
Ursolic acid, found in apple skin, could help tackle Australia's obesity problem. Image: Shutterstock
An apple a day keeps the doctor — and the fat — away.
Eating an apple a day can keep the fat away — and help you stay healthy. Scientists at the University of Iowa (UI) have found a natural compound in apple peel boosts calorie burning and could dramatically reduce levels of obesity, a growing problem in Australia and the Western world.
Ursolic acid, which is responsible for the waxy sheen on apples, has previously been shown to help build muscle, and keeps cholesterol and blood sugar under control. Researchers at UI found that the compound also increased muscle mass and ‘good’ brown fat in mice, even when they were fed a high-fat diet. Muscle mass and brown fat are recognised for their calorie-burning potential.
In the study published in the journal PLoS ONE researchers fed mice a high fat diet for several weeks, with half of the rodents receiving the apple peel compound. They found that mice in the ursolic acid group ate more than the other mice, however gained less weight and also maintained normal blood sugar levels and did not develop obesity-related fatty liver disease.
“Ursolic acid increased skeletal muscle. Interestingly, it also reduced obesity, pre-diabetes and fatty liver disease. The increased muscle may be sufficient to explain how ursolic acid reduces obesity,” says Christopher Adams, who led the study. “However, we were surprised to find that ursolic acid also increased brown fat, a fantastic calorie burner. This increase may also help protect against obesity.”
Babies and children have more brown fat, which burns calories and helps keep them warm. By adulthood, all but a small amount of the brown fat cells have turned to white fat, which stores excess energy for later use. Experts have long been seeking ways to boost levels of adult brown fat to curb the obesity crisis.
“We don’t know how ursolic acid increases brown fat. Most importantly, we don’t know if ursolic acid will benefit people. Our next step is to determine if it can help patients,” adds Adams.
Previous research has shown apples help reduce the risk of stroke, bowel and breast cancers and even heart attacks. An apple with its skin on is a good source of fibre and has about 53 calories. Added to a balanced and nutritious diet, apples might even rival fish for their health benefits.
Source: Eureka Alert