Review supports metabolic benefits of EGCG from green tea

19-Dec-2016 - Last updated on 19-Dec-2016 at 14:50 GMT

Supplements containing epigallocatechin-3-gallate (EGCG) from green tea may increase energy expenditure and impact metabolic rates, and help with weight management, says a new meta-analysis.

Data from eight randomized control trials indicated that doses of 300 mg of EGCG may promote the breakdown of fat, and help with weight management.

“From the available evidence in this systematic review and meta-analysis, it is clearly evident that EGCG has the propensity of increasing metabolic rate even at low dose (ca. 300 mg per day), as resulted in difference in RQ [respiratory quotient] including EE [energy expenditure] measures of energy metabolism,” wrote the authors in The Journal of Nutritional Biochemistry.

Tea benefits

The review supports an ever-growing body of science supporting the potential benefits of green tea (Camellia sinensis) and its constituents, most notably EGCG.

Green tea contains between 30% and 40% of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3% and 10%. Oolong tea is semi-fermented tea and is somewhere between green and black tea. The four primary polyphenols found in fresh tealeaves are EGCG, epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC).

Analysis details

Scientists from Taiyo Kagaku Co. Ltd., the University of Mie, and Aichi Medical University in Japan included eight randomized controlled trials in their systematic review and meta-analysis. The trials provided data from a total of 268 people, with the dosages used ranging from 300 to 800 milligrams per day, and the duration ranging from two days to 12 weeks.

Crunching the numbers revealed that, compared with placebo, EGCG supplementation was associated with moderately reduces RQ and accelerates EE, but no statistically significant changes were observed in fat oxidation (fat breakdown).

“Possibly, EGCG alone has the potential to increase metabolic rate at 300 mg dose,” wrote the researchers. “Collectively, the outcome supports the findings that EGCG has an effect on metabolic parameters. However, the large prospective trials are needed to confirm the findings.”

Source: The Journal of Nutritional Biochemistry
Volume 43, May 2017, Pages 1–10
“Physiological effects of epigallocatechin-3-gallate (EGCG) on energy expenditure for prospective fat oxidation in humans: A systematic review and meta-analysis”
Authors: M.P. Kapoor et al.