Green Tea - Metabolism Booster or Not?

Green tea is a popular supplement for lowering cholesterol and blood pressure, and is also sometimes hyped as a weight loss supplement due to it's metabolism boosting properties. There is a lot of evidence that it may help with cardiovascular health, but can green tea improve metabolism as well? And is it any good for losing weight, as a result? There are plenty of indications that it can raise your body's metabolism, but it may be a weak effect and thus not strong enough to cause weight loss all by itself.

There have been a few studies that have suggested an increase in metabolism from taking green tea. One small study gave a placebo to one third of the subjects, just caffeine to another third, and green tea to the final third. All subjects were placed in a respiratory chamber specially designed to measure energy usage, and the ones taking green tea had a 4% increase in energy metabolism over those who took just caffeine. Although green tea contains caffeine, this suggests that there is an effect over and above that explainable by caffeine alone.

So there is at least some effect. Another study on just mice discovered that the mice taking green tea had not only increased metabolism, but also improved cholesterol levels and less fat in the liver. This was performed on mice with a known obesity gene. In other studies, green tea has been shown to be a potentially good way of lowering cholesterol and blood pressure as well, which can help lead to improved cardiovascular health, if not strong weight loss per se.

The mechanics behind this is a chemical called epigallocatechin gallate (EGCG), a chemical present in many teas that acts as an anti-oxidant and metabolism booster. In addition to EGCG, green tea also contains tanins, another anti-oxidant. Anti-oxidants are important because they help clean up maverick oxygen molecules (called free radicals) roaming through the body that can cause cell damage.

Overall, while green tea does boost metabolism a bit, it is a small effect and not enough to make noticeable weight loss a reality all by itself. However, every bit of metabolism increase does help a bit, and coupled with a good diet and regular exercise, green tea may help add to overall cardiovascular health, thus cutting the risk for some of the biggest killer diseases such as heart attacks and stroke.