tea is rich in flavonoids, a group of plant pigments commonly
known as bioflavonoids. Flavonoids function as antioxidants,
protecting the body against some types of cancer; evidence
that a subclass of flavonoids called "tea catechins"
helps control fat oxidation suggests that green tea may play
a role in weight management.
The December 1999 American Journal of Clinical Nutrition
included a study that explored this potential influence of
green tea on weight loss. The authors began by explaining
that ≥fundamentally, there are only two ways to treat obesity:
reduce energy intake or increase energy expenditure.≤ Relying
on this premise, they compared the effect of green tea vs.
placebo on 24-hour energy expenditure (EE ≠ a higher EE means
the body is burning more calories) and respiratory quotient
(RQ ≠ a lower RQ means the body is metabolizing more fat).
On three separate occasions, subjects (10 men) randomly
received one of three treatments at breakfast, lunch and dinner:
green tea extract (50 mg caffeine, 90 mg epigallocatechin
gallate); caffeine (50 mg); or placebo. Subjects who ingested
the green tea extract demonstrated a significant increase
in EE and a significant decrease in RQ compared to subjects
who ingested caffeine or placebo.
The authors note that caffeine had no effect on EE or RQ,
even in amounts equivalent to those found in the green tea
extract (50 mg). Their results emphasize the potential ability
of green tea (independent of caffeine) to "influence
body weight and body composition."
Dulloo AG, Duret C, Rohrer D, et al. Efficacy of a green
tea extract rich in catechins polyphenols and caffeine in
increasing 24-h energy expenditure and fat oxidation in humans.
American Journal of Clinical Nutrition, Dec. 1999: Vol. 70,
For additional information on nutrition, go to http://www.chiroweb.com/tyh/nutrients.html