Chronic effects of catechin ingestion on energy expenditure by brown adipose tissue in humans - Brown adipose tissue and catechin

Whole-body energy expenditure (EE) at 27C and 19C was measured in 10 healthy male subjects, before and 5 wk after daily ingestion of beverages containing 1080 mg or 0 mg (placebo) catechin. Before the ingestion of either catechin or placebo, EE at 19C was slightly higher than that at 27C. After the 5-wk ingestion of catechin, EE at 19C was markedly higher than that at 27C, while EE at 27C was similar to that before the ingestion. Cold-induced thermogenesis (CIT), calculated from the difference in EE at 19C and 27C, was about 198 kcal/day after catechin ingestion, which was significantly higher than that before the ingestion (92 kcal/day). After placebo ingestion, CIT was 99 kcal/day, being almost equal to that before the ingestion (70 kcal/day). Cold-induced fat oxidation also increased significantly after the catechin treatment, but not after the placebo treatment. No notable effect of catechin ingestion was found in body weight and body fat content. Considering that CIT is an index of brown adipose tissue (BAT) activity, the present results suggest that daily ingestion of catechin may recruit BAT in humans. 1. The 3rd International Conference on Recent Advances and Controversies in Measuring Energy Metabolism, October, 2014, Tokyo, Japan