Thousands of years ago tea was utilized for medicinal purposes and modern research has helped confirm the prudence behind such actions. Recent studies have indicated that the tea plant, Camellia sinensis, contains an abundance of cancer-fighting phytochemicals, the most promising of which is catechin. A tannin derivative, catechin is what provides tea with its astringency and can be found naturally in grapes and berries as well. Though it occurs in both black and green teas, since the drinks only differ in the way the leaves are processed, catechin is found in much higher levels in green teas. Moreover, though epidemiological studies are inconclusive as of yet, they suggest that members of societies that drink significant amounts of green tea live longer than those that do not.