In the study, conducted at the University of Parma in Italy, researchers held a trial with two groups of men, both with a pre-cancerous condition that normally progresses to cancer it 30% of men. One group was given a placebo to take, whereas the second group was given 600 milligrams of green tea catechins a day, "equivalent to 12-15 cups of green tea infusion, that is about two times the average intake in Asian countries."
Nine out of the 30 men given the placebo group developed full-blown prostate cancer, a rate of 30%. But only 1 man in the gren-tea group developed cancer, a rate of only 3%. In other words only one-tenth the rate of those who didn't drink green tea.
Said the scientist in charge of the study: "To our knowledge, this is the first study showing that [green tea catechins] have potent in vivo chemoprevention activity for human prostate cancer." He also said that a collaborative study involving U.S. and Italian researchers on the effect of green tea on breast and colon cancer rates is in the works.