Green tea polyphenols protect against sunburn and improve skin quality
Skin protection strategies during sun-drenched activities while minimizing vitamin D attenuating sunscreens can include green tea polyphenols according to a study recently published in The Journal of Nutrition. The authors first observe:
"Dietary constituents including polyphenols and carotenoids contribute to endogenous photoprotection and modulate skin characteristics related to structure and function of the tissue. Animal and in-vitro studies indicate that green tea polyphenols affect skin properties."
They performed a 12-wk, double-blind, placebo-controlled study during which 60 female volunteers consumed either a beverage with green tea polyphenols or a control drink. During the study they measured skin photoprotection, structure, and function at baseline, 6 weeks and 12 weeks. Their data showed impressive benefits:
"Following exposure of the skin areas to 1.25 minimal erythemal dose of radiation from a solar simulator, UV-induced erythema decreased significantly in the intervention group by 16 and 25% after 6 and 12 wk, respectively. Skin structural characteristics that were positively affected included elasticity, roughness, scaling, density, and water homeostasis."
Additionally...
"Intake of the green tea polyphenol beverage for 12 wk increased blood flow and oxygen delivery to the skin. Likewise, in a separate, randomized, double-blind, single-dose (0.5, 1.0, and 2.0 g) study of green tea polyphenols, blood flow was maximized at 30 min after ingestion."
The green tea polyphenol beverage used in the study provided a dose of 1402 mg total catechins per day. Because the average 6 ounce cup of green tea contains between 50 and 100 mg of catechins and can vary widely depending on the tea and other factors, taking green tea polyphenols in a reliable supplemental form is more practical than attempting to drink fifteen or more cups of tea. There is no good reason why the authors' conclusion does not also apply to men:
"In summary, green tea polyphenols delivered in a beverage were shown to protect skin against harmful UV radiation and helped to improve overall skin quality of women."
While generally safe, because there is some evidence that green tea catechins may enhance the Th2 (humoral) immune response, clinicians should bear this in mind and individuals receiving treatment for Th2-dominant autoimmune disorders should discuss the use of green polyphenols with their provider.