BACKGROUND: Catechins, the major component of green tea extract, have various physiologic effects. There are few studies, however, on the effects of catechins on body fat reduction in humans. It has been reported that the body mass index (BMI) correlates with the amount of malondialdehyde and thiobarbituric acid-reactive substances in the blood.
OBJECTIVE: We investigated the effect of catechins on body fat reduction and the relation between oxidized LDL and body fat variables.
DESIGN: After a 2-week diet run-in period, healthy Japanese men were divided into 2 groups with similar BMI and waist circumference distributions. A 12-week double-blind study was performed in which the subjects ingested 1 bottle oolong tea/day containing 690 mg catechins (green tea extract group; n = 17) or 1 bottle oolong tea/day containing 22 mg catechins (control group; n = 18).
RESULTS: Body weight, BMI, waist circumference, body fat mass, and subcutaneous fat area were significantly lower in the green tea extract group than in the control group. Changes in the concentrations of malondialdehyde-modified LDL were positively associated with changes in body fat mass and total fat area in the green tea extract group.
CONCLUSION: Daily consumption of tea containing 690 mg catechins for 12 week reduced body fat, which suggests that the ingestion of catechins might be useful in the prevention and improvement of lifestyle-related diseases, mainly obesity.
Nagao T, Komine Y, Soga S, Meguro S, Hase T, Tanaka Y, Tokimitsu I. Ingestion of a tea rich in catechins leads to a reduction in body fat and malondialdehyde-modified LDL in men. Am J Clin Nutr. 2005 Jan;81(1):122-9.