Most metabolic disorders, which are characterized by excessive amounts of lipid or fat contents in the blood (hyperlipidemia), can be treated and prevented by following a healthy diet. A recent study published in the British Journal of Nutrition by scientists in Korea revealed fermented green tea (FGT) plays an important role in lipid metabolism by preventing the onset of obesity and cardiovascular events.
Generally, an imbalance in metabolic energy expenditure and intake leads to increased accumulation of fat, especially triglycerides (TAG), in different body tissues and results in the onset of various metabolic disorders such as obesity, type 2 diabetes, and cardiovascular diseases (CVD). Several drugs employed for treating increased lipid levels (hyperlipidemia) were found to be associated with serious medical complications. For this reason, natural products have been used in ameliorating hyperlipidemia and its related metabolic disorders by activating AMP-activated protein kinase (AMPK) and inhibiting the enzyme 3-hydroxy-3-methyl-glutaryl-CoA reductase. Green tea extract and its by-products not only have a significant impact on fatty acid metabolism but also enhance the activity of antioxidants in the body.
An animal experiment was conducted by Lee and his team in order to understand the role of fermented green tea (FGT) activity on lipid and glucose levels. Firstly, Dawley male rats (6-week-old rats) were maintained in a chamber (12 h dark for 12 h in a light cycle) with temperature ranging from 22–25°C with 40–50% humidity and fed with normal chow ad libitum for 1 week. For understanding the effect of fermented green tea (FGT) on TGA levels, researchers subjected animals to four different treatment groups: Saline, Triton (a lipoprotein lipase inhibitor), Triton + FGT, or Triton + fenofibrate (an anti-cholesterol medication).
Interestingly, study findings revealed that FGT had a significant effect on obesity by inhibiting pancreatic lipase activity (which is responsible for the breakdown of dietary fat) and reducing TAG levels by 26%. Secondly, pancreatic lipase activity was evaluated in Golden Syrian male hamsters (9-week-old) for understanding the mechanism of FGT influence on lipid metabolism. Based on the diet, which was administered orally, all the hamsters were divided into four different groups: Controls (water with the western diet), FF (positive control:western diet with 100 mg/kg body weight of FF) and two FGT groups (200 and 400 mg/kg body weight of FGT with the western diet). The results indicated a 22% increase in energy expenditure by various mechanisms through the induction of serotonin, a neurotransmitter, and activation of lipogenic gene expression. Finally, gut microbiota analysis indicated that FGT is associated with anti-obesity activity as it reduced the number of Firmicutes bacteria in hamsters. Therefore, FGT plays an important role in reducing plasma TAG levels through different molecular methods indicating that it is an important natural agent for preventing the onset of hypertriglyceridemia and obesity.
In conclusion, FGT act as an important hypotriglyceridemic agent for regulating abnormalities in lipid metabolism and its associated complications. Further research on the enhancement of gut bacteria by FGT would provide a better understanding of its hypotriglyceridemic properties.
Written By: Manche Santoshi, PhD