Black and green teas come from the same plant, but they are processed differently and contain different antioxidants. Consider drinking both (perhaps alernating days) to get the greatest disease protection. According to epidemiological and animal evidence, green tea may inhibit breast, digestive, and lung cancers. Green tea's catechins, powerful antioxidants, may protect cells from free radical damage.
Flavonoids in black tea appear to reduce the stickiness of platelets, a heart disease risk factor. A 2002 study in the Americal Journal of Clinical Nutrition found that Dutch citizens who drank at least 375 ml (about 1 1/2 cups) of black tea a day were less likely to die of a heart attack than non-tea drinkers.
(Source: Natural Health magazine, March 2003.)