Green Tea Tag

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

Brain Aging Green Tea Dementia Polyphenol

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

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

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

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

A daily cup of coffee could reduce your risk of heart disease and diabetes by half. academic.oup.com

Sleep Heart Disease Diabetes Biomarkers Coffee Green Tea Caffeine Stroke Cardiovascular

Drinking your daily cup of coffee or tea might do more than give you a boost—it could lower your risk of developing multiple serious cardiometabolic conditions simultaneously, like diabetes, heart disease, or stroke. A recent study found that moderate coffee or caffeine consumption may cut your risk of cardiometabolic multimorbidity by as much as 50%.

Researchers analyzed data from more than 172,000 participants enrolled in the UK Biobank who had no cardiometabolic diseases at the start. Participants reported their coffee, tea, and caffeine consumption; about half provided blood samples for metabolic marker analysis.

They found that people who drank about three cups of coffee daily (or consumed 200 to 300 milligrams of caffeine daily) were 40% to 50% less likely to develop multiple cardiometabolic diseases than those who drank little or no caffeine. They also discovered that specific blood markers, such as certain lipid components, were linked to coffee and caffeine consumption and a lower risk of cardiometabolic conditions.

These findings suggest that moderate coffee or caffeine intake reduces the risk of developing cardiometabolic diseases but also slows their progression if they occur. Other evidence points to the many health benefits associated with coffee and caffeine, but it’s crucial to remember their effects on sleep. Learn more in this Aliquot featuring Drs. Guido Kroemer, Satchin Panda, Elissa Epel, Matthew Walker, and Rhonda Patrick

Polyphenols in tea may reduce symptoms and progression of Parkinson's disease. pubmed.ncbi.nlm.nih.gov

Parkinson's Green Tea Neurodegeneration Polyphenol

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.

Adding sugar to tea or coffee increases the risk of premature death by up to 11 percent. www.ncbi.nlm.nih.gov

Coffee Green Tea Mortality Sugar

Tea and coffee provide many health benefits, but for some people, the beverages are often a source of added sugar. A recent study found that adding sugar to tea or coffee increased the risk of premature death by 6 percent; adding sugar to coffee alone increased the risk by 11 percent.

Researchers tracked the health of more than 2,900 men enrolled in the Copenhagen Male Study over thirty years. The men provided information about their tea and coffee consumption and whether they added sugar to these beverages.

The researchers found that about a third of the men added sugar to their tea or coffee. Those who did were about 6 percent more likely to die prematurely from any cause than those who didn’t add sugar. Adding sugar to coffee alone increased the risk of dying early by about 11 percent.

The findings from this large, epidemiological study suggest that adding sugar to tea or coffee increases the risk of dying early, negating some of the longevity benefits often ascribed to the two beverages.

Sugars are natural components of the human diet, found in fruits, vegetables, and dairy products. However, the refined sugar typically added to beverages like tea or coffee is a highly processed product derived from sugar cane or sugar beets. It undergoes rapid metabolism in the body, causing insulin and blood sugar levels to skyrocket. Nearly 75 percent of adults in the US get about one-tenth of their daily calories from added, refined sugar. Learn more about the effects of sugar on human health in this episode featuring Dr. Rhonda Patrick.

Polyphenols found in tea and coffee may reduce the risk of diabetes. pubmed.ncbi.nlm.nih.gov

Diabetes Insulin Resistance Coffee Green Tea Polyphenol

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.

Green tea catechins, resveratrol, curcumin and metformin reduced amyloid plaque formation in herpes-induced Alzheimer's disease tissue models. (2022) neurosciencenews.com

Alzheimer's Green Tea Curcumin Resveratrol Metformin

From the article:

They have tested 21 different compounds in Alzheimer’s-afflicted neural cells in the lab, measuring the compounds’ effect on the growth of sticky beta amyloid plaques. These plaques develop in the brains of people with Alzheimer’s.

[…]

The initial screening was done in simpler models, and compounds that had a positive effect were then tested in the 3D neural tissue model. That model is created using a nonreactive silk sponge seeded with human skin cells that, through genetic reprogramming, are converted into neural stem cell progenitors.

Those cells grow and populate the sponge, “which allows for 3D network formation of neurons similar to what you’d see in the human brain,” Cairns says.

The initial screen found five compounds had “really robust prevention of these plaques,” she says. In addition to the green tea compounds and resveratrol, they found curcumin from turmeric, the diabetic medication Metformin, and a compound called citicoline prevented plaques from forming and did not have anti-viral effects.

View full publication

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

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

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

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

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

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

Drinking tea may reduce the risk of cardiovascular disease and premature death. journals.sagepub.com

Green Tea Cardiovascular

Cardiovascular disease is the number one killer worldwide, claiming the lives of nearly 18 million people each year. Health experts estimate that more than 75 percent of all cardiovascular diseases are preventable through healthy lifestyle habits. Findings from a 2020 study suggest that drinking tea is a healthy lifestyle habit that reduces the risk of cardiovascular-related disease and death and all causes of premature death.

Teas – black, green, or white – are among the most popular beverages in the world. Their consumption is linked to a wide range of health benefits, including lower blood pressure, improved blood sugar regulation, and greater weight loss in people with obesity.

The researchers drew on data collected during the China-PAR project, an ongoing study of cardiovascular and metabolic disease risk among three cohorts of adults living in China. They used data from more than 100,000 participants to investigate links between tea consumption and cardiovascular-related disease and death, as well as all causes of premature death. Their analysis accounted for a wide range of demographic and lifestyle habits, including age, sex, family history, education, smoking, and dietary patterns, among others.

They found that roughly one-third of the participants were regular tea drinkers, consuming three or more tea drinks per week. Regular tea drinkers were 22 percent less likely to die from cardiovascular disease and 15 percent less likely to die from all causes of premature death. Drinking tea also appeared to extend healthspan – the number of years lived disease-free. Regular tea drinkers lived 1.41 years longer free of cardiovascular disease and had 1.26 years longer life expectancy at the index age of 50 years compared to non-drinkers.

These findings suggest that regular tea consumption reduces the risk of cardiovascular-related disease and death and all causes of premature death. Tea drinking may also extend the number of years a person lives disease-free.

Teas are rich in polyphenols – a broad class of bioactive plant-based compounds that confer beneficial properties to humans. Learn more about polyphenols in our overview article.

Link to study abstract.

Polyphenols prevent leaky gut syndrome. www.eurekalert.org

Gut Microbiome Green Tea Polyphenol Intestinal Permeability Lipopolysaccharide

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.

Link to full publication.

Higher caffeine consumption increases glaucoma risk in genetically susceptible people. www.mountsinai.org

Coffee Green Tea Eyes

Consuming caffeinated beverages such as tea and coffee is a common practice in many cultures around the world. While tea and coffee contain beneficial plant compounds such as antioxidants that lower the risk of disease, the caffeine in tea and coffee increases blood pressure, which may contribute to hypertension-related diseases such as chronic kidney disease, stroke, and glaucoma. Findings of a recent report detail the relationship between caffeine consumption and glaucoma risk.

In glaucoma, the pressure of fluid inside the eye (called intraocular pressure) increases, damaging the optic nerve at the back of the eye. Over time, as damage to the optic nerve accumulates, the risk of vision loss increases. While previous research investigating acute caffeine intake has demonstrated an increase in intraocular pressure following caffeine conumption, research on chronic caffeine consumption has found no relationship between caffeine intake and glaucoma risk. The risk of habitual caffeine consumption may depend on genetics, as other research has found a positive relationship between habitual caffeine intake and glaucoma in those with genetic susceptibility.

The authors conducted a genome-wide association study, a type of study in which researchers look for associations between gene variations called single-nucleotide polymorphisms and disease prevalence. The authors collected genetic data, clinical data measuring intraocular eye pressure, and self-reported dietary data regarding coffee and tea consumption from more than 100,000 participants enrolled in the United Kingdom Biobank study. Next, the authors calculated each participant’s polygenic risk score, which estimates an individual’s genetic susceptibility to a specific disease. Finally, the authors performed a Mendelian randomization analysis, which measures variation in specific genes in order to examine the cause and effect relationship between environmental factors (coffee consumption and total caffeine intake) and disease (glaucoma) risk.

The data revealed that greater total caffeine intake was associated with lower intraocular pressure, but the relationship was not statistically significant. Participants consuming the most caffeine (232 milligrams of caffeine per day or more, the amount in 20 ounces of coffee) had a reduction in intraocular pressure of 0.10 millimeters of mercury (the unit used for blood and eye pressure) compared to participants with the lowest caffeine intake (less than 87 milligrams per day, the amount in one 8-ounce cup of coffee).

Among participants with a high polygenic risk score for glaucoma, however, consuming greater amounts of caffeine (more than 480 milligrams per day, the amount in 42 ounces of coffee) was significantly associated with an increase in intraocular pressure of 0.35 millimeters of mercury compared to participants consuming the least caffeine (less than 80 milligrams per day, the amount in 7 ounces of coffee). While the authors found no overall relationship between caffeine intake and glaucoma, participants with high polygenic risk scores consuming 321 milligrams of caffeine per day or more were four times more likely to develop glaucoma.

The authors concluded that they found no relationship between caffeine consumption and glaucoma risk in the general population. However, their analyses revealed a significant relationship between higher caffeine consumption and increased risk of high intraocular pressure and glaucoma incidence in those with the highest genetic susceptibility for the disease.

Link to full report.

Drinking oolong tea promotes fat burning. www.eurekalert.org

Obesity Green Tea Polyphenol

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.

Link to full study.

Drinking tea at least three times a week is linked with a longer and healthier life. www.eurekalert.org

Aging Green Tea Polyphenol

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.

Link to full study.

Adding vitamin C to green tea increases the bioavailability of the antioxidants present in the green tea. www.sciencedaily.com

Vitamin C Green Tea Vitamin A Antioxidant

Catechins are bioactive compounds present in green tea. One well-known catechin, epigallocatechin gallate (EGCG), is a potent scavenger of reactive oxygen species and has demonstrated antioxidant, anti-inflammatory, and anticarcinogenic properties in both clinical and in vitro studies. Some evidence suggests that adding vitamin C to green tea might increase the bioavailability of the catechins present in green tea.

Consumers of green tea commonly add milk, lemon, or other substances to their tea. To assess the impact that these additives have on catechin bioavailability, the authors of the study added varying quantities of citric acid, BHT and EDTA (common preservatives), ascorbic acid (vitamin C), milk (cow’s, soy, and rice), and citrus juice (orange, grapefruit, lemon, and lime) to prepared tea. Then they subjected the tea formulations to simulated digestive processes and measured the amount of catechins they recovered.

They found that overall, green tea catechin recovery was poor, with more than 80 percent loss of catechins during digestion. Adding milk to tea increased catechin recovery considerably, but the greatest improvements were observed with the addition of vitamin C or citrus juices, the latter of which increased recovery to 98 percent.

Citrus juices contain bioactive compounds that might influence catechin recovery, but they are also rich in vitamin C. These findings suggest that consumption of green tea with vitamin C, especially in conjunction with other bioactive compounds in citrus juices, increases the recovery of the beneficial components present in the tea.

Link to study abstract.

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