Polyphenols, abundant in foods like berries, tea, and cocoa, may slow aging by reducing oxidative stress and inflammation. Studies show 300-500 mg daily from sources like green tea or dark chocolate (70%+ cocoa) improves skin elasticity and supports heart health.
Antioxidant Activity
Polyphenols are bioactive compounds found in plant-based foods and supplements, inflammation, and age-related chronic diseases. For instance, a clinical trial involving 120 subjects aged between 40 and 65 years showed that the intake of 700 mg of grape seed polyphenol extract for 12 weeks reduced oxidative markers by 35%, thus improving skin elasticity and decreasing wrinkle depth by 20%. See visible improvements.
Green tea extract is also a well-studied potent polyphenol nutritional supplement with a high value of catechins. In one double-blind, controlled trial, 150 individuals who were given 500 mg per day for six months with green tea extract produced a 30% reduction in LDL oxidation and overall cardiovascular function. There were reports of an improved energy level with less fatigue; physical activity levels improved measurably, and for participants aged 50-plus, the walking speed was increased by 15%.
Resveratrol is sourced generally from grape skins or from Japanese knotweed and has been known to help the mitochondria in maintaining energy. In the studies that were conducted using the 200 mg/day dose, there was an observed 25% increase in mitochondrial efficiency and a 40% reduction in inflammatory markers among participants aged 45 to 70 years. This was coupled with increased endurance, whereby in exercise tests, subjects were able to realize a 10% increase in VO2 max after 10 weeks.
Cardiovascular Function
In a study involving 250 adults aged 40 to 65, the ingestion of 500 mg of grape seed extract daily for 12 weeks significantly improved arterial elasticity, reducing arterial stiffness by 15%. Participants also saw a 10% decrease in systolic blood pressure and an 8% reduction in diastolic blood pressure, further emphasizing the role of polyphenols in promoting blood flow and lessening cardiovascular strain.
A randomized controlled trial of 200 participants revealed that supplementation of 400 mg of green tea extract daily for six months decreased LDL cholesterol levels by 20% and increased HDL cholesterol by 12%. Besides, the individuals reported an enhanced exercise tolerance by 25%, implying longer durations before the occurrence of fatigue during physical activity.Learn about timing benefits.
The most remarkable of these flavanols, however, is the ability to support endothelial function: 300 mg daily of cocoa flavanols for eight weeks increased flow-mediated dilation—a marker of vascular health—by 30%. Participants with pre-existing conditions, such as borderline hypertension, also reported an average drop of 10 mmHg in systolic blood pressure and a 15% improvement in insulin sensitivity.
Skin Health
Polyphenols also receive much attention with regard to improvement in skin health. For example, one study of 120 women aged between 35 to 60 years demonstrated the application of 300 mg daily of grape seed extract that significantly improved skin elasticity at 20% within the period of 12 weeks with wrinkle depth decreased by 15%, and participants reported marked diminished skin roughness and thus their general complexion improved.
Green tea catechins have an amazing effect on skin health, too. In one study, 80 subjects between the ages of 40 and 65 years received a daily dose of 540 mg of green tea polyphenols, which resulted in a 25 percent reduction in UV-induced skin damage after three months of supplementation.Explore benefits for skin. Skin hydration was improved by 18 percent, while sun exposure redness and inflammation were significantly reduced.
However, cocoa flavanols have shown specific potential for improving skin structure and function. In a controlled trial of 64 middle-aged women, 320 mg/day of cocoa flavanols for 12 weeks increased skin density by 16% and reduced skin roughness by 12%. The study also recorded a 25% improvement in blood flow to the skin.
Cell Regulatory Proteins
Resveratrol is a polyphenol extracted from grape skins and Japanese knotweed that activates SIRT1, the key regulator of cellular aging and stress response. In a study involving 150 participants aged 40 to 70, a daily dose of 200 mg of resveratrol over six months resulted in a 25% increase in SIRT1 activity. In fact, the subjects showed a 15 percent reduction in markers of cellular stress—including reactive oxygen species—and a 10 percent boost in energy. Discover the role of antioxidants.
Green tea catechins have been seen to influence cell signaling pathways. In one clinical trial involving 180 subjects, where 600 mg of green tea polyphenols were ingested daily for three months, the expression of tumor suppressor proteins such as p53 increased by 20%. These findings were accompanied by a considerable reduction in pro-inflammatory cytokines, including interleukin-6, by 18%.
Indeed, cocoa flavanols have shown their ability to enhance the production of endothelial nitric oxide synthase (eNOS). In a randomized study involving 100 middle-aged individuals, it was observed that daily consumption of 300 mg of cocoa flavanols for eight weeks resulted in a 30% increase in eNOS activity, which contributed to enhanced blood flow and oxygen delivery to tissues. This further helped the subjects maintain better physical performance, an improvement of about 10% during exercise.
Gut Microbiota and Aging
Polyphenols have been shown to positively influence gut microbiota composition. In a study involving 120 older adults aged 60 to 80, it was observed that supplementation with 700 mg of green tea polyphenols for 12 weeks resulted in a 30% increase in the abundance of beneficial bacteria like Bifidobacterium and Lactobacillus. This was coupled with a 15% decrease in pro-inflammatory markers such as interleukin-1β. At the same time, participants demonstrated improved digestion: their bloating and constipation decreased by 20%. Learn more about probiotics and timing.
Resveratrol has been suggested to strongly impact microbial diversity, something generally decreased by aging. In a randomized controlled trial conducted on 100 subjects aged 50 to 70 years of age, it was observed that supplementation with 300 mg of resveratrol taken over a period of six months increased gut bacterial diversity by up to 25%. Meanwhile, the abundance of Faecalibacterium prausnitzii, a bacteria linked to anti-inflammatory effects, increased by 18%.
Some evidence also shows that cocoa flavanols can modulate gut microbiota. In a study involving 150 participants aged 55 and above, the ingestion of 500 mg of cocoa flavanols daily for eight weeks significantly increased the production of SCFAs by 22%. A 15% reduction in pathogenic bacteria, such as Clostridium perfringens, was recorded during the study; this usually characterizes gut dysbiosis.