Five cups of green tea daily rejuvenates skin
Women over 40 can make their skin younger-looking and softer by drinking five cups of green tea a day. Dermatologists at the University of Witten-Herdecke in Germany drew this conclusion from a study in which 60 women aged 40-65 participated. According to the researchers, green tea protects the skin against the ultraviolet radiation in sunlight too.Green tea
Not so long ago green tea was so hip that we unworldly and nerdy as we are didn't dare write about it. Meanwhile interest in green tea has waned and we plucked up enough courage to read the study that Ulrike Heinrich published in 2011 in the Journal of Nutrition.

Heinrich gave 30 women 1 litre say five cups of a product from the Coca-Cola Company lab, every day for 12 weeks. Coca-Cola sponsored the study. The composition of the product is shown below. If you compare it with analyses of green tea like you'd make at home, you'll notice almost no difference.

A control group of 30 women were given a placebo.Skin
Before, halfway through, and at the end of the 12 weeks, the researchers exposed a small piece of each woman's skin to UV light, and measured how much the skin burned [a-value]. As you can see below, green tea supplementation gave the skin some protection against UV radiation. All the women were of skin type 2: European, fair-skinned, burned easily but did tan a little.

Younger skin
The skin of the women in the control group did not change; that of the women in the experimental group did. Their skin became softer and less flaky. The photo below shows the change in skin texture of a random subject in the experimental group. The white patches are flakes of skin.

Green tea improved the circulation in the skin and the oxygen supply to the skin cells.

"Improvements of skin structure may be related to flavanol mediated increases in cutaneous blood flow", the researchers write. "Microcirculation is important for nutrient and oxygen supply of the skin and an improved delivery likely affects skin condition and appearance."
"The present study demonstrated that dietary constituents protected skin and improved overall skin quality", the researchers summarise. "Regular consumption of a beverage rich in tea flavanols contributed photoprotection against harmful UV radiation and helped maintain skin structure and function."

J Nutr. 2011 Jun;141(6):1202-8.