A study performed at the University of Geneva in Switzerland, reported that green tea extract may be useful in weight management1. As part of their study, the investigators measured the 24-hour energy expenditure of 10 healthy men receiving three doses of caffeine (50 mg), green tea extract (containing 50 mg caffeine and 90 mg epigallocatechin), or a placebo per day.
The study’s authors reported that, treatment with green tea was associated with a ``significant increase'' (+4%) in daily energy expenditure as compared with the placebo. The study confirmed that this effect was not linked to the relatively small amounts of caffeine found in tea, since subjects receiving similar amounts of caffeine displayed no change in daily energy output. Thus, according to their analysis, green tea extract would be useful in weight management since it increases energy expenditure. The mechanisms behind this action are as yet unclear. One proposed mechanism is that the catechins in green tea may work with other chemicals to increase levels of fat oxidation and thermogenesis, during which the body burns fat as fuel to generate heat. Interestingly, the researchers noted that this action did not raise heart rates in the subjects. Based on these findings, green tea is a safe alternative to stimulant diet drugs, which are contraindicated in obese individuals with hypertension and other cardiovascular complications. Sabinsa Corporation supplies green tea extracts standardized for 40% and 75% total catechins.
- American Journal of Clinical Nutrition 1999;70:1040-1045
