For Popeye, spinach was the key to extra muscle. For the mice in a new University of Iowa study, it was apples, or more precisely a waxy substance called ursolic acid that's found in apple peel. The UI study, published in the June 8 issue of the journal Cell Metabolism, showed that ursolic acid reduced muscle atrophy (also known as muscle wasting) and promoted muscle growth in mice. It also reduced fat, blood sugar levels, cholesterol and triglycerides in the animals. The findings suggest that the compound may be useful for treating muscle wasting and possibly metabolic disorders such as...