Green tea extract and the effects on weight in men.




Am J Clin Nutr

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Green tea has long been used in much of the world as a popular beverage and a respected medicinal agent. Early Chinese medical literature lists green tea as an agent to promote digestion, improve mental faculties, decrease flatulence and regulate body temperature. The earliest known record of use dates back to around 2700 B.C. Today, ceremonies, celebrations, relaxation time and ordinary meals usually consist of tea in most parts of the world, except where coffee has become the more popular beverage, like the United States.

Green tea has antioxidant properties. This means it has the ability to protect against oxidative damage to tissues and red blood cells. Also, the caffeine and catechin polyphenols contained in green tea may work together to enhance the body's thermogenic activity, thus increasing the rate at which the body breaks down fat.1

A recent study published in the American Journal of Clinical of Nutrition stated that there are few studies on the effects of green tea extract catechins on body fat. This small study took place in Japan and included 35 men. The men were divided into two groups and all had similar BMI (Body Mass Index) and waist circumference. One group received 1 bottle of oolong tea containing 690 mg of catechins (from green tea) while the other group received tea containing only 22 mg. This continued for a 12-week period. The results showed that those receiving the 690 mg had lower BMI, body weight, and waist circumference when compared to the lower group. The authors concluded that, “Daily consumption of tea containing 690 mg catechins for 12 wk reduced body fat, which suggests that the ingestion of catechins might be useful in the prevention and improvement of lifestyle-related diseases, mainly obesity.”2


1. Dulloo AG, Sevdoux J, Girardier L, et al. Green Tea and Thermogenesis: Interactions Between Catechin-polyphenols, Caffeine and Sympathetic Activity. Int J Obes Relat Metab Disord. Feb2000;24(2):252-8.
2. Nagao T, et al. Ingestion of a tea rich in catechins leads to a reduction in body fat and malondialdehyde-modified LDL in men. Am J Clin Nutr. Jan 2005;81(1):122-129.