An Overview of Research on the Potential Health Benefits of Tea



Preliminary research suggests that drinking tea may have effects on body weight, fat accumulation and insulin activity. While it may be premature to draw firm conclusions based on early research, key findings include the following:

  • Green Tea extract was found to significantly increase 24 hour energy expenditure and fat oxidation in healthy men49.
  • After three months of consumption of Green Tea extract by moderately obese patients, body weight decreased by 4.6 percent and waist circumference decreased by 4.48 percent50.
  • Researchers examined mice which were fed either a low-fat diet, high-fat diet or high-fat diet supplemented with 0.1-0.5 percent tea catechins for 11 months. The scientists then measured body weight, fat tissue mass and liver fat content and discovered that supplementation with tea catechins resulted in a significant reduction of high-fat diet-induced body weight gain and visceral and liver fat accumulation51.
  • Researchers at the Unites States Department of Agriculture (USDA) conducted a study to examine the insulin-enhancing properties of tea and its components. An in vitro test using a fat cell assay found that tea, as normally consumed, increased insulin activity >15-fold. Green, Black and Oolong Tea all yielded insulin-increasing results. The researchers separated the components of the tea using a high-performance liquid chromatography and discovered that several known compounds found in tea were shown to enhance insulin, helping cells recognize and respond to the hormone – the greatest activity was elicited by EGCG followed by epicatechin gallate, tannins, and theaflavins52.