2 Muscle-Preserving Foods

Approximately 1 out of 3 adults age 50 and older suffer from sarcopenia, a progressive loss of muscle mass and strength, which can affect a person's energy and ability to perform daily activities.   Christopher Adams, from the University of Iowa (Iowa, USA), and colleagues explored the cause of age-related muscle weakness and atrophy, discovering the first example of a protein that causes muscle weakness and loss during aging. The protein, ATF4, is a transcription factor that alters gene expression in skeletal muscle, causing reduction of muscle protein synthesis, strength, and mass. The researchers also identified two natural compounds ursolic acid and tomatidine –found in apples and green tomatoes, respectively – which reduce ATF4 activity in aged skeletal muscle. The team fed elderly mice with age-related muscle weakness and atrophy a diet lacking or containing either 0.27 percent ursolic acid, or 0.05 percent tomatidine for two months. The scientists found that both compounds increased muscle mass by 10%, and more importantly, increased muscle quality, or strength, by 30%.  Writing that: “These results elucidate ATF4 as a critical mediator of age-related muscle weakness and atrophy,” the study authors submit that: “these results identify ursolic acid and tomatidine as potential agents and/or lead compounds for reducing ATF4 activity, weakness, and atrophy in aged skeletal muscle.”