Thursday, February 22, 2007

Antioxidants in Green Tea

Tea contains vitamins A, C, and E as well as health-promoting compounds called Flavonoids. The flavonoids, called polyphenols, act as antioxidants that counter the effects of reactive oxygen molecules that result from normal body functions and contribute to aging and chronic disease.

One subgroup of polyphenols, called catechins, is abundant in green tea (China Green Tea - Japan Green Tea), especially tea made from the very top of the bush. Catechins were discovered in the 1970s, when medical researchers were looking for the reason people in Japan's Shizuoka Prefecture - a major tea-growing area - had much lower rates of cancer than other Japanese, even when they were very heay smokers. One catechin in particular, epigallocatechin gallate (EGCg), is found in no other plant than tea, and it's one of the most potent antioxidants yet discovered - up to twenty times stronger than Vitamin E. Numerous studies have found EGCg to be effective in preventing and inhibiting cancer growth.

Catechins make up as much as 30 percent of the dry weight of green tea leaves, but only three to ten percent of black tea. Steeping the leaves for three to five minutes releases the optimal amount of catechins.

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