Going green, reducing red
Researchers randomly selected sixty 40- to 65-year-old women to drink a tea beverage with polyphenols--the healthful nutrients found in green tea--or a green tea-like beverage without polyphenols, for 12 weeks. Neither the participants nor the researchers knew which women were selected to drink which version of the tea.
All of the women in the study had type II skin on the Fitzpatrick phototyping scale. On this scale, type II skin is characterized by light to normal ultraviolet light (UV) sensitivity, and generally includes people of middle European skin type, with blond or light brown hair.
The women were exposed to a solar simulator, a UV lamp that can cause sunburn and tanning, at the start of the study and 6 and 12 weeks later. Skin color was measured before, and 24 hours after, solar simulator exposure. The amount of exposure was 1.25 times the minimal erythema dose--or 1.25 times the smallest amount of sun exposure that leads to a slight reddening of the skin. The researchers collected other measures of skin health, including elasticity, roughness, scaling, skin density, and delivery of blood and oxygen to the skin.
Compared with women drinking the beverage without polyphenols, the women who drank the polyphenol-rich green tea beverage had
- 16% less skin color change after UV exposure at six weeks,
- 25% less skin color change after UV exposure at twelve weeks,
- less skin roughness and scaling,
- improved skin elasticity and density, and
- significantly improved blood and oxygen flow to the skin.
Finding your green tea favorites
This study suggests that green tea polyphenols can protect skin against harmful UV radiation and improve skin quality of women with fair to moderate skin pigmentation. Use our tips to work more green tea into your summer sipping plan:
- Get loose. Try loose green for the most benefit. One cup of green tea brewed from loose leaves provides around 200 mg of polyphenols.
- Go icy. Try a thermos of iced green tea for your next outing to the beach or a picnic. Brew tea as you would if planning to drink hot, then refrigerate for several hours in a glass container to chill before adding ice.
- Add citrus. Sip green tea with a squeeze of lemon for best absorption of healthy nutrients. The vitamin C can prevent polyphenols from breaking down.
- Avoid dairy. Adding milk to green tea may decrease the benefit by blocking polyphenol absorption.
- Drink liberally. Aim for up to seven cups of green tea daily to reach the level of polyphenols--around 1,400 mg per day--the women in the study drank. Replace your morning coffee with green tea, or try decaf green tea if you need to limit your caffeine intake.
(J Nutr 2011;141:1202-8)