UV light from the sun is well known to trigger uncontrolled cell proliferation that can lead to cancer. Sunscreens protect against the suns harmful rays by physically blocking UV photons. The new findings suggest that tea polyphenols, in contrast, interrupt chemical pathways that lead to skin cancer, offering post-exposure protection. Zigang Dong and his colleagues at the University of Minnesota in Austin, found that shaven lab mice subjected to UVB light and then swabbed with a green tea polyphenol solution exhibited decreased levels of cancer-promoting enzymes and proteins as compared with mice that did not receive the polyphenol treatment. (Black tea contains similar polyphenols.)
Other studies have hinted that drinking tea may deter skin cancer, but Dong, who presented the new findings yesterday at a meeting of the American Chemical Society in New York City, believes that a topical application of tea polyphenols could be a better approach. "Drinking tea may help, but youd have to drink a large amount to accumulate in the skin, perhaps as many as 10 cups a day," he notes. "Its easier to concentrate it in a cream form, and its probably more effective." The team is currently working to develop just such a polyphenol lotion, human testing of which could begin a few years from now.