Green Tea Studied for Fat Metabolism

Epigallocatechin gallate (EGCG), a bioactive constituent of green tea, decreases fat deposition into tissues, according to a recent study. Previous research indicates that green tea has significant antioxidant activity, supports balanced lipid levels and optimizes metabolism.

Mice were fed a high-fat diet supplemented with varying dosages of EGCG. After 4-7 days of supplementation, the mice were evaluated for body composition, food intake and digestibility, lipid oxidation, incorporation of dietary lipids into tissues and gene expression.

The study showed that after short-term EGCG supplementation, the mice showed increased energy excretion without affecting food or energy intake. Fat and nitrogen excretion was also enhanced with EGCG intake. Furthermore, EGCG supplementation supported balanced triglyceride levels and glycogen (the storage form of glucose) in the liver after eating. The mice also showed an increase in dietary lipid oxidation (used for energy production) and a reduction in the incorporation of dietary lipids into liver, skeletal muscle and fat tissue. In addition, EGCG intake mitigated the effects of a high-fat diet on intestinal substrate transporters and down-regulated the genes in the liver for synthesizing lipids in the postprandial (after-eating) state.

The researchers concluded that EGCG decreases food digestibility, which affects substrate metabolism of intestinal mucosa and liver, leading to increased postprandial fat oxidation and reduced incorporation of dietary lipids into tissues.

Reference:

Friedrich M, Petzke KJ, Raederstorff D, Wolfram S, Klaus S. Acute effects of epigallocatechin gallate from green tea on oxidation and tissue incorporation of dietary lipids in mice fed a high-fat diet. Int J Obes (Lond). 2011 Jul 12. Published Online Ahead of Print.