Magazine article Clinical Psychiatry News

Green Tea Boosts Metabolism without Increasing Heart Rate

Magazine article Clinical Psychiatry News

Green Tea Boosts Metabolism without Increasing Heart Rate

Article excerpt

LONDON -- Green tea consumption may play a role in stemming the world-wide tide of obesity, Dr. Mary L. Hardy said at a symposium on alternative and complementary therapies sponsored by the universities of Exeter and Plymouth.

One area of current obesity research involves the process of thermogenesis. Stimulation of this process, which is controlled by the sympathetic nervous system, increases basal energy expenditure and fat oxidation. Many plant compounds, such as catechins and caffeine in tea, exert stimulatory effects on thermogenesis, Dr. Hardy explained.

Unlike sympathomimetic drugs and ephedrine, however, green tea extracts do not increase heart rate and are not associated with adverse cardiovascular effects.

"Safety concerns with ephedrine-containing diet aids have spurred interest in safer alternatives such as green tea," said Dr. Hardy of the center for dietary supplement research in botanicals at the University of California, Los Angeles.

In a recent open-label trial, green tea extract AR25 (Exolise) was administered to 70 moderately obese patients for 3 months. The mean body mass index of the study participants was 28.9 on enrollment.

Patients took two 375-mg capsules twice daily, for a total daily epigallocatechin gallate dose of 270 mg.

By week 12, body weight decreased by a mean of 4.6% and waist circumference by 4.48% (Phytomedicine 9[1]:3-8, 2002).

The investigators noted, "Stimulation of thermogenesis and fat oxidation by the green tea extract AR25 was not accompanied by an increase in heart rate. In this respect, the green tea extract is distinct from sympathomimetic drugs, whose use as antiobesity thermogenic agents is limited by their adverse cardiovascular effects and, hence, is particularly inappropriate for obese individuals with hypertension and other cardiovascular complications. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.