Scientists in Taiwan studied the effect of green tea extract on 78
obese women aged 16 to 60 years. They found no significant improvement
in body weight, body mass index and weight circumflex. There were
significant improvements in LDL cholesterol and triglyceride.
Effect of green tea extract on obese women: A randomized, double-blind, placebo-controlled clinical trial.
Clin Nutr. 2008 May 9. [Epub ahead of print]. Hsu CH, Tsai TH, Kao YH, Hwang KC, Tseng TY, Chou P.
AIMS: To examine the effect of green tea extract (GTE) on obese
women and to explore the relationship between GTE and obesity-related
hormone peptides. METHODS: A randomized, double-blind,
placebo-controlled clinical trial was conducted from July 2006 to June
2007 in Taipei Hospital, Taiwan. Seventy-eight of 100 obese women aged
between 16 and 60years with BMI>27kg/m(2) and who had not received
any other weight control maneuvers within the last 3months completed
this study. The subjects were randomly divided into Groups A and B.
Group A (n=41) received GTE while Group B (n=37) took cellulose as a
placebo, one capsule (400mg) three times each day for 12weeks. The body
weight (BW), body mass index (BMI) and waist circumflex (WC) were
measured at the beginning of the study and after 12weeks of treatment
with GTE. The data were compared and expressed as % reduction. RESULTS:
There was only a 0.3% reduction in BW (0.15kg) after 12weeks of
treatment with GTE. There was no statistical difference in % reduction
in BW, BMI and WC between the GTE and placebo groups. Within group
comparison revealed that the GTE group had significant reduction in
LDL-cholesterol and triglyceride, and marked increase in the level of
HDL-cholesterol, adiponectin and ghrelin. On the other hand, the
placebo group showed significant reduction in triglyceride only, and a
marked increase in the level of ghrelin alone. CONCLUSIONS: This study
showed no statistical difference in % reduction in BW, BMI and WC
between the GTE and placebo groups after 12weeks of treatment. The
intake of GTE (491mg catechins containing 302mg EGCG) for 12weeks is
considered safe as shown by the results.