Green tea catechins, thermogenesis and fat oxidation
Green tea for weight loss: catechins and caffeine: increased thermogenesis. (Clinical Rounds)
By Nancy Walsh
Published in Family Practice News - February 1, 2004.
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LONDON - Green tea consumption may play a role in stemming the worldwide tide of obesity, according to researcher Dr. Mary L. Hardy, of the Center for dietary supplement research in botanicals at the University of California, Los Angeles.
Dr Hardy was speaking at a symposium on alternative and complementary therapies sponsored by the universities of Exeter and Plymouth.
Thermogenesis
Dr Hardy reported on an area of current obesity research involving the process of thermogenesis. Thermogenesis is controlled by the sympathetic nervous system. When the process is stimulated, there is an increase in energy expenditure and fat oxidation.
Catechins found in green tea are a thermogenesis stimulant.
Safer alternative
Unlike sympathomimetic drugs and ephedrine, however, green tea extracts do not increase heart rate and are not associated with adverse cardiovascular effects.
Dr Hardy said that safety concerns with ephedrine-containing diet drugs had encouraged research into safer alternatives such as green tea.
She reported a study in which a group of 70 moderately obese patients taking green tea extract over 3 months showed average body weight decreases 4.6%. Averge waist circumference fell by 4.48% (Phytomedicine 9[1]:3-8, 2002).
In another study daily consumption of green tea extract resulted in an increase in the metabolic rate equivalent to a 4% increase in energy expenditure (Am. J. Clin. Nutr. 70[6]:1040-45, 1999).
