Green tea extract with exercise reduces fatty liver disease, study finds

The combination of green tea extract and exercise reduced the severity of obesity-related fatty liver disease by 75 percent in mice fed a high-fat diet, according to new research from the Pennsylvania State University in Centre County, Pennsylvania, and published in The Journal of Nutritional Biochemistry.

In the study, mice fed a high-fat diet for 16 weeks that consumed green tea extract and exercised regularly by running on a wheel were found to have just a quarter of the lipid deposits in their livers compared to those seen in the livers of a control group of mice. Mice that were treated with green tea extract alone or exercise alone had roughly half as much fat in their livers as the control group.

Researchers also measured the protein and fat content in their feces. They found that the mice that consumed green tea extract and exercised had higher fecal lipid and protein levels.

Nonalcoholic fatty liver disease is a significant global health problem that is expected to worsen, researchers said in a statement. Because of the high prevalence of risk factors such as obesity and type 2 diabetes, fatty liver disease is forecast to afflict more than 100 million people by 2030.

The researchers found that mice treated with both green tea extract and exercise had higher expression of genes related to the formation of new mitochondria. That gene expression is important, researchers said, because it provides markers that will help researchers understand the mechanism by which green tea polyphenols and exercise might work together to mitigate fatty liver deposits.

More research is needed to see if there is a synergy created by green tea extract and exercise working together to reduce fat deposited in the liver, or if the effects are simply additive. However, the results point to a potential health strategy for people, researchers said.

"I believe people should engage in more physical activity, and replacing high-calorie beverages with decaffeinated, diet green tea, which has no calories, is a smart move," said Joshua Lambert, PhD, associate professor of food science and lead author of the study. "Combining the two might have health benefits for people, but we don't have the clinical data yet."