Polyphenol
Polyphenols featured article
Polyphenols comprise a group of antioxidant compounds found in a variety of plants consumed as foods and beverages. Polyphenols are one of the most common classes of bioactive compounds found in plants, along with alkaloids (e.g., berberine), organosulfur compounds (e.g., sulforaphane), and terpenoids (e.g., beta carotene). A growing body of evidence suggests that polyphenols have disease-fighting properties, although the evidence to support these claims varies in quality.
Research has demonstrated some degree of efficacy of polyphenol consumption for:
- reducing intestinal hyperpermeability (i.e., leaky gut syndrome)
- increasing antioxidant defenses
- reducing cardiovascular disease risk
- ameliorating metabolic syndrome
- improving memory, cognitive function, and mood
- promoting good quality sleep
Chemically, polyphenols...
Episodes
Dr. Rhonda Patrick covers lithium microdosing, reducing homocysteine, aluminum's link to cancer, and beta-alanine and alpha-lipoic acid supplements.
In this clip, Dr. Rhonda Patrick explains how PPO in bananas affects polyphenols and how vitamin C acts as an inhibitor.
Dr. Rhonda Patrick discusses silicone safety, grounding, pentadecanoic acid, and the potential benefits of olive leaf extract and peptides.
-
Exercise Biomarkers Vitamin E Genetics Eyes Caffeine Folate Sulforaphane Sauna Antioxidant Dairy Polyphenol Supplements Wearable TechnologyDr. Rhonda Patrick covers lithium microdosing, reducing homocysteine, aluminum's link to cancer, and beta-alanine and alpha-lipoic acid supplements.
-
In this clip, Dr. Rhonda Patrick explains how PPO in bananas affects polyphenols and how vitamin C acts as an inhibitor.
-
Dr. Rhonda Patrick discusses silicone safety, grounding, pentadecanoic acid, and the potential benefits of olive leaf extract and peptides.
-
Rhonda Alzheimer's Cancer Sleep Hormones Omega-3 Stem Cells Sauna Blood Sugar Polyphenol Red Light TherapyDr. Rhonda Patrick discusses resistant starch, red light therapy risks, stem cells, and the link between benzodiazepines and dementia in her latest Q&A session.
-
Dr. Rhonda Patrick explores creatine, dairy's effect on polyphenols, eggs' health impact, and new weight loss drugs like Ozempic in her latest Q&A.
-
Rhonda Curcumin Resveratrol Sulforaphane Sauna Berberine Polyphenol Carotenoids Moringa Supplements SteviaDr. Rhonda Patrick explores iodine supplementation, choline & TMAO, curcumin safety, and red yeast rice in her latest Q&A.
-
Dr. Rhonda Patrick explores supplemental tyrosine, lion's mane, cordyceps, aging tests, and sunscreen's efficacy and safety in a Q&A.
-
Dr. Rhonda Patrick answers audience questions on various health, nutrition, and science topics in this Q&A session.
Topic Pages
-
Cocoa flavonoids (chocolate)
stub
Chocolate cocoa flavonoids are polyphenolic flavan-3-ols that scavenge reactive oxygen species and enhance endothelial nitric-oxide synthase activity.
-
Intestinal permeability
Polyphenols reduce intestinal permeability by activating AMPK and Nrf2 pathways that upregulate tight-junction proteins occludin and claudin.
-
Polyphenol-rich diets and neurodegeneration (glycemic control)
stub
Polyphenols and polyphenol-rich diets improve glycemic control, reducing AGE-induced oxidative-neuroinflammatory damage underlying neurodegeneration.
-
Polyphenols
Polyphenols are secondary plant metabolites with multiple phenolic hydroxyls that scavenge reactive species via hydrogen-atom or electron donation.
News & Publications
-
Inflammation and depression are often linked, particularly in older adults, who tend to experience chronic low-grade inflammation and elevated rates of depression. A recent study found that anti-inflammatory interventions may help reduce symptoms of depression and the risk of developing depression in older adults.
Researchers conducted a systematic review and meta-analysis of 31 randomized, placebo-controlled trials that assessed the effects of anti-inflammatory therapies on depression in older adults. The various anti-inflammatory agents included omega-3 fatty acids, nonsteroidal anti-inflammatory drugs, and plant-based compounds. The researchers included only trials with at least 20 participants.
The analysis revealed that anti-inflammatory treatments were more effective than placebos in reducing depression symptoms among older adults. On average, people receiving these treatments exhibited a moderate improvement in symptom severity compared to those taking a placebo. Omega-3 fatty acids and plant-based compounds, such as curcumin and soy protein, appeared particularly beneficial. There was also some evidence suggesting that these treatments might help prevent depression, although the results were not statistically conclusive.
These findings suggest that targeting inflammation is a promising strategy for managing depression in older adults, especially those with chronic inflammation. Learn more about links between inflammation and depression in Aliquot #36: Inflammation and Depression, part 2
-
High levels of lycopene, a powerful antioxidant found in tomatoes, correlated with an 11% lower risk of cancer development and a 24% lower risk of cancer-associated death. www.frontiersin.org
Tomatoes are a rich source of lycopene, a powerful antioxidant that may help protect against cancer and cancer-related death. A recent study found that people with the highest blood levels of lycopene were 11% less likely to develop cancer and 24% less likely to die from it than those with the lowest levels.
Researchers analyzed data from 121 prospective studies involving more than 100,000 people with cancer and more than 10,000 cancer-related deaths. They focused on studies that reported tomato intake, lycopene levels in the blood, or dietary lycopene consumption and how those related to cancer risk and death.
Compared with people who had the lowest lycopene levels, those with the highest had an 11% lower risk of developing cancer. High tomato and lycopene intake were each linked to a 5% lower cancer risk. When looking at cancer deaths, people who consumed the most tomatoes were 16% less likely to die from cancer, and those who consumed the most lycopene were 24% less likely. Higher blood levels of lycopene also lowered the risk of dying from lung cancer (the leading cause of cancer deaths) by 35%. In addition, a modest increase in blood lycopene—about 10 micrograms per deciliter—was tied to a 5% drop in overall cancer risk.
These findings suggest that a diet rich in tomatoes and other lycopene-containing foods could offer modest protection against cancer and may even reduce the risk of dying from it. Lycopene is a carotenoid compound found in tomatoes and watermelon. Learn more about lycopene and other carotenoids in our overview article.
-
Strawberry consumption boosts thinking speed and lowers systolic blood pressure by 3% in older adults. www.sciencedirect.com
Cognitive decline and cardiovascular disease often go hand in hand—and both become more common with age. Nutrition plays a key role in protecting brain and heart health, and certain fruits rich in antioxidants may offer targeted benefits. A recent study found that consuming fresh strawberries daily improved cognitive function and lowered systolic blood pressure by an average of 3% in older adults.
Researchers provided 35 healthy adults, ages 60 to 78, a strawberry powder or a placebo each day for eight weeks. Each person tried both options in random order, with a four-week break in between. The strawberry powder, made from freeze-dried fruit, delivered the same nutrients and antioxidants as two cups of fresh strawberries. The researchers measured the participants' cognitive function using standard tests and tracked markers of heart health, including blood pressure, waist size, blood lipids, and antioxidant levels.
The participants' thinking speed improved during the strawberry phase, while episodic memory improved modestly during the placebo phase. After eight weeks of strawberry consumption, systolic blood pressure dropped by an average of 3%, and waist size decreased slightly. Participants' blood antioxidant capacity increased with strawberries but decreased with the placebo. Triglycerides increased during the placebo period but remained stable with strawberries.
The findings from this small study suggest that regular strawberry intake supports brain and heart health in older adults. Strawberries are rich in polyphenols. Learn more about polyphenols in our overview article.
-
Curcumin, a compound derived from turmeric, aids in reducing muscle damage and soreness after intense exercise, potentially speeding up recovery. www.tandfonline.com
Intense exercise—especially eccentric movements like downhill running or heavy weightlifting—can cause microscopic muscle damage, inflammation, and soreness. While this process is part of adaptation, excessive damage can delay recovery and hinder performance. A recent study found that curcumin, a compound derived from turmeric, may help reduce muscle damage and soreness, potentially speeding up recovery.
Researchers analyzed the findings of 11 studies on curcumin and exercise-induced muscle damage. The various studies focused on healthy adults who exercised regularly and took curcumin before, during, or after workouts.
The analysis revealed that curcumin supplementation may ease muscle soreness, reduce inflammation, and improve recovery after strenuous exercise. However, the benefits depended on dose (which ranged from 90 milligrams to 2.5 grams), bioavailability, and timing, with post-exercise supplementation appearing most effective.
These findings suggest that curcumin could be a useful supplement for athletes looking to minimize muscle soreness and recover faster. However, its low bioavailability may limit its effectiveness. In addition, the investigators noted that many of the studies were small, limiting their findings' applicability. Curcumin is a polyphenolic compound. Learn more about polyphenols in our overview article.
-
Gray hair is often considered an inevitable part of aging, but evidence suggests lifestyle strategies—including diet—could slow it down. A recent study in mice found that luteolin, a plant-derived antioxidant, may help prevent hair graying by targeting key cellular processes.
Researchers tested the effects of three antioxidants—luteolin, hesperetin, and diosmetin—on hair graying in mice prone to premature graying. They applied the compounds topically and administered them orally, then analyzed changes in hair color, stem cell activity, and molecular markers associated with aging hair follicles.
Luteolin, but not the other antioxidants, substantially reduced hair graying in the mice. Both topical and oral luteolin helped maintain communication between hair follicle stem cells and melanocyte stem cells,which are essential for pigment production. Mice treated with luteolin also had fewer aging-related changes in these cells, suggesting it protects against age-related hair follicle dysfunction.
These findings suggest that luteolin is a promising candidate for an anti-graying treatment. Luteolin is abundant in celery, green pepper, broccoli, carrots, and olive oil, and is also available as a dietary supplement. Learn about other strategies to slow or prevent hair graying in this episode featuring Dr. Rhonda Patrick.
-
Anthocyanins, potent antioxidants in berries, boost cognitive function in people at higher risk of dementia, particularly those with high inflammation. www.sciencedirect.com
Anthocyanins, the compounds that give berries their deep red and purple hues, may do more than add color to a meal. Evidence suggests these potent antioxidants protect brain health, particularly in people at higher risk of dementia. A recent study found that anthocyanins improved cognitive function in people with high inflammation levels, but not those with lower inflammation.
Researchers conducted a 24-week randomized, placebo-controlled trial to examine anthocyanins' effects on cognition. They categorized participants into two groups based on inflammation levels, using blood biomarkers to make the distinction. Each participant received either anthocyanins or a placebo, and the researchers measured cognitive function before and after the intervention.
The cognitive test results indicated that participants with high inflammation experienced marked cognitive improvements after anthocyanin treatment, while those with lower inflammation saw no benefit. Interestingly, participants in the high-inflammation group had higher body mass indexes, greater diabetes prevalence, and lower HDL (“good”) cholesterol levels.
These findings suggest that anthocyanins improve cognitive function among people with high inflammation. Anthocyanins are polyphenolic compounds. Learn more about polyphenols in our overview article.
-
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.
-
A diet abundant in antioxidants, iron-chelating nutrients, and polyunsaturated fatty acids mitigates harmful iron accumulation in the brain, preserving cognitive function. www.sciencedirect.com
Although iron is essential for many physiological processes in the body, it can also be harmful, inducing oxidative stress and hindering neurogenesis. The body typically stores iron in protein complexes until needed, but these storage processes decline with age, leading to iron accumulation in body tissues. A recent study revealed that iron can build up in the brain, impairing cognitive function. Nevertheless, dietary components can help reduce iron accumulation in the brain and maintain cognitive health.
Researchers examined the brain health of 72 cognitively healthy older adults by conducting brain scans at baseline and two to three years later. Participants provided details about their dietary habits, physical activity, and overall health. They also underwent cognitive tests that evaluated their episodic memory and executive function.
The brain scans revealed that iron levels increased markedly over time, and higher iron accumulation correlated with poorer cognitive function. However, a higher intake of antioxidants, vitamins, iron-chelating nutrients, and polyunsaturated fatty acids mitigated iron accumulation. Iron-chelating nutrients include polyphenolic compounds, such as gallic acid and catechins (in tea), caffeic acid (in coffee), quercetin (in apples and onions), ellagic acid (in walnuts and pomegranates), curcumin (in turmeric) and others.
These findings suggest that diet mitigates iron accumulation in the brain, ultimately influencing cognitive health. Interestingly, alcohol can promote iron accumulation in the brain. Learn more in this episode featuring Dr. Rhonda Patrick.
-
Stress damages the heart and blood vessels, increasing the risk of cardiovascular events like heart attack or stroke. Stress can also drive people to make poor dietary choices, often leading to overeating or consuming high-fat, low-nutrient foods instead of healthier options like fruits and vegetables. A recent study found that cocoa flavanols help counteract the harmful effects of stress and unhealthy meals on the heart and blood vessels.
The study involved 23 healthy young adults. Each participant ate a high-fat meal (buttered croissants, cheese, and whole milk) paired with either a high-flavanol cocoa drink or a low-flavanol cocoa drink before completing an eight-minute stress task. Researchers measured their blood vessel function, brain oxygen levels, blood flow, blood pressure, and mood multiple times before and after the stress challenge.
Participants who drank the high-flavanol cocoa maintained better blood vessel function after stress than those who consumed the low-flavanol drink. Blood vessel function declined considerably within 30 minutes of the stress task in the low-flavanol group but was preserved with high flavanol intake. At 90 minutes, blood vessel function improved beyond pre-stress levels in the high-flavanol group. The two groups had similar stress-related changes in blood pressure, brain oxygenation, and mood.
The findings from this small study suggest that flavanol-rich foods help protect the cardiovascular system during stressful periods, even when accompanied by unhealthy meals. Flavanols are polyphenolic compounds in dark chocolate, berries, apples, and tea. Evidence suggests flavanols exert potent antioxidant and anti-inflammatory properties. Learn more about flavanols and other polyphenols in our overview article.
-
Mediterranean diet variations, rich in polyphenols and targeted at metabolic health, halve brain atrophy markers, slowing age-related brain shrinkage by up to 50% over 18 months. www.sciencedirect.com
Brain atrophy occurs naturally with aging, but certain factors such as type 2 diabetes, high blood pressure, and inflammation can accelerate this process, increasing the risk of cognitive decline. However, eating a healthy diet may help slow brain aging. A recent study found that two versions of the Mediterranean diet reduced markers of brain atrophy by 50% over 18 months compared to general healthy eating guidelines.
Researchers assigned participants aged 50 or older with abdominal obesity or abnormal blood lipids to one of three diets: one that followed standard healthy dietary guidelines, a calorie-restricted Mediterranean diet (which included walnuts and olive oil and substituted chicken and fish for lamb and beef), or a “green” calorie-restricted Mediterranean diet enriched with polyphenols from green tea and mankai, an aquatic plant. The participants underwent brain imaging to assess hippocampal atrophy, a key marker of brain aging, and the researchers tracked changes in body weight, blood sugar, and inflammation over the study period.
Participants following the green Mediterranean diet showed the greatest preservation of brain volume, particularly in the hippocampus. They also experienced improvements in HbA1c (a marker of long-term blood glucose control), insulin resistance, fasting glucose, and C-reactive protein. Improvements in blood sugar levels and inflammation were closely linked to better brain health outcomes, and greater intake of polyphenol-rich foods like mankai and green tea further enhanced these benefits.
Mankai, also called duckweed, is rich in polyphenols, omega-3 fatty acids, dietary fiber, and many micronutrients, including iron and vitamin B12. The polyphenols in mankai exert robust antioxidant activity and support healthy blood glucose levels—critical elements in maintaining brain health.
These findings suggest that diets rich in polyphenols and designed to improve metabolic health may help protect against age-related brain atrophy and keep the brain biologically younger. Learn more about the health benefits of polyphenols in our overview article.
-
Just 1.5 teaspoons of olive oil daily reduces the risk of death from dementia by 28%, regardless of genetic factors. jamanetwork.com
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.
-
Olive oil is rich in bioactive compounds, including polyphenols, carotenoids, and oleic acid. It’s a fundamental component of the Mediterranean diet and is associated with a wide range of health benefits. A recent study found that high olive oil intake—more than 3 tablespoons daily—reduces the risk of early death from all causes by 20%.
Researchers analyzed data from nearly 23,000 adults enrolled in a long-term cohort study in Italy. Participants completed questionnaires about their olive oil consumption, defined as high (3 tablespoons or more daily) or low (1.5 tablespoons or less daily). The researchers collected information about the participants' lifestyles, assessed their overall diet quality, and measured their biomarkers associated with chronic disease risk.
They found that compared to low olive oil intake, high intake lowered the risk of early death from all causes by 20%, cancer by 23%, and cardiovascular disease by 25%. However, They found that the effect of high olive oil intake on reducing the risk of dying from all causes and cancer was slightly lower when considering the participants' biomarkers.
These findings suggest that olive oil reduces the risk of early death from all causes, including cancer and cardiovascular disease. The polyphenols in olive oil exert potent antioxidant, anti-inflammatory, and anti-cancer effects. Learn more about the health benefits of polyphenols in our overview article.
-
Urolithin A, a compound derived from pomegranates and walnuts, boosts mitophagy and enhances cognitive function in aged mice. neurosciencenews.com
Mitochondrial function declines with aging, driving many age-related conditions, including Alzheimer’s disease. A recent study in mice found that urolithin A, a compound derived from pomegranates and walnuts, promotes mitophagy – the targeted destruction of damaged mitochondria – in the brain.
Researchers fed older mice urolithin A (200 milligrams per kilogram of body weight) daily for five months. They subjected the animals to various learning and memory tests, assessed their sense of smell, and examined their brains.
They found that urolithin A markedly improved the animals' learning, memory, and sense of smell, enhanced memory-related brain functions, and reduced the accumulation of amyloid-beta and tau protein (hallmarks of Alzheimer’s disease). Urolithin A also improved the function of lysosomes, cellular structures that play a crucial role in mitophagy, by breaking down and recycling damaged mitochondria.
These findings suggest that urolithin A boosts mitophagy in mice, improving brain health and cognitive function. Urolithin A is a byproduct of gut microbial metabolism of ellagic acid, a bioactive compound found in pomegranates and walnuts. The capacity to form urolithin A from ellagic acid varies considerably from person to person (depending on gut microbial composition) and decreases with age.
Due to the low quantities of ellagic acid in foods and the poor conversion rate, achieving a human dose comparable to that used in this study likely would require supplemental intake. Nevertheless, the findings align with other evidence suggesting that long-term dietary intake of foods containing ellagic acid benefits cognitive health.
-
Polyphenols in tea may reduce symptoms and progression of Parkinson's disease. pubmed.ncbi.nlm.nih.gov
Parkinson’s disease is a progressive neurodegenerative disorder characterized by loss of dopamine-producing neurons, motor impairments, and the accumulation of alpha-synuclein, a neuronal protein that regulates synaptic vesicle movements and neurotransmitter release. However, a growing body of evidence suggests that dietary components protect against the development and progression of the condition. A 2015 study found that polyphenols in tea mitigated neuronal loss, motor impairments, and alpha-synuclein accumulation in a primate model of Parkinson’s disease.
Researchers treated a group of monkeys with Parkinson’s disease with a mixture of tea polyphenols, including epicatechin, epicatechin gallate, epigallocatechin, and epigallocatechin gallate (commonly known as EGCG), daily for 80 days. Another group of monkeys received no treatment. The researchers assessed the animals' motor function every two weeks and examined their brains.
They found that treatment with tea polyphenols alleviated motor impairments and neuronal loss in the monkeys and reduced alpha-synuclein accumulation. Monkeys that didn’t receive polyphenols showed marked disease progression.
These findings suggest that tea polyphenols exert neuroprotective properties in a primate model of Parkinson’s disease. Polyphenols are one of the most common classes of bioactive compounds found in plants. Evidence suggests they exert potent anti-inflammatory, antioxidant, and cardioprotective properties. Learn more about polyphenols in our overview article.
-
Eating blueberries multiple times a week slashes the risk of age-related macular degeneration by up to 64 percent. www.sciencedirect.com
Age-related macular degeneration is the leading cause of vision loss in older adults. However, evidence suggests that some dietary components reduce the risk of the disease. A recent study found that eating blueberries cuts the risk of age-related macular degeneration by 64 percent.
The study involved roughly 35,000 middle-aged and older women enrolled in the Women’s Health Study. Researchers used questionnaires to collect information about the women’s blueberry intake and eye health for about 11 years.
They found that eating blueberries one to three times a month reduced the risk of age-related macular degeneration by 10 percent, eating them once a week by 29 percent, more than once a week by 32 percent, and two or more times a week by 64 percent. Eating more blueberries didn’t show a protective effect against developing cataracts; however, higher anthocyanin intake did confer a 10 percent reduction in risk.
Blueberries are rich in anthocyanins – a class of flavonoid compounds that exert robust antioxidant and anti-inflammatory properties via hormetic effects. Learn about the hormetic effects of anthocyanin-rich blueberries as well as other hormetic compounds in this smoothie recipe video.
-
Apple cider vinegar promotes weight loss and improves metabolism in young people with overweight or obesity. nutrition.bmj.com
Obesity and overweight are growing global public health concerns, especially among young people. Evidence suggests that apple cider vinegar supports weight loss and improves metabolic health. A recent study found that young people who took apple cider vinegar for 12 weeks lost more weight and exhibited better metabolic parameters than those who took a placebo.
The study involved 120 teens and young adults with overweight or obesity. Participants received 5, 10, or 15 milliliters (5 milliliters = 1 teaspoon) of apple cider vinegar or a placebo diluted in water daily for 12 weeks. They didn’t make any changes to their diets or activity levels. Researchers measured the participants' anthropometrics (weight, body mass index, waist/hip circumferences, and body fat ratio) and blood glucose, triglyceride, and cholesterol levels at the beginning of the study and again at four-week intervals.
They found that participants who took apple cider vinegar lost weight in a dose- and time-dependent manner, with those taking higher doses manifesting the greatest weight loss, which increased as the study progressed. All anthropometric measures improved, too, as did blood glucose, triglyceride, and cholesterol levels. None of the participants taking the vinegar experienced any adverse or ill effects.
These findings suggest that apple cider vinegar promotes weight loss and improves metabolic parameters in young people with overweight or obesity. The investigators noted that these effects occurred without changes to the participants' diets or activity levels, suggesting the effects arose from the vinegar itself. Apple cider vinegar is made by fermenting apple juice. It is rich in vitamins, minerals, amino acids, and polyphenols such as flavonoids, which may confer some of apple cider vinegar’s benefits. Learn about the health benefits of other polyphenols in our overview article.
-
Cinnamon is one of the most consumed spices in the world, popular in both sweet and savory dishes in many cuisines. Evidence suggests cinnamon improves lipid profiles and protects against damage induced by oxidative stress, improving metabolic profiles in people with type 2 diabetes. New research now shows that a component of cinnamon may promote hair growth.
Researchers studied the effects of cinnamic acid, a component of cinnamon, on hair growth. First, they treated dermal papilla cells (cells involved in hair formation and development) with varying concentrations (0 to 2,000 micrograms per milliliter, µg/mL) of cinnamic acid. They found that low to moderate concentrations of the compound (less than 500 µg/mL) increased the production of genes involved in hair growth and enhanced the activity of receptors for oxytocin, a hormone, in the cells.
Next, they studied the effects of cinnamic acid on hair follicle organoids called follicloids. Organoids are three-dimensional tissue cultures produced from stem cells that mimic the structure and activity of the organ from which they are derived. They applied varying concentrations (0, 50, 100, and 500 µg/mL) of cinnamic acid to the follicloids and measured hair growth for 10 days. They found that concentrations of 100 to 500 µg/mL of cinnamic acid promoted hair growth in the follicloids by the eighth day.
These findings suggest that cinnamic acid is a viable option for promoting hair growth by targeting the oxytocin receptor. Recent research found that oxytocin promotes hair growth, but because oxytocin breaks down rapidly and is a relatively large molecule, it isn’t a good candidate for use in pharmaceutical or cosmetic treatments to grow hair. However, cinnamic acid is a naturally occurring polyphenol with potent antioxidant, anti-inflammatory, and anti-cancer properties. Learn more about polyphenols in our overview article.
-
Epicatechin-rich cocoa boosts endogenous antioxidant production and mitochondrial function while protecting against muscle damage in people with peripheral artery disease. pubmed.ncbi.nlm.nih.gov
Peripheral artery disease affects roughly 230 million people worldwide and arises when plaque accumulation in the arteries impairs the delivery of oxygen-rich blood to the muscles, causing pain with physical activity. A recent study found that cocoa flavanols promote the production of endogenous antioxidants and proteins involved in mitochondrial function in people with peripheral artery disease.
The study involved 16 people with peripheral artery disease who were enrolled in COCOA-PAD, a six-month randomized controlled trial in which participants who received a cocoa beverage containing 15 grams of cocoa (providing 75 milligrams of epicatechin, a flavanol compound) daily showed marked improvements in walking performance and less pain with activity. Researchers examined muscle samples taken before and after the trial to study changes in muscle fibers, endogenous antioxidants (heme oxygenase-1 and NAD(P)H dehydrogenase [quinone] 1), and energy-related proteins.
They found that participants who received the cocoa beverage had higher levels of endogenous antioxidants, correlating with less muscle damage. They also had higher levels of UQCRC2, a protein critical for energy production in the mitochondria.
These findings suggest that cocoa flavanols promote the synthesis of endogenous antioxidants and proteins involved in energy production and point toward a mechanism for the beneficial effects observed in COCOA-PAD. Because heme oxygenase-1 and NAD(P)H dehydrogenase [quinone] 1 are targets of nuclear factor erythroid 2-related factor 2 (Nrf2), the investigators posited that the mechanism driving the beneficial effects of cocoa flavanol supplementation is Nrf2 activation.
Nrf2 is a protein typically found in the cytoplasm of mammalian cells. Nrf2 can relocate to the nucleus, where it regulates the expression of hundreds of antioxidant and stress response proteins that protect against oxidative damage triggered by injury and inflammation. Although this study found that cocoa induces Nrf2, one of the most robust inducers of Nrf2 is sulforaphane, a compound derived from broccoli. Learn more about sulforaphane and Nrf2 in this clip featuring Dr. Jed Fahey.
-
Daily cinnamon supplementation averaging 2,100 milligrams – roughly a teaspoon – shows promise in managing type 2 diabetes. pubmed.ncbi.nlm.nih.gov
Cinnamon is one of the most consumed spices in the world, popular in both sweet and savory dishes in many cuisines. Evidence suggests cinnamon improves lipid profiles and protects against damage induced by oxidative stress. A recent systematic review and meta-analysis found that cinnamon helps maintain healthy blood glucose levels and reduces insulin resistance in people with type 2 diabetes.
Researchers analyzed the findings of 24 clinical trials investigating the effects of cinnamon supplementation on blood glucose levels. The various trials included more than 1,800 participants from 11 nations.
The analysis revealed that cinnamon supplementation reduced fasting blood glucose levels, hemoglobin A1c concentrations, and insulin resistance (without lowering insulin) in people with type 2 diabetes. The trials varied in duration from six to 16 weeks, and daily cinnamon doses ranged from 120 to 6,000 milligrams, averaging 2,100 milligrams – roughly a teaspoon.
These findings suggest that cinnamon improves symptoms of type 2 diabetes and may be a valuable adjunct to traditional therapies. Cinnamon is rich in polyphenols, a broad class of plant bioactive compounds. Learn more about polyphenols in our overview article.
-
A single 8-ounce serving of 100 percent fruit juice daily promotes weight gain in children. pubmed.ncbi.nlm.nih.gov
Whole fruits are rich in vitamins, minerals, and bioactive compounds that promote health. They also contain essential fiber, which supports digestion and regulates blood sugar levels. Fruit juices, on the other hand, contain little fiber, are high in natural sugars, and can cause rapid blood sugar spikes, impairing metabolism. A recent systematic review and meta-analysis found that consuming 100 percent fruit juice promotes weight gain in children.
Researchers analyzed the findings of 42 randomized clinical trials investigating the effects of consuming 100 percent fruit juice on body weight. The various trials included more than 45,000 children and 268,000 adults.
They found that for every additional serving of juice (defined as 8 ounces) per day, the children showed a modest increase in body mass index, a proxy for body fatness. However, the findings in adults were mixed, with studies that didn’t adjust for caloric intake observing greater body weight gain than those that didn’t.
These findings suggest that a single serving of 100 percent fruit juice daily promotes weight gain in children – a noteworthy finding considering that roughly half of children and teens in the U.S. consume at least one serving of fruit juice a day. An 8-ounce serving of 100 percent orange juice contains about 110 calories and 20 grams of sugar, while a medium-sized whole orange contains approximately 62 calories and 12 grams of sugar. Encouraging the consumption of whole fruits versus fruit juices may influence body weight in children.
-
Flavonoid supplementation emerges as a promising treatment for non-alcoholic fatty liver disease. onlinelibrary.wiley.com
Non-alcoholic fatty liver disease, or NAFLD, causes fat accumulation in the liver, inflammation, and insulin resistance. It’s the most common chronic liver condition among people in the United States, affecting roughly 90 percent of people with obesity, or about 38 percent of the overall population. A recent systematic review and meta-analysis found that flavonoid supplementation reduces the risk of developing NAFLD.
Researchers reviewed the findings of 12 randomized controlled trials investigating the effects of flavonoid supplementation in people with NAFLD. They found that flavonoid supplementation improved markers of liver function (liver enzymes) and reduced blood lipids (triglycerides and cholesterol), inflammatory markers (TNF-alpha and NF-kappa B), and fat accumulation in the liver, suggesting that flavonoid supplementation is a viable option for managing and treating NAFLD.
Flavonoids are bioactive compounds found in many fruits and vegetables. Evidence suggests they exert a wide range of beneficial effects in humans, including anti-inflammatory, antioxidant, and lipid-lowering activities, as well as counteracting insulin resistance. Higher flavonoid intake is associated with a lower risk of NAFLD progression in older adults with overweight or obesity.
Evidence suggests sulforaphane, a bioactive compound derived from broccoli, also benefits liver health. Learn more about sulforaphane in our comprehensive overview article.
-
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.
-
Naringenin, a citrus fruit flavonoid, preserves muscle mass in aging while enhancing exercise capacity and aerobic metabolism efficiency (animal study). medicalxpress.com
Muscle mass declines markedly with age, with up to 8 percent muscle mass loss occurring per decade after age 30. Evidence suggests that naringenin, a flavonoid compound found in citrus fruits, maintains muscle mass in aging. Mice that ate a diet supplemented with naringenin showed improved muscle endurance and grip strength.
Researchers supplemented the diets of young adult mice, middle-aged mice, and mice prone to muscular dystrophy (accelerated muscle loss) with naringenin. Then, they assessed naringenin’s effects on exercise capacity and aerobic metabolic levels in skeletal muscle.
They found that young adult and middle-aged mice receiving naringenin could run farther than those that did not. Middle-aged mice also showed improved grip strength and increased calf muscle size. Mice prone to developing muscular dystrophy ran farther and showed improved grip strength.
The researchers attributed these improvements in muscle endurance to naringenin’s capacity to increase the number of oxidative myofibers (muscle fibers that use oxygen) and improve the overall efficiency of aerobic metabolism in the body. They found that Sp1, a transcription factor that influences gene expression in muscle, likely mediated naringenin’s effects.
These findings indicate that naringenin may preserve muscle mass in aging and disease. Other dietary components, such as omega-3 fatty acids, influence muscle maintenance, too. Learn more in this episode featuring Dr. Chris McGlory.
-
Cardiovascular aging is characterized by marked functional decline and increased cardiovascular disease risk. Evidence suggests that flavonols, a broad class of bioactive compounds found in cocoa and other fruits, exert cardioprotective effects, bolstering cardiorespiratory fitness. A recent study shows that older adults who took cocoa flavonols experienced a nearly 10 percent gain in peak oxygen consumption, a marker of cardiorespiratory fitness, during exercise.
Researchers conducted a study involving 68 healthy older adults aged 55 to 79. Half of the participants took 1,000 milligrams of cocoa flavonols daily for a month, while the other half took a placebo. The researchers measured the participants' peak oxygen consumption during exercise and assessed other aspects of their cardiovascular health, including blood pressure and blood vessel health.
They found that participants who took the cocoa flavonols showed marked improvements in their cardiorespiratory fitness. Their oxygen use during exercise increased by nearly 10 percent, and their exercise capacity increased by more than 6 percent. Their resting systolic and diastolic blood pressures decreased by 5.4 mmHg and 2.9 mmHg, respectively, and their blood vessel function improved by 1.3 percent. Those who took the placebo didn’t demonstrate these improvements.
These findings suggest that cocoa flavonols benefit older adults' cardiovascular health by improving fitness levels and other health markers, potentially promoting better heart health in aging. Interestingly, the benefits of cardiorespiratory fitness extend to cognitive function, too. Learn more in this clip featuring Dr. Axel Montagne.
-
Consuming 500 milligrams of cocoa flavanols daily improves hippocampal memory function in older adults, study finds. www.pnas.org
Dietary components play critical roles in cognitive function as we age. A new study shows that flavanols – bioactive compounds found in tea, apples, berries, grapes, cocoa, and other fruits and vegetables – improve memory. People who took a flavanol-rich cocoa supplement performed better on memory tests than those who didn’t.
Researchers conducted a three-year study involving more than 3,500 older adults. Half of the participants received a cocoa extract containing 500 milligrams of flavanols daily, while the other half received a placebo. The researchers gave the participants memory tests before and after the intervention, and they assessed the participants' overall diet quality using the Healthy Eating Index.
They found that people with higher flavanol intake and better overall diet quality at the beginning of the study had better memory performance, particularly in tasks involving the hippocampus – the area of the brain responsible for memory consolidation. However, after one year of intervention, the researchers found that memory improved among those with lower diet quality or low flavanol intake.
These findings suggest that low dietary flavanol intake contributes to age-related cognitive decline, specifically hippocampal-dependent memory, but flavanol supplementation counteracts these effects. They also underscore the importance of including flavanol-rich foods in the diet throughout the lifespan for optimal cognitive performance.
Evidence suggests flavanols promote angiogenesis (the formation of new blood vessels), which is crucial for adequate blood flow to the brain. Learn how blood flow to the brain influences cognitive function in this episode featuring Dr. Axel Montagne.
-
Artificial intelligence tool shows 96 percent accuracy in early Parkinson's disease diagnosis. parkinsonsnewstoday.com
Early diagnosis of Parkinson’s disease is important because many commonly used treatments for the condition are more effective when administered early on. New research suggests that a new artificial intelligence tool can help diagnose Parkinson’s disease well before symptoms manifest, with 96 percent accuracy.
Researchers used machine learning to analyze metabolites – byproducts of metabolism – in the blood of 78 people, half of whom had Parkinson’s disease.
They found that the machine learning tool was approximately 96 percent accurate when differentiating between healthy people and those with Parkinson’s disease, based on their blood metabolites. They also found that people with Parkinson’s disease were more likely to have high levels of a poly-fluoroalkyl substance in their blood and low levels of triterpenoids, cholestane steroids, and diacylglycerol.
Polyfluoroalkyl substances, also known as PFAS, are man-made chemicals used in food packaging, household products, and drinking water. PFAS are not excreted in bodily fluids like sweat or urine; rather, they persist in the body for indefinite periods and are often referred to as “forever chemicals.” Triterpenoids, cholestane, and diacylglycerol are plant-based bioactive dietary compounds that exert antioxidant and neuroprotective effects.
These findings suggest that machine learning is a useful tool in detecting Parkinson’s disease early based on metabolites in blood. They also highlight possible interventions to reduce the risk of developing the disease, such as reducing exposure to PFAS and including plant-based bioactive compounds in the diet. Learn more about Parkinson’s disease in this episode featuring Dr. Giselle Petzinger.
-
Eating blueberries may improve athletic performance. www.nutraingredients.com
A new study shows that eating wild blueberries, which are rich in bioactive compounds called anthocyanins, may improve athletic performance. After young men consumed freeze-dried wild blueberries for two weeks, their fat oxidation rates during exercise increased by more than 43 percent.
During exercise, fats and carbohydrates undergo oxidation, providing fuel for contracting muscles. At lower exercise intensity, the body relies primarily on fat oxidation; at higher intensity, the body shifts more toward carbohydrate oxidation. During endurance training, the body’s carbohydrate stores can deplete, causing fatigue and impairing athletic performance.
The study involved 11 healthy, aerobically fit men. The men ate 25 grams of freeze-dried wild blueberry powder (roughly equivalent to a cup of fresh blueberries and providing 325 grams of anthocyanins) every day for two weeks. Before and after the intervention, researchers measured men’s fat utilization at 65 percent of their peak oxygen consumption while exercising.
They found that the men’s fat oxidation increased by 19.7 percent after exercising for 20 minutes, 43.2 percent after 30 minutes, and 31.1 percent after 40 minutes. Conversely, their carbohydrate oxidation decreased by 10.1 percent after 20 minutes, 19.2 percent after 30, and 14.8 percent after 40. The men’s lactate levels were lower, too, likely due to improved blood flow.
Anthocyanins are polyphenolic compounds that exert antioxidant, anti-inflammatory, and cardioprotective effects, among others. It’s noteworthy that freeze-drying blueberries induces considerable anthocyanin losses. Eating fresh blueberries may provide even greater benefits to athletic performance.
The findings from this small study suggest that consuming anthocyanin-rich blueberries promotes fat oxidation, thereby enhancing athletic performance. Further studies in larger populations are needed to confirm these effects.
-
Polyphenols found in tea and coffee may reduce the risk of diabetes. pubmed.ncbi.nlm.nih.gov
Drinking tea and coffee may reduce the risk of developing type 2 diabetes, a 2022 study found. Men that drank a beverage enriched in polyphenols present in tea and coffee had lower blood glucose levels and improved insulin sensitivity than those who drank a placebo.
Eleven healthy men drank a beverage that contained either polyphenols from tea (catechins) and coffee (chlorogenic acids) or a placebo every day for three weeks. Both beverages provided 119 milligrams of caffeine – a little more than the amount present in one cup of coffee. At the end of the three weeks, they ate a high-fat, high-carbohydrate meal, and then researchers measured their blood glucose, insulin, and other metabolic markers.
The researchers found that consuming the catechin- and chlorogenic-rich beverage reduced the men’s blood glucose levels when consumed with a high-fat or high-carbohydrate meal. Their insulin sensitivity and levels of hormones involved in glucose metabolism increased, as well.
Catechins are polyphenolic compounds found in tea, cocoa, and berries. Evidence suggests that catechins ameliorate symptoms associated with diabetes. Chlorogenic acids are polyphenolic compounds found in coffee, apples, and berries. Evidence suggests that chlorogenic acids reduce inflammation, a key player in the pathophysiology of diabetes.
-
Eating a polyphenol-rich diet may cut abdominal fat. bmcmedicine.biomedcentral.com
Eating a Mediterranean-style diet, which is abundant in polyphenol-rich fruits, vegetables, olive oil, legumes, and nuts, helps reduce abdominal fat, a 2022 study found. People who followed a Mediterranean-style diet supplemented with a polyphenol-rich shake for 18 months lost twice as much abdominal fat as those who consumed a lower-polyphenol diet.
Researchers assigned nearly 300 people to follow one of three diets plus exercise: a Mediterranean-style diet that included walnuts; a Mediterranean-style diet that included walnuts, green tea, and a shake that contained duckweed (a polyphenol-rich aquatic plant native to Asia); and a diet that adhered to conventional healthy dietary guidelines. They measured the participants' body weight and waist circumference and conducted magnetic resonance imaging (MRI) studies to assess their abdominal fat at the beginning and end of the intervention.
They found that participants who followed the two variations of the Mediterranean/walnut diets lost body weight and their waist circumferences decreased, compared to those who followed the healthy dietary guidelines. However, MRIs revealed that while those who followed the Mediterranean/walnut diet lost 6.0 percent of their abdominal fat, those who followed the Mediterranean/walnut diet that included tea and duckweed lost 14.1 percent of their abdominal fat – more than twice as much.
Walnuts are rich in the polyphenolic compound ellagic acid. Bacteria in the human gut break down ellagic acid to produce urolithins. Scientists have identified about 20 urolithins, but the most studied of these is urolithin A, which exerts potent anti-obesity effects.
Duckweed is rich in polyphenols, carotenoids, omega-3 fatty acids, fiber, and many micronutrients, including iron and vitamin B12. The polyphenols in duckweed exert robust antioxidant activity and support healthy blood glucose levels – critical elements in maintaining healthy body weight and waist circumference.
-
Commercial phytoestrogen supplements containing genistein-like soy isoflavones significantly reduced bone loss by up to 9%. (2009) www.sciencedaily.com
Plant-based estrogen supplements aren’t as effective at maintaining bone health as claimed.
Plant-derived estrogen-like compounds found in dietary supplements are not as effective at reducing bone loss as claimed, a 2009 study showed. When compared to conventional therapies such as hormones or anti-osteoporosis drugs, the plant-based treatments were roughly four to five times less effective at reducing bone loss.
Over a period of 50 days, 11 postmenopausal women received six different treatments: soy cotyledon (the first leaves to appear on the plant), soy germ, kudzu (a plant used in traditional and folk medicine), red clover, risedronate (a drug used to treat osteoporosis), and estrogen combined with progesterone. Researchers measured the women’s bone loss after each treatment.
They found that the different treatments reduced bone loss to varying degrees: estrogen combined with progesterone, 24 percent; risedronate, 22 percent; soy cotyledon, 9 percent; soy germ, 5 percent. Red clover and kudzu had only marginal effects on reducing bone loss. Bone loss is a common feature of aging, especially among post-menopausal women.
Estrogen preserves bone health and is commonly prescribed as a treatment for women with osteoporosis. However, estrogen therapies and many common anti-osteoporosis drugs carry health risks. Plant-derived estrogen-like compounds, often referred to as phytoestrogens, are often touted as viable alternatives to conventional therapies.
This study demonstrates that plant-based therapies are less effective at reducing bone loss than hormonal or pharmaceutical therapies. They also underscore the importance of building bone mass in early life. Resistance exercise has been shown to preserve and even increase bone mass in postmenopausal women. Learn more about the effects of resistance training on bone health in this episode featuring Dr. Brad Schoenfeld.
-
Long-term estrogen treatment reduced androgen levels in female monkeys by up to 53% and increased cortisol levels. (2004) www.sciencedaily.com
From the article:
“Our findings suggest that it might be important for women taking estrogen after menopause to also take androgen supplements – which can include testosterone,”
[…]
Half of the monkeys were given oral contraceptives, which contain estrogen, in their diets for 26 months. All animals then had their ovaries removed to make them menopausal.
For the next three years, the animals were divided into three groups based on diet. One group ate soy that didn’t contain isoflavones, which are natural plant estrogens; one group ate soy with the isoflavones intact, and one group’s diet was soy without isoflavones and Premarin [conjugated estrogen], or estrogen therapy, added.
[…]
The researchers measured levels of the major androgens, which include dehydroepiandrosterone sulfate (DHEA-S), androstenedione (A4), and testosterone. Monkeys who took the oral contraceptives before menopause had DHEA-S levels that were 27 percent lower than the monkeys who didn’t take contraceptives. Levels of A4 were 53 percent lower, and levels of testosterone were 50 percent lower. These effects did not continue into menopause.
In the postmenopausal phase of the study, treatment with soy plus Premarin resulted in DHEA-S levels that were 29 percent lower than the monkeys who ate soy without isoflavones (control group) and 35 percent lower than the group eating soy with isoflavones. Total levels of testosterone were 52 percent lower than the control group and 41 percent lower than the group eating soy with isoflavones.
The researchers had suspected that the plant estrogens would also suppress androgen production. While this didn’t prove true, they did find that these monkeys had smaller adrenal glands than monkeys that didn’t consume the isoflavones.
The adrenal gland, located near the kidneys, uses cholesterol to make the androgen hormones and to make cortisol, a hormone associated with high levels of stress. The researchers found that while estrogen treatment lowered levels of androgen hormones, levels of cortisol increased.
-
Pomegranate juice improves blood pressure and reduces arterial plaques in people with atherosclerosis. www.clinicalnutritionjournal.com
Pomegranate juice reduces symptoms associated with the narrowing of arteries that supply the brain, a small study has found. Patients who drank pomegranate juice for one year experienced improvements in blood pressure, antioxidant status, and carotid artery thickness (an indicator of the extent of plaque buildup in the arteries).
The study involved 19 people who had atherosclerosis with carotid artery stenosis, a condition in which the arteries that supply the brain thicken and narrow due to the accumulation of plaque. Ten of the participants drank 50 milliliters (about 1.7 ounces) of pomegranate juice daily for one year, while the remaining nine participants did not consume any pomegranate juice. The researchers assessed various aspects of the participants' cardiovascular health before, during, and after the intervention.
They found that several parameters of cardiovascular health improved after one year of pomegranate juice consumption. For example, the participants' carotid artery thickness decreased by up to 30 percent and their blood pressure decreased by 21 percent. In addition, their total antioxidant status increased by 130 percent. Participants who didn’t drink pomegranate juice did not experience these improvements, and in some cases, their cardiovascular measures worsened.
This small study shows that drinking pomegranate juice may improve symptoms associated with narrowing of the arteries. Pomegranates are rich in various bioactive polyphenols, including tannins, ellagic acid, and anthocyanins, that exert potent antioxidant, anti-inflammatory, or cardioprotective effects in humans.
-
A meta-analysis of more than 884 studies (RCTs) finds omega-3, folic acid and CoQ10 among the micronutrients that reduce cardiovascular risk. (2022) www.sciencedaily.comVitamin D Vitamin C Omega-3 Melatonin Magnesium Curcumin Selenium Folate Zinc Polyphenol Carotenoids Cardiovascular Supplements
Omega-3 fatty acids, folic acid, and CoQ10 reduce the risk of cardiovascular disease.
Some nutritional components benefit cardiovascular health, but others have no effect on cardiovascular health or may even harm it, according to a recent study. Nutritional components providing the greatest benefit include omega-3 fatty acids, folic acid, and coenzyme Q10 (CoQ10), a vitamin-like compound produced in the body.
Researchers analyzed the findings of more than 880 trials involving more than 880,000 participants that investigated the benefits of various macronutrients, micronutrients, and bioactive compounds on cardiovascular health.
They found that the nutritional components had varied effects on cardiovascular health. For example, while omega-3 fatty acids, folic acid, and CoQ10 reduced the risk of cardiovascular disease, selenium and vitamins C, D, and E had no effect on the risk for either cardiovascular disease or type 2 diabetes (which often coincides with cardiovascular disease). On the other hand, beta-carotene (a vitamin A precursor) increased the risk of death from all causes. The researchers did not investigate the effects of the various nutritional components in combination versus alone.
This analysis demonstrates that nutrition plays important roles in maintaining cardiovascular and metabolic health and supports the findings of large, epidemiological studies that have demonstrated that adherence to dietary patterns that are rich in omega-3 fatty acids, folic acid, and CoQ10, such as the Mediterranean Diet, for example, improves cardiometabolic health.
-
A flavonoid compound found in onions and citrus fruits improves sperm quality, a recent study in pigs has found. The compound, called taxifolin, also improved the animals' gut microbial makeup.
Researchers fed a group of pigs their regular food supplemented with taxifolin. They fed another group their regular food only. After the animals had been on their respective diets for about two months, the researchers assessed several aspects of the pigs' sperm quality and quantified the types and numbers of the bacteria in the pigs' guts.
They found that the animals that ate the taxifolin-supplemented food exhibited improvements in their sperm motility – an indicator of sperm health – as well as increased sperm production. The type and number of beneficial bacteria in the animals' guts increased, whereas harmful bacteria decreased. Gut bacteria play important roles in overall health.
Taxifolin is a naturally occurring compound found in a variety of edible plants](https://www.spandidos-publications.com/10.3892/mmr.2017.8271). Also known as dihydroquercetin, taxifolin is chemically related to quercetin](https://www.foundmyfitness.com/topics/quercetin). Evidence suggests that taxifolin exerts antioxidant, anti-inflammatory, and anticancer properties.
This study’s findings suggest that taxifolin, a flavonoid compound found in commonly consumed foods, may improve reproductive health. Learn more about flavonoids and other polyphenols in our overview article.
-
Several environmental and lifestyle factors can lower testosterone levels. (2020) www.tandfonline.comVitamin D Diet Obesity Sleep Hormones Stress Magnesium Testosterone Zinc Polyphenol Oxidative Stress
From the publication:
Many factors, including external, environmental and internal factors, influence testosterone levels. The impact of energy intake derived from a testosterone-boosting diet depends on a human body mass. In the case of people of healthy body mass, insufficient energy intake may result in a reduction in testosterone levels in men. The same energy deficit in obese people, may, in turn, result in a neutral or positive impact on the levels of the hormone. Undoubtedly, nutritional deficiency, and particularly of such nutrients as zinc, magnesium, vitamin D, together with low polyphenols intake, affects the HPG [hypothalamic–pituitary–gonadal] axis. The levels of mental and oxidative stress can also adversely impact the axis. The higher the cortisol levels in a human body, or the higher its daily fluctuation, the lower the testosterone levels. What is more, the effect seems to be strengthened by excessive body weight, which is related to the increased oxidative stress affecting the functions of the Leydig cells. Other factors which might disrupt testosterone synthesis may be the length and quality of sleep. Even though the issue is relatively unknown, it appears that both sleep deprivation (shorter than five hours) and low quality of sleep (sleeping with the light on, sleeping during the day, under the influence of alcohol) impact the testosterone levels negatively.
-
Female reproductive steroids provide anti-inflammatory and antibody production suggesting COVID-19 symptom protection. (2020) www.sciencedaily.com
From the article
Female reproductive steroids, estrogen and progesterone and its physiologically active metabolite, allopregnanolone, provide anti-inflammatory functions, reshape competence of immune cells, stimulate antibody production and promote respiratory epithelial cell repair, and inhibit the ACE2 receptor, the door of access for the novel coronavirus (SARS-CoV-2) to infect the organism, suggesting they may protect against COVID-19 symptoms, according to Pinna’s report. The paper is published in Trends in Endocrinology and Metabolism.
Pinna became interested in the role of reproductive steroids in COVID-19 pathology in March when early case reports showed COVID-19 positive pregnant women who had no COVID-19 symptoms, had escalated symptoms – severe enough to require intensive care – immediately after giving birth. The severity of symptoms coincided with a rapid drop of estradiol, progesterone, and allopregnanolone.
“Hormones that help sustain the pregnancy – like progesterone – are 100 times more concentrated in a pregnancy’s third trimester. Estradiol, allopregnanolone, and progesterone all have important anti-inflammatory functions and are involved in resetting the immune system. This suggests that pregnant women became symptomatic, and some were even admitted to the ICU, after delivering their babies because of the rapid drop in these hormones,” said Pinna. “The correlation was really striking.”
According to recent CDC data, in the United States, 38,071 women who were pregnant contracted COVID-19, with 51 deaths – 0.13%. For non-pregnant women, the death toll is 2%.
“Pregnant women are 15 times less likely to die from COVID than other women,” said Pinna.
Additionally, nutrition may also play a role when diets are enriched with phytoestrogens – plant-produced ‘estrogen’ – (in foods such as soybeans, lentils, oats). Phytoestrogens have the ability to bind directly to human estrogen receptors, or can be converted to estradiol by the microbiome.
-
How cranberries could improve memory and ward off dementia www.sciencedaily.com
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.
-
Reservatrol strengthens tight-junction proteins in the blood-brain barrier and protects against oxidized LDL academic.oup.com
Abstract
“Cerebrovascular endothelial cells (CEC) comprise the blood-brain barrier (BBB). In a previous study, we showed that oxidized LDL (oxLDL) can induce apoptosis of mouse CEC. Resveratrol possesses chemopreventive potential. This study aimed to evaluate the effects of resveratrol on oxLDL-induced insults to mouse CEC and its possible mechanisms. Exposure of mouse CEC to 200 μmol/L oxLDL for 1 h did not cause cell death but significantly altered the permeability and transendothelial electrical resistance of the cell monolayer. However, resveratrol completely normalized such injury. As for the mechanisms, resveratrol completely protected oxLDL-induced disruption of F-actin and microtubule cytoskeletons as well as occludin and zona occludens-1 (ZO-1) tight junctions. The oxLDL-induced decreases in the mitochondrial membrane potential and intracellular ATP levels were normalized by resveratrol. Exposure of mouse CEC to 200 μmol/L oxLDL for 24 h elevated oxidative stress and simultaneously induced cell apoptosis. However, resveratrol partially protected against oxLDL-induced CEC apoptosis. The oxLDL-induced alterations in levels of Bcl-2, Bax, and cytochrome c were completely normalized by resveratrol. Consequently, resveratrol partially decreased oxLDL-induced activation of caspases-9 and -3. Therefore, in this study, we show that resveratrol can protect against oxLDL-induced damage of the BBB through protecting disruption of the tight junction structure and apoptotic insults to CEC.”
-
Combined anthocyanins and bromelain supplement improves endothelial function and skeletal muscle oxygenation status in adults: a double-blind placebo- pubmed.ncbi.nlm.nih.gov
A combined pineapple and berry supplement improves vascular function.
Cardiovascular disease is a major public health threat, with deaths from cardiovascular diseases expected to reach 23 million by 2030. A diet rich in fruits and vegetables is known to reduce heart disease risk, in part due to the antioxidant and anti-inflammatory compounds provided by the diet that reduce oxidative stress and improve vascular function. Findings from a new report show that a supplement containing bromelain and anthocyanin antioxidants improves blood vessel function and muscle oxygenation.
Bromelain is a compound found in pineapple that breaks down protein, called a protease. In the kitchen, bromelain is used to tenderize meat, but in the medical field, topically applied bromelain is an approved treatment to promote wound healing. Research shows that bromelain has anti-inflammatory and antithrombotic properties that may improve vascular function and reduce cardiovascular disease risk. Anthocyanins are blue- and purple-colored pigments found in fruits and vegetables that absorb free radicals in the blood stream, reduce inflammation, and reduce blood pressure.
The authors recruited 18 healthy adults who engaged in regular recreational physical activity and randomly assigned them to receive either a placebo or a supplement containing 465 milligrams of hawthorn extract (source of anthocyanins), 480 milligrams of tart cherry powder (source of anthocyanins), and 400 milligrams of bromelain. One hour after the participants consumed the treatment, the researchers measured heart rate, blood pressure, flow mediated dilation (a measure of endothelial function), muscle oxygenation, and muscle fatigue and collected a blood sample. The participants returned two weeks after their first visit and repeated the same testing after receiving the treatment (placebo or anthocyanin+bromelain) they did not receive the first time.
The anthocyanin+bromelain supplement led to a marked increase in total serum antioxidant capacity. Participants consuming the active supplement experienced a statistically significant increase in flow mediated dilation and reduction in systolic blood pressure. The anthocyanin+bromelain supplement increased muscle oxygenation during a leg extension exercise, but did not affect diastolic blood pressure, resting heart tate, or muscle fatigue.
These results show that supplementation with anthocyanins and bromelain acutely improves vascular function in healthy adults; however, additional research is needed to understand the long-term effects of supplementation on cardiovascular disease risk.
-
Berries are a colorful and nutritious food containing many types of bioactive compounds, including anthocyanins, a type of polyphenol with blue/purple pigment. Anthocyanins from berries such as blueberries, black raspberries, chokeberries, and bilberries are recognized for their ability to protect against cardiovascular and neurodegenerative diseases. Findings of a recent systematic review provide robust evidence demonstrating the beneficial effects of anthocyanins on cognitive performance and cardiovascular disease risk factors.
Cognitive performance refers to a set of mental skills such as attention, memory, psychomotor speed, and executive function that develop through early adulthood and then decline in old age. As the world population ages, cognitive impairment is a growing public health concern that requires targeted strategies for prevention. Impaired vascular function, a factor that contributes to poor brain health and cognitive performance with age, may be modifiable with diet and lifestyle changes. Previous research has demonstrated that eating blueberries improves vascular function (measured with flow mediated dilation) in healthy men; but further research is needed to understand the molecular mechanisms.
Polyphenols are a large class of bioactive compounds found in fruits, vegetables, teas, coffee, wine, and olive oil with antioxidant properties because of their many phenol rings. Due to their special cyclized electron structure, phenols capture and neutralize oxygen radicals and reflect light at unique wavelengths, giving them vibrant color. A previous systematic review of research on blueberries found good evidence to support their ability to improve memory, executive function, and psychomotor function in adults with mild cognitive impairment; however, less research has focused on total anthocyanins in the diet.
The authors searched for studies investigating the six most anthocyanin-rich fruits (i.e., blackcurrant, black raspberry, blueberry, bilberry, chokeberry, and elderberry). They selected all randomized, placebo-controlled intervention studies in humans that investigated at least one cardiometabolic or cognitive performance parameter for inclusion in their analysis. Although methods of data collection used among the studies widely varied, the authors extracted data from their selected studies and combined it into clusters for comparison.
The authors of the review investigated the effects of berry anthocyanin supplementation on memory in 14 studies with mostly older adult participants, revealing improved memory, especially verbal memory, and symptoms of mild cognitive impairment. In young and middle-aged adults, multiple studies found improvements in attention and psychomotor speed with anthocyanin supplementation. The research revealed that short-term berry supplementation was sufficient to produce benefits on attention and psychomotor speed, but long-term supplementation was best for memory.
All studies that measured flow mediated dilation, the most accurate measure of vascular function, found an improvement following anthocyanin supplementation except for one study in smokers. Long-term berry supplementation also lowered blood pressure in adults at high risk for cardiometabolic disease, but not healthy adults, indicating that individual characteristics alter a person’s response to anthocyanin supplementation.
This large systematic review provides robust evidence for the beneficial effects of berry anthocyanins on multiple markers of cognitive and cardiovascular performance.
-
Extra virgin olive oil high in polyphenols improves antioxidant status in adults. pubmed.ncbi.nlm.nih.gov
Cardiovascular disease is facilitated by chronic oxidative stress and vascular inflammation. Antioxidant compounds such as the polyphenols found in olive oil may reduce cardiovascular disease risk by resolving oxidative stress and inflammation. Findings of a recent report demonstrate the ability of high-polyphenol olive oil to reduce oxidative stress, especially in adults at high risk for cardiometabolic diseases.
Oxidative compounds in the bloodstream damage the cells that line blood vessels, called endothelial cells. Increased concentrations of adhesion molecules, proinflammatory cytokines such as interleukin-6 and C-reactive protein, and oxidized low-density lipoprotein (LDL) cholesterol contribute to endothelial dysfunction and the generation of atherosclerotic plaques. Increased concentrations of antioxidant enzymes in the blood decrease oxidative damage and reduce the risk of chronic diseases such as cardiovascular disease.
The authors recruited 50 participants (between ages 18 and 75 years) who were not consuming dietary supplements or high amounts of olive oil (greater than one tablespoon per day). They assigned participants to consume about four tablespoons per day of either high-polyphenol or low-polyphenol olive oil for three weeks. After a two-week wash-out period, participants consumed the opposite treatment for three weeks. The researchers measured total antioxidant capacity and plasma concentrations of oxidized LDL cholesterol and C-reactive protein (a marker of inflammation) before and after each treatment.
High-polyphenol olive oil consumption significantly reduced oxidized LDL cholesterol and increased total antioxidant capacity. These changes were greatest in participants who were at high risk for cardiometabolic disease due to their high waist circumference. There were no significant statistical differences between the high-polyphenol and low-polyphenol olive oil treatments.
Consumption of high-polyphenol olive oil increased antioxidant capacity and reduced markers of inflammation and oxidative stress, especially in participants with high cardiometabolic risk.
-
Polyphenols prevent leaky gut syndrome. www.eurekalert.org
Intestinal hyper-permeability, often referred to as “leaky gut,” is a condition in which the gaps between the cells that line the gut expand. These gaps allow pathogens such as bacteria or endotoxins (i.e., lipopolysaccharide, a major component of the cell membrane of gram-negative bacteria) to leak through the intestinal wall and pass directly into the bloodstream. Leaky gut is common among older adults, putting them at risk for many acute and chronic diseases. Findings from a recent study suggest that a polyphenol-rich diet reduces the risk of leaky gut in older adults.
Polyphenols are bioactive compounds present in fruits and vegetables. Evidence suggests that polyphenols influence the composition and function of the gut microbiota, have beneficial effects on gut metabolism and immunity, and exert anti-inflammatory properties.
The randomized, controlled, crossover trial involved 51 adults (60 years and older) who were living in a residential care facility and had elevated zonulin, a biomarker of impaired gut barrier function. Half of the participants followed their typical diet, but they substituted some items with polyphenol-rich foods while maintaining the same caloric and nutrient intake for eight weeks. The other half consumed their normal diet with no substitutions. After eight weeks, the two groups switched to the opposite diet. Participants underwent physical exams before, during, and after the study and provided blood and fecal samples for analysis.
The polyphenol-rich foods included berries, blood oranges (and their juice), pomegranate juice, green tea, apples, and dark chocolate. On average, participants who ate the polyphenol-rich diet consumed 1391 milligrams of polyphenols per day, while those who ate a typical diet consumed only 812 milligrams of polyphenols per day. The study investigators noted that participants on the polyphenol-rich diet had higher levels of beneficial gut bacteria than those on the typical diet. They also noted that metabolites from cocoa and green tea polyphenols were associated with having higher levels of butyrate (a short-chain fatty acid that benefits gut health) and lower levels of zonulin. These changes improved overall gut health in the study participants, but the participants' age, baseline zonulin levels, and numbers of beneficial gut bacteria, especially those of the Porphyromonadaceae family, influenced the extent of benefit.
These findings suggest that polyphenol-rich foods improve gut health and reduce the risk of leaky gut in older adults. They also underscore the importance of developing dietary habits that promote consumption of polyphenol-rich foods throughout the lifespan. For an easy way to get more polyphenols in your diet, try this polyphenol-rich smoothie.
-
Eating spices reduces chronic inflammation. academic.oup.com
Obesity causes chronic inflammation, which promotes atherosclerosis and cardiovascular disease. Previous research suggests that spices such as cinnamon, cumin, and ginger exert short-term anti-inflammatory effects; however, studies with longer durations are needed to confirm these findings. Authors of a recent study found that four weeks of spice consumption reduced inflammation and altered monocyte function in adults at risk of cardiometabolic disease.
Monocytes are white blood cells that respond to infection by promoting inflammation. Obesity and dyslipidemia cause inappropriate activation of monocytes, promoting chronic inflammation in the arteries. Pro-inflammatory monocytes carrying excess lipids, called foam cells, accumulate in arterial walls, narrowing the arteries and restricting blood flow. Consuming spices that contain anti-inflammatory bioactive compounds may help reduce cardiovascular disease risk.
The authors recruited 71 participants and assigned them to consume a standard American diet with added spices in three doses: low (a dash), medium (a quarter teaspoon), or high (a half teaspoon). Participants consumed each dose of spices for four weeks and completed the doses in random order. The spice mixture contained the most common spices used in the United States, the most abundant of which were cinnamon, coriander, ginger, cumin, and parsley. Participants provided blood samples at multiple points throughout the study. Finally, the investigators isolated monocytes from the participants’ blood and exposed the cells to bacterial endotoxin in order to promote inflammation.
Compared to baseline, participants had lower fasting serum levels of the pro-inflammatory cytokine interleukin-6 following four weeks of the medium dose spice blend. The monocytes from these participants also secreted less interleukin-6 when challenged with bacterial endotoxin. Participants consuming the medium and high spice blends had fewer foam cells and more conventional monocytes than participants consuming the low spice blend.
The authors concluded that spices reduced fasting inflammation and altered monocyte behavior. They did not know why the medium dose was more effective in reducing inflammation than the high dose, but they hypothesized that the high dose of spices may have contained such a high level of polyphenols that it promoted oxidative stress. More research is needed to test this hypothesis. This study was funded by the McCormick Science Institute.
-
Daily apple consumption decreases multiple markers of obesity-associated inflammation. academic.oup.com
Obesity is characterized by chronic low-grade inflammation, which contributes to the development of cardiovascular disease. While processed foods and beverages high in saturated fats and simple sugars are associated with a higher risk of cardiovascular disease, diets rich in plant-based foods, including fruits, are associated with a lower risk. Findings of a recent report detail the effects of daily apple consumption on inflammation, endotoxemia, and metabolism.
Causes of obesity-associated inflammation include leaky gut, a condition where the intestinal barrier is compromised, leading to increased levels of bacterial endotoxin (toxins that are released when bacteria die) in the bloodstream (called endotoxemia). This increase in endotoxin levels activates white blood cells to secrete pro-inflammatory cytokines such as interleukin (IL)-6 and IL-17. Plant foods such as apples are beneficial for people with obesity because they are rich in bioactive compounds that decrease inflammation and dietary fibers that strengthen the gut barrier.
The researchers recruited 46 participants with overweight and obesity and directed them to avoid foods and beverages rich in polyphenols and/or dietary fibers (e.g., coffee, vegetables, grains, beans, and red/purple/blue fruits) for two weeks. Next, they assigned half of the participants to consume three Gala apples per day for six weeks or to avoid apples. Both groups continued to eat a diet with limited polyphenols and dietary fibers. Participants provided blood samples for the collection of white blood cells and measurement of pro-inflammatory cytokines. After isolating the white blood cells, the researchers stimulated them with endotoxin and measured their response.
Apple consumption decreased plasma C-reactive protein (a pro-inflammatory cytokine) by 17 percent, IL-6 by 12 percent, and endotoxin-binding protein by 20 percent compared with no apple consumption. White blood cells from participants who consumed apples secreted 28 percent less IL-6 and 11 percent less IL-17. While apple consumption increased total antioxidant capacity in blood by 10 percent, it had no effect on cardiovascular disease markers.
These findings suggest that six weeks of daily Gala apple consumption helped mitigate inflammation in those consuming a diet low in polyphenols and fiber, a common feature of the Western diet pattern. Apple consumption may decrease cardiovascular disease risk in those with obesity, even without weight loss.
-
Leaky gut decreases the beneficial effects of dietary polyphenol compounds in older adults. pubs.acs.org
Polyphenols are a group of bioactive compounds found in plant-based foods that have beneficial effects in the body. Bacteria in the human gut break down polyphenols into smaller compounds to increase their absorption. Authors of a recent study aimed to measure the relationship between gut health and the absorption of beneficial polyphenols in older adults.
As humans age, the quality of the population of microbes that comprise the gut microbiota decreases, leading to poor gut barrier integrity and causing contents of the gut to leak into the bloodstream, a condition commonly referred to as “leaky gut.” This leaking of toxins, viruses, and bacteria is associated with increased inflammation and disease risk. In addition to causing a leaky gut, poor microbiota quality may decrease the beneficial effects of polyphenol-rich plant foods.
The authors tested the effects of a polyphenol-rich diet in 51 adults (greater than 60 years of age) residing in an assisted living setting. Participants consumed either the normal menu prepared by their facility for eight weeks or a menu that included three servings of polyphenol-rich fruits, teas, and cocoa for eight weeks and then switched to the opposite diet. The researchers collected blood samples to measure serum zonulin, a marker of gut barrier integrity, and urine samples to analyze polyphenol metabolite content before and after each diet period.
Overall, serum zonulin decreased following eight weeks of a polyphenol-rich diet, meaning that gut barrier integrity improved. Participants who started the trial with better gut barrier integrity had a significantly greater increase in blood levels of polyphenol metabolites compared to participants with leakier guts. The metabolites found in the group with greater gut barrier integrity were microbial-derived, suggesting these participants had a more health-promoting gut microbiota.
Based on these results, the authors hypothesize that changes in the gut microbiota damage the gut barrier and cause a subsequent reduction in the absorption of dietary polyphenol compounds. They conclude that personalized diet plans could be effective for managing leaky gut in older adults.
-
Drinking oolong tea promotes fat burning. www.eurekalert.org
Tea from the leaves of the Camelia sinensis plant is one of the most widely consumed beverages worldwide. Its consumption is associated with a variety of beneficial health effects. Findings from a recent study suggest that oolong tea consumption promotes weight loss.
Many types of tea from Camelia sinensis exist, but they are generally classified as green, oolong, or black. The differences in the three types arise during processing, where they undergo various degrees of oxidation. Green tea is unoxidized; oolong tea is partially oxidized; and black tea is fully oxidized. Tea contains several bioactive compounds, including catechins and caffeine. Catechins are polyphenolic compounds that exert antioxidant properties. Caffeine is a potent stimulant.
The intervention study involved 12 healthy non-obese men between the ages of 20 and 56 years. The participants consumed one of three beverages at breakfast and lunch for three 14-day sessions: oolong tea containing 51.8 milligrams of caffeine and 48.5 milligrams of catechins; a beverage containing 51.8 milligrams of caffeine; or a placebo beverage. A washout period of about two weeks separated each session. The men drank no other beverages containing caffeine or alcohol during the study period. They underwent 24-hour indirect calorimetry to monitor their metabolism and polysomnographic sleep recording to gauge their sleep quality.
The authors of the study found that fat oxidation increased by roughly 20 percent when the participants drank the oolong tea or pure caffeine beverage, but not when they drank the placebo beverage. The effects of consuming oolong tea continued to a greater degree while the participants were asleep. Neither of the caffeine-containing beverages promoted an increase in the men’s energy expenditure, and none of the men exhibited alterations in sleep quality, suggesting that they developed a tolerance to the stimulatory effects of caffeine.
These findings suggest that oolong tea stimulates fat oxidation, especially during the overnight fast.
-
Coffee consumption reduces risk of metastasis and death among people with colorectal cancer. www.sciencedaily.com
Colorectal cancer, the third most common cancer among men and women living in the United States, will likely claim the lives of more than 50,000 people this year. The cancer often metastasizes, or spreads, to other sites, particularly the lungs, liver, or brain, decreasing a person’s chances of survival from the disease. Findings from a new study suggest that drinking coffee reduces the risk of colorectal cancer metastasis.
Coffee contains a multitude of polyphenolic compounds that appear to exert beneficial health effects, including quercetin, chlorogenic acid, and others. Drinking coffee is linked with reduced disease burden and increased lifespan, possibly due to coffee’s ability to induce autophagy. Other evidence suggests that coffee’s beneficial effects arise from its antioxidant and anti-inflammatory effects as well as its capacity to maintain healthy blood insulin levels – a critical aspect in colorectal cancer outcomes.
The prospective observational cohort study involved more than 1,100 people with colorectal cancer who were enrolled in a larger randomized clinical trial investigating the efficacy of chemotherapy drugs. The study participants, who were between the ages of 51 and 67 years, provided information about what they ate and drank using a food frequency questionnaire.
Over a period of approximately five years, 93 percent of the participants experienced disease progression, or they died. Participants who drank coffee were less likely to die than those who did not, and this association was dose dependent. For example, those who drank two to three cups per day were 18 percent less likely to die, and those who drank four cups per day were 36 percent less likely to die. These associations held true regardless of whether they drank caffeinated or decaffeinated coffee.
These findings suggest that drinking coffee reduces the risk of disease progression and death in people with advanced or metastatic colorectal cancer. A key player in suppression of tumor growth is autophagy, a biological process that inhibits cancer-cell survival and induces cell death. Learn more about how coffee induces autophagy in this clip featuring autophagy expert, Dr. Guido Kroemer.
-
A compound in blueberries dampens the body's immune response and reduces inflammation. www.eurekalert.org
A critical component of the body’s immune response to pathogens, damaged cells, or irritants is inflammation. Chronic inflammation, however, can promote the development of chronic inflammatory disorders. Findings from a new study suggest that pterostilbene, a polyphenolic compound present in blueberries, can reduce the risk of developing chronic inflammatory disorders by altering the activity of dendritic cells and T cells.
Pterostilbene is a polyphenolic compound that demonstrates antioxidant, anti-inflammatory, and anti-cancer properties, as well as many other beneficial effects. Closely related to resveratrol, pterostilbene is found in blueberries and a tropical tree commonly known as heartwood.
Dendritic cells and T cells are key elements of the body’s immune responses. Dendritic cells initiate the adaptive immune response, which in turn activates T cells. Activated T cells produce interleukin (IL)‐2 to facilitate their proliferation and subsequent differentiation into various helper T cells, including Th1, Th2, Th17, or regulatory T cells (Tregs). Over-activation of Th1, Th2, and Th17 cells can lead to immune disorders, such as inflammatory bowel diseases, atopic dermatitis, and psoriasis. Conversely, Treg cells produce IL‐10, an anti-inflammatory protein, to reduce inflammation and impair disease progression.
The authors of the study used an in vitro cell culture system to assess the effects of pterostilbene and related compounds on immune cell response. They looked at the activity of dendritic cells and T cells in the presence or absence of the compounds to evaluate their immunosuppressive activity.
They found that pterostilbene suppressed T cell‐proliferation and decreased the Th1 and Th17 population in a dose‐dependent manner but did not affect the population of Th2 cells. The presence of pterostilbene markedly increased Treg differentiation was markedly increased.
Then the authors of the study assessed the effects of pterostilbene on mice that had ulcerative colitis, a type of inflammatory bowel disease. They gave the mice pterostilbene in their drinking water for a week. They found that the mice that consumed the pterostilbene had fewer symptoms associated with their disease and lower levels of tumor necrosis factor-alpha, a type of pro-inflammatory protein.
Taken together, these findings indicate that pterostilbene exhibits immunosuppressive activity by directing T cell differentiation toward Treg cells rather than Th1 and Th17 cells. Furthermore, oral consumption of pterostilbene may reduce colonic inflammation associated with an inflammatory bowel disease.
-
Drinking tea at least three times a week is linked with a longer and healthier life. www.eurekalert.org
Tea is one of the most commonly consumed beverages in the world, especially in Asian countries. It is rich in tannins, catechins, and other polyphenolic compounds that elicit beneficial health effects associated with reduced risk of cardiovascular disease, cancer, and type 2 diabetes. A recent study suggests that habitual tea drinkers may live longer than non-habitual drinkers.
The prospective cohort study involved more than 100,000 adults living in China who completed questionnaires about their tea consumption. Those who drank tea three or more times per week were classified as habitual tea drinkers, while those who drank tea fewer than three times per week were classified as non-habitual tea drinkers. Hospital records and death certificates provided data about mortality rates and causes among the participants during a follow-up period of approximately eight years, on average.
The findings revealed that habitual tea drinkers were 22 percent less likely to die heart disease and stroke and were 15 percent less likely to die from all causes of premature death compared to non-habitual drinkers. The habitual tea drinkers were also more likely to live longer (about one year and three months) and cardiovascular disease-free (nearly one and one-half years) than non-habitual drinkers.
These findings underscore the role of diet in improving healthspan and longevity and suggest that minor modifications can markedly influence disease risk.
-
Low-density lipoproteins (LDL) are formed in the liver and transport lipid molecules to cells. Often referred to as the “bad cholesterol,” LDL can drive cardiovascular disease if it becomes oxidized within the walls of arteries. LDL particles exist in different sizes, ranging from large, “fluffy” molecules to small, dense molecules. Scientific evidence suggests that small, dense LDL particles are more susceptible to oxidative modification. Findings from a new study suggest that diets that include avocados may help reduce LDL oxidation.
The randomized, controlled trial involved 45 men and women between the ages of 21 and 70 years. The participants, who were overweight or obese and had elevated LDL cholesterol levels, followed three different diets for a period of five weeks each: a low-fat diet, a medium-fat diet with avocado, and a medium-fat diet with oleic acids (found in olive and canola oils).
Avocados are rich sources of monounsaturated fatty acids. They also contain polyphenols and lutein, a carotenoid compound that quenches and scavenges reactive oxygen species.
After five weeks on the diet with avocado, the participants' levels of oxidized LDL cholesterol (especially the small, dense LDL cholesterol particles) were lower than their baseline levels or after completing the low- or moderate-fat diets. Concentrations of large, fluffy LDL particles were unchanged. Participants also had higher levels of lutein. These findings suggest that consuming avocados as part of an overall heart-healthy diet may reduce the risk of developing cardiovascular disease.
-
A new study by my mentor Dr. Bruce Ames proposes that 10 known compounds be classified as potential longevity vitamins due to their interaction with proteins that protect against diseases of aging. The concept is based on the Triage Theory, which classifies proteins and enzymes as either survival proteins, needed for survival and reproduction, or longevity proteins, which protect against future damage and are sacrificed in case of vitamin shortage, leading to an acceleration of insidious diseases of aging.
These putative “longevity vitamins” include: ergothioneine (a fungal antioxidant found in mushrooms), queuine (a bacterial metabolite found in the gut), PQQ (a bacterial metabolite in soil that is taken up by plants ), lutein and zeaxanthin (concentrated in leafy greens), lycopene (found in tomatoes), alpha- and beta-carotene, and cryptoxanthin (all plant antioxidant carotenoids), astaxanthin (a marine carotenoid found in salmon and krill), and taurine (found in meat).
-
Reaction time and mood were improved in young individuals that consumed blackcurrant berry drink with 500 mg of polyphenols compared to placebo. www.tandfonline.com
Reaction time and mood were improved in young individuals that consumed blackcurrant berry drink with 500 mg of polyphenols compared to placebo in a small pilot randomized controlled trial. EEG data also showed the blackcurrant drink changed brainwave activity.
This was a small trial with a crossover study design, which means each person serves as their own control. Both the blackcurrant drink and the placebo drink had 6.98 g of sugar (glucose +fructose). They also both had the same amount of vitamin C…the only difference was that the placebo drink lacked the 500 mg of polyphenols.
Conclusions cannot be made from this trial alone since it was a small pilot trial. However, there is a growing body of clinical trials showing polyphenols positively affect brain function in both young and old individuals.
I understand that it would not be possible to make a placebo drink if the whole fruit was used…but I think it is better to consume the berries with the fiber which changes the way sugar is metabolized and also has benefits for the gut microbiome.
More reading: https://www.ncbi.nlm.nih.gov/pubmed/26690214?dopt=Abstract