Good news for green-tea drinkers and supplementers like me. The Journal of Investigative Dermatology reported a few days ago on the mechanism of the inhibition of UVB-induced skin tumor development.

The article is reasonably technical, but I’ll summarize the results here:

Green tea polyphenol (GTP) supplementation in mice prevents photocarcinogenesis (i.e., skin cancer). I’ve not mentioned this before, so here’s a link to a review on the matter.

Salient points from above-mentioned review:

Extensive in vitro and in vivo studies have been conducted to determine the anti-UV carcinogenic effects of green tea. It has been found that the oral administration of GTPs (a mixture of polyphenolic components isolated from green tea) in the drinking water of mice results in significant protection against UV-induced skin carcinogenesis in terms of tumor incidence, tumor multiplicity and tumor size, compared to those mice that were not given GTPs in their drinking water.

The mice that were given crude water extracts of green tea as a sole source of drinking water developed a lesser number of tumors compared to those mice that were not given water extracts of green tea. The administration of GTPs in drinking water or the topical application of EGCG also induced partial regression or inhibition of the tumor growth of established skin papillomas in mice.

The researchers in this case showed that GTP supplementation in mice reduced the levels of inflammation markers cyclooxygenase-2, prostaglandin E2, proliferating cell nuclear antigen, and cyclin D1, and proinflammatory cytokines tumor necrosis factor-alpha, IL-6, and IL-1-beta. UVB-induced DNA damage was rapidly resolved in the GTP-supplemented mice compared with the wild type mice.

The major contribution of this study was that all these effects appear to be mediated through interleukin 12.

Personally, I have been supplementing with Now Foods EGCg Green Tea extract, available from bulknutrition.com. At 4 capsules per day, this is apparently equivalent to 12 cups of green tea. Hopefully this will keep me skin cancer free!