By Richard Firshein D.O., published on March 1, 1998 - last reviewed on June 9, 2016
QUESTION: I've heard that green tea can prevent cancer, although it contains caffeine. Is there any truth to these claims?
ANSWER: Green tea is a delicate, delicious-tasting beverage whose leaves, unlike those of black tea, have not been roasted, although both teas contain caffeine. Green tea contains substances called flavonoids and phenolic acids, which are powerful antioxidants. These compounds are believed to inhibit the first stage of cancer formation, the so-called "initiation phase." Studies have shown that green tea consumption lowers risk of stomach and prostate cancer, and research in Europe has found that increasing tea intake in general—whether black or green—was associated with lower cancer rates. A study of 35,000 post-menopausal women showed that drinking at least two cups of tea a day protected against cancers in the bladder and digestive tract. It's good to see tea's anti-cancer properties being recognized.