More importantly, the scientists found that prostate cancer cells grew more slowly when placed in a medium containing blood serum of men who had consumed either green or black tea for five days compared to serum collected before the men began their tea-drinking regimen. Serum from men who drank comparable amounts of diet or regular soda showed no such slowing in cancer cell proliferation.
The study was reported at Experimental Biology 2004, in Washington, D.C., as part of the scientific program of the American Society of Nutritional Sciences, one of the six sponsoring scientific societies of this large multi-disciplinary meeting.
Recent animal and epidemiological studies have suggested tea may have anti-tumor effects against carcinoma of the prostate, and many of the polyphenolic components of tea have been found in the prostate and many other tissues in rats and mice after chronic consumption of green tea polyphenols in drinking water.
Dr. Susanne Henning, UCLA Center for Human Nutrition, says the UCLA research team - a combination of nutrition scientists and urologists - focused on the possible effect of tea polyphenols on factors named polyamines and the enzymes responsible for the production of polyamines. Elevated levels of polyamines have been associated with malignancy in humans, including prostate cancer, and - since polyamines are present in prostate tissue in high concentration - are considered a logical target for chemoprevention of prostate cancer.
Five days before they were to undergo radical prostatectomy, 20 men with prostate cancer were randomly assigned to consume daily either five cups of green tea, five cups of black tea, or diet or
Contact: Sarah Goodwin
Federation of American Societies for Experimental Biology