What if I told you that green tea’that favorite of the tree-hugging crowd’could jack up your metabolism, help you exercise better, decrease your risk of cancer and walk your dog? Okay, three out of four ain’t bad. The proof is in the bag’the tea bag, that is.
Green tea contains a high level of polyphenolic compounds known as catechins. A group of scientists studied the effects of catechin-rich green-tea extract on endurance capacity, energy metabolism and fat oxidation in mice over a 10-week period. Mice fed GTE prolonged their swimming times to exhaustion by 8 to 24 percent. The effects were dose dependent and accompanied by greater increases in fat oxidation, or burning.
In addition, the GTE-laced diet increased the level of beta-oxidation activity in skeletal muscle (another indicator of better fat burning). Plasma lactate concentrations were significantly decreased after exercise, with simultaneous increases in free fatty acid concentrations in plasma.
According to the study, stimulating fatty acid use is a promising strategy for improving endurance capacity, and GTE fits the stimulation profile. GTE also contains a substance called theanine, a glutamate derivative that decreases doxorubicin-induced adverse reactions, such as the induction of the lipid peroxide level and the reduction of glutathione peroxidase activity in normal tissues. In English, that means theanine lessens oxidative damage. In other words, GTE can help maintain the health of your cells.
Even in severely damaged muscles GTE can be of benefit. For example, Duchenne muscular dystrophy is a disorder characterized by lethal muscle wasting due to the lack of a protein called dystrophin. In one study investigators tested whether the antioxidant properties of GTE could diminish muscle necrosis (death) in mice that had muscular dystrophy. For four weeks, beginning on their day of birth, the subjects got a diet supplemented with 0.01 percent or 0.05 percent green-tea extract. The feeding regimen significantly and dose-dependently reduced necrosis in fast-twitch-muscle fibers but had no effect on slow-twitch fibers. The approximate effective dose in humans is about seven cups of green tea per day. If you’re a tea drinker, go green. IM
Editor’s note: Jose Antonio, Ph.D., is the chief science officer of Javalution (www.javafit.com) and the president of the International Society of Sports Nutrition (www.sportsnutritionsociety.org).