Monday August 14

Green Tea May Help Prevent Skin Cancer - U.S. Team

By Rachel Brand

CHICAGO (Reuters) - Drinking four or more cups of green tea a day may help stave off skin cancer and could be similarly effective if incorporated into skin care creams, researchers said on Monday.

The brew, which is especially popular in Asia, where cancer is rarer than in the West, contains antioxidants that are known to prevent skin cancer in mice and may prevent it in humans, a report summarizing recent research into green tea said.

Previous research has suggested substances in green tea called polyphenols can kill tumor cells and may starve cancerous growths by limiting blood vessel growth around them.

``Based on epidemiological and mouse models, we can say drinking four or five cups a day may be very helpful for protection,'' the report's author, Santosh Katiyar of Case Western Reserve University, said in a phone interview.

But he cautioned that green tea was a preventive step, not a cure, for skin cancer.

``It is a prevention. ... As long as I take it, I am protected,'' said Katiyar, who drinks two cups of green team a day.

The report appeared in the Archives of Dermatology, a journal published by the American Medical Association.

The leaf and bud of the camellia plant are the basis of both green and black tea. But unlike black tea, which is fermented, green tea is steamed dry immediately after harvesting, which leaves it with larger amounts of polyphenols.

Its most effective polyphenol is epigallocatechin gallate (EGCG), the report said.

Past studies of mice exposed to ultraviolet light have shown that feeding them green tea or applying EGCG to their skin protected them from the reddening, blistering and cell division associated with the early stages of skin cancer.

Recent experiments have shown that when applied to human skin that has been exposed to the sun, EGCG prevented both inflammation and the development of leukocytes, white blood cells that can be a marker for cancer, Katiyar said.

Many skin care manufacturers have used the mouse research to justify including green tea extracts in their skin care products, he said. But he challenged the effectiveness of skin care products incorporating green tea.

``It is unlikely that these skin care products have been tested in controlled clinical trials, and the concentration of (polyphenolic compounds) in these preparations is not uniform,'' he said. He urged further clinical testing and trials.