Researchers at the University of Iowa have discovered that a waxy substance known as ursolic acid found in apple peels reduces muscle atrophy and promotes muscle growth in mice. It was also found to reduce fat, blood sugar levels, cholesterol and triglycerides, hence, could be used in treating muscle wasting and metabolic disorders such as diabetes. “Muscle atrophy causes many problems. It is very common and affects everyone at some point in their lives, during illness or aging. However, there is no medicine for it,” said Christopher Adams, Endocrinologist and senior author of the study. “We studied muscle gene activity in people with atrophy and used that information to find chemicals that might block it. One of those chemicals was especially interesting. It is called ursolic acid and it is particularly concentrated in apple peels,” he added. According to the researchers, ursolic acid reduced muscle atrophy by helping insulin and insulin-like growth factor-1 (IGF1) to build muscles. “It did this by helping two hormones that build muscle: insulin-like growth factor-1 (IGF1) and insulin. Because ursolic acid stimulates muscle growth, it reduces muscle atrophy. Surprisingly, it had some other beneficial effects in mice, for example, it reduced body fat, and lowered blood glucose and cholesterol.” Additionally, although ursolic acid increased muscle weight in mice, it did not increase total body weight. Furthermore, mice fed ursolic acid were found to have less body fat than mice not fed the compound. The study was published in the current issue of the Cell Metabolism journal.
