News & Perspectives

Green Tea for Prostate Health

Men who enjoy the mellow flavor and soothing ritual of green tea breaks throughout the day may also be lowering their risk of prostate cancer. Mounting scientific evidence indicates this humble beverage harbors powerful antioxidants called polyphenols, which may be even more potent than vitamin C and vitamin E in their ability to mop up potentially cancer-causing free radicals.

Japanese men, who commonly drink four to six cups of green tea daily, have a significantly lower mortality rate from prostate cancer than Westerners. And the incidence of prostate cancer in China, whose population consumes green tea regularly, is the lowest in the world.

Evidence from a growing number of animal and lab studies suggests that green tea may be protecting these men against prostate cancer. A Mayo Clinic study this past year found that the main polyphenol in green tea, called EGCG, inhibits the growth of prostate cancer cells and in high concentrations destroys them. Scientists at Case Western Reserve University in Cleveland reported this year that green tea polyphenols inhibit an enzyme that is over-expressed in prostate cancer, indicating that green tea might be effective in prostate cancer prevention. And a preliminary study by Japanese researchers at Kobe University showed that mice fed a green tea extract and then injected with a substance that causes prostate cancer were less likely to grow tumors than control animals.

Prostate and other cancers
Although the evidence for humans is not yet conclusive, Hasan Mukhtar, Ph.D., professor at Case Western Reserve University and a prominent researcher in this area, believes there is "a strong indication that green tea is protective for prostate as well as esophageal and stomach cancers." The black teas so popular in the West, such as orange pekoe, Darjeeling, and the breakfast teas, may have similar benefits. Black and green teas come from the same plant, Camellia sinensis, and both contain cancer-fighting polyphenols. In a large-scale study of more than 35,000 postmenopausal Iowa women (American Journal of Epidemiology, 7/96), those who drank two or more cups of tea daily were less likely to develop cancers of the urinary or digestive tract.

Suggested dose:
Having a few cups of green or black tea daily (Dr. Mukhtar thinks "about four cups a day may be sufficient") seems a good bet. To derive the most benefit, drink freshly brewed tea and avoid powdered or instant tea. Add milk, lemon, honey, or sugar as you see fit: These do not interfere with absorption of the antioxidants. Capsules containing green tea extract (500 mg a day) are a suitable alternative for those who don't like the taste of green tea. When using supplements, but those standardized to contain at least 50% polyphenols, the active ingredients in green tea.

Date Published: 12/03/2000
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