Ursolic acid, a substance that occurs naturally in apple peels, has recently been shown to help prevent obesity, metabolic syndrome, and fatty liver disease in mice. The study, conducted at the University of Iowa, found that the ursolic acid produced increased skeletal muscle and brown (good) fat in the test mice. The increased muscle mass and brown fat increased the mice’s resting metabolism, burning more calories.
The mice in the study were fed a high-fat diet, which has previously been shown to induce obesity and metabolic syndrome in mice. The mice that were also fed ursolic acid had reduced levels of obesity, metabolic syndrome, and fatty liver disease. This is despite the fact that the mice fed ursolic acid ate more than the mice that ate only the high-fat diet.
Additionally, the mice that were fed ursolic acid had normal blood glucose levels, gained less weight than the other mice, and did not have any fatty liver disease. There was no difference in the amount of exercise between the two groups of mice.
It is unknown if ursolic acid will have the same result of increased skeletal muscle and increased brown fat in humans.
Ursolic Acid Increases Skeletal Muscle and Brown Fat and Decreases Diet-Induced Obesity, Glucose Intolerance and Fatty Liver Disease; PLoS One; June 20, 2012