enzymes involved in glycogen breakdown affected brain cell health, analyzed molecular changes through metabolomics and genomics, and examined how tau protein interacts with glycogen inside cells.

They found that both fruit flies and human neurons with tau-related damage had unusually high levels of glycogen. When they boosted the activity of an enzyme called glycogen phosphorylase, which breaks down glycogen, symptoms of tauopathy improved dramatically: The fruit flies showed fewer signs of neurodegeneration, and human neurons became healthier. Dietary restriction had similar effects by naturally increasing glycogen breakdown, redirecting glucose metabolism away from energy production and toward a stress-reducing pathway called the pentose phosphate pathway.

These findings suggest that tau-related brain diseases worsen when glycogen builds up in neurons, and that breaking down this excess sugar protects brain cells. By interrupting what appears to be a vicious cycle between glycogen and tau accumulation, this approach could offer a powerful new direction for treating Alzheimer's disease, frontotemporal lobar degeneration, and related conditions. Intermittent fasting promotes the breakdown of glycogen, likely contributing to its brain-protective effects. Learn more in this clip featuring Dr. Mark Mattson.

Multidomain lifestyle program involving high-intensity exercise, diet, and cognitive training provides a 14% annual improvement in cognitive function in older adults—especially those at risk of decline. jamanetwork.com

Brain Dementia Diet Exercise

Protecting brain health in later life may require more than just solving puzzles or eating leafy greens. As dementia cases rise globally, researchers are exploring whether lifestyle changes can alter the brain's trajectory. A recent study found that older adults who followed a structured, high-intensity lifestyle program improved global cognitive function by about 14% more per year than those who received only low-intensity, self-guided advice.

Researchers conducted a large two-year clinical trial involving 2,111 adults aged 60 to 79 who were sedentary, had unhealthy diets, and met at least two additional risk criteria, such as a family history of memory problems or cardiometabolic risk factors. The researchers randomly assigned participants to either a structured program that included regular moderate- to high-intensity exercise, adherence to the MIND diet, cognitive training, social engagement, and cardiovascular monitoring, or a self-guided version with general health recommendations but far less support and structure.

After two years, both groups showed cognitive improvement, but the structured intervention group experienced a greater gain in global cognition—about 0.243 standard deviations per year—compared with 0.213 for the self-guided group, translating to an approximately 14% greater annual improvement in cognitive function. The benefit was consistent across genetic risk groups and was especially strong for participants who started with lower cognitive scores.

These findings suggest that a comprehensive, hands-on lifestyle program can offer meaningful cognitive benefits for older adults at risk of decline—especially those starting from a lower baseline. A crucial element of the intervention was exercise. Learn more about the immense effects of exercise on cognitive function in aging in this clip featuring Dr. Martin Gibala.

Walking 7,000 steps daily is linked to lower health risks, including a 47% lower risk of dying, 25% lower risk of heart disease, 38% lower risk of dementia, and 22% lower depressive symptoms. www.thelancet.com

Cancer Dementia Exercise Heart Disease

Step counting has gone from a fitness fad to a potential cornerstone of public health, with 10,000 steps daily being the standard recommendation. But how many steps do adults really need to protect against serious health problems like heart disease, cancer, or dementia? A recent study found that people who walked 7,000 steps per day had a 47% lower risk of dying from any cause compared with those who walked only 2,000 steps.

In this large-scale systematic review and meta-analysis, researchers analyzed data from 57 studies conducted across 35 distinct groups. They included only prospective studies that tracked adults over time using devices to measure daily steps and assessed a wide range of health outcomes. They examined dose-response relationships—meaning how changes in step counts related to health risks—and rated the strength of the evidence.

Their analysis revealed that taking more daily steps was consistently linked to lower risks of dying early from any cause, developing or dying from heart disease, dying from cancer, developing type 2 diabetes or dementia, experiencing depressive symptoms, or having a fall. The greatest reductions in risk were seen around 7,000 steps per day, which was associated with a 47% lower risk of death, a 25% lower risk of developing heart disease, a 38% lower risk of dementia, and a 22% lower risk of depressive symptoms. Some benefits continued to increase with more steps, but gains tapered off beyond 7,000 in many cases.

These findings suggest that while 10,000 steps per day remains a valuable goal for active people, a more attainable target of 7,000 steps could deliver substantial health benefits for the broader population. Learn how exercise like walking reduces the risk of cancer in this episode featuring Dr. Kerry Courneya.

Antidiabetes drugs semaglutide and tirzepatide potentially lower dementia and stroke risk by up to 37% in patients with type 2 diabetes and obesity. jamanetwork.com

Dementia Diabetes Drug Obesity

Type 2 diabetes and obesity increase a person's risk of developing dementia and other forms of neurodegeneration, particularly when the two conditions occur together. However, newer antidiabetes drugs may mitigate this risk. A recent study found that people taking the antidiabetes drugs semaglutide or tirzepatide were 37% less likely to develop dementia than those taking other diabetes medications.

Researchers analyzed electronic health records from more than 60,000 adults in the United States who had both type 2 diabetes and obesity. All participants began treatment with semaglutide, tirzepatide, or another type of antidiabetic medication between late 2017 and mid-2024. The researchers matched participants in the different treatment groups by age, sex, and health status and tracked their health for up to seven years.

People who took semaglutide or tirzepatide had a 37% lower risk of dementia, a 19% lower risk of stroke, and a 30% lower likelihood of dying during the study period than those on other antidiabetic drugs. These benefits were even greater among people over age 60, women, and those with a body mass index between 30 and 40. However, the risk of Parkinson's disease and brain bleeds did not differ between the groups.

These findings suggest that antidiabetes drugs like semaglutide and tirzepatide offer protection against cognitive decline and stroke, possibly extending life expectancy in people with type 2 diabetes and obesity. Semaglutide and tirzepatide are GLP-1RA drugs. Learn more about this class of medication in Aliquot #128: The Expanding Role of Weight Loss Drugs

Addressing hearing loss in older adults could potentially delay or prevent up to 32% of dementia cases. jamanetwork.com

Dementia Hearing

Most older adults experience some degree of hearing loss, yet few recognize that it may increase their risk of cognitive decline. A recent study found that nearly one-third of dementia cases over an eight-year period might be linked to hearing loss measured with a hearing test.

Researchers monitored nearly 3,000 older adults, aged 66 to 90, for up to eight years. All participants had normal cognition at the beginning and underwent a hearing test and a self-assessment of their hearing. The researchers compared the number of new dementia cases over time with each participant’s hearing status at the start of the study.

They found that up to 32% of dementia cases could be attributed to hearing loss. This link held true even for those with mild hearing loss. However, individuals who only reported hearing issues without a hearing test did not exhibit the same increased risk—likely because self-reporting often underestimates actual hearing loss. The proportion of dementia cases associated with hearing loss was highest among individuals aged 75 and older, women, and white participants.

These findings suggest that treating hearing loss, particularly when identified through a proper hearing test, could delay or even help prevent dementia in many older adults. A key driver of noise-induced hearing loss is inflammation, which is also linked with dementia. Learn more in Aliquot #90: Inflammation and the Early Seeds of Dementia — and Its Prevention

Regular use of math and reading skills could prevent cognitive decline with age. www.science.org

Aging Dementia

Conventional wisdom suggests that cognitive skills begin to decline in early adulthood, but this assumption may be misleading. A recent study found that cognitive skills—specifically math and reading skills—actually improve into one’s forties before experiencing a decline, and using these skills regularly is crucial in determining how abilities change over time.

Researchers analyzed data from a previous German study that monitored more than 3,200 adult participants over time, allowing for the identification of genuine age-related changes in cognitive abilities. They also considered measurement errors that could skew results.

They found that math and reading skills continued to improve into the participants' forties. After that, literacy declined slightly, while numeracy dropped more sharply—but only for participants with below-average skill usage. Those who regularly engaged in complex tasks at work or home, particularly white-collar and highly educated participants, maintained or improved their skills well beyond midlife. However, women experienced steeper declines in numeracy as they aged.

These findings suggest that cognitive decline is not inevitable. Remaining mentally engaged through work and daily activities may help preserve or enhance cognitive abilities beyond middle age. Maintaining healthy blood flow to the brain through vigorous exercise can support cognitive function in aging. Learn more in this episode featuring Dr. Rhonda Patrick.

Menopausal hormone therapy accelerates tau protein buildup in brain regions linked to Alzheimer's in women over 70, potentially contributing to their higher vulnerability to the disease. www.science.org

Brain Alzheimer's Hormones Dementia

According to some estimates, Alzheimer’s disease will affect nearly 14 million Americans by 2060, with women comprising two-thirds of those cases. Research indicates that this disparity arises from the buildup of tau, a protein linked to cognitive decline, which occurs earlier and progresses more rapidly in women. A recent study found that menopausal hormone therapy accelerates tau accumulation in older women, potentially contributing to this heightened risk.

The study involved 146 cognitively healthy women between the ages of 51 and 89. Researchers used brain scans to measure the accumulation of amyloid-beta and tau proteins in the women’s brains and gathered information about their menopausal hormone usage.

They found that women over 70 who had used hormone therapy showed faster tau buildup in key brain regions linked to Alzheimer’s disease. This increase in tau was also associated with greater cognitive decline. However, in younger women—those under 70—hormone therapy had little to no effect on tau accumulation.

These findings suggest that the timing of hormone therapy plays a critical role in brain health, supporting the idea that initiating treatment earlier in menopause may be safer. Understanding how hormone therapy influences tau buildup could help refine guidelines for menopausal treatment and Alzheimer’s risk reduction. Learn more about factors that influence the risk of Alzheimer’s disease in this clip featuring Dr. Dale Bredesen.

Being socially active may delay dementia onset by five years. alz-journals.onlinelibrary.wiley.com

Aging Dementia

A lively social life might be one of the best defenses against dementia. With more than 50 million people affected worldwide and care costs soaring into the hundreds of billions, finding ways to delay dementia is a public health priority. A recent study found that older adults who were more socially active developed dementia about five years later than those who were the least socially engaged.

Researchers tracked nearly 2,000 older adults without dementia as part of the Rush Memory and Aging Project. Each year, participants underwent cognitive assessments to determine whether they had developed mild cognitive impairment or dementia.

Over nearly seven years of follow-up, 545 participants developed dementia, and 695 developed mild cognitive impairment. On average, the least socially active participants developed dementia at about age 87, while the most socially active participants developed it at about age 92—a five-year difference. The same pattern emerged for mild cognitive impairment.

These findings suggest that social activity could be a powerful, community-wide strategy for delaying dementia, ultimately improving older adults' quality of life and reducing healthcare costs. Dietary components, including omega-3 fatty acids, play a critical role in reducing the risk of dementia, too. Learn more in this episode featuring Dr. Rhonda Patrick.

Regular aerobic exercise in older rats reduces brain inflammation, nerve fiber demyelination, and iron-triggered cell death—potential contributors to Alzheimer's pathology. pubmed.ncbi.nlm.nih.gov

Exercise Brain Alzheimer's Inflammation Dementia Iron

The pathological brain changes that drive Alzheimer’s disease may begin as much as 20 years before cognitive signs become evident. However, evidence indicates that exercise can slow or prevent these changes. A recent study involving older rats found that regular aerobic exercise reduces age-related inflammation in the brain and improves the balance between nerve fibers and their protective myelin coating.

Researchers had older rats exercise on a treadmill for eight weeks. Then, they examined the rats' brain tissue and analyzed changes in tau protein, amyloid plaques, and iron levels.

They discovered that older rats engaging in regular physical exercise experienced reduced age-related inflammation and improved balance between nerve fibers and their protective myelin coating. They also learned that excessive iron in oligodendrocytes—cells that support and insulate nerve fibers—triggers a type of cell death known as ferroptosis, possibly contributing to the formation of amyloid-beta plaques linked to Alzheimer’s. They identified statistical connections between tau and amyloid proteins (hallmarks of Alzheimer’s), iron levels, and cells in the hippocampus, a brain region crucial for memory.

These findings indicate that iron plays a critical role in Alzheimer’s pathology, but exercise can mitigate some of these effects. Learn more about preventing and reversing Alzheimer’s disease in this episode featuring Dr. Dale Bredesen.

GLP-1 receptor agonists may lower risks for major illnesses like dementia and seizures. www.nature.com

Diabetes Drug Dementia Weight Loss Cardiovascular

Ozempic, Wegovy, and other glucagon-like peptide-1 (GLP-1) drugs have catapulted into the mainstream of diabetes care, with more than 15 million people in the U.S. currently taking one. Evidence suggests GLP-1 drugs have many off-target effects—both good and bad—but healthcare providers don’t currently know the full extent of the drugs' effects. However, a recent analysis found that GLP-1s may reduce the risk of dementia, seizures, respiratory illnesses, cardiometabolic disorders, and certain infections more effectively than other diabetes drugs and typical care.

Using the U.S. Department of Veterans Affairs healthcare databases, researchers identified roughly two million people with diabetes who were using a GLP-1 drug, one of three common anti-diabetes drugs (sulfonylureas, DPP4 inhibitors, or SGLT2 inhibitors), or continuing their usual care without adding new therapies. They tracked the participants' health for about 3.6 years.

They found that GLP-1 use was associated with a reduced risk of dementia (8%), seizures (10%), respiratory illnesses (10% to 25%), cardiometabolic disorders (7% to 22%), and certain infections (12% to 25%). However, the drugs were associated with an increased risk of gastrointestinal issues (5% to 20%), low blood pressure (10%), kidney problems (10% to 15%), arthritic disorders (10% to 16%), and pancreatitis (15% to 20%).

These findings suggest that GLP-1 receptor agonists offer promising benefits for people with diabetes while highlighting potential risks. Further research will illuminate the full range of the drugs' effects. Learn more about GLP-1 drugs in this clip featuring Dr. Rhonda Patrick.

Regular green tea consumption correlates with fewer cerebral white matter lesions, potentially reducing the risk of stroke, dementia, and disability. www.nature.com

Brain Aging Green Tea Dementia Polyphenol

About half of your brain is white matter—a network of nerve fibers that allow for the exchange of information and communication within the brain. Aging and lifestyle factors can damage the white matter, increasing the risk of stroke, dementia, and disability. However, a recent study found that the brains of regular green tea drinkers have fewer white matter lesions than non-drinkers.

The study included nearly 8,800 older adults living in Japan. Participants provided information about their green tea and coffee consumption and underwent magnetic resonance imaging to assess their brain health and volume.

They found that higher green tea consumption correlated with fewer cerebral white matter lesions but had little effect on brain volumes, even after accounting for demographic, lifestyle, and health factors. People who drank about three cups (~20 ounces) of green tea daily had 3% less white matter damage in their brains than those who drank just one cup (~7 ounces). Those who drank around seven to eight glasses (~50 ounces) daily had 6% less damage. Coffee consumption did not affect white matter or brain volume, suggesting that green tea protects against white matter damage.

Green tea contains epigallocatechin gallate (EGCG), a polyphenolic compound that exerts robust antioxidant, anti-inflammatory, and neuroprotective effects. Evidence suggests that EGCG reduces the buildup of amyloid beta and tau—two proteins involved in the pathophysiology of Alzheimer’s disease. Learn more about EGCG and other polyphenols in our overview article.

Enhanced cardiorespiratory fitness boosts cognitive performance in processing speed, memory, and attention control—even among those at high risk for Alzheimer's. bjsm.bmj.com

Exercise Aging Memory Dementia

Cardiorespiratory fitness measures the body’s aerobic capacity—the ability to deliver oxygen to skeletal muscles—during sustained physical activity. A recent study found that better cardiorespiratory fitness boosts cognitive performance, even among people at greater risk for cognitive decline, such as older adults and APOE4 carriers.

Researchers collected information from more than 600 older adults regarding their age, sex, education, use of beta-blockers (drugs that lower heart rate), and APOE4 gene status (a genetic risk factor for Alzheimer’s). The participants underwent cardiorespiratory fitness testing on a treadmill. They also completed a comprehensive battery of neuropsychological tests to assess their cognitive function across multiple domains, including processing speed, executive function, working memory, episodic memory, and attention control.

Participants with higher cardiorespiratory fitness performed better on all cognitive assessment domains than those with poorer fitness—even among those at greater risk for cognitive decline, such as older adults and APOE4 carriers. Additionally, women, participants with fewer years of education, and those taking beta-blockers demonstrated greater cognitive performance in processing speed and executive function.

These findings suggest that better cardiorespiratory fitness in later life protects against cognitive decline.Although robust exercise is the best way to boost cardiorespiratory fitness, sauna use does, too. Learn more in our members-only report, Sauna Use: Implications for Aging and the Brain.

Supplemental vitamin D is linked to a 40% lower risk of Alzheimer's in cognitively healthy older adults. alz-journals.onlinelibrary.wiley.com

Vitamin D Alzheimer's Aging Dementia Supplements

As the global population ages and the risk of Alzheimer’s disease increases, identifying lifestyle factors that may prevent or forestall the disease is becoming increasingly important. A recent study found that people who take vitamin D supplements are 40% less likely to develop Alzheimer’s than those who don’t supplement.

The study involved more than 12,000 cognitively healthy older adults. Researchers gathered information about the participants' vitamin D supplementation practices and whether they developed Alzheimer’s over 10 years.

They found that participants who took any form of supplemental vitamin D (D2, D3, or D3 with calcium) had a 40% lower risk of developing Alzheimer’s than non-supplementers. This effect was more robust in women, those with normal cognition, and people without the APOE4 gene (a risk factor for Alzheimer’s).

These findings suggest that supplemental vitamin D protects against Alzheimer’s. However, this was an observational study, so other factors might have influenced the participants' Alzheimer’s risk. For example, those who took supplemental vitamin D had higher education than those who didn’t. Research suggests that higher educational attainment is associated with a lower risk of Alzheimer’s.

Nevertheless, vitamin D is essential for human health, and most people living in the U.S. have low vitamin D levels, potentially driving the growing number of Alzheimer’s cases. Learn more about vitamin D’s effects on the brain in this episode featuring Dr. Rhonda Patrick.

Glyphosate exposure in mice accelerates Alzheimer's disease processes, with the herbicide's metabolites persisting in brain tissue six months after initial exposure. jneuroinflammation.biomedcentral.com

Brain Alzheimer's Dementia Pollution

Glyphosate, a widely used herbicide, has been linked to widespread inflammation and neuronal damage in the brain. A recent study in mice found that glyphosate and its primary metabolite, aminomethylphosphonic acid, persist in brain tissue for months after exposure, potentially contributing to neurodegenerative changes.

Researchers exposed ordinary mice and mice prone to developing Alzheimer’s to varying doses of glyphosate daily for 13 weeks. Six months later, they examined the animals' brain tissues for lingering glyphosate, metabolites, and key markers of Alzheimer’s pathology, including amyloid-beta plaques, tau tangles, and inflammation.

They discovered that glyphosate’s primary metabolite remained in brain tissue even after six months of non-exposure. Glyphosate-exposed Alzheimer’s-prone mice had lower survival rates, more difficulty in spatial memory tasks, and increased markers of Alzheimer’s pathology, including larger and more numerous amyloid-beta plaques and higher levels of phosphorylated tau protein. Both groups of mice exhibited persistent inflammation in their brains and blood.

These findings suggest that glyphosate exposure may contribute to long-lasting brain changes, accelerating processes involved in Alzheimer’s disease. Learn how to mitigate exposures to environmental toxins like glyphosate in this Aliquot featuring Drs. Dale Bredesen, Michael Snyder, and Rhonda Patrick.

Beta-hydroxybutyrate, a ketone used by the brain during fasting or exercise, may help counteract toxic protein buildup in aging and Alzheimer's disease. pmc.ncbi.nlm.nih.gov

Brain Alzheimer's Diet Ketosis Dementia Protein Ketogenic Diet

Protein misfolding in the brain is a central player in both aging and Alzheimer’s disease, driving toxic protein buildup and brain cell dysfunction. However, evidence indicates that ketones—a critical brain fuel produced during fasting or exercise—may help reduce or prevent this damage. A recent cell study found that beta-hydroxybutyrate, a type of ketone, helps protect the brain by targeting toxic proteins for disposal.

Researchers delivered beta-hydroxybutyrate to brain cells collected from mice and monkeys via an exogenous ketone ester. They examined the cells for changes in protein solubility and pathways involved in protein breakdown. They also studied beta-hydroxybutyrate’s effects on pathological proteins, such as amyloid-beta, in a nematode model of Alzheimer’s disease.

They found that beta-hydroxybutyrate made pathological proteins insoluble, preventing their toxic spread while promoting their clearance through autophagy, the cell’s natural recycling process. This effect was specific to pathological proteins and wasn’t the result of changes in acidity or random chemical interactions. Beta-hydroxybutyrate also reduced amyloid-beta toxicity in nematodes.

These findings suggest that a ketone ester of beta-hydroxybutyrate counteracts the toxic buildup of proteins in aging and Alzheimer’s disease. Further research is needed to translate these results to humans. Learn more about how ketone ester supplementation may improve brain health in this episode featuring Dr. Mark Mattson.

Diagnosis of type 2 diabetes before the age of 50 nearly doubles the risk of dementia, while concurrent obesity triples the risk. journals.plos.org

Obesity Diabetes Dementia

Type 2 diabetes is becoming increasingly common among younger adults, shifting from its traditional association with older populations. A recent study found that the age at which a person develops type 2 diabetes influences their risk of developing dementia, with obesity more than tripling risk, especially at younger ages.

Researchers tracked more than 1,200 adults aged 50 and older who had diabetes but no dementia at the start of the study. They grouped participants based on the age they were diagnosed with diabetes—before age 50, in their 50s, 60s, or 70s—and by whether they had obesity. They tracked new dementia cases for about 10 years, using cognitive assessments and considering factors like lifestyle and medication use.

They found that people diagnosed with diabetes at younger ages had higher dementia risks than those diagnosed after 70. Those diagnosed before age 50 were nearly twice as likely to develop dementia, and obesity more than tripled this risk. Among obese participants diagnosed with diabetes before age 50, dementia risk was highest.

These findings suggest that diabetes, especially in the setting of obesity, markedly increases dementia risk. Self-monitoring of blood glucose levels can help identify pre-diabetes—a precursor to diabetes—providing a window of opportunity to prevent the disease with lifestyle and dietary changes. Learn more in this clip featuring Dr. Michael Snyder.

Rapid increases in frailty levels, especially among women, amplify dementia risk by up to 73%. pubmed.ncbi.nlm.nih.gov

Exercise Aging Dementia

Frailty isn’t just about getting older—it’s a key indicator of biological age that can signal an increased risk for many health concerns, including dementia. A recent study found that rapid increases in frailty increase the risk of dementia by as much as 73%, especially among females.

Researchers analyzed data from four large studies involving nearly 88,000 adults aged 60 and older. They measured participants' frailty levels at the start and monitored their health, including the development of dementia, over several years.

They found that in the years before dementia began to manifest, frailty tended to increase. Participants with the most rapid increases in frailty were 18% to 73% more likely to develop dementia than those with slower frailty progression. Frailty was more common in females than males among those who developed dementia, with the greatest differences seen in the years leading up to dementia onset.

These findings suggest that measuring frailty could help identify people at greater risk for dementia, serving as an early target for strategies to reduce dementia risk through public health interventions and lifestyle changes. One powerful lifestyle approach for reducing dementia risk is exercise—especially the vigorous kind. Learn more in this episode featuring Dr. Rhonda Patrick.

Physical activity at any intensity boosts mental speed almost immediately, equating cognitive function to that of people four years younger. pubmed.ncbi.nlm.nih.gov

Exercise Brain Alzheimer's Aging Memory Dementia

Exercise boosts brain health, but some evidence suggests that even ordinary activities like dog walking or gardening can sharpen the mind. A recent study found that physical activity—no matter the intensity—can improve mental speed.

The study involved 90 healthy participants between the ages of 40 and 65. Using smartphones, participants reported their physical activity five times daily and completed brief cognitive tasks to measure mental speed and memory. The smartphones captured activity levels ranging from light chores to vigorous exercise and assessed how these influenced brain function in real-time.

The results indicated that being active within the previous 3.5 hours improved mental speed, equating to the cognitive function of someone four years younger. Both light and moderate-to-vigorous activities offered similar benefits. While memory accuracy did not improve, reaction times in memory tasks mirrored the gains in mental speed, especially in people who were more active overall.

These findings suggest that everyday physical activity can deliver immediate cognitive benefits, potentially offering a simple way to boost brain health at any intensity level. Learn more about the brain benefits of exercise in the Cognitive Enhancement Blueprint, a members-only perk.

Frequent use of common household chemicals—including fluoride-based anti-caries agents, air fresheners, and disinfectants—increases the risk of cognitive decline in older adults. pubmed.ncbi.nlm.nih.gov

Brain Aging Dementia Pollution Dental

Cognitive decline—especially among older adults with dementia—can profoundly affect a person’s quality of life and increase their dependency on others. Evidence suggests that environmental exposures influence the risk of dementia. A recent study found that certain household chemicals, widely used for personal hygiene, cleaning, and disinfecting, may pose an unexpected risk for cognitive decline** in older adults.

Researchers analyzed data from a large cohort study of adults over 65. They evaluated how frequently the participants used eight common household chemicals, including insecticides, air fresheners, and disinfectants, and then examined whether these products were linked to declines in cognitive function.

They found that frequent use of anti-caries agents raised the likelihood of developing cognitive decline by 68%, while frequent use of air fresheners increased it by 148%, and disinfectants raised it by 40%. In general, more frequent chemical use was linked with worsening cognitive function.

Anti-caries agents prevent or reduce the development of dental caries, also known as cavities or tooth decay. Common anti-caries agents include fluoride mouth rinses, toothpaste formulations, and dental varnishes or sealants. Air fresheners contain various indoor pollutants, including phthalates and benzene. When these substances react with ozone, they create harmful byproducts that can harm the central nervous system. Sulforaphane, a bioactive compound derived from broccoli, boosts the excretion of pollutants like benzene. Learn more in this clip featuring Dr. Jed Fahey.

Increased iron levels in the brain worsen cognitive test performance by as much as 10% in older adults, a phenomenon linked to brain atrophy and decline in memory and attention. pubmed.ncbi.nlm.nih.gov

Brain Alzheimer's Aging Memory Dementia Iron

Iron is an essential nutrient that participates in oxygen transport, energy production, and other critical processes. However, iron can accumulate in the brain, impairing memory and thinking abilities, especially in conditions like Alzheimer’s. A recent study found that older adults with higher brain iron levels perform poorly on cognitive tests.

Researchers used specialized MRI techniques to measure iron levels and atrophy in the brains of 770 older adults. Of these participants, 219 underwent cognitive testing roughly every year for about three years. The researchers focused on crucial brain regions associated with normal aging and Alzheimer’s disease to explore the relationship between iron buildup, brain atrophy, and cognitive performance.

They found that higher iron levels were linked to worse cognitive performance, particularly in memory and attention. Participants with the highest iron levels in aging-related brain regions were more likely to experience cognitive decline over time, performing up to 10% worse on cognitive tests than those with lower iron levels. Additionally, increased iron levels corresponded with more severe brain atrophy in these regions.

These findings suggest that brain iron accumulation impairs cognitive function and may be an early warning sign for the condition. Other lifestyle factors contribute to cognitive losses and brain atrophy, too, including alcohol consumption. Learn more in this episode featuring Dr. Rhonda Patrick.

Distinct gut microbes found in cognitively impaired older adults—a potential link to beneficial species via dietary intervention and regular exercise. read.qxmd.com

Brain Gut Aging Dementia Microbes

The gut-brain axis may hold more clues about cognitive decline than previously realized, with some evidence suggesting that gut microbial populations might influence brain health and cognitive function. A recent study found that older adults with cognitive impairment had distinct differences in their gut microbes compared to those without impairment.

Researchers assigned 229 adults aged 60 and older to one of two groups based on their cognitive function. They analyzed the diversity and composition of the participants' gut microbes and used machine learning to identify key bacterial species associated with cognitive impairment. They also investigated how lifestyle factors such as diet and exercise influenced these bacterial populations.

They found that participants with cognitive impairment had less diverse gut microbial populations than those without, indicating a potential link between less microbial diversity and cognitive decline. They noted that higher numbers of specific bacteria, including Megamonas, Blautia, and Veillonella, were associated with better cognitive function. They also found that higher fruit intake and regular exercise were linked to increased abundance of these beneficial species.

These findings suggest that maintaining a healthy gut microbiota through diet and exercise is essential in preserving cognitive function as we age. Time-restricted eating helps promote gut microbial diversity. Learn more in this clip featuring Dr. Satchin Panda.

A moderate intake of choline—two to three eggs worth—may cut your risk of cognitive decline in half. www.ncbi.nlm.nih.gov

Brain Diet Dementia Acetylcholine

Cognitive decline is a growing concern as populations age, and diet may play a key role in preserving cognitive function. A 2021 study found that people with moderate choline intake—about the amount in two to three eggs or a serving of salmon—were half as likely to experience cognitive decline than those with low intake.

Researchers categorized roughly 2,400 older adults enrolled in NHANES based on their daily choline intake: low (less than 188 milligrams), moderate (188 to 400 milligrams), or high (more than 400 milligrams). Then, they ranked them according to their performance on various cognitive tests.

They found that people with moderate choline intake were 33% to 50% less likely to have low cognitive function than those with the lowest intake. Interestingly, those with higher intake didn’t perform better on the cognitive tests, suggesting a “sweet spot” for choline intake.

These findings indicate that incorporating moderate amounts of choline-rich foods into one’s diet may protect brain health during aging. This protective effect may be due to choline’s role in producing acetylcholine, a neurotransmitter involved in neurogenesis, synapse formation, learning, and memory. In addition, research in animal models shows that choline deficiency increases the risk of Alzheimer’s disease and damages vital organs in mice.

Choline is found in many foods. Good sources of this essential nutrient include: - Eggs (1 large): ~147 milligrams - Fish (salmon, 3 ounces, cooked): ~187 milligrams - Cauliflower (1 cup, cooked): ~72 milligrams - Beef (3 ounces, cooked): ~78 milligrams Learn more about choline’s role in brain health in this Q&A featuring Dr. Rhonda Patrick.

Just 1.5 teaspoons of olive oil daily reduces the risk of death from dementia by 28%, regardless of genetic factors. jamanetwork.com

Brain Diet Genetics Dementia Polyphenol

What we eat and drink can profoundly affect our disease risk as we age. A recent study found that consuming just 1.5 teaspoons of olive oil daily can reduce the risk of death from dementia by 28%, even among APOE4 carriers, a potent genetic risk factor for dementia.

Researchers asked more than 92,000 healthy, middle-aged adults about their olive oil consumption over a 28-year period. They conducted genetic analyses to determine whether the participants carried the APOE4 gene. Then, using national death records, they ascertained which of the participants died of dementia.

They found that more than 4,700 of the participants died of dementia during the study period. People who carried one APOE4 allele were roughly twice as likely to die from dementia; those with two APOE4 alleles were five to nine times more likely. However, people who consumed 7 grams or more of olive oil daily—roughly 1.5 teaspoons—were 28% less likely to die of dementia than those who didn’t consume olive oil, regardless of their APOE4 status. Replacing 5 grams (about a teaspoon) of margarine or mayonnaise with an equivalent amount of olive oil reduced the risk of death from dementia by as much as 14%.

These findings suggest that eating olive oil markedly reduces the risk of death from dementia. Olive oil contains healthy fats and polyphenols—bioactive compounds with potent antioxidant and anti-inflammatory properties. Learn more about polyphenols in our overview article.

Tiny brain hemorrhages found in 17% of people who've had a concussion—increasing their risk for dementia. jamanetwork.com

Brain Dementia Concussion Blood-Brain Barrier

“Seeing stars,” “getting your bell rung,” and “knocked for a loop” are everyday phrases often used to describe experiencing a concussion. However, these expressions can downplay that even a “mild” concussion is a traumatic brain injury with the potential for lasting, harmful effects, including dementia. A recent study found that 17% of people who have had a concussion have microbleeds—tiny hemorrhages—in their brains.

The study involved more than 600 middle-aged adults with normal cognitive function. Researchers asked the participants if they had ever experienced a concussion—defined as a blow to the head where they lost consciousness—then assessed their brain health using magnetic resonance imaging (MRI). Then, they gave the participants various cognitive tests and asked about their sleep, mood, and overall health.

They found that more than one-third of the participants had experienced a concussion. Of these, 17% had evidence of brain microbleeds, and the more concussions they experienced, the more microbleeds they had. Those who had experienced a concussion tended to have poorer sleep and more gait disturbances, depression symptoms, and memory deficits than those without a concussion.

Microbleeds are markers of cerebral small vessel disease—age-related blood vessel impairments in the brain. These impairments compromise the blood-brain barrier, contributing to the development of cardiovascular disease, dementia, and stroke.

These findings suggest that even mild concussions damage the brain, increasing a person’s risk of dementia. Other studies have demonstrated that mild concussions cause acute and chronic brain damage, and people who experience three or more concussions tend to exhibit cognitive deficits that worsen with each subsequent concussion.

We’ve covered small vessel disease in great detail: - Listen to researcher Dr. Axel Montagne describe the prevalence of this condition as a cause of dementia. - Read more about the condition in our overview article.

Excess body fat in the arms and belly increases the risk of neurodegenerative disease. www.neurology.org

Brain Alzheimer's Aging Fat Dementia Neurodegeneration

Although many factors influence whether a person develops neurodegenerative diseases like Alzheimer’s and other forms of dementia, excess body fat stands out as a notable risk factor. Some research suggests that where that body fat is located modulates that risk, with a new study finding that higher body fat in the arms and belly increases the likelihood of neurodegenerative disease.

The study involved more than 412,000 people enrolled in the UK Biobank study. Researchers measured the participants' body composition and tracked their health for about nine years.

They found that participants with greater muscle strength, bone density, and body fat in their legs were 6% to 25% less likely to develop neurodegenerative diseases. However, those with more body fat in their arms and bellies were 13% to 18% more likely to develop neurodegenerative diseases. Between 10% and 35% of the link between these body composition patterns and neurodegenerative diseases was attributable to the influence of cardiovascular diseases—particularly cerebrovascular diseases.

Cerebrovascular disease is an umbrella term for conditions that affect the blood vessels that supply the brain, such as strokes and aneurysms. Exercise helps maintain the health of these blood vessels, reducing the risk of neurodegenerative diseases. Learn more in this episode featuring Dr. Axel Montagne.

Frequent nightmares linked to quadruple cognitive decline risk, especially among men. www.thelancet.com

Aging Sleep Dementia

Nightmares and bad dreams are common occurrences, with many adults experiencing them monthly. However, a growing body of evidence points to links between nightmares and cognitive function. A recent study found that people who have frequent nightmares have a fourfold greater risk for cognitive decline and dementia.

The study involved 605 adults enrolled in MIDUS, an ongoing survey of middle-aged and older adults living in the United States. Participants provided information about their sleep quality and distressing dream frequency over about seven years. They also completed cognitive tests and reported whether they had been diagnosed with dementia.

Middle-aged participants who had weekly distressing dreams were four times more likely to experience cognitive decline during the seven years than those without bad dreams. Older adults with weekly bad dreams were more than twice as likely to experience cognitive decline. The connection between bad dreams and cognitive decline was more robust among men.

These findings suggest that distressing dreams predict cognitive decline risk, potentially aiding early diagnosis and treatment. Dreams play essential roles in creativity and inspiration. Learn more in this clip featuring Dr. Matthew Walker.

Men with low testosterone are five to six times more likely to develop dementia. alz-journals.onlinelibrary.wiley.com

Brain Hormones Testosterone Dementia Neurodegeneration

Testosterone is the primary male sex hormone, crucial for maintaining fertility and maintaining male sexual characteristics. Some evidence suggests testosterone is neuroprotective. A recent study found that lower testosterone levels are linked with a higher risk for dementia.

The study involved 581 cognitively healthy older men living in China. Researchers assessed the men’s cognitive function and measured their levels of testosterone and neurofilament light chain, a structural protein that maintains neuronal health and connectivity. Neurofilament light chain is a biomarker for neuronal damage and degenerative diseases, including Alzheimer’s.

They found that men with lower testosterone levels were roughly five times more likely to experience cognitive decline than those with high levels. Those with low testosterone and high neurofilament light chain levels were approximately six times more likely to experience cognitive decline.

These findings suggest that lower testosterone and neurodegeneration synergistically contribute to cognitive decline in men. Learn more about low testosterone in this clip featuring Dr. Peter Attia.

Smoking accelerates cognitive decline by 17% over a decade. www.eurekalert.org

Exercise Alzheimer's Alcohol Dementia

Smoking has numerous harmful effects on health, including increased risks of lung cancer, heart disease, and stroke. Evidence indicates smoking also contributes to cognitive decline, affecting memory and fluency. A recent study found that smoking accelerates cognitive decline by as much as 17% over time.

Researchers examined data from more than 32,000 cognitively healthy adults aged 50 to 104 from 14 European countries. They grouped participants according to whether they smoked, engaged in regular exercise, were socially active, and drank moderately—defined as less than or equal to two alcoholic drinks per day for men or one drink per day for women. Then, they analyzed the effects of lifestyle on memory and fluency decline over 10 years.

They found that non-smokers maintained relatively stable memory and fluency scores over the 10 years. However, smokers experienced up to 17 percent greater decline in memory and up to 16 percent greater decline in fluency, even after considering other factors that influence cognitive aging, including age at baseline, gender, country, education, wealth, and chronic conditions. Interestingly, healthy lifestyle behaviors offset some of the risks associated with smoking, with smokers who exercised, socialized, and drank moderately exhibiting cognitive declines comparable to non-smokers.

These findings suggest that smoking markedly increases cognitive decline, increasing the risk for Alzheimer’s disease and other forms of dementia. Quitting smoking can be challenging, but mindfulness techniques can help. Learn more about mindfulness in this clip featuring Dr. Ashley Mason.

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Chronic inflammation in early adulthood can impair cognitive performance by midlife, with 39% of young adults showing high inflammation levels. pubmed.ncbi.nlm.nih.gov

Brain Alzheimer's Aging Inflammation Memory Dementia

Research demonstrates that inflammation in later life harms the brain, increasing the risk of dementia and cognitive decline. However, scientists don’t fully understand the effects of inflammation that begins in early adulthood. A recent study found that inflammation during early adulthood markedly impairs cognitive performance in midlife.

The research involved more than 2,300 young adults (aged 24 to 58) enrolled in the Coronary Artery Risk Development in Young Adults study. Researchers tracked the participants' inflammation levels, measured by C-reactive protein (CRP), for about 18 years. Five years after their last CRP measurement, the participants completed tests that measured their verbal memory, processing speed, executive function, verbal fluency, category fluency, and overall cognition.

The researchers identified three inflammation patterns among the participants: lower stable (45%), moderate/increasing (16%), and consistently higher (39%). Participants with consistently higher CRP levels were 67 percent more likely to experience poor processing speed and 36 percent more likely to have poor executive function than those with stable, low CRP levels. Those with moderate/increasing CRP levels were twice as likely to have poor processing speed. There were no significant associations between CRP levels and memory, verbal fluency, category fluency, or overall cognition.

One of the many ways inflammation harms the brain is through its effects on pericytes, tiny cells that surround the brain’s blood vessels and help maintain the blood-brain barrier. Inflammation causes pericytes to release pro-inflammatory cytokines, compromising the barrier and facilitating neurodegeneration. Learn more about links between inflammation, pericytes, and cognitive decline in this clip featuring Dr. Axel Montagne.

These findings indicate that more than one-third of young adults have high inflammation levels, adversely affecting executive function and processing speed by midlife. They also underscore the importance of managing inflammation throughout life. Omega-3 fatty acids have potent anti-inflammatory effects. Learn more in this episode featuring Dr. Bill Harris.

Intensive lifestyle modification that includes diet, exercise, and stress management improves cognitive function and slows disease progression in older adults with mild cognitive impairment while also reversing biomarkers of Alzheimer's disease. link.springer.com

Exercise Alzheimer's Diet Omega-3 Probiotics Stress Meditation Magnesium Dementia Supplements

Mild cognitive impairment is often a precursor to Alzheimer’s disease, marking the initial stages of cognitive decline that precede more severe dementia. Evidence suggests lifestyle factors mediate the progression of mild cognitive impairment. A recent study found that intensive lifestyle modification improves cognitive and functional performance and slows disease progression in older adults with mild cognitive impairment.

Researchers conducted a randomized controlled trial involving 49 participants aged 45-90 with mild cognitive impairment or early dementia due to Alzheimer’s disease. Half of the participants received the usual care, while the other half received a 20-week intensive lifestyle intervention. The researchers assessed the participants' cognitive and functional performance and measured plasma biomarkers associated with Alzheimer’s before and after the intervention.

They found that participants in the intervention group showed considerable improvements in cognition and function compared to the control group. In addition, Aβ42/40 ratios increased in the intervention group but decreased in the control group.

The Aβ42/40 ratio is a measure of the relative levels of two forms of amyloid-beta protein (Aβ42 and Aβ40) in the blood or cerebrospinal fluid. It is a biomarker used to assess the presence and progression of Alzheimer’s disease. Lower ratios typically indicate higher levels of brain amyloid-beta plaques, a hallmark of the disease. An increase in the Aβ42/40 ratio, as observed in the intervention group, suggests a potential reversal or slowing of amyloid-beta plaque accumulation, indicating an improvement in disease pathology.

These findings suggest that intensive lifestyle modification has profound effects on Alzheimer’s disease progression in older adults with mild cognitive impairment. FoundMyFitness has a wealth of information about the various components used in this intensive protocol, which included:

Diet: A whole-food, minimally processed, plant-based diet, high in complex carbohydrates and low in harmful fats and refined sugars.
Exercise: Daily aerobic activities and resistance training exercises three times weekly.
Stress management: Daily meditation, yoga, stretching, relaxation exercises, and breathing technique sessions.
Group support: Group sessions, including supervised exercise, stress management practices, support groups, and lifestyle lectures, three times weekly.
Supplements: Daily supplements, including omega-3 fatty acids, curcumin, a multivitamin/mineral, coenzyme Q10, vitamin C, vitamin B12, magnesium L-threonate, lion’s mane mushroom, and a probiotic.

Diets rich in omega-3s and antioxidants slow brain aging and improve cognitive function in older adults. www.nature.com

Nutrition Diet Aging Omega-3 Mental Health Vitamin E Dementia

While brain aging is an inevitable part of growing older, lifestyle factors, particularly diet, can influence the rate at which this aging occurs. A recent study found that older adults with diets rich in omega-3 fatty acids, antioxidants, and vitamins demonstrate slower brain aging and better performance on cognitive tests.

Researchers administered cognitive tests and brain imaging scans to 100 healthy older adults. They also measured 13 nutrition-related biomarkers in the participants' blood.

They identified two brain aging patterns among the participants, with one group exhibiting accelerated aging and the other slower aging. Further analysis revealed that distinct dietary patterns distinguished the two groups. In particular, the intake of specific nutrients positively influenced brain health and cognitive function, including: - Alpha-linolenic acid (an omega-3 fatty acid found in nuts and seeds, such as walnuts and chia) - Eicosapentaenoic acid (an omega-3 fatty acid found in fatty fish, such as salmon) - Lutein (a polyphenol found in green leafy vegetables, such as kale) - Zeaxanthin (a polyphenol found in brightly colored vegetables, such as orange bell peppers and butternut squash) - Vitamin E (found in seeds and nuts, such as sunflower seeds and hazelnuts) - Choline (found in a variety of foods, including eggs and soybeans) These patterns were consistent even when considering the participants' demographics, fitness levels, and body measurements.

These findings suggest that nutrient-rich diets are critical for maintaining cognitive health and decelerating the brain’s aging process. They also highlight the importance of dietary choices as potential tools to manage and mitigate age-related cognitive decline. Learn about other lifestyle choices that slow cognitive and physical aging in this episode featuring Dr. Rhonda Patrick.

Chronic migraines increase the risk of developing vascular dementia by 33 percent – even for younger, otherwise healthy individuals. journals.plos.org

Brain Magnesium Dementia Migraine

Migraine is a neurological disorder commonly manifested as severe headache pain accompanied by nausea, vomiting, and light sensitivity. Approximately 15 percent of people worldwide experience migraine, with women reporting migraine more often than men. A new study shows that migraine increases a person’s risk of vascular dementia.

Researchers used data from a large, population-based cohort study involving nearly 6 million adults with or without regular migraines. They tracked the participants' health for about ten years and assessed their risk for developing vascular dementia.

They found that people with chronic migraines were 33 percent more likely to develop vascular dementia than those without. Those with episodic migraines were 16 percent more likely. The risk of developing vascular dementia was greater among younger people, women, non-smokers, and those without hypertension or diabetes.

These findings suggest that migraine increases the risk of developing vascular dementia, possibly manifesting in younger, otherwise healthy adults. Migraines and vascular dementia share many pathophysiological traits that may explain their interconnected risk. For example, both conditions elicit alterations in cerebral blood flow, with migraines characterized by impaired blood vessel tone and responsiveness and vascular dementia characterized by chronic cerebrovascular insufficiency. In addition, inflammatory processes contributing to brain endothelial dysfunction play a critical role in both disorders.

However, some evidence suggests magnesium prevents migraines. Learn more in this clip featuring Dr. Rhonda Patrick.

High-intensity training outperforms moderate exercise in boosting cognitive function. bmcsportsscimedrehabil.biomedcentral.com

Exercise Brain Dementia BDNF

The connection between physical exercise and enhanced cognitive function is well-established. However, the extent of benefit varies markedly depending on the intensity of the physical activity. A recent study found that high-intensity interval training (HIIT) boosted reaction time and cognitive flexibility better than moderate-intensity continuous exercise (MICE).

The study involved 28 elite male boxers in their mid-twenties. The participants underwent cognitive performance tests and provided blood samples in five scenarios: after an hour of rest, immediately after HIIT, one hour after HIIT, immediately after MICE, and one hour after MICE.

The blood tests revealed that participants' serum brain-derived neurotrophic factor (BDNF) levels immediately after exercise were considerably higher after HIIT than after rest or MICE. Interestingly, serum levels of S100B and neuron-specific enolase (proteins associated with brain injury) were also higher after HIIT than after rest but were comparable to those after MICE. HIIT and MICE improved cognitive performance, but HIIT was better at improving reaction time and incongruent task assessments (which measure cognitive flexibility).

These findings suggest that HIIT and MICE elicit beneficial effects on the brain, with HIIT outperforming MICE in certain arenas. These effects may be attributable to increased BDNF, a growth factor known to influence neuronal health and mediate the beneficial cognitive effects associated with exercise. Learn more about BDNF in the Cognitive Enhancement Blueprint, located in the Members' Library.

Vision problems predict dementia risk nearly 10 years before diagnosis. www.ncbi.nlm.nih.gov

Aging Eyes Dementia

People with dementia often experience visual problems, which range in severity from difficulty seeing contrasts or colors to impaired understanding of spatial relationships. These visual problems typically manifest early in dementia, indicating that early vision testing may help identify those at risk. A recent study found that visual problems may predict dementia nearly 10 years before diagnosis.

The study involved more than 8,600 participants in a large, population-based prospective cohort. At the beginning of the study, participants took two visual sensitivity tests (simple and complex), which assess how quickly a person can process visual information and react to it. Researchers tracked the participants' cognitive and physical health for about 15 years.

They found that vision problems predicted participants' dementia risk an average of 9.6 years before a clinical diagnosis. A low score on the simple visual sensitivity test was associated with a 39 percent greater risk of developing dementia, and a low score on the complex test was associated with a 56 percent greater risk. These risks persisted even after accounting for the participants' ages. Interestingly, the vision testing was more sensitive to variables commonly associated with dementia risk (such as age, gender, and education) than traditional dementia assessments.

These findings suggest that visual problems predict future dementia risk. They also bolster previous research demonstrating that horizontal eye movements, such as those used when reading or viewing television, improve memory. Other lifestyle factors, including sleep, influence dementia risk, too. Learn more in this video featuring Dr. Rhonda Patrick.

Higher-dose omega-3 supplementation elevates blood levels, even in Alzheimer’s high-risk APOE4 carriers, but obesity may hinder its brain availability. content.iospress.com

Brain Alzheimer's Obesity Omega-3 Genetics Dementia

Omega-3 fatty acids play critical roles in maintaining brain health and function, potentially reducing the risk of developing Alzheimer’s disease. People who carry the APOE4 gene variant and those with obesity have a higher risk of developing the disease, suggesting that differences in metabolism could be a factor. A 2022 study found that obesity influenced the amount of omega-3 in plasma phospholipid form that is important for brain transport.

Fifty people (half of whom carried the APOE4 gene) took 2.5 grams of combined docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) daily for six months. Because omega-3 fatty acids must be in the free fatty acid form or phospholipid form to cross the blood-brain barrier, researchers measured these forms of the fatty acids in the participants' plasma before and after the intervention. They also investigated whether APOE genotype or body mass index (BMI, a proxy for overweight and obesity) influenced these measures.

They found that supplemental omega-3s increased by up to fourfold in all participants, regardless of APOE status. However, participants with a high BMI experienced lower plasma phospholipid omega-3 increases than those with a low BMI. Having a high BMI is a well-established risk factor for Alzheimer’s disease. Interestingly, APOE4 did not influence the amount of plasma phospholipid omega-3.

They also lend support to evidence suggesting that APOE4 carriers do not respond to lower dose omega-3 supplementation as well as non carriers possibly because they do not transport DHA in free fatty acid form across the blood-brain barrier as well. However, the transport of the phospholipid form of DHA across the blood-brain barrier bypasses the default in tight junctions, potentially providing a better means of DHA transport for people with the APOE4 gene and lowering their risk of developing the disease. Learn more about APOE4 and DHA transport in this peer-reviewed article by Dr. Rhonda Patrick.

Exercise preserves cognitive function in mice by inhibiting neuroinflammation. www.sciencedirect.com

Exercise Brain Inflammation Memory Dementia NRF2

Cognitive function typically declines with aging, but evidence suggests physical activity can help mitigate some of these declines. A recent study in mice found that exercise improves memory and spatial learning by inhibiting neuroinflammation, primarily via the actions of irisin, a myokine, and brain-derived neurotrophic factor (BDNF), a growth factor and signaling protein.

Researchers conducted a two-part study to investigate the effects of regular, low-intensity exercise on cognitive function in mouse models of inflammation-driven memory impairment and microglia (brain immune cell) degeneration.

First, they assessed the animals' neuroprotective and antioxidant marker levels and subjected them to various memory and behavioral tests. They found that exercise reduced memory problems and cognitive losses by increasing the expression of irisin. In turn, irisin activated BDNF and nuclear factor erythroid 2-related factor 2 (Nrf2), reducing inflammation and blocking the activity of BACE-1, an enzyme critical for amyloid-beta production.

Then, they studied the effects of irisin on microglia. They found irisin blocked the NF-κB/MAPK/IRF3 pro-inflammatory signaling pathway. It also lowered pro-inflammatory markers while increasing the expression of Nrf2.

Nrf2 is a cellular protein that activates the transcription of more than 200 cytoprotective proteins that protect against oxidative stress due to injury, inflammation, and normal aging processes. It is an element of the Keap1-Nrf2-ARE biological pathway, a mediator of protective responses to oxidative and electrophilic stressors. Hormetic stressors like exercise, heat exposure, and dietary components trigger Nrf2 activity. Sulforaphane, a compound derived from broccoli, is the most potent naturally occurring hormetic inducer of Nrf2 activity. Learn more about Nrf2 in this clip featuring Dr. Jed Fahey.

For more information about the cognitive benefits of exercise (as well as other lifestyle behaviors), check out our Cognitive Enhancement Blueprint in the Member Library.

Omega-3 fatty acids preserve blood-brain barrier integrity, maintaining cognitive function. onlinelibrary.wiley.com

Brain Omega-3 Dementia Blood-Brain Barrier

The blood-brain barrier is a collection of membranes that separate the central nervous system from the peripheral circulation, facilitating the passage of nutrients and signaling compounds while excluding harmful substances. Loss of blood-brain barrier integrity increases the risk of many neurodegenerative diseases, including dementia and Alzheimer’s. A 2021 study found that having a higher omega-3 index preserves the blood-brain barrier and maintains cognitive function in older adults.

Researchers assessed the cognitive performance of 45 healthy older adults. They measured the participants' red blood cell omega-3 concentrations (“omega-3 index”) and evaluated their blood-brain barrier integrity using magnetic resonance imaging.

They found that participants with a higher omega-3 index had greater blood-brain barrier integrity than those with a lower index. They also performed better on tests of memory and language (functions most affected by Alzheimer’s disease) but not on executive function, speed, or motor control assessments.

These findings suggest that higher blood concentrations of omega-3 fatty acids (measured via the omega-3 index) preserve blood-brain barrier integrity, potentially protecting against cognitive losses. The omega-3 index measures the amount of the omega-3 fatty acids EPA and DHA as a percentage of total fatty acids in red blood cell membranes. Evidence suggests it is a reliable biomarker of sudden cardiac death risk and may provide a means of standardizing methodologies used in clinical trials, facilitating more accurate interpretation of clinical trial outcomes. Learn more about the omega-3 index in our overview article.

Higher vitamin D levels are linked to 18 percent lower dementia risk in older adults with prediabetes. pubmed.ncbi.nlm.nih.gov

Vitamin D Alzheimer's Diabetes Genetics Dementia

Lifestyle and nutritional factors influence the risk of dementia, particularly among people with prediabetes – a condition characterized by elevated blood sugar levels that are not high enough to be classified as diabetes. A recent study found that higher vitamin D levels may reduce the risk of developing dementia in older adults with prediabetes.

Researchers drew on data collected from a large cohort of more than 34,000 older adults enrolled in the UK Biobank, all of whom had prediabetes but did not have dementia at the start of the study. They measured the participants' blood vitamin D levels and monitored them for the development of dementia, including Alzheimer’s disease and vascular dementia, for approximately 12 years. Their analysis also considered genetic variations that could influence the relationship between vitamin D levels and dementia risk.

They found that participants with higher blood vitamin D levels were 18 percent less likely to develop any type of dementia, with similar findings for Alzheimer’s disease and vascular dementia. The protective effect of vitamin D was particularly robust in participants who did not carry polymorphisms (genetic variants) related to the vitamin D receptor, highlighting a potential interaction between genetics and vitamin D levels in dementia risk.

These findings suggest that maintaining adequate levels of vitamin D benefits brain health, especially in older adults with prediabetes, a group at elevated risk for dementia. They add to the growing body of evidence supporting the importance of vitamin D for overall health and emphasize the need for further research to understand the mechanisms behind its protective effects on the brain. Learn more about vitamin D in our comprehensive overview article.

A ketogenic diet restores long-term potentiation, a crucial mechanism for learning and memory, to healthy levels in mice prone to Alzheimer's-like symptoms, implicating ketone bodies as potential therapeutic agents. www.ucdavis.edu

Alzheimer's Diet Aging Ketosis Memory Dementia Ketogenic Diet

A ketogenic diet – a high-fat, low-carbohydrate dietary pattern – offers potential benefits in various health contexts, including weight management and seizure control. Some evidence suggests that the ketogenic diet is beneficial in preventing or treating neurodegenerative diseases, such as Alzheimer’s and dementia. A recent study in older mice found that a ketogenic diet improves memory functions and increases lifespan.

Researchers compared the effects of a seven-month ketogenic diet to a standard diet in mice prone to developing Alzheimer’s-like symptoms. They examined the hippocampal region of the animals' brains, a crucial area for memory and learning, to gauge the diet’s effects on synaptic plasticity – the brain’s ability to form and reorganize synaptic connections, especially in response to learning or new experiences.

They found that mice on the ketogenic diet experienced restoration of their long-term potentiation – a measure of synaptic strength and a fundamental mechanism for learning and memory – to levels comparable to healthy mice. They attributed this restoration to the marked elevation of beta-hydroxybutyrate (BHB), a ketone body produced during the ketogenic diet. They also found that the diet triggered enhancements in several key pathways and molecules associated with synaptic plasticity, including notable increases in specific enzymes and brain-derived neurotrophic factor (BDNF), particularly in female mice.

BDNF is crucial for cognitive functions, providing support for neuronal survival, growth, and differentiation and enhancing learning and memory by strengthening and creating synaptic pathways. Elevated BDNF levels correlate with better cognitive performance, whereas its deficiency is linked to various mental and neurodegenerative disorders, highlighting its significance in brain health. Learn more about BDNF in our overview article.

These findings suggest that a ketogenic diet ameliorates memory impairments and bolsters neuronal health in an Alzheimer’s mouse model, primarily through the action of BHB and its enhancement of synaptic plasticity. Learn more about beta-hydroxybutyrate in our overview article.

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Yoga improves memory and boosts cognition in older women at risk for Alzheimer's, demonstrating increased hippocampal connectivity and expression of anti-aging markers. www.sciencedaily.com

Exercise Brain Alzheimer's Aging Memory Dementia

Yoga is an ancient Indian practice that engages the mind and body through physical poses, breathing techniques, and meditation. Robust scientific evidence suggests that yoga benefits both mental and physical health. A new study found that Kundalini yoga – a type of yoga that involves specific postures, breathing techniques, and meditation – boosted cognition and memory in older women at risk of developing Alzheimer’s disease.

The study involved 63 older women who had self-reported memory problems and cerebrovascular conditions – risk factors for Alzheimer’s. About half the women participated in a weekly yoga session, while the other half participated in weekly memory training. Researchers assessed the women’s cognitive function and moods before and after the two interventions. They also measured markers of aging and inflammation in the women’s blood and assessed changes in their brains using magnetic resonance imaging (MRI).

They found that the women who participated in yoga experienced marked improvements in memory, increased connectivity in the hippocampus, and increased expression of anti-inflammatory and anti-aging markers** compared to those who did memory work only. The MRIs revealed that the brains of the women in the yoga group showed less age-related volume loss.

Women are at greater risk of developing Alzheimer’s disease than men, partly due to having higher rates of cardiovascular conditions, many of which share risk factors with Alzheimer’s. In addition, the decrease in protective estrogen during menopause may also amplify cognitive declines.

These findings suggest that Kundalini yoga benefits women at risk for Alzheimer’s disease. Evidence indicates that vigorous exercise can boost cognitive function, too. Learn more in this episode featuring Dr. Martin Gibala.

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Alcohol consumption is linked to increased iron accumulation in the brain, potentially impairing memory, learning, and reward-processing functions. journals.plos.org

Brain Alcohol Dementia Iron

Iron is an essential mineral, best known for its critical role in cellular oxygen transport. However, having too much iron in the brain drives cognitive deficits. A 2022 study found that alcohol consumption promotes iron deposition in the brain, compromising cognitive function, even among moderate drinkers.

The investigation involved nearly 21,000 adults enrolled in the UK Biobank study. Participants provided information about their alcohol intake and completed a battery of cognitive tests. Researchers performed magnetic resonance imaging scans to assess iron levels in the participants' brains and livers.

They found that, on average, participants consumed about 18 units of alcohol per week, roughly equivalent to ten 12-ounce beers or ten 5-ounce glasses of wine. Participants who consumed as few as 7 units of alcohol per week had higher levels of iron in the brain’s putamen and caudate (in the basal ganglia) and in the substantia nigra (in the midbrain), areas involved in learning, memory, reward processing, and movement. Higher iron levels in the basal ganglia were associated with slower executive function, lower fluid intelligence, and slower reaction times. Those who consumed more than 11 units of alcohol per week had higher iron levels in their livers.

These findings suggest that moderate alcohol consumption has marked effects on the brain and cognition, likely due to excess iron deposition. Alcohol consumption is associated with a wide range of health problems, including heart disease, stroke, liver dysfunction, and cancer. However, vigorous exercise can help reduce alcohol cravings. Learn more in this video featuring Dr. Rhonda Patrick.

Multivitamin/mineral supplements enhance memory and cognitive function in older adults, a finding from the COSMOS trial. www.sciencedirect.com

Brain Alzheimer's Aging Micronutrients Dementia

As the global population ages, the number of people at risk for Alzheimer’s disease and other forms of dementia increases. A robust and growing body of evidence indicates that lifestyle influences the risk of developing dementia. A recent study found that multivitamin/mineral supplements improve memory and slow cognitive aging in older adults – roughly equivalent to reducing cognitive aging by two years.

Researchers investigated the effects of multivitamin/mineral supplementation on cognitive function in a subset of participants enrolled in the COSMOS study, a randomized, double-blind, placebo-controlled trial involving more than 21,000 older adults (60 years or older) in the U.S. Participants in COSMOS were randomly assigned to receive one of three interventions: cocoa extract (providing 500 milligrams of flavanols daily, including 80 milligrams of epicatechin), a multivitamin/mineral supplement, or both, daily for two years. A fourth group received a placebo. In the subset, called COSMOS-Clinic, 573 participants underwent extensive brain function tests before and after the study and again two years later.

They found that multivitamin/mineral supplementation conferred modest improvements in overall cognitive function over two years in participants enrolled in the subset, particularly in episodic memory – the ability to recall specific events, experiences, and contextual details from one’s past. They did not observe improvements in the participants' executive function or attention. However, a meta-analysis involving more than 5,000 participants from the COSMOS-Clinic, COSMOS-Mind, and COSMOS-Web studies demonstrated that multivitamin/mineral supplementation markedly improved overall cognition and episodic memory.

These findings from the COSMOS trials suggest that multivitamin/mineral supplementation – a low-cost, low-effort intervention – improves cognitive function in older adults. They also highlight the role of adequate nutrition throughout the lifespan and support the “micronutrient triage theory” – the idea that the body prioritizes the utilization of micronutrients for metabolic pathways needed for survival and reproduction over those used for long-term health. Learn more about micronutrient triage theory in this clip featuring Dr. Bruce Ames.

Sulforaphane from broccoli sprouts shows promise in preventing Alzheimer's disease – boosting memory and enhancing mitochondrial function in mice. www.mdpi.com

Brain Alzheimer's Mitochondria Dementia Sulforaphane Oxidative Stress

Alzheimer’s disease affects more than 24 million people worldwide, with numbers expected to grow as the population ages. A growing body of evidence links mitochondrial dysfunction and oxidative stress to the development of Alzheimer’s disease. A recent study in mice found that sulforaphane, a bioactive compound derived from broccoli and broccoli sprouts, boosts memory, improves mitochondrial function, and reduces oxidative stress.

Researchers studied normal mice and mice prone to developing a condition similar to Alzheimer’s. They fed half of each type of mice standard mouse chow. They fed the other half normal chow supplemented with a broccoli sprout powder rich in glucoraphanin and myrosinase – the precursors to sulforaphane. They subjected the mice to various memory tests and assessed their mitochondrial function.

They found that Alzheimer’s disease-prone mice that ate the broccoli sprout powder-supplemented chow performed better on memory tests than those that didn’t. These mice demonstrated higher levels of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC1α) and mitochondrial transcription factor A – proteins that regulate mitochondrial biogenesis (the production of new mitochondria). They also showed upregulated expression of cellular antioxidant defense system components that protect against oxidative stress.

These findings suggest that sulforaphane from broccoli sprouts prevents age-related cognitive decline by maintaining mitochondrial function, thereby reducing oxidative stress in mice.

Sulforaphane is an isothiocyanate compound with robust antioxidant, anti-inflammatory, and anti-cancer effects. It reduces oxidative stress by switching on the activity of Nrf2, a cellular protein that activates the transcription of cytoprotective proteins that protect against oxidative stress due to injury and inflammation. Sulforaphane is the most potent naturally occurring inducer of Nrf2. Learn how to grow your own broccoli sprouts – a terrific source of sulforaphane – in this short video.

Strawberry consumption enhances memory and mood in middle-aged adults, potentially reducing dementia risk. www.uc.edu

Brain Diet Aging Metabolism Dementia Polyphenol

With age, cognitive and metabolic dysfunction increases, often coinciding. However, evidence suggests that consuming berries improves cognitive and metabolic health. A recent study found that strawberry consumption improved memory and mood in overweight people with mild cognitive decline.

Researchers recruited 34 overweight middle-aged adults with insulin resistance who reported mild cognitive decline. Half of the participants consumed a strawberry powder supplement daily for 12 weeks, while the other half consumed a placebo. Both groups abstained from all berry consumption throughout the study. The researchers assessed the participants' cognitive and metabolic functions and moods before and after the intervention.

They found that those who consumed the strawberry powder exhibited better memory function and fewer symptoms of depression than those who consumed the placebo. However, they did not show any improvements in metabolic function.

These findings suggest that strawberry supplementation improves cognitive function in middle-aged adults, potentially reducing the risk of dementia, but has little effect on metabolic function. The study’s authors attributed the lack of metabolic response to the relatively low dose and the study’s short duration.

Strawberries are rich in anthocyanins, a class of polyphenolic compounds that exert potent antidiabetic, anticancer, anti-inflammatory, and anti-obesity effects in humans. Anthocyanins lend their characteristic blue, red, or purple hues to strawberries, blueberries, and other fruits and vegetables. Learn about other polyphenols in our overview article.

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Cigarette smoking reduces brain volume, accelerating the brain's aging process. medicalxpress.com

Brain Alzheimer's Aging Dementia

Smoking cigarettes damages multiple organs, including the brain, possibly explaining why as many as 14 percent of Alzheimer’s cases worldwide are linked to smoking. A new study shows that cigarette smoking reduces brain volume, accelerating normal brain aging.

Researchers investigated the relationship between smoking and brain volume in more than 32,000 adults enrolled in the UK Biobank study. They used a set of guidelines (called Bradford Hill’s criteria) to determine whether a potential cause-and-effect relationship exists between a specific factor (such as smoking) and a health outcome (such as a disease). They also investigated whether genetic factors predispose some people to initiate smoking.

They found that regular smoking, especially heavier smoking, was linked to notable brain shrinkage, especially in terms of total gray matter volume. The more years a person smoked, the greater the shrinkage. They also found that daily smoking played a role in the relationship between the genetic risk score for smoking initiation and the total gray matter volume.

These findings suggest that smoking cigarettes reduces drives brain volume losses, effectively aging the brain prematurely. They also align with other research demonstrating that regular (daily or nearly daily) cigarette smoking increases relative brain aging, driving poor cognitive function and declines in fluid intelligence. Many habits like smoking (and overeating) can be broken using mindfulness techniques. Learn more in this clip featuring Dr. Ashley Mason.

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Hearing aids reduce the risk of early death in older adults with hearing loss by 24 percent. www.thelancet.com

Aging Dementia Hearing Mortality

Hearing loss is a common feature of aging and a known risk factor for poor quality of life, depression, dementia, and early death. Roughly two-thirds of adults over 70 have some degree of hearing loss, but few seek out treatment. A recent study found that hearing aids reduce the risk of premature death in older adults with hearing loss by 24 percent.

The study involved more than 9,800 adults (average age, 48 years) enrolled in the NHANES studies. Participants underwent hearing tests and completed questionnaires about their hearing aid use over a ten-year period.

The tests and questionnaires revealed that nearly 15 percent of the participants had some hearing loss. However, fewer than 13 percent of those with hearing loss regularly used hearing aids. Those with hearing loss who did wear hearing aids were 24 percent less likely to die prematurely than those who didn’t, even after taking demographics, hearing levels, and medical history into account.

These findings suggest hearing aids reduce the risk of premature death in older adults with hearing loss. Other evidence demonstrates that hearing aids benefit older adults at high risk for cognitive decline. Interestingly, another study found that the risk of developing mild hearing loss was nearly 30 percent lower among people who adhered to healthy dietary patterns such as the DASH diet or the Mediterranean diet, suggesting that diet may play a role in preventing mild hearing loss.

Poor oral health may triple Alzheimer's disease risk. www.brainandlife.org

Alzheimer's Dementia Dental

Oral health is intricately linked to overall well-being, with emerging research identifying associations between poor oral health and an increased risk of many chronic diseases, including cardiovascular disease, diabetes, and cancer. A recent study found that oral diseases associated with tooth loss more than tripled the risk of developing Alzheimer’s disease.

Researchers assessed Alzheimer’s disease risk among more than 32 million people. They categorized the participants as having normal or poor oral health and assessed serum biomarkers associated with Alzheimer’s, including blood glucose, lipids, and C-reactive protein (a marker of inflammation).

They found that more than 1.2 million participants had poor oral health, while the remainder had normal oral health. Those with poor oral health were more than twice as likely to develop Alzheimer’s disease than those with normal oral health, regardless of age, gender, or serum biomarkers. Those with oral conditions associated with tooth loss were more than three times more likely to develop Alzheimer’s.

The findings from this large epidemiological study suggest that poor oral health markedly increases a person’s risk for developing Alzheimer’s disease. In vitro research further supports these findings, demonstrating that oral bacteria colonize the brain and release toxins that disrupt the blood-brain barrier, impairing its function and increasing the risk of Alzheimer’s. And research in mice shows that oral bacteria over-stimulate microglia, impairing their ability to eliminate amyloid-beta, a harmful protein linked to Alzheimer’s.

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Dementia cases could surpass previous estimates by 40 percent, highlighting the need for prevention. medicalxpress.com

Alzheimer's Aging Dementia

Nearly 50 million people worldwide live with Alzheimer’s disease or another form of dementia — a number projected to triple in the coming decades. However, a recent study suggests the number could be even higher, as much as 40 percent more than previous estimates.

Researchers analyzed data from the English Longitudinal Study of Ageing, a long-term study of older adults living in England and Wales. They identified dementia cases from among more than 90,000 people. Then, they analyzed how dementia incidence changed over time based on age, sex, and education.

They found that dementia incidence decreased by 28.8 percent between 2002 and 2008 and then increased by 25.2 percent between 2008 and 2016 (nearly 3 percent per year). People with lower educational attainment experienced a slower decline in dementia during 2002-2008 and a more rapid increase after 2008, demonstrating growing disparities. The researchers predicted that if dementia incidence continues to rise at the same pace observed from 2008 to 2016, the number of people living with dementia will roughly double by 2040.

These findings suggest that the number of people with dementia will be markedly higher in the coming decades. Evidence suggests lifestyle factors influence a person’s dementia risk. Learn how sauna use, exercise, sleep, and dietary components, such as omega-3 fatty acids and sulforaphane exert robust anti-aging effects on the brain, potentially preventing or forestalling dementia.

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A new study reveals a surprising link between triglycerides and reduced risk of dementia in older adults. www.sciencedaily.com

Dementia Triglycerides Metabolic Syndrome Cardiovascular

Triglycerides, the most common type of fat in the body, serve as a vital energy source and aid in absorbing fat-soluble vitamins. However, elevated levels of triglycerides, often associated with unhealthy dietary habits and certain metabolic conditions, have been linked to an increased risk of atherosclerosis, cardiovascular disease, and other metabolic disorders. Now, findings from a recent study suggest that higher triglyceride levels reduce the risk of dementia by as much as 18 percent.

Researchers drew on data from more than 86,000 healthy older adults enrolled in the UK Biobank and ASPREE studies. They measured the participants' triglyceride levels and assessed different aspects of their cognition, such as memory, language, and reasoning. Then, they determined the effects of triglyceride levels on these cognitive measures.

They found that participants with higher triglyceride levels (normal to high-normal) were 18 percent less likely to develop dementia and experienced a slower decline in their overall cognitive abilities over time than those with lower triglyceride levels. Those with the highest levels of triglycerides were 36 percent less likely to develop dementia than those with the lowest levels. These results were consistent even after considering other factors that could affect the outcomes.

These findings suggest that higher triglyceride levels protect against dementia, counter to current thinking about triglycerides. They also highlight the need for further investigation to understand whether this link is causal and whether components of triglycerides benefit cognitive function.

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Accelerated biological aging is linked to a 40 percent higher risk of vascular dementia and stroke. medicalxpress.com

Aging Dementia Environment Cardiovascular

Aging is the collective physiological, functional, and mental changes that accrue in a biological organism over time. However, people age at different rates, a consequence of both genetic and environmental factors. A recent study found that people whose biological age is five years older than their chronological age are roughly 40 percent more likely to develop vascular dementia or experience a stroke than those whose biological and chronological ages align.

Using 18 routinely measured clinical biomarkers, researchers calculated the biological ages of more than 325,000 people enrolled in the UK Biobank study. Then, they evaluated how older biological age influenced the occurrence of neurological conditions, including dementia of all types, stroke, Parkinson’s disease, and motor neuron disease, over a nine-year follow-up period.

They found that nearly 1,400 participants developed dementia, and more than 2,500 experienced a stroke. Having an older biological age that was five years older than chronological age increased the participants' risk of dementia by 26 percent, vascular dementia by 41 percent, and stroke by 39 percent. The findings were consistent even after considering various disease-specific risk factors.

These findings suggest that accelerated biological aging markedly increases the risk of dementia and stroke. Age acceleration can result from intrinsic factors, such as normal metabolism and genetics, or extrinsic factors, such as diet, smoking, and exercise. Learn how epigenetic changes influence biological aging in our overview article.

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Pericytes are pivotal in the formation and storage of long-term memories. www.sciencedaily.com

Brain Hormones Memory Dementia Stroke Blood-Brain Barrier

Tiny contractile cells surrounding the brain’s capillaries called pericytes regulate vascular blood flow and maintain blood-brain barrier integrity. Pericytes detach from the blood vessels in aging, driving the pathophysiology of neurological dysfunction, vascular dementia, and stroke. A recent study in rodents shows that pericytes also play roles in long-term memory formation.

Researchers measured the amount of insulin-like growth factor 2 (IGF2) produced by various cells in the hippocampus of rodents. IGF2, a peptide hormone produced in multiple tissues, regulates growth during fetal development and participates in the cell cycle throughout the lifespan. After determining that pericytes contributed the greatest amount of hippocampal IGF2, they assessed learning’s influence on IGF2.

They found that learning increased pericyte IGF2 production in the hippocampus, especially in the dentate gyrus, a highly vascularized area responsible for episodic memory – long-term memory that involves conscious recollection of previous experiences and their associated contexts, such as sounds and smells. Animals lacking the ability to produce IGF2 in their pericytes exhibited poor learning and memory.

The detachment and loss of pericytes play a crucial role in the progression of cerebral small vessel disease and neurodegenerative disorders that involve blood-brain barrier dysfunction. These specialized endothelial cells envelop a significant portion, up to 80 percent, of the brain capillary surface area in the cortex and hippocampus of the human brain. They also enwrap the tiniest vessels constituting the blood-brain barrier.

Exercise mitigates the proinflammatory state that drives pericyte loss in aging, possibly providing a mechanism for exercise’s memory-enhancing effects. Learn more about links between exercise, pericytes, and brain health in this episode featuring Dr. Axel Montagne.

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Greater blood pressure variability is linked with cognitive decline in older adults. www.sciencedaily.com

Brain Aging Dementia Blood Pressure

Scientists have long understood that high blood pressure increases a person’s risk for cognitive decline and dementia. Now, evidence suggests that blood pressure variability carries similar risks. A recent study found that older adults with higher blood pressure variability performed worse on cognitive tests than those with lower variability.

Blood pressure variability occurs in response to various physiological and environmental factors that influence arterial blood pressure. Scientists classify blood pressure variability according to five types: short-term (beat to beat), short-term (24 hours), mid-term (day to day), long-term (less than five years), or very long-term (more than five years). People with high blood pressure tend to have higher variability than those with normal pressure.

Researchers measured the blood pressure of 70 older adults (aged 60 to 80) without dementia over several days. The participants took cognitive tests and underwent tests to determine their arterial stiffness – a well-established cardiovascular risk factor for cognitive impairment and closely linked with high blood pressure.

The researchers found that regardless of the participants' average blood pressure, those with high systolic short-term exhibited poor attention and psychomotor speed, and those with mid-term blood pressure variability showed poor executive function. Those with higher systolic short-term blood pressure variability tended to have higher arterial stiffness.

These findings suggest that higher blood pressure variability influences cognitive function, potentially reflecting early-stage decline better than average blood pressure. They also underscore the importance of maintaining healthy blood pressure throughout the lifespan. Learn how lifetime high blood pressure increases dementia risk in this clip featuring Dr. Axel Montagne.

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Agricultural PM2.5 pollution significantly worse for dementia risk: 13 percent increase compared to 5 percent from wildfires. www.sciencedaily.com

Aging Dementia Pollution

Particulate matter in air pollution is a mixture of solid particles and liquid droplets. It forms fine inhalable particles with diameters typically 2.5 micrograms (PM2.5) or less. Exposure to particulate matter promotes oxidative stress and increases the risk of developing many chronic diseases, including cardiovascular disease, cancer, hypertension, and diabetes. A recent study found that particulate matter in air pollution from agriculture increases the risk of dementia in older adults.

The study involved more than 27,000 adults enrolled in the Environmental Predictors of Cognitive Health and Aging study. Participants were over the age of 50 and dementia-free at the time of enrollment. Using spatiotemporal and chemical transport models, researchers assessed the participants' exposure to PM2.5 from nine emission sources over a 10-year period.

They found that exposure to higher levels of PM2.5 increased the risk of dementia by 8 percent. When they examined specific PM2.5 sources, they discovered that agriculture PM2.5 increased dementia risk by 13 percent, while wildfire PM2.5 increased risk by 5 percent.

These findings suggest that reducing PM2.5 pollution, particularly from agricultural and wildfire sources, could benefit cognitive health in older adults. However, further research is necessary to validate these findings and explore potential intervention strategies.

Evidence suggests that sulforaphane, a bioactive compound derived from broccoli, counters some of the harmful effects of particulate matter. Learn more about sulforaphane in our comprehensive overview article.

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Time-restricted feeding corrects Alzheimer’s circadian disruptions in mice, reducing amyloid protein accumulation and improving memory. www.sciencedaily.com

Brain Alzheimer's Dementia Time-Restricted Eating

Alzheimer’s disease is the most common form of dementia, affecting more than 55 million people worldwide. People with Alzheimer’s disease often experience altered circadian rhythms, manifesting as altered sleep/wake cycles and difficulty in falling and staying asleep. A new study in mice suggests that time-restricted eating restores normal circadian rhythmicity and reduces amyloid-beta plaque formation in the brain.

Using a mouse model of Alzheimer’s disease, researchers gave one group of mice free access to food throughout the day but fed another group on a time-restricted schedule (limited to a six-hour window each day), translating to about 14 hours of fasting for humans. Then, they evaluated the animals' gene expression, amyloid-beta accumulation, and cognitive performance.

They found that the mice fed on the time-restricted schedule had better memory function, were less hyperactive at night, followed a more regular sleep schedule, and experienced fewer disruptions during sleep than the mice allowed free access to food. The restricted mice also performed better on cognitive assessments and exhibited less amyloid-beta accumulation in the brain. Time-restricted feeding also normalized gene expression in the hippocampus, an area of the brain involved in memory and often affected by Alzheimer’s disease.

These findings suggest that time-restricted eating mitigates the behavioral symptoms and pathological features associated with Alzheimer’s disease. Robust evidence indicates that time-restricted eating influences multiple aspects of human health. Learn more about time-restricted eating in this clip featuring Dr. Satchin Panda.

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Enhancing brain health in older adults: Olfactory stimulation via aromatherapy shows promise in cognitive function preservation. neurosciencenews.com

Brain Alzheimer's Memory Dementia Nose

The limbic system – a complex system of nerves and networks in the brain – supports many brain functions, including memory, emotion, and learning. The olfactory system is the only sensory system directly linked to this critical brain region. A new study shows that olfactory stimulation via aromatherapy may enhance limbic system function, potentially preserving or improving cognitive function in older adults.

Researchers assigned 23 older adults (aged 60 to 85) to an olfactory-enriched or control group. Using an aromatherapy diffuser, they exposed the enriched group to seven essential oil scents (rose, orange, eucalyptus, lemon, peppermint, rosemary, and lavender – one per night) for two hours per night for six months. They exposed the control group to a similar routine but with minimal amounts of scent. The participants underwent neuropsychological assessments and functional magnetic resonance imaging (fMRI) scans at the study’s outset and again after six months.

The assessments revealed that the participants who received olfactory enrichment demonstrated a 226 percent improvement on learning and memory tests. Notably, only six of the 12 participants improved, five stayed the same, and one did worse, calling the data into question. The fMRIs showed that the enriched group also exhibited enhanced function in the left uncinate fasciculus – an area of the brain that plays a crucial role in memory, language, emotion, and memory retrieval.

These findings suggest that olfactory enrichment administered at night improves cognitive and neural functioning and may provide an effective and low-effort means to improve brain health. This study was very small, so larger trials are needed to confirm the benefits of aromatherapy on cognitive health.

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Hearing aids show promise in reducing dementia risk by half in high-risk older adults, new study reveals. www.cnn.com

Diet Aging Dementia Hearing

Older adults with hearing loss are more likely to experience cognitive decline and an increased risk of developing dementia. However, a new study suggests that hearing aids can moderate this risk. Older adults with hearing loss who wore hearing aids were nearly half as likely to develop dementia as those who didn’t.

Researchers recruited nearly 1,000 older adults aged 70 to 84 with untreated hearing loss. About half of the participants received hearing aids, and the other half received health education counseling. The researchers assessed the participants' cognitive function every six months for three years.

They found no difference in cognitive decline between the two groups when considering the entire cohort. However, when they looked at specific subgroups, they found that the effect of hearing aids on cognitive change varied according to the participants' risk profiles. Specifically, hearing aids appeared to reduce cognitive change in older adults with a higher risk of decline but not in those with a lower risk.

These findings suggest that hearing aids benefit older adults with a higher risk of cognitive decline. Approximately two-thirds of all adults over 70 have some degree of hearing loss. Evidence suggests that adhering to healthy dietary patterns such as the DASH diet or the Mediterranean diet reduces the risk of mild hearing loss by nearly 30 percent, highlighting potential links between diet, dementia, and hearing loss. Learn more about dietary strategies to reduce the risk of dementia in this episode featuring Dr. Dale Bredesen.

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Vitamin D Brain Aging Dementia

Vitamin D is a steroid hormone that plays critical roles in many physiological processes, including blood pressure regulation, immune function, and cell growth. Findings from a new study suggest that vitamin D prevents dementia. People who took vitamin D were 40 percent less likely to develop dementia than those who didn’t.

The study involved more than 12,000 older adults who did not have dementia at enrollment. Researchers categorized the participants based on their vitamin D exposure: those exposed to vitamin D before dementia onset and those not exposed before dementia onset. They also examined different forms of vitamin D (calcium + vitamin D, cholecalciferol [D3], and ergocalciferol [D2]) to see if their effects on dementia rates varied and explored potential interactions with other risk factors for dementia, such as age, sex, education, race, cognitive function, depression, and apolipoprotein E4 (APOE4) status.

They found that participants exposed to vitamin D had a 40 percent lower risk of developing dementia. They were also dementia-free longer than those without vitamin D exposure. These effects were evident across various forms of vitamin D. Further analysis revealed that sex, cognitive status, and APOE4 status influenced the extent of vitamin D’s effects on dementia risk. For example, females, people with normal cognitive function, and those who did not carry the APOE4 gene variant seemed to gain greater protection against dementia.

These findings suggest that vitamin D supplementation holds promise as a preventive measure for dementia, especially for people at higher risk of developing the condition. However, more research is required to fully understand the mechanisms behind this association and establish specific vitamin D supplementation guidelines to reduce dementia risk. Learn more about vitamin D in our comprehensive overview article.

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Every 1 percent drop in body weight slows brain aging by nearly nine months, highlighting the substantial, and often overlooked, neuroprotective benef elifesciences.org

Brain Obesity Aging Dementia Sulforaphane Weight Loss Neurodegeneration

Excess body fat harms multiple organ systems, including the central nervous system, potentially accelerating brain aging. A new study shows that a 1 percent weight loss delays brain aging by nearly nine months.

Researchers conducted a study involving 102 participants enrolled in the DIRECT-PLUS study who underwent an 18-month lifestyle intervention to promote weight loss. Using magnetic resonance imaging, the researchers assessed the resting-state functional connectivity in the participants' brains and predicted their brain ages. They also evaluated how various health factors, such as body measurements, blood markers, and fat deposits, affect brain aging.

They found that the brain age prediction model accurately predicted the participants' chronological ages. They also found that brain aging slowed by 8.9 months for every 1 percent of body weight loss, an effect linked with improved liver health and reduced liver, visceral, and subcutaneous fat. Their analysis revealed that lower consumption of processed foods, sweets, and beverages delayed brain aging.

These findings suggest that weight loss may benefit the brain’s aging process, potentially slowing its aging trajectory. They also underscore the importance of maintaining a healthy weight throughout the lifespan to support overall brain health. Sulforaphane, a bioactive compound derived from broccoli, benefits brain health and may influence its aging, too. Learn more in this episode featuring Dr. Rhonda Patrick.

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Presence hallucinations, such as sensing an unseen person, in early Parkinson's may signal faster cognitive decline. www.medicalnewstoday.com

Brain Parkinson's Dementia

Cognitive decline and hallucinations are common features of late-stage Parkinson’s disease. However, during the early stages of the disease, many people experience minor hallucinations – such as sensing an unseen person nearby or seeing a shadow pass in one’s peripheral vision – potentially indicating future cognitive deline. A recent study found that people with Parkinson’s disease who experienced minor hallucinations exhibited altered brain wave activity.

Researchers interviewed 75 people with Parkinson’s disease to determine whether they experienced minor hallucinations. Then, using electroencephalography (EEG), they analyzed their brain wave activity. They repeated the EEG five years later.

They found that those who experienced minor hallucinations – roughly half of the participants – had altered theta oscillations in the frontal part of their brains. These alterations were associated with poorer cognitive abilities in the frontal and subcortical regions of the brain. At the five-year follow-up, they found that participants with more frontal theta alterations during the initial assessment had a greater decline in their frontal and subcortical cognitive functions.

Theta oscillations are rhythmic, electrical brain waves occurring at approximately four to eight cycles per second, typically observed during deep relaxation, daydreaming, and certain stages of sleep. Theta waves play a crucial role in various cognitive processes, such as memory formation, learning, and spatial navigation. They enable communication and synchronization between brain regions, facilitating efficient information processing and integration.

These findings suggest that changes in frontal theta oscillations could be an early marker for cognitive decline in people with Parkinson’s disease. Exercise may slow the progression of Parkinson’s disease. Learn more in this episode featuring Parkinson’s expert Dr. Giselle Petzinger.

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Exercise, vitamin D, and cognitive training boost cognitive function. link.springer.com

Vitamin D Exercise Brain Aging Dementia

Changes in brain function and connectivity often occur many years before the clinical manifestation of cognitive impairment and dementia. A new study shows that lifestyle modifications, including exercise, vitamin D intake, and cognitive training, improve functional brain connectivity in older adults with mild cognitive impairment.

The study involved 120 older adults (ages 60 to 80 years) with mild cognitive impairment. The participants engaged in 30 minutes of cognitive training and 60 minutes of exercise three times a week for 20 weeks. Thirty-eight of the participants received vitamin D supplements, while the remainder received a placebo. Researchers measured the participants' functional brain connectivity using MRI before and after the interventions.

They found that physical exercise alone, exercise combined with cognitive training, or exercise combined with both cognitive training and vitamin D supplementation increased functional brain connectivity in regions of the brain’s default mode network, including the hippocampus and angular gyrus.

The default mode network is a collection of interconnected neural structures involved in attention and focus. Disturbances in default mode network connectivity are associated with poor working memory, reduced performance, and work-related productivity losses.

This study’s findings suggest that lifestyle behaviors, particularly exercise, enhance functional brain connectivity, potentially staving off age-associated cognitive decline. Learn more about the effects of exercise on the brain in this episode featuring Dr. Axel Montagne.

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Is omega-6 a villain? New study highlights omega-6, -7, and -9 may promote better memory and a larger brain volume. medicalxpress.com

Nutrition Brain Dementia

A recent study showed that people with higher blood concentrations of key fatty acids had larger brain volumes and better cognitive function than those with lower concentrations.

Researchers collected nutrition-related blood biomarkers, brain images, and memory and intelligence scores of 111 older adults. Then, using a data-fusion approach, they investigated how these factors work together to promote brain and cognitive health in aging.

They found that participants with higher blood concentrations of omega-6, -7, and -9 fatty acids tended to score higher on memory tests than those with lower concentrations. They also had larger gray matter volumes.

These findings suggest that nutrition plays a critical role in brain health and cognitive function in aging. They also underscore the importance of consuming healthy fats for optimal brain health.

Studies like this one emphasize that omega-6 fatty acids are not inherently villainous; rather, they become problematic when they serve as a marker for processed food consumption. In certain contexts, specific omega-6 fatty acids, particularly linoleic acid, exhibit beneficial effects. Instead of eliminating omega-6 fatty acids found in healthy foods, it may be more effective to focus on reducing processed food intake while increasing consumption of omega-3 fatty acids and whole foods containing beneficial forms of omega-6, -7, and -9. By consuming more whole foods, we benefit from not only the presence of healthy omega-6, -7, and -9 fatty acids, but also from fiber, the food matrix, improved glycemic impact, and an abundance of micronutrients that are often stripped away in processed foods. This holistic approach to nutrition ensures that we receive the full spectrum of nutrients required for optimal health.

In addition, although older research showed that the ratio of omega-6s to omega-3s in blood was cause for concern, those concerns are likely unfounded. Rather than focusing on decreasing omega-6 intake to improve the ratio, most people would probably benefit from increasing omega-3 intake instead to improve overall blood concentrations. Learn more about the omega-6/omega-3 ratio in this clip featuring Dr. Bill Harris.

Omega-6s are found in sunflower seeds; walnuts; and pumpkin seeds. They are also found in safflower, sunflower, corn, and soybean oils. Omega-7s are found in salmon, anchovies, macadamia nuts, olive oil, and avocados. Omega-9s are found in various nut oils.

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Deep breathing exercises moderate heart rate variability – and may reduce Alzheimer's disease risk. gero.usc.edu

Brain Alzheimer's Meditation Dementia Breathing Technique

Deep breathing exercises may reduce the risk of Alzheimer’s disease, a new study shows. People who practiced deep breathing exercises had blood lower levels of amyloid-beta protein – a risk factor for Alzheimer’s disease.

The study involved 108 healthy adults. Half of the participants practiced slow-breathing techniques in a 10-second rhythm (five seconds in, five seconds out) to maximize their heart rate variability. The other half tried to keep their heart rate steady by practicing relaxation techniques, such as picturing calm settings or listening to calming music. Each group practiced their respective techniques for about 20 minutes, twice daily for four weeks.

They found that participants who practiced the slow-breathing techniques (inducing greater heart rate variability) had lower blood levels of amyloid-beta 40 and 42 – two toxic proteins that are typically increased in people with Alzheimer’s disease – than those who kept their heart rates steady. The reductions in the two amyloid-beta proteins corresponded to decreased production of proteins involved in noradrenergic signaling, part of the body’s “fight-or-flight” response.

Heart rate variability refers to the physiological phenomenon of variation in the time interval between heartbeats, measured by the variation in the beat-to-beat interval. Decreased parasympathetic nervous system activity or increased sympathetic activity will lead to lower heart rate variability, a robust predictor of poor health outcomes, including a greater risk of death after a heart attack.

These findings suggest that breathing techniques that moderate heart rate variability reduce amyloid-beta burden in healthy people, potentially reducing the risk of Alzheimer’s disease. Learn about other strategies to reduce the risk of Alzheimer’s disease in this episode featuring Dr. Dale Bredesen.

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Exercise and supplemental lactate may improve cognitive function. www.nature.com

Exercise Brain Dementia BDNF Lactate

Lactate boosts cognitive function in mice, according to a new study. Mice had better spatial working and long-term memory after exercising and receiving supplemental lactate.

Researchers studied the effects of exercise – with or without supplemental lactate – on cognitive function in mice. The mice engaged in moderate-intensity exercise (about 55 to 60 percent of their VO2 max) five days a week for five weeks. This level of intensity is just below the “lactate threshold” – the point at which lactate builds up in the bloodstream and compromises performance. At the end of the five-week period, they tested the animals' memory skills.

They found that exercise plus supplemental lactate improved the animals' spatial working and long-term memory. In addition, the expression of various proteins produced in the hippocampus, including FNDC5 (also called irisin) and brain-derived neurotrophic factor (BDNF), increased, suggesting that supplemental lactate augments the beneficial effects of exercise on the hippocampus and subsequent cognitive function.

Lactate is a compound produced in muscles during exercise via the breakdown of glucose. It is thought to participate in a sort of “lactate shuttle” in which it is transported from the muscles into tissues like the heart and brain, where it is used for energy. Evidence suggests that lactate mediates some of the benefits of exercise on learning and memory via inducing neuronal BDNF expression. Learn more about the lactate shuttle and its effects on the brain in this episode featuring Dr. George Brooks.

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Low bone density may increase dementia risk. www.medscape.com

Nutrition Brain Aging Dementia Bone Small Vessel Disease

A new study shows that having low bone density may increase a person’s risk for cerebral small vessel disease – a driver of dementia. People with the lowest bone density in their upper femur were twice as likely to develop dementia over a ten-year period than those with the highest bone density.

Researchers categorized nearly 1,200 people over the age of 50 years according to their small vessel health status and bone density. They also measured serum bone turnover markers and microRNAs related to cerebral small vessel disease and bone metabolism.

They found that cerebral small vessel disease scores increased as bone mineral density decreased. They also found that levels of microRNA-378f, a non-coding RNA molecule that inhibits bone formation, were higher among participants with low bone density.

In older adults, dementia and low bone mineral density often coincide. In addition, physical inactivity and poor nutrition, common among people with dementia, can accelerate bone loss. Scientists don’t fully understand the extent to which bone loss is present before the onset of dementia, however. (Read more about bone health in the two reviews presented below.)

The findings from this study suggest that bone and brain health are closely linked, possibly via a bone-brain axis that regulates brain health. However, whether bone loss causes cerebral small vessel disease and subsequent dementia remains unclear. The findings also highlight the importance of maintaining bone health throughout the lifespan. Learn how resistance exercise helps increase bone density in this clip featuring Dr. Brad Schoenfeld.

High blood pressure in early adulthood is linked to late-life neurodegeneration and loss of white matter integrity. www.news-medical.net

Brain Aging Dementia Blood Pressure Neurodegeneration

A new study shows that having high blood pressure in early adulthood harms brain health later in life, especially in men. Men who had high blood pressure as young adults had poorer brain health than those with normal blood pressure.

Researchers performed brain scans on 427 older adults to assess their brain volume and white matter integrity. Then they compared the scans of those who had high blood pressure in early adulthood (between the ages of 30 and 40 years) with those who had normal blood pressure.

They found that those who had high blood pressure had lower brain volumes and poorer white matter integrity – an indication of impaired cognitive plasticity. The link between high blood pressure and lower brain volume was stronger in men, especially in the frontal cortex and cerebral gray matter.

These findings suggest that prolonged exposure to high blood pressure has marked effects on brain health later in life, increasing one’s risk of dementia. Exercise can have profound blood pressure-reducing effects, however. Learn more about the brain-protective effects of exercise in this clip featuring Dr. Axel Montagne.

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Higher cardiovascular fitness may delay the onset of dementia by 9.5 years. www.medscape.com

Exercise Brain Aging Dementia Cardiovascular

Higher cardiovascular fitness delays brain aging and the onset of dementia in women, a 2018 study showed. Women with high cardiovascular fitness levels experienced nearly a decade’s delay in dementia onset than those with moderate fitness levels.

The study involved 191 middle-aged women. Participants completed a cycling test to gauge their cardiovascular fitness and underwent regular neuropsychiatric testing to determine if they developed dementia during their lifetime.

Compared to women with moderate cardiovascular fitness levels, women with high cardiovascular fitness levels were 88 percent less likely to develop dementia. However, those with low fitness levels were 41 percent more likely to develop dementia. Higher fitness delayed the onset of dementia by 9.5 years compared to those with moderate fitness.

Cardiovascular fitness is a measure of how well the heart, lungs, and blood vessels transport oxygen to the muscles during exercise. Exercise contributes to cardiovascular fitness because it exerts robust effects on the cardiovascular system, boosting heart rate, blood pressure, and cardiac output. Interestingly, sauna use exerts similar effects on the cardiovascular system. Learn more in our overview article.

These findings suggest that cardiovascular fitness protects against dementia in women. Learn more about the effects of cardiovascular fitness on brain health in this short video featuring Dr. Rhonda Patrick.

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Magnesium may delay age-related brain shrinkage. www.medscape.com

Brain Diet Aging Magnesium Dementia

Magnesium may protect the brain from age-related volume losses, a new study showed. People with the highest magnesium intake had larger brain volumes than those with lower intake – a protective effect that corresponded to roughly one year less aging.

The study involved more than 6,000 adults between the ages of 40 and 73 years enrolled in the UK Biobank study. The participants completed questionnaires about their typical daily magnesium intake. They also underwent brain scans that measured their brain volumes and identified the presence of white matter lesions – areas in the brain that often indicate cerebral small blood vessel disease, a risk factor for dementia.

The scans revealed that participants with the highest magnesium intake – 550 milligrams or more daily – had larger gray matter and hippocampal volumes than those with normal intake (about 350 milligrams daily). In middle-aged adults, this effect on brain health corresponded to about one year of aging. The protective effects of magnesium were more pronounced in women than in men.

Magnesium is an essential mineral. It is found in green leafy vegetables, legumes, nuts, seeds, and whole grains, and is widely available as a dietary supplement. Evidence suggests that low magnesium levels are involved in the pathogenesis of various age-related brain disorders. In addition, people with Alzheimer’s disease often have lower magnesium levels than healthy people. More than half of people living in the United States likely have magnesium deficiency

These findings suggest that magnesium protects the brain against age-related volume losses, which are associated with dementia. It also aligns with other research showing that people who follow the MIND diet, which emphasizes the consumption of magnesium-rich green leafy vegetables, were 40 percent less likely to develop Alzheimer’s disease.

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Eating a Mediterranean-style diet may reduce dementia risk. bmcmedicine.biomedcentral.com

Nutrition Diet Dementia

Eating a Mediterranean-style diet may reduce dementia risk. A new study shows that eating a Mediterranean-style diet reduces the risk of dementia. Older adults with higher adherence to a Mediterranean-style diet were 23 percent less likely to develop dementia than those with lower adherence.

The study involved more than 60,000 adults enrolled in the UK Biobank study. Researchers scored the participants' adherence to the Mediterranean Diet based on reports of their normal dietary intake. They estimated each participant’s genetic risk for dementia and reviewed their medical records to learn if they had been diagnosed with dementia over a period of roughly nine years.

They found that higher adherence to a Mediterranean-style diet was linked with a 14 to 23 percent lower risk of developing dementia during the study period. Interestingly, they did not identify an interaction between adherence to a Mediterranean-style diet and the participants' genetic risk for dementia, suggesting that eating a healthy diet could reduce the risk of developing dementia even among those who are genetically predisposed to the condition.

The Mediterranean Diet is a dietary pattern that emphasizes fruits, vegetables, whole grains, legumes, and healthy fats, such as those in nuts, avocados, and olives. Evidence suggests that the healthy fats in salmon and their roe (eggs) protect the brain against cognitive decline. Learn more about the health benefits of salmon roe in our overview article.

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Three or more concussions may worsen brain function later in life. www.sciencedaily.com

Brain Alzheimer's Aging Dementia Concussion Lactate

Experiencing multiple concussions increases a person’s risk of poor brain function later in life, a new study shows. People who experienced three or more concussions exhibited cognitive deficits that worsened with each subsequent concussion.

Researchers collected self-reported concussion histories from more than 5,700 adults between 50 and 70 years old. They administered cognitive tests to gauge changes in the participants' brain function every year for up to four years.

They found that participants who experienced three mild concussions in their lifetime had difficulty with attention and performing complex tasks later in life. Participants who experienced four mild concussions had difficulty with processing speed and working memory – an aspect of cognitive function that allows a person to remember information for relevant tasks. However, experiencing even one moderate-to-severe concussion impaired the participants' attention and the ability to perform complex tasks and process information.

These findings underscore the risks associated with even mild brain injury. Some evidence suggests that lactate and ketones may be beneficial in treating brain injury. Learn more in this clip featuring Dr. Dominic D'Agostino.

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Lowering blood pressure reduces the risk of dementia. www.sciencedaily.com

Aging Dementia Blood Pressure

Lowering high blood pressure later in life reduced a person’s risk of dementia by 13 percent, a recent study has found. This was true even after considering other factors that increase dementia risk.

Researchers analyzed the findings of five large studies investigating the effects of reducing blood pressure in older adults (average age, 69 years) on the risk of dementia. The studies involved more than 28,000 people from 20 countries and spanned roughly four years.

They found that reducing high blood pressure cut the risk of a person developing dementia by approximately 13 percent, even after considering a person’s age, sex, history of stroke, body mass index, and whether they had diabetes. When they looked at specific ranges of systolic blood pressure, they noted that the greatest risk reduction – 23 percent – was seen among those whose systolic pressure was less than 147 mmHg.

Nearly two-thirds of adults living in the United States have high blood pressure, defined as having a systolic pressure of 130 mmHg or higher or a diastolic pressure of 80 mmHg or higher. High blood pressure increases a person’s risk for heart disease and stroke and contributes to small vessel disease, a major risk factor for cardiovascular disease, dementia, and stroke.

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APOE4 disrupts fat metabolism in brain cells, increasing Alzheimer's disease risk – but choline may restore normal metabolism. news.mit.edu

Nutrition Brain Alzheimer's Micronutrients Dementia

Disrupted fat metabolism drives the link between the APOE4 gene and Alzheimer’s disease risk, according to a new study. Choline supplementation helps restore normal fat metabolism, however.

Researchers studied the effects of the APOE4 gene on fat metabolism in astrocytes – a type of brain cell. They found that astrocytes that carried the APOE4 gene accumulated unsaturated triglycerides, causing an imbalance in the types of fats in the cells. However, when they applied choline to the cells, the normal balance was restored.

Choline is an essential nutrient that participates in the synthesis of fats necessary for cell membrane integrity and function. It is produced in the liver and is also found in foods such as eggs, meat, fish, beans, and nuts and as a dietary supplement. Most people living in the United States don’t consume enough choline – 550 milligrams per day for men and 425 milligrams per day for women – potentially increasing their risk for various diseases.

The findings from this cell study suggest that APOE4-driven impairments in fatty acid metabolism increase the risk of developing Alzheimer’s disease, but supplemental choline may reduce this risk. Other evidence suggests that impaired brain transport of DHA, a type of omega-3 fatty acid, increases Alzheimer’s disease risk. Learn more in this open-access, peer-reviewed article by Dr. Rhonda Patrick.

Read study abstract.

Newly identified APOE4 gene variant cuts Alzheimer's disease risk – rather than increasing it. jamanetwork.com

Alzheimer's Genetics Dementia

People who carry a newly identified variant of the APOE4 gene are more than 50 percent less likely to develop Alzheimer’s disease than non-carriers, a new study shows. Carriers of an APOE3 variant are more than 60 percent less likely to develop the disease.

Researchers analyzed the genetic makeup of more than 544,000 people. The participants included people who had been diagnosed with Alzheimer’s disease, those with a first-degree relative who had the disease, and those who were healthy.

The researchers found that two rare variants reduced the participants' risk of developing Alzheimer’s disease. Carriers of an APOE4 variant called R251G were 56 percent less likely to develop the disease, and carriers of an APOE3 variant called V236E were 63 percent less likely.

APOE is a protein involved in lipid transport. There are three known forms of the APOE gene that influence Alzheimer’s disease risk: APOE2, APOE3, and APOE4. APOE4 is the primary genetic risk factor for Alzheimer’s disease. Having one APOE4 allele typically increases a person’s Alzheimer’s disease risk as much as threefold; carrying two APOE4 alleles typically increases a person’s risk as much as 15-fold. However, this newly identified sub-type of APOE4 markedly alters that risk and adds complexity to discussions about the role of genetics in Alzheimer’s disease.

These findings suggest that some variants of the APOE gene may be protective against Alzheimer’s disease. Although genetics play key roles in Alzheimer’s disease risk, lifestyle does, too. Eating a healthy diet, exercising, meditating, and sauna use may forestall or even prevent the onset of the disease. Learn more about preventing Alzheimer’s disease in this episode featuring Dr. Dale Bredesen.

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Memory-enhancing effects of hippocampal estrogen receptor activation involve metabotropic glutamate receptor signaling, mouse study suggests. (2013) www.sciencedaily.com

Brain Alzheimer's Hormones Memory Neurotransmitter Estrogen Dementia

From the article:

The research, published in the the Journal of Neuroscience today, focused on estrogen effects in a brain region called the hippocampus, which deteriorates with age or Alzheimer’s disease. The researchers found that each of the two known estrogen receptors rapidly activate a specific cellular pathway necessary for memory formation in the hippocampus of female mice, but only if they interact with a certain glutamate receptor, called mGluR1.

The study revealed that when this glutamate receptor is blocked, the cell-signaling protein ERK cannot be activated by the potent estrogen, 17β-estradiol. Because ERK activation is necessary for memory formation, estradiol failed to enhance memory among mice in which mGluR1 was blocked.

Frick’s team also found evidence that estrogen receptors and mGluR1 physically interact at the cell membrane, allowing estradiol to influence memory formation within seconds to minutes.

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Vitamin D may protect against dementia and cognitive impairment. apple.news

Vitamin D Brain Alzheimer's Dementia

People with higher brain concentrations of vitamin D were 25 to 33 percent less likely to develop dementia or cognitive impairment, a recent study has found. Those with higher vitamin D concentrations also performed better on tests of cognitive function than those with lower concentrations.

The study involved 290 participants enrolled in the Rush Memory and Aging Project who had undergone regular physical and cognitive assessments when they were alive and agreed to donate their brains for study upon their deaths. Researchers measured concentrations of vitamin D in four regions of the participants' brains and reviewed the participants' cognitive assessments.

They found that higher brain concentrations of vitamin D were associated with 25 to 33 percent lower odds of having dementia or mild cognitive impairment at the last assessment before death. Participants with higher vitamin D concentrations had better word recall, working memory, episodic memory, and perceptual speed – the ability to compare similarities and differences quickly and accurately among sets of letters, numbers, objects, pictures, or patterns.

The findings from this study suggest that vitamin D is neuroprotective. Vitamin D is a fat-soluble vitamin that is stored in the liver and fatty tissues of the body. Perhaps best known for its role in maintaining calcium balance and bone health, vitamin D plays critical roles in many physiological processes. Poor vitamin D status is implicated in the pathogenesis of many acute and chronic diseases, including rickets, osteoporosis, multiple sclerosis, and cancer. Learn more about vitamin D in our overview article.

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Estrogen therapy initiated around the onset of menopause may protect the hippocampus from shrinking, thereby reducing the risk of Alzheimer's. (2016) www.sciencedaily.com

Brain Alzheimer's Hormones Estrogen Dementia

From the article:

A sample of 80 women who had used estrogen supplements through menopause was compared with 80 women who had never used estrogen supplements. All had participated in the Nord-Trøndelag Health Study (HUNT), a general population-based study in mid-Norway.

[…]

MRIs of the brains of the women in the study showed that those who had taken estrogen supplements throughout menopause had a larger hippocampus. The hippocampus is one of the most important structures for memory and sense of place, and is one of the structures that is affected early in the progression of Alzheimer’s disease.

“We also examined the shape of the hippocampus and found that areas where hormone therapy had the greatest effect are the same areas that are affected by Alzheimer’s disease in its early stages,” says Pintzka.

Other studies have shown that women who start estrogen supplements several years after menopause do not benefit from the same positive effect on the hippocampus.

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Reproductive events related to shorter cumulative endogenous estrogen exposure in women may be associated with higher dementia risk. (2022) www.sciencedaily.com

Hormones Pregnancy Estrogen Dementia

From the article:

[…] used data from the UK Biobank to examine the risk of all cause dementia and reproductive factors in 273,240 women as well as the number of children in those women and in 228,965 men.

After controlling for age, socioeconomic status, smoking, body mass index (BMI), and other elements, certain events related to shorter cumulative exposure to internally produced estrogen – such as older than average age at first period, younger than average age at menopause, and having a hysterectomy – were associated with higher dementia risk.

Pregnancy, even aborted pregnancy, longer reproductive span, older age at menopause, and use of contraceptive pills were associated with a lower risk of all-cause dementia.

For both men and women, compared with having two children, having no children or four or more were apparently associated with greater risk of dementia.

The study has limitations including the retrospective reporting on reproductive factors that can be subject to bias, and the fact that UK Biobank is a relatively healthy cohort of affluent people of white British ancestry so may not be representative of a broader population.

Gong adds, “Reproductive events related to shorter exposure to endogenous estrogen in women were associated with higher dementia risk, and these findings highlight the vulnerability in dementia risk pertaining to women. However, the similar association between the number of children and dementia risk observed for women and men indicates that the risk variation in women may be more related to social and behavioural factors in parenthood, rather than biological factors involved in childbearing.”

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Plant-based dietary components may prevent cognitive decline. www.sciencedaily.com

Diet Aging Dementia

Although epidemiological and observational data support the role of nutrition in maintaining cognitive health in aging, establishing which components of a diet support brain health is difficult and error-prone when relying on food intake surveys and biomarker studies. A recent metabolomics study identified specific dietary components associated with either preventing or promoting cognitive decline.

Metabolomics is an emerging field of study that involves the measurement of all metabolites – the intermediate or end products of metabolism – in a biological specimen. Many metabolites are produced when food is digested and further metabolized by gut microbes.

The investigators analyzed food-related and microbiota-derived metabolites in the blood of more than 800 adults living in two distinct regions of France. The participants completed a battery of neuropsychological tests and provided information about their overall health.

The investigators found that plant-based food metabolites (from cocoa, coffee, mushrooms, and red wine) and microbiota-derived metabolites (from microbial metabolism of polyphenol-rich apples, cocoa, green tea, blueberries, oranges, and pomegranates) appeared to exert a protective effect against cognitive decline. Conversely, metabolites derived from caffeine, alcohol, and artificial sweeteners appeared to promote cognitive decline.

These findings suggest that specific plant-based dietary components protect against cognitive decline and support the rationale for a plant-rich diet. Some evidence suggests that a ketogenic diet promotes cognitive function and protects the brain against cognitive decline. Learn how to incorporate fiber-rich plant-based foods into a ketogenic diet in this clip featuring Dr. Dominic D'Agostino.

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In the U.S., 40 Percent of All-Cause Dementia Is Preventable www.alzforum.org

Dementia

Nearly half of all Alzheimer’s disease and dementia cases are preventable and tied to lifestyle factors, such as obesity in midlife and not exercising.

Alzheimer’s disease and dementia are age-related disorders characterized by memory loss, cognitive decline, and behavioral changes. As many as 55 million people worldwide have dementia, a figure expected to triple in the next three decades. Findings from a recent study suggest that more than 40 percent of all Alzheimer’s disease and related dementia cases in the United States are attributable to a small number of modifiable lifestyle factors.

The investigators drew on data collected in the Behavioral Risk Factor Surveillance Survey, a telephone interview-based survey of adults living in the United States. Their analysis included nearly 380,000 adults (aged 65 years and older) who provided health, lifestyle, and demographic information about factors that influence dementia risk, including physical inactivity, smoking, depression, low education, diabetes, midlife obesity, midlife hypertension, and hearing loss.

They found that eight modifiable risk factors drove more than one-third of Alzheimer’s disease and related dementias among people living in the United States. Most of these cases were attributable to having obesity in midlife, not exercising, and low education. The percentage of preventable Alzheimer’s disease and related dementia cases was higher for men than women and higher among Blacks and Hispanics than among Caucasians and Asians.

These findings suggest that lifestyle factors play critical roles in Alzheimer’s disease and dementia risk. Learn more about how lifestyle influences Alzheimer’s disease and dementia risk in this episode featuring Dr. Dale Bredesen.

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Low levels of vitamin D were associated with lower brain volumes and an increased risk of dementia and stroke, genetic analyses suggest causal effect unisa.edu.au

Vitamin D Brain Aging Dementia

Vitamin D deficiency is associated with the development of dementia.

Vitamin D is a fat-soluble vitamin that plays critical roles in many physiological processes, such as blood pressure regulation, immune function, and cell growth. Poor vitamin D status is implicated in the pathogenesis of many acute and chronic diseases, including rickets, osteoporosis, multiple sclerosis, cancer, and COVID-19. Evidence from a recent study suggests that vitamin D deficiency is associated with the development of dementia.

Health experts disagree on the terminology and cutoffs used to determine vitamin D status. The Institute of Medicine (IOM) has determined that serum vitamin D concentrations less than 30 nmol/L (less than 12 ng/mL) place people “at risk for vitamin D deficiency”; those ranging from 30 to 50 nmol/L (12 to 20 ng/mL) place some populations “at risk for inadequacy”; and those of 50 nmol/L (20 ng/mL) or greater are considered “sufficient.” However, the Endocrine Society has suggested that vitamin D concentrations ranging from 52.5 to 72.5 nmol/L (21 to 29 ng/mL) define “insufficiency,” and those less than 20 ng/mL (50 nmol/L) define “deficiency.”

The study involved more than 425,000 healthy adults (ages 60 to 73 years) enrolled in the UK Biobank study who had undergone magnetic resonance imaging (MRI) studies to assess brain volumes and whose vitamin D status was known. The investigators categorized the participants according to their vitamin D status based on literature and Institute of Medicine and Endocrine Society Clinical Practice guidelines. They collected information about the participants' demographics, lifestyles, and various health factors and tracked the participants for approximately 10 years. Then they used Mendelian randomization, a research method that provides evidence of links between modifiable risk factors and disease based on genetic variants within a population, to identify causal links between vitamin D status and brain health, dementia, and stroke.

They found that lower total brain volume tended to reflect a higher rate of dementia and stroke. The participants with low vitamin D concentrations were more likely to have lower brain volumes, an increased risk for dementia and stroke, and more white matter hyperintensities (brain lesions that indicate small vessel disease) than those with high concentrations. Vitamin D conferred the greatest protection against dementia at concentrations of 50 to 74.9 nmol/L. The Mendelian randomization revealed that participants whose concentrations were less than 25 nmol/L were 54 percent more likely to develop dementia.

These findings suggest that low vitamin D increases a person’s risk for dementia. The authors suggested that as many as 17 percent of dementia cases might be prevented by achieving vitamin D sufficiency (50 nmol/L). Learn more about the beneficial health effects of vitamin D in our overview article.

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How cranberries could improve memory and ward off dementia www.sciencedaily.com

Memory Dementia Polyphenol

Eating polyphenol-rich cranberries improves memory and neural functioning in older adults.

As many as 55 million people worldwide have dementia, a figure expected to triple in the next three decades. Evidence suggests that dietary patterns and components may reduce the risk of developing dementia. Findings from a recent study suggest that eating cranberries improves memory and neural functioning in older adults.

Cranberries, like many other red, purple, or blue fruits, are rich in bioactive compounds called polyphenols, including anthocyanins, proanthocyanidins, flavonols, and others. Robust evidence indicates that these compounds exert antioxidant, anti-inflammatory, and/or neuroprotective effects in humans.

The investigators conducted a randomized, placebo-controlled trial involving 60 healthy adults between the ages of 50 and 80 years. Half of the participants consumed 4.5 grams of freeze-dried cranberry powder (to be mixed in liquid) every day for 12 weeks. The daily portion of supplemental cranberry powder was roughly equivalent to eating about one-half cup of fresh cranberries and provided 59 milligrams of anthocyanins, 281 milligrams of proanthocyanidins, and 20 milligrams of flavonols. The other half of the participants consumed a similar-looking non-nutritive powder for the duration of the study. Before, during, and after the intervention, participants underwent cognitive testing and provided blood samples for biochemical assessment. A subset of participants underwent magnetic resonance imaging (MRI) studies.

At the end of the intervention, participants who received the cranberry powder exhibited improvements in visual episodic memory. In addition, their low-density lipoprotein cholesterol (which contributes to atherosclerosis and impaired brain function) decreased. The MRIs revealed that the supplemented group had increased blood flow to areas of the brain involved in memory formation and consolidation.

These findings suggest that polyphenol-rich cranberries improve memory and aspects of neural functioning in older adults. It is noteworthy, however, that many commercial cranberry products contain copious amounts of added sugar to counter the berries' tartness. Because sugar can have harmful effects on brain and metabolic health, consuming unsweetened cranberries (or other berries) will likely have the greatest benefits on cognition.

Greater visceral and total body fat associated with vascular brain injury and impaired cognitive scores www.sciencedaily.com

Brain Obesity Dementia Metabolic Syndrome Blood-Brain Barrier Small Vessel Disease Visceral Fat

From the article:

In the study, 9,166 participants were measured by bioelectrical impedance analysis to assess their total body fat.

As well, 6,733 of the participants underwent magnetic resonance imaging (MRI) to measure abdominal fat packed around the organs known as visceral fat, and the MRI also assessed vascular brain injury – areas in the brain affected by reduced blood flow to the brain.

[…]

Co-author Eric Smith, a neurologist, scientist and an associate professor of clinical neurosciences at the University of Calgary, said that “preserving cognitive function is one of the best ways to prevent dementia in old age. This study suggests that one of the ways that good nutrition and physical activity prevent dementia may be by maintaining healthy weight and body fat percentage.”

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Four pathologies of SVD associate with dementia: white matter hyperintensities, cerebral microbleeds, lacunar infarcts, enlarged perivascular spaces www.sciencedaily.com

Brain Dementia Cardiovascular Blood-Brain Barrier Small Vessel Disease

The four pathologies that were detectable by MRI included:

moderate-to-severe white matter hyperintensities - blood pressure is a risk factor for this one
deep cerebral microbleeds
lacunar infarcts
enlarged perivascular space.

From the article:

The subjects were given cognitive tests and brain MRIs. The MRIs were examined for four main components of small vessel disease (SVD). These four components, which include evidence of microbleeds and minor strokes, then were added to create a total SVD score. The score ranges from zero points (no SVD) to 4 points (severe SVD).

The study found that that 61 percent of the subjects had zero points on the total SVD score, 20 percent had 1 point, 12 percent had 2 points, 5 percent had 3 points and 2 percent had 4 points. The higher the SVD score, the greater the cognitive decline. Researchers also found that each individual component of SVD predicted cognitive decline as well as the total SVD score did.

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Anesthesia and Surgery Impair Blood–Brain Barrier and Cognitive Function www.frontiersin.org

Brain Dementia Blood-Brain Barrier IL-6

Surgery and anesthesia may contribute to cognitive impairment.

Anesthesia, a medical treatment that involves the use of anesthetic drugs, is a widely accepted strategy for managing pain during surgery. Evidence suggests that mice that have undergone surgery that involved anesthetic treatment exhibited signs of postoperative cognitive impairment. Findings from a 2017 study suggest that surgery in combination with the anesthetic drug isoflurane induces blood-brain barrier dysfunction, contributing to cognitive impairment.

Anesthetic drugs can be administered orally, intravenously, or via inhalation. Isoflurane is one of the most common inhaled anesthetics used in humans. Scientists don’t fully understand the mechanisms by which inhaled anesthetics work, but they appear to affect the central nervous system by depressing neurotransmission pathways. Previous research has shown that isoflurane increases several markers of inflammation.

The investigators wanted to determine whether the effects of surgery and anesthesia on blood-brain barrier permeability and cognitive function were related to age and/or the action of interleukin-6 (IL-6), a proinflammatory molecule. The experiment involved three types of mice: young female mice, old female mice, and young female mice that don’t carry the gene for IL-6. Previous research has shown that female mice are more vulnerable to the cognitive impairment associated with surgery and anesthesia. Half of the mice underwent a simple surgical procedure under anesthesia (isoflurane), while the remaining half did not. After the mice that had had surgery recovered, the investigators assessed all the animals' cognitive performance via a maze test, measured IL-6 in the animals' blood, and quantified proteins involved in maintaining blood-brain barrier integrity in the animals' brains.

They found that the mice that underwent anesthesia and surgery had greater blood-brain permeability and higher IL-6 levels than those that did not undergo the procedures. Notably, permeability increased as IL-6 levels and age increased. Levels of proteins involved in maintaining blood-brain barrier integrity were lower in the mice that underwent the procedure, and older mice were more likely to experience cognitive deficits after the procedures than younger mice.

These findings suggest that surgery with anesthesia induces cognitive decline in an age-dependent manner, and this decline may be due to inflammatory processes that drive blood-brain barrier dysfunction. Learn more about the blood-brain barrier in our new overview article.

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Environmental toxins inhaled through nose may induce inflammation which culminates in the deposit of Lewy bodies in the brain, promoting Parkinson's www.sciencedaily.com

Brain Parkinson's Aging Dementia Neurodegeneration Lipopolysaccharide

Lewy bodies found in olfactory areas suggest not only is lost smell a sign of neural damage, but rather a direct link to the mechanism creating the disorder:

The loss of a sense of smell is known to be one of the earliest signs of Parkinson’s disease (PD) and can even appear years before the characteristic tremors and loss of motor function are seen. Some scientists believe that olfactory dysfunction may not just be a sign of broader neural damage, but rather may have a more direct linkage to the generation of the disorder itself. In support of this idea, deposits of a protein called alpha-synuclein that form Lewy bodies can be found in olfactory areas, as well as in dying dopamine neurons whose loss triggers PD, and mutations in the gene encoding alpha-synuclein produce PD.

Inflammation triggered in the areas where the olfactory neurons project (recapitulated by lipopolysaccharide) culminate in alpha-synuclein that can cross the blood-brain barrier:

Results of the study, published in the journal Brain Pathology, showed that application of an irritating component of a bacterium’s cell wall induces inflammation in the areas exactly where the olfactory neurons project, called the olfactory bulb. Moreover, these areas show the hallmark signs of PD, depositions of alpha-synuclein, the core components of Lewy bodies. PD is characterized by progressive motor and non-motor symptoms linked to alpha-synuclein pathology and the loss of dopaminergic neurons in the nigrostriatal system. Toxic aggregates of alpha-synuclein can arise from either overexpression of the protein, changes in protein modifications, and from hereditary mutations.

[…]

“Data from our study show that the bacterial trigger does not move across the blood-brain barrier,” said Quan. “Rather, a sequential inflammatory activation of the olfactory mucosa triggers a subsequent expression of inflammatory molecules within the brain, propagating the inflammation.”

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50% of all dementias and Alzheimers may start with leaky blood-brain barrier www.sciencedaily.com

Alzheimer's Aging Inflammation Dementia Blood-Brain Barrier Lipopolysaccharide

From the article:

“Many scientists have focused their Alzheimer’s disease research on the buildup of toxic amyloid and tau proteins in the brain, but this study and others from my lab show that the problem starts earlier – with leaky blood vessels in the brain,” said Berislav Zlokovic, senior author of the study

Reducing fibrinogen that enters the brain through leaky gatekeeping may be important for preventing decline:

Fibrinogen develops blood clots so wounds can heal. When gatekeeper cells are compromised, an unhealthy amount of fibrinogen slinks into the brain and causes white matter and brain structures, including axons (nerve fibers) and oligodendrocytes (cells that produces myelin), to die.

Leaky blood-brain barrier caused by cerebral small vessel disease increases the prevalence of white-matter hyperintensities and brain damage www.sciencedaily.com

Brain Aging Dementia Blood-Brain Barrier Small Vessel Disease

Poor blood-brain barrier integrity drives white matter losses.

White matter hyperintensities are areas in the brain that appear as intense white spots on magnetic resonance imaging (MRI) scans. They are often indicators of cerebral small blood vessel disease and are considered a risk factor for dementia. A 2021 study found that breaches in blood-brain barrier integrity are associated with brain tissue losses and precede the appearance of white matter hyperintensities.

The blood-brain barrier, a specialized system of endothelial cells that shields the brain from toxins present in the blood, supplies the brain’s tissues with vital nutrients and substances necessary for neuronal and metabolic function. The structural integrity of the blood-brain barrier is therefore critical for homeostatic maintenance of the brain microenvironment.

The study involved 43 patients (average age 58 years) who had been diagnosed with cerebral small vessel disease, as evidenced by having experienced a stroke or demonstrating mild cognitive impairment. At the beginning of the study and two years later, participants underwent a variety of MRI techniques that quantified their overall blood-brain barrier permeability as well as the areas surrounding white matter hyperintensities.

The MRIs revealed that participants who had the greatest amount of leaky brain tissue at the beginning of the study exhibited greater white matter tissue losses two years later. These tissue losses translated to greater permeability, a phenomenon particularly evident in the areas surrounding the brain lesions associated with white matter hyperintensities.

These findings suggest that losses in blood-brain barrier integrity damage brain tissue, driving increased permeability and white matter losses. In turn, these changes potentiate the disease processes associated with cerebral small vessel disease. Learn more about the blood-brain barrier in our overview article.

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Mid-life long duration antibiotic use of >= two months linked to poorer scores in cognition, learning, working memory, and attention in later life www.sciencealert.com

Brain Aging Microbiome Performance Memory Antibiotics Dementia

Antibiotic use in midlife increases a person’s risk for neuropsychiatric diseases.

Antibiotics are prescribed for a wide range of infectious diseases. In 2015, healthcare providers in the United States wrote nearly 270 million antibiotic prescriptions – more than 800 antibiotic prescriptions for every 1,000 people. Health experts estimate that 30 percent of these prescriptions were likely unnecessary. Findings from a new study suggest that antibiotic use in midlife increases a person’s risk for neuropsychiatric diseases.

The study included approximately 15,000 midlife participants (average age, 55 years) enrolled in the Nurses’ Health Study II, an ongoing prospective cohort study of female nurses. The participants completed questionnaires regarding their general health, diet, lifestyle, and medication use during the previous four years, including antibiotic use and the reason for which the antibiotic was prescribed. The investigators categorized the participants' cumulative antibiotic use as none, one to 14 days, 15 days to two months, and two months or more. Participants also completed a battery of neuropsychological tests.

The investigators found that participants who took antibiotics for at least two months over the previous four years were more likely to perform worse on neuropsychological tests than participants who did not take antibiotics. The influence of antibiotic use on neuropsychological test scores was roughly equivalent to three to four years of aging. These findings held true even after considering other factors that could influence cognitive function, including age and coexisting illnesses.

These findings suggest that longer exposure to antibiotics in midlife negatively influences cognitive health, underscoring the importance of moderating antibiotic use in older adults. They also support findings from animal studies that suggest antibiotic use early in life alters neuropeptide signaling pathways that influence behavioral development. Learn more about the effects of antibiotic use in early life in this clip featuring Dr. Eran Elinav.

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Maintaining a lower systolic blood pressure (less than 120 mm Hg) may reduce the amount of white matter lesions, reducing risk of dementia www.sciencedaily.com

Brain Aging Dementia Blood Pressure

Maintaining a systolic blood pressure of 120 or less may protect against dementia and cognitive decline. Nearly two-thirds of adults living in the United States have hypertension (high blood pressure), defined as having a systolic pressure of 130 or higher or a diastolic pressure of 80 or higher. Hypertension damages small blood vessels in the eyes, kidneys, and other tissues, increasing the risk for disease and dysfunction. A 2019 study found that intensive blood pressure control in patients with hypertension reduces the risk of developing small blood vessel damage-related white matter lesions in the brain.

Intensive blood pressure control is an aggressive treatment protocol for hypertension that seeks to achieve a target systolic blood pressure goal of 120 or less. This differs from standard treatment protocols, which stipulate that within three months of starting medication therapy to reduce high blood pressure, a patient’s target pressures (systolic and diastolic) should be less than 140/90. After three months, the target pressures should be less than 130/80.

White matter lesions are areas in the brain that appear as intense white spots on magnetic resonance imaging (MRI) scans. They are often indicators of small blood vessel disease and are considered a risk factor for dementia.

The study involved 670 adults (average age, 67 years) who had hypertension. Roughly half of the participants underwent intensive blood pressure control treatment, while the other half underwent standard treatment. The investigators performed MRI scans of all participants at the beginning of the intervention and again about four years later.

They found that participants who underwent intensive blood pressure control had fewer white matter lesions in their brains compared to those who underwent the standard treatment. Interestingly, those who underwent intensive treatment exhibited greater brain volume losses than those who underwent standard treatment, but this difference was not statistically significant.

These findings suggest that intensive blood pressure control reduces white matter lesions in the brains of people with hypertension and support findings from a related study that demonstrated that intensive blood pressure control may reduce the risk of adverse cognitive outcomes.

Hypertension is highly preventable with lifestyle modifications that involve diet and exercise. For example, dietary components, such as potassium and magnesium quercetin and vitamin D lower blood pressure. Aerobic exercise also lowers blood pressure. Learn about other beneficial effects of aerobic exercise in our overview article.

Link to full publication.

Elevated blood pressure as low as 135/85 may result in enhanced brain aging: damage may build up over years, starting in a person's twenties www.sciencedaily.com

Brain Heart Disease Dementia Blood Pressure

Currently selected for this coming member’s digest by team member Melisa B.

From the article:

“Compared to a person with a high blood pressure of 135/85, someone with an optimal reading of 110/70 was found to have a brain age that appears more than six months younger by the time they reach middle age.”

[…]

“By detecting the impact of increased blood pressure on the brain health of people in their 40s and older, we have to assume the effects of elevated blood pressure must build up over many years and could start in their 20s. This means that a young person’s brain is already vulnerable,” he said.

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Damage to the brain among elderly, known as white matter hyperintensities, prominent in people with history of subclinically elevated blood pressure www.sciencedaily.com

Brain Dementia Blood Pressure

From the article:

The research, carried out by Dr Karolina Wartolowska, a clinical research fellow at the Centre for Prevention of Stroke and Dementia, University of Oxford, UK, looked for damage in the brain called “white matter hyperintensities” (WMH). These show up on MRI brain scans as brighter regions and they indicate damage to the small blood vessels in the brain that increases with age and blood pressure. WMH are associated with an increased risk of stroke, dementia, physical disabilities, depression and a decline in thinking abilities.

Dr Wartolowska said: “Not all people develop these changes as they age, but they are present in more than 50% of patients over the age of 65 and most people over the age of 80 even without high blood pressure, but it is more likely to develop with higher blood pressure and more likely to become severe.”

[…]

The researchers found that a higher load of WMH was strongly associated with current systolic blood pressure, but the strongest association was for past diastolic blood pressure, particularly when under the age of 50. Any increase in blood pressure, even below the usual treatment threshold of 140 mmHg for systolic and below 90 mmHg for diastolic, was linked to increased WMH, especially when people were taking medication to treat high blood pressure.*

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A high-polyphenol diet is protective against age-related brain shrinkage. www.eurekalert.org

Brain Alzheimer's Obesity Aging Green Tea Nuts Dementia Urolithin A

“The effect of diet on age-related brain atrophy is largely unproven.

This 18-month clinical trial longitudinally measured brain structure volumes by magnetic-resonance-imaging…Abdominally obese/dyslipidemic participants were randomly assigned to (1)-healthy dietary guidelines (HDG), (2)-Mediterranean (MED) diet, or (3)-Green-MED diet (MED diet higher in polyphenols and lower in red/processed meat). All subjects received free gym memberships and physical activity guidance. Both MED groups consumed 28g/day walnuts (+440 mg/d polyphenols). The Green-MED group consumed green-tea (3-4 cups/day) and Mankai (Wolffia-globosa strain, 100g frozen-cubes/day) green shake (+800mg/day polyphenols).

Compared to younger participants, atrophy was accelerated among those ≥ 50 years. In subjects ≥50years, HOC decline and LVV expansion were attenuated in both MED groups, with the best outcomes among Green-MED diet participants, as compared to HDG. Similar patterns were observed among younger subjects. Improved insulin sensitivity over the trial was the strongest parameter associated with brain atrophy attenuation (p<0.05). Greater Mankai, green-tea and walnuts intake and less red and processed meat were significantly and independently associated with reduced HOC decline (p<0.05). Elevated urinary levels of the Mankai-derived polyphenols: urolithin-A (r = 0.24;p = 0.013) and tyrosol (r = 0.26;p = 0.007) were significantly associated with lower HOC decline.

A Green-MED, high-polyphenol diet, rich in Mankai, green tea and walnuts and low in red/processed meat is potentially neuroprotective for age-related brain atrophy."

A pro-inflammatory diet contributes to brain aging and cognitive decline. n.neurology.org

Diet Inflammation Dementia

Inflammation, a critical element of the body’s immune response, occurs when the body is exposed to harmful stimuli, such as pathogens, damaged cells, or irritants. As a person ages, their immune system becomes more pro-inflammatory, leading to unresolved or chronic inflammation and driving many age-related diseases and cognitive decline. Authors of a new report suggest that eating a pro-inflammatory diet may further contribute to the inflammatory state associated with aging, driving cognitive decline.

Diet plays key roles in immune function and inflammation, and robust evidence indicates that some components of diet promote inflammation, while others dampen or even resolve it. To score the inflammatory potential of dietary components, researchers have developed the Diet Inflammatory Index, a quantitative means of assessing the effects of diet on aspects of human health, ranging from inflammatory biomarkers in blood to the presence of chronic disease. The Index, which has been used in hundreds of studies and meta-analyses, is supported by diverse lines of evidence, including laboratory, observational, and interventional studies.

The authors recruited more than 1,000 older adults (average age, 73 years) who were enrolled in the Hellenic Longitudinal Investigation of Aging and Diet study. They collected detailed information about the types and quantities of the foods that participants regularly ate and assigned each participant’s diet a Diet Inflammation Index score. They tracked the participants for about three years and noted whether they were diagnosed with dementia.

They found that for every unit increase in the Diet Inflammation Index, the risk for developing dementia increased by 21 percent. As a result, participants whose diets had the highest inflammatory potential were three times more likely to develop dementia than those whose diets had the lowest inflammatory potential.

These findings suggest that dietary components modulate the inflammatory state associated with aging and drive the risk for developing dementia. Although these findings were based on observational data and do not assign causality, they highlight the roles that lifestyle changes may play in preserving cognitive function in aging. Learn more about how lifestyle changes can influence health and slow the effects of aging in this episode featuring Dr. Elisa Epel.

Link to study abstract.

Hypertension in mid-life reduces brain volume and increases risk of dementia. neurosciencenews.com

Alzheimer's Dementia Blood Pressure Stroke

Many people develop hypertension (high blood pressure) with age, putting them at risk of cardiovascular disease, chronic kidney disease, retinal damage, and stroke. Hypertension is also a risk factor for Alzheimer’s disease and dementia, due to damage caused by years of vessel injury, microbleeds, and lesions. Authors of a recent study report that hypertension diagnosed in early or midlife, but not late life, is a predictor of dementia.

Because hypertension damages the delicate small blood vessels of the heart, kidneys, eyes, brain, and other organs, it is a risk factor for a wide range of chronic diseases. Previous research has shown that hypertension, by restricting blood flow, reduces brain volume in key areas associated with dementia, such as the prefrontal cortex and hippocampus. As the number of young adults with hypertension increases to an estimated 1.6 billion globally by 2025, research on the risks of hypertension in earlier life are needed.

The authors collected data from more than 135,000 participants with hypertension and 135,000 matched control participants without hypertension from the United Kingdom Biobank, a long-term study of United Kingdom citizens. The researchers categorized participants into four categories: younger than 35 years; 35 to 44 years; 45 to 54 years; and 55 to 64 years. They used magnetic resonance imaging data to measure brain volume, and hospital records, death records, and self-reports to assess dementia status. Participants in the study provided data at a baseline appointment between 2006 and 2010 and at a follow-up appointment between 2014 and 2021.

Participants diagnosed with hypertension at any age had smaller brain volume than their matched control participant without hypertension. Participants diagnosed earlier in life had the greatest reductions, with participants diagnosed between ages 35 and 44 exhibiting a 0.8 percent loss in volume and participants before age 35 exhibiting a 1.2 percent loss. Specifically, hypertension was associated with loss of peripheral cortical gray matter, brain tissue necessary for higher brain functions such as learning, memory, and attention. Participants diagnosed with hypertension between ages 35 and 44 were at a 61 percent higher risk of dementia than the matched control participants without hypertension.

The authors concluded that hypertension diagnosed in early mid life, but not late life, is associated with decreased brain volume and increased risk of dementia. Lifestyle strategies that reduce blood pressure, such as exercise, sauna use, dietary modification, and stress management, may reduce dementia risk.

Beige fat protects against dementia by reducing visceral-like properties of subcutaneous fat www.sciencedaily.com

Brain Dementia Cold Stress Visceral Fat

The color of fat tissue – white, brown, or beige – dictates the role the tissue plays in the body. Whereas white fat is involved in lipid storage and the release of free fatty acids for energy, brown fat is involved primarily in thermogenesis – the production of heat. Beige fat, which is typically co-located with white fat, can exhibit either storage or thermogenic properties, depending on environmental conditions. It also exerts anti-inflammatory properties via induction of interleukin 4, an anti-inflammatory molecule. White fat can convert to beige fat, a process known as “beiging.” Findings described in a recent report suggest that beige fat mediates the neuroprotective effects of subcutaneous fat.

Subcutaneous fat, which is composed of both white and beige fat, is stored just beneath the skin. Commonly associated with a “pear” shape, it may protect against dementia. Visceral fat, on the other hand, is composed of white fat. It is stored in the abdominal cavity close to internal organs such as the liver, pancreas, and intestines. An excess of visceral fat, often referred to as central obesity or abdominal obesity, is commonly associated with an “apple” shape and an increased risk for chronic disease, including dementia.

The authors of the report conducted a two-part study using a type of mouse genetically modified to lack the gene that promotes beiging. Without beiging, subcutaneous fat behaves more like visceral fat.

In the first part of the study, they fed either a low-fat or high-fat diet to the genetically modified mice and normal mice for one month. They tested the animals' cognitive function and measured markers of inflammation and immune activation. Both groups of mice became obese on the high-fat diet, but cognitive tests revealed that the mice without beige fat showed signs of early cognitive impairment while the normal mice did not. The mice without beige fat also exhibited rapid, robust inflammatory responses to the high-fat diet, including activation of microglial cells (a type of immune cell found in the brain). Microglia activation promotes inflammation, harms brain health, and contributes to dementia.

In the second part of the study, the authors transplanted subcutaneous fat from young, lean healthy mice into the abdominal areas of the obese, cognitively impaired mice. The recipient mice experienced improvements in memory and synaptic plasticity – the ability to form new connections between neurons.

These findings suggest that beige fat drives the neuroprotective and anti-inflammatory effects of subcutaneous fat in mice. A growing body of evidence suggests that cold exposure promotes beiging of white fat. Learn more about the health effects of cold exposure in our overview article.

Link to full publication.

Depression is associated with muscle loss in older adults. journals.plos.org

Aging Depression Muscle Dementia

Sarcopenia, the loss of muscle mass with age, is related to falling, poor oral health, and chronic disease. Sarcopenia is a progressive disorder, but early interventions with diet and exercise may improve health outcomes. Authors of a new report investigated the relationship between sarcopenia progression, depression, dementia, and hypertension.

Body composition shifts across the lifespan, with a progression toward lower muscle mass and increased fat mass after age of 60. Because fat and muscle participate in whole-body metabolism and hormone signaling, this shift in body composition contributes to the development of age-related diseases. Previous research has reported a link between sarcopenia, cognitive impairment, and depressive symptoms in older Korean men, but research is needed in additional demographic groups.

The authors collected data from more than 750 adults aged 60 years and older living in Japan. Participants completed surveys to measure depression and dementia status and underwent a physical examination that included the measurement of blood pressure, height, muscle mass, grip strength, and walking speed. The investigators classified participants as having sarcopenia if they had low skeletal muscle index (i.e., the ratio of the muscle in a person’s arms and legs to their height), poor grip strength, and slower walking speed. They defined pre-sarcopenia as having a low skeletal muscle index with normal grip strength and walking speed. Finally, they classified participants with a normal skeletal muscle index as robust.

Sarcopenia was associated with increased age and depression severity, but reduced hypertension. Compared to robust participants, those with pre-sarcopenia were more likely to have depression and hypertension. However, sarcopenia was not associated with dementia, which the authors noted may have been due to the small number of participants (only 49) with dementia.

The authors suggested that future research should explore strategies for management of depression, dementia, and hypertension in the prevention of sarcopenia.

Eating processed meat increases risk for dementia, but eating unprocessed meat might be protective. academic.oup.com

Alzheimer's Dementia

Dementia is a broad term that includes Alzheimer’s disease, vascular dementia, and other forms of the condition. It is characterized by the loss of memory, language, problem-solving skills, and/or other aspects of cognitive function. Approximately 50 million people worldwide have dementia. A recent study investigated links between meat consumption and dementia risk.

Meat is rich in several essential nutrients, including protein, iron, zinc, and vitamin B12. Findings from epidemiological studies suggest that diets high in red and processed meats increase a person’s risk for type 2 diabetes, cardiovascular disease, cancer (particularly colorectal cancer), and all causes of premature death.

The present study involved more than 493,000 adults enrolled in the UK Biobank, a biomedical database containing health information about people living in the United Kingdom. The participants completed a food frequency questionnaire in which they provided answers about their meat consumption, to include processed meat, unprocessed poultry, and unprocessed red meat (beef, lamb, and pork). The authors of the study defined “processed meat” as bacon, ham, sausages, meat pies, kebabs, burgers, and chicken nuggets.

They found that eating unprocessed red meat was linked with a lower risk of dementia and Alzheimer’s disease, whereas eating processed meat was linked with higher risk. They did not identify any associations between poultry consumption and dementia risk. Each additional 50-gram per day increment in unprocessed red meat intake decreased their risk for all causes of dementia by 19 percent and decreased their risk for Alzheimer’s disease by 30 percent. In contrast, each additional 25-gram per day increment in processed meat intake increased a person’s risk for all types of dementia by 44 percent and increased their risk for Alzheimer’s disease by 52 percent.

High levels of protein and iron in unprocessed red meat may partially explain the link between unprocessed meat intake and lower risk of dementia. Adequate protein intake has been linked with lower dementia risk in older adults, and iron is necessary for many aspect of brain health, including the production of neurotransmitters and myelin. On the other hand, processed meat contains nitrites and N-nitroso compounds, which may promote oxidative stress, lipid peroxidation, and activation of proinflammatory cytokines or other mechanisms potentially involved in the development of dementia.

These findings suggest that eating processed meat increases a person’s risk for developing dementia but eating unprocessed meat does not. They also underscore the importance of distinguishing between processed and unprocessed meat in nutrition studies. This was a large, well-designed prospective study that accounted for multiple confounding factors, including age, gender, ethnicity, socioeconomic status, educational level, BMI, physical activity level, smoking status, typical sleep duration, stroke history, family history of dementia, and dietary factors (including consumption of vegetables, fruits, fish, tea, coffee, and alcohol).

Link to full article.

Spermidine supplementation improves memory performance in older adults with subjective cognitive decline. pubmed.ncbi.nlm.nih.gov

Brain Alzheimer's Autophagy Dementia Supplements

Spermidine is a polyamine compound that may increase health span due to its ability to induce autophagy, the process by which the body removes damaged and dysfunctional cells. In animal models, spermidine supplementation has been shown to prevent memory loss. Findings from a recent report detail the first experiment exploring the effects of spermidine supplementation on memory in older adults without dementia.

Episodic memory, which records specific events, situations, and experiences, declines with age, but this loss may be impeded by certain lifestyle interventions, such as caloric restriction. The effects of spermidine in the body mimic caloric restriction, making it a promising therapy for the reversal of memory loss. Previous research demonstrates the ability of spermidine supplementation to restore memory performance in fruit flies; however, the effects of spermidine supplementation on memory performance in humans are unknown.

The authors recruited 30 adults (aged 60 to 80 years) with subjective cognitive decline, a condition associated with objective cognitive decline and Alzheimer’s disease. They assigned half of the participants to consume a capsule containing 750 milligrams of a spermidine-rich plant extract containing 1.2 milligrams of spermidine daily for three months, while the other half consumed a placebo supplement. Participants completed memory assessments and other cognitive testing before and after the supplement period.

Participants consuming the spermidine supplement had moderately enhanced memory performance after three months compared to those who took the placebo. In particular, permidine supplementation enhanced mnemonic discrimination, the ability to differentiate between new and previously encountered items. There was no difference in other cognitive functions between groups.

The authors concluded that spermidine supplementation may be an effective treatment for slowing cognitive decline in older adults with subjective cognitive impairment. They noted that this was a small pilot trial and that larger clinical trials are needed to expand on these results.

Link to full report.

Mushroom consumption is associated with a reduced risk of cognitive impairment in older adults with dementia. www.sciencedaily.com

Brain Mushroom Dementia

Mild cognitive impairment is an intermediary stage between normal cognitive functioning and dementia and may be treatable with diet and lifestyle interventions. Mushrooms contain a number of bioactive compounds, such as hericenones and erinacines, that increase nerve growth factor production and ergothione, an antioxidant and cytoprotective compound. One group of researchers examined the relationship between mushroom consumption and mild cognitive impairment in older adults.

Previous research has shown that mushroom intake improved cognitive performance among Norwegian participants (ages 70 to 74 years). Another epidemiological study in Japanese participants (ages 65 years and older) found that mushroom consumption of at least three times per week or more was associated with a 19 percent reduced risk of dementia. However, the effect of mushroom consumption on the risk of mild cognitive impairment is unknown.

The authors reviewed data from over 600 participants without dementia (ages 60 years and older) from a study in Singapore aiming to identify dietary factors that are associated with healthy aging. Participants provided data regarding demographics, lifestyle, diet, health history, cognitive function, and psychological well being, among others. The researchers interviewed participants to assess their mushroom intake and measured participants’ cognitive function using a standardized questionnaire.

Participants who consumed greater than two servings of mushrooms per week (1.5 cups of cooked mushrooms, about 300 grams) were 43 percent less likely to have mild cognitive impairment than those who consumed mushrooms less than once per week. This association was independent of age, sex, education, cigarette smoking, alcohol consumption, hypertension, diabetes, heart disease, stroke, physical activities, and social activities. Participants with mild cognitive impairment were more likely to have hypertension and diabetes and were less active in social activities.

The results of this cross-sectional study support the potential of mushroom consumption in delaying the development of cognitive decline. The authors noted that a strength of their study was their accounting of lifestyle and health factors.

Link to full report.

Inadequate sleep increases a person's risk of developing Alzheimer's disease and dementia. neurosciencenews.com

Alzheimer's Sleep Dementia

Sleep is essential for human health. Not getting enough sleep or having poor, fragmented sleep increases a person’s risk of developing many chronic illnesses, including cardiovascular disease, hypertension, diabetes, stroke, obesity, and depression. Findings from a new study suggest that inadequate sleep increases a person’s risk of developing Alzheimer’s disease and dementia.

Alzheimer’s disease and dementia are age-related disorders characterized by memory loss, cognitive decline, and behavioral changes. Nearly 50 million people are living with Alzheimer’s disease or a related dementia worldwide, a number expected to triple by the year 2050.

The authors of the study drew on data from the National Health and Aging Trends Study, an on-going longitudinal study of adults living in the United States who are over the age of 65 years. More than 2,800 participants (average age, 76 years) completed questionnaires about their sleep quality, including time to sleep onset, sleep duration, and snoring. The authors collected information about the participants' cognitive health or death from any cause for up to five years after completion of the questionnaires.

They found that participants who reported getting fewer than five hours of sleep per night were twice as likely to develop dementia compared to those who had seven to eight hours of sleep per night. Taking a long time to fall asleep (more than 30 minutes) increased the risk of dementia 45 percent. The authors also found that getting fewer than five hours of sleep per night, daytime sleepiness, and regular napping increased the risk of all causes of premature death.

These findings indicate that short sleep duration and sleep-associated problems among older adults increase the risk of developing dementia and dying prematurely. The research of sleep expert Dr. Matthew Walker focuses on identifying certain windows of vulnerability during a person’s life when interventions might improve sleep quality to prevent or delay age-related cognitive decline. Learn more in this clip.

Link to study abstract.

Dietary patterns that include cheese and wine may promote cognitive health. www.research.iastate.edu

Alzheimer's Aging Dementia

Fluid intelligence – the ability to creatively solve problems without prior knowledge or learning – declines with age. Greater losses of fluid intelligence are associated with increased risk of Alzheimer’s disease. Findings from a recent study suggest that dietary factors protect against fluid intelligence losses.

Nutrition plays critical roles in maintaining cognitive health. Evidence indicates that adherence to dietary patterns that include fruits, vegetables, nuts, and olive oil reduces the risk of developing Alzheimer’s disease. People who carry gene variants that increase their risk of Alzheimer’s disease may benefit from consuming foods that are rich in DHA, a type of omega-3 fatty acid.

The study involved nearly 1,800 people between the ages of 46 and 77 years who were enrolled in the UK Biobank Prospective Study. The participants completed three fluid intelligence tests over a period of several years to assess their ability to creatively solve problems without prior knowledge or learning. They also completed food frequency questionnaires regarding their dietary intake.

The authors of the study found that daily cheese consumption provided the most protection against age-related fluid intelligence losses. They also found that alcohol consumption, especially red wine, provided protection. Eating lamb was associated with better cognitive performance but eating other types of red meat was not. In general, eating too much salt promoted cognitive decline, especially among high-risk groups.

These findings suggest that dietary modifications can promote cognitive health in aging. One mechanism that may drive these benefits is autophagy, a cellular recycling program that is crucial in maintaining neuronal health. Caloric restriction mimetics, such as spermidine (present in aged cheese) and resveratrol (present in red wine), “trick” cells into inducing autophagy even in the setting of sufficient nutrient levels. Watch Dr. Guido Kroemer describe the autophagy-inducing effects of calorie restriction mimetics such as spermidine and resveratrol.

A loss of BDNF, as a result of viral strategy, may be responsible for a type of dementia that occurs in 30 percent of untreated HIV-positive patients www.sciencedaily.com

Brain HIV Dementia BDNF

From the article:

The research team found that even though HIV does not infect neurons, it tries to stop the brain from producing a protein growth factor – mature brain derived neurotrophic factor (mature BDNF) – that Mocchetti says acts like “food” for brain neurons.

[…]

Mocchetti believes that HIV stops production of mature BDNF because that protein interferes with the ability of the virus to attack other brain cells. It does this through the potent gp120 envelope protein that sticks out from the viral shell – the same protein that hooks on to brain macrophages and microglial cells to infect them. “In earlier experiments, when we dumped gp120 into neuronal tissue culture, there was a 30-40 percent loss of neurons overnight. That makes gp120 a remarkable neurotoxin.”

Human Immunodeficiency Virus Type 1 Alters Brain-Derived Neurotrophic Factor Processing in Neurons

Women with a BDNF genetic variant experience fewer negative cognitive effects during chemotherapy. www.sciencedaily.com

Brain Cancer Dementia BDNF

Chemotherapy-associated cognitive impairment is a side-effect of chemotherapy in which people experience difficulties with concentration, decision making, and memory. Findings from a 2015 study suggest that women with a BDNF gene variation experience fewer cognitive problems during chemotherapy compared to those without this variation.

BDNF is a growth factor that is involved in the growth and repair of neurons. BDNF is expressed in the prefrontal cortex and hippocampus regions of the brain, which are involved in executive function, learning, and memory. A common variation in the BDNF gene called a single nucleotide polymorphism, or SNP, can alter how the BDNF protein functions. The SNP, known as Val66Met, results in the amino acid valine being replaced with methionine in the BDNF protein. Researchers have studied how the Val66Met SNP affects various aspects of cognition.

Previous research has demonstrated that women with breast cancer who were treated with chemotherapy experienced varying levels of cognitive decline. The current study investigated whether genetics, particularly variations in the BDNF gene, might make a person more susceptible to experiencing these effects.

The prospective cohort study involved 145 women (average age, 51 years) with early-stage breast cancer who were scheduled to receive chemotherapy. The authors of the study evaluated the participants' cognitive function using neuropsychological tools before, during, and at the end of chemotherapy treatment. Also, the researchers determined which version of the BDNF gene each participant possessed. If a patient’s test score during or at the end of treatment was 15 percent lower than baseline, they were considered to have cognitive impairment.

The authors observed that 54 women experienced cognitive impairment after treatment; however, those with the Met allele had fewer problems with verbal fluency and multitasking compared to those with the Val allele, particularly in older participants. This information may allow for early interventions in preventing cognitive impairment during chemotherapy.

These findings suggest that women may differ in their susceptibility to chemotherapy-associated cognitive impairment depending on which version of the BDNF gene they carry. Further research is required to confirm these findings, and brain imaging studies are needed to determine if these findings are the result of changes in brain anatomy.

Link to full study.

Increased visceral fat impairs cognition through chronic microglial activation mediated by IL-1 beta release [animal research] www.sciencedaily.com

Brain Inflammation Memory Fat Dementia Weight Loss NLRP3 Visceral Fat

Scientists find that visceral fat, a type of adipose tissue that produces high levels of inflammatory signals known as adipokines, impair learning and memory in mice by setting off an inflammatory cascade mediated by the release of IL-1 beta, which crosses the blood-brain barrier leading to chronic activation of microglia.

From the article:

“We have identified a specific signal that is generated in visceral fat, released into the blood that gets through the blood brain barrier and into the brain where it activates microglia and impairs cognition.”

Visceral fat as the ring leader:

They looked further and found that just transplanting the visceral fat caused essentially the same impact as obesity resulting from a high-fat diet, including significantly increasing brain levels of interleukin-1 beta and activating microglia. Mice missing interleukin-1 beta’s receptor on the microglia also were protected from these brain ravages.

[…]

To measure cognitive ability, the scientists looked at mice’s ability to navigate a water maze after 12 weeks on a high- or low-fat diet. They found it took the normal, or wild type, mice consuming the higher fat diet as well as the visceral transplant recipients with NLRP3 intact longer to negotiate the water maze. In fact, while they could reach a platform they could see, they had trouble finding one beneath the water’s surface that they had been taught to find. Mice with the interleukin-1 receptor knocked out, could find it just fine, Stranahan says.

The high-fat diet, transplant mice also had weaker connections, or synapses, between neurons involved in learning and memory. Mice on a high-fat diet but missing NLRP3 were spared these changes, like mice on a low-fat diet.

Greater BDNF expression in brain tied to up to 50% slower decline in memory in older people (for those in top decile of expression) www.sciencedaily.com

Brain Alzheimer's Memory Dementia BDNF

A study of BDNF gene expression in post-mortem brain tissue found that BDNF may provide a buffer against dementia, particularly when higher expression is found in the context of the classical Alzheimer’s brain pathology of amyloid-beta plaques and tau tangles.

From the article:

For the study, 535 people with an average age of 81 were followed until death, for an average of six years. They took yearly tests of their thinking and memory skills, and after death, a neurologist reviewed their records and determined whether they had dementia, some memory and thinking problems called mild cognitive impairment or no thinking and memory problems. Autopsies were conducted on their brains after death, and the amount of protein from BDNF gene expression in the brain was then measured.

[…]

The rate of cognitive decline was about 50 percent slower for those in the highest 10 percent of protein from BDNF gene expression compared to the lowest 10 percent. The effect of plaques and tangles in the brain on cognitive decline was reduced for people with high levels of BDNF. In the people with the highest amount of Alzheimer’s disease hallmarks in their brains, cognitive decline was about 40 percent slower for people with the highest amount of protein from BDNF gene expression compared to those with the lowest amount.

Exercise improves blood flow to the brain and cognitive function in older adults. www.sciencedaily.com

Exercise Aging Dementia

Poor blood flow to the brain, a common feature of aging, is associated with an increased risk of stroke and cognitive dysfunction. A recent study demonstrated that exercise improves brain blood flow and improves cognitive function in older adults.

The intervention study involved 206 healthy, cognitively intact middle-aged and older adults (average age, 66 years) with low physical activity levels. The participants engaged in a supervised aerobic exercise program three days per week, gradually increasing from 20 to 40 minutes over a period of six months. They also completed an unsupervised exercise session one day per week during the six-month period. The authors of the study assessed the participants' cognitive performance, cerebrovascular function, and overall fitness on three separate occasions over a period of 12 months.

After completing the six months of exercise, the authors of the study noted that the study participants improved by nearly 6 percent on measures of working memory, flexible thinking, and self-control. They improved by nearly 2.5 percent on tests of verbal fluency, comparable to abilities seen in person five years younger. Blood flow to the brain increased by nearly 3 percent, suggesting that cerebrovascular function is a critical aspect of maintaining or improving memory and verbal skills.

Link to study abstract.

Aerobic exercise induces changes in blood flow in brain regions involved in memory. www.sciencedaily.com

Exercise Dementia

Mild cognitive impairment and memory loss often precede the development of Alzheimer’s disease, a neurodegenerative disorder characterized by progressive memory loss, spatial disorientation, cognitive dysfunction, and behavioral changes. Aerobic exercise has been shown to improve memory function in older adults. Findings from a new study suggest that exercise improves cerebral flood flow in regions of the brain involved in memory.

The prospective clinical trial involved 30 older men and women (average age, 66 years) with mild cognitive impairment. Half of the participants engaged in a supervised aerobic exercise 25 to 30 minutes per session for three times per week, gradually increasing to 30 to 40 minutes per session for three or four times per week. The other half of the participants engaged in stretching only. At the end of the 12-month study period, the authors of the study assessed the participants' memory function, cardiorespiratory fitness, and cerebral blood flow.

The participants who took part in the exercise program exhibited marked improvements in memory function and cardiorespiratory fitness. They also demonstrated increased blood flow to the anterior cingulate cortex region of their brains, an area associated with empathy, impulse control, emotion, and decision-making.

Interestingly, the exercising group showed reduced blood flow to the posterior cingulate cortex, an area of the brain associated with internally directed thought and the default mode network. The posterior cingulate cortex is highly sensitive to age-related cognitive decline, Alzheimer’s disease, and dementia. The authors of the study suggested that once this area of the brain is affected by cognitive impairment, exercise can’t forestall further impairments. Instead, the exercise-induced changes in blood flow indicate a compensatory mechanism to shift brain activity to other regions.

These findings suggest that exercise can forestall the effects of age-related cognitive decline. Many older adults are unable to participate in exercise due to physical limitations, however. Sauna use is an exercise mimetic that induces the activity of heat shock proteins, a class of proteins that provide protection against neurodegenerative conditions like Alzheimer’s disease. Learn more about the exercise-like effects of sauna use in our overview article.

Link to study abstract.

Regular physical exercise reduces the incidence of dementia in a dose-dependent manner. onlinelibrary.wiley.com

Exercise Dementia

Dementia, a form of cognitive decline that interferes with normal daily living, affects approximately 50 million people worldwide. Findings from a recent study suggest that regular physical exercise can reduce the risk of developing dementia.

Dementia commonly occurs in older age and is characterized by a progressive loss of memory, executive function, and reasoning. Approximately 70 percent of all dementia cases are due to Alzheimer’s disease. Previous research has demonstrated that the incidence of dementia is influenced by non-modifiable risk factors, such as increasing age, ethnicity, and the presence of a genetic variant known as APOE4.

Researchers are less certain about modifiable factors that may alter dementia risk, including health behaviors such as exercise. The current retrospective cohort study investigated which individuals developed dementia and the factors associated with its incidence.

The study involved 206,073 people over the age of 50 years who were enrolled in the Health Check Ubon Ratchathani Project in Thailand. The authors of the study questioned participants about their medical and personal history, including the use of medications and exercise habits. Six years later, investigators reviewed the participants' electronic medical records for the incidence of physician‐diagnosed dementia. They found that a lack of physical exercise was associated with an increased risk of developing dementia in a dose-dependent manner. Exercising three to five days per week reduced the risk of dementia by 37 percent as compared to no physical exercise, while exercising more than five days per week reduced dementia risk by 59 percent.

These findings suggest that physical exercise at least three days a week can reduce the risk of developing dementia. Further clinical trials with longer follow-ups are needed to confirm the impact of lifestyle factors on dementia risk.

Link to the study abstract.

12 weeks of high-intensity interval training improves memory by 30% in older adults between the ages of 60 and 88. www.sciencedaily.com

Exercise Brain Aging Memory Dementia Aerobic

Cognitive decline and associated memory loss are common features of aging, affecting approximately 16 million people living in the United States. A recent study found that high-intensity interval training improves memory in older adults.

The study involved 64 sedentary older adults between the ages of 60 and 88 years who were randomized to participate in 12 weeks of high-intensity interval training, moderate continuous training, or stretching (which served as the control group). Each of the participants' memory and executive functions were assessed before the training began.

The participants in the high-intensity group performed four intervals of high-intensity exercise on a treadmill for four minutes, followed by a period of recovery. The participants in the moderate continuous group performed a single set of moderate-intensity aerobic exercise for approximately 50 minutes.

At the end of the study period, participants who engaged in high-intensity exercise performed better on memory tests than those who engaged in moderate continuous training or stretching only. The participants who saw the greatest fitness gains also saw the greatest memory improvements. Both high-intensity interval and moderate continuous exercise improved executive function in the participants.

These findings suggest that aerobic exercise, especially if it includes high-intensity interval training, has the potential to enhance memory in older adults.

Link to study abstract.

A 28% lower risk of dementia and better cognition was associated with a high intake of dietary phosphatidylcholine mainly from eggs and meat in men. www.sciencedaily.com

Alzheimer's Omega-3 Dementia Acetylcholine Neurons

A 28% lower risk of dementia and better scores on tests for memory and linguistic abilities was associated with a high intake of dietary phosphatidylcholine mainly from eggs and meat in men.

Choline is an important precursor to the neurotransmitter acetylcholine which plays an important role in cognition. Phosphatidylcholine is a very important component of cell membranes that make up neurons and also combines with the omega-3 fatty acid DHA to form lysophosphatidylcholine DHA which is transported across the blood-brain barrier. I published a paper last year on the important role DHA in phosphatidylcholine form plays in preventing Alzheimer’s disease particularly in people genetically predisposed to the disease.

This new study was an observational study so causation cannot be established. Future clinical trials need to be done before definitive conclusions can be made.

Link to my study on DHA and Alzheimer’s disease: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6338661/

higher acid-sphingomyelinase associated with disease progression in Alzheimer's www.ncbi.nlm.nih.gov

Alzheimer's Parkinson's Mental Health Cannabinoid Neurotransmitter Dementia

“Pharmacological restoration of ASM to the normal range improves pathology in AD mice The ASM-mediated lysosomal/autophagic dysfunction in AD prompted us to examine possible therapeutic implications of this pathway. To decrease ASM in APP/PS1 mice, we undertook pharmacological inhibition using amitriptyline-hydrochloride (AMI) for 4 mo (Fig. 9 A). AMI is a known inhibitor of ASM that can cross the blood–brain barrier. At 9 mo of age, AMI-treated APP/PS1 mice exhibited decreased ASM activity compared with vehicle-treated mice (Fig. 9 B). Other sphingolipid metabolites were not changed (Fig. 9 C). Aβ levels were decreased in the AMI-treated APP/PS1 mice compared with the nontreated littermates.”

“ASM activity is known to be increased by environmental stress and in various diseases, and is elevated in AD patients (He and Schuchman, 2012). One downstream consequence of increased ASM is elevated ceramide, contributing to cell death, inflammation, and other common disease findings. Although elevated ASM is known to occur in AD, the cellular mechanisms that link ASM and AD have not been fully characterized. The data presented here suggest a previously unknown role of ASM in the down-regulation of lysosomal biogenesis and inhibition of lysosome-dependent autophagic proteolysis. The findings also establish proof of concept for ASM inhibitor therapy in AD.”

People that consumed 2 sugary drinks a day are more likely to have poorer memory and smaller overall brain volume. www.sciencedaily.com

Brain Alzheimer's Inflammation Dementia Sugar Blood Sugar

People that drank two or more sugary beverages of any kind per day were more likely to have poorer memory, smaller overall brain volume, and a significantly smaller hippocampus. Researchers also found that higher intake of diet soda, at least one per day, was associated with smaller brain volume.

In a second study, researchers looked at whether participants had suffered a stroke or been diagnosed with dementia due to Alzheimer’s disease. Interestingly, there was no association between sugary beverage intake and stroke or dementia. But people who drank at least one diet soda per day were nearly 3 times as likely to develop stroke and dementia.

While no of this data proves causation, there is a growing body of research showing that excess refined sugar does increase inflammation which crosses the blood-brain barrier and acceleration brain aging. Regarding the diet soda, there have been studies linking artificial sweeteners to disruption of the gut microbiome which also causes inflammation which can lead to brain aging.

Daily tea consumption (green, black or oolong) was associated with a 50% reduced risk of cognitive decline. www.sciencedaily.com

Brain Alzheimer's Aging Depression Dementia Caffeine Antioxidant Dairy

Daily tea consumption (green, black or oolong) was associated with a 50% reduced risk of cognitive decline and a 86% lower risk in people genetically predisposed (ApoE4 gene) for Alzheimer’s disease.

The mechanism for the cognitive benefit is unclear and may include catechins, theaflavins, thearubigins and L-theanine which are all anti-inflammatory and have antioxidant activity. However, caffeine itself cannot be ruled out as a contributing factor as well.

While this data is an association and does not prove causation, the data was adjusted for many different factors that affect health and it still found the 50% and 86% reductions. The health factors that were adjusted for in the analysis included age, gender, education, smoking, alcohol consumption, body mass index, hypertension, diabetes, heart diseases, stroke, depression, ApoE4, physical activity, social and productive activities, vegetable and fruit consumption, fish consumption, and daily coffee consumption.

Using sauna 4-7x per week lowered dementia risk by 66% & Alzheimer's risk by 65% after adjusting for diet/lifestyle. ageing.oxfordjournals.org

Fulltext Alzheimer's Aging Heat Stress Dementia Blood Pressure Protein

This study included over 2,000 middle-aged men that were followed for 20 years. The results were adjusted for many possible confounding factors including baseline age, alcohol consumption, BMI, physical exercise, socioeconomic status, systolic blood pressure, smoking status, type 2 diabetes, previous heart attack, resting heart rate and serum low-density lipoprotein cholesterol.

One of the reasons I find this study so compelling even though it is associative data and does not establish causality is because the sauna activates heat shock proteins, which have been shown in countless animal studies to play a causal role in preventing Alzheimer’s disease and other neurodegenerative diseases.

Anyone that follows me knows that I talk about saunas ALOT. I have a couple of videos where I discuss the effects of the sauna on longevity and in muscle mass and endurance. I discuss the role of heat shock proteins in both videos. I also have free reports with references covering all these topics that you can download on my website (foundmyfitness.com). Sauna longevity video: https://www.youtube.com/watch?v=eWKBsh7YTXQ Sauna muscle/endurance video: https://www.youtube.com/watch?v=aHOlM-wlNjM&t=1s

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How To Use Coffee To Live Longer (Full Guide & Research)

Why Vitamin D Deficiency Accelerates Brain Aging

Q&A #61 with Dr. Rhonda Patrick (8/3/24)

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