Obesity is the result of a chronic imbalance between energy intake and expenditure. The energy excess from food is metabolized in the liver-tissue to fatty acids, which are then released to the blood stream. Here they are taken up by fat cells and stored in the adipose tissue. In case of a demand for energy the whole process is reversed: fatty acids are now transported to the liver again, where they are degraded and provide new energy by a process called ß-oxidation.
Hyun-Jin Kim, Gyeongsang National University, Republic of Korea, and colleagues tested the impact of green tea on the lipid metabolism. They used mice, either fed a normal or a high-fat diet (HFD), and supplemented the food with either normal or caffeine- and theanine-enriched green tea. The metabolic profiles of the liver tissue were subsequently analyzed by liquid-chromatography mass spectrometry (LC-MS). As expected, ß-oxidation is reduced under HFD, since requirements for energy are already met by this diet. However, the supplement of caffeine- and theanine-enriched green tea leads to an alleviation of HFD-induced changes: it reactivates the ß-oxidation, resulting in enhanced fatty acid degradation and a reduction in adipose tissue.
- Green tea changes serum and liver metabolomic profiles in mice with high-fat diet-induced obesity,
Lan-Sook Lee, Ji Hea Choi, Mi Jeong Sung, Jin-Young Hur, Haeng Jeon Hur, Jong-Dae Park, Young-Chan Kim, Eun-Ji Gu, Byungjin Min, Hyun-Jin Kim,
Mol. Nutr. Food Res. 2015.