In a new study, researchers found that ursolic acid from apple peels reduced muscle atrophy (muscle wasting) and promoted muscle growth in mice. It also reduced fat, blood sugar, cholesterol, and triglyceride levels. The findings suggest that this natural remedy may be useful for treating muscle wasting and possibly metabolic disorders, such as diabetes.
Muscle atrophy, which is common as we grow older, can cause big problems. And there is no medicine you can take for it that will be effective. The researchers studied people with atrophy and used that information to find chemicals that might block the condition. One of those chemicals is ursolic acid — and it’s particularly concentrated in apple peels.
Could it be the reason behind an apple a day keeping the doctor away? Testing it in mice, which is where new medical ideas tend to begin, the researchers found that ursolic acid increased the size and strength of the mice’s muscles. It did so by helping two hormones that build muscle: insulin-like growth factor-1 (IGF1) and insulin. Because ursolic acid increased muscle, it reduced muscle atrophy. The additional benefits were a surprise: lowering body fat, blood glucose, and cholesterol.
When searching for a compound that could prevent atrophy, the researchers found that ursolic acid caused a pattern of gene expression that is the opposite of the pattern caused by atrophy. This suggested that ursolic acid might reverse atrophy. In follow-up experiments, the mice fed ursolic acid were indeed protected from muscle atrophy caused by both fasting and nerve damage. Furthermore, healthy mice fed ursolic acid developed larger, stronger muscles than mice that did not receive the compound.
All of this is something to consider for those who tend to peel their apples prior to munching on them. In many fruits, you never know w