Sarcopenia, or loss of muscle mass, is a common byproduct of aging, usually beginning between the ages of 40 and 45. The exact cause of sarcopenia remains unknown, but scientists believe an imbalance in muscle-protein synthesis and breakdown that occurs as people age is responsible. Researchers in France now believe that the elderly may be able to reduce, or even prevent, age-related muscle loss by consuming a diet rich in leucine, an essential amino acid.
In the study, two groups of rats - one young, one elderly - were fed diets supplemented with leucine. Before going on the leucine-rich diet, the older rats had shown a pattern toward excessive protein breakdown after a meal. After being fed the leucine diet for 10 days, however, the older rats' patterns of muscle-protein breakdown and synthesis were "totally suppressed," and appeared almost identical to the patterns seen in the younger rats.
Leucine cannot be manufactured by the body, and as such must be ingested through dietary protein. Good sources of leucine include meat, dairy products, soy, and beans; leucine also is available as a dietary supplement. If you are concerned about losing muscle, talk to your doctor of chiropractic about choosing foods and supplements that are high in leucine and incorporating them into your diet. For more information, visit www.chiroweb.com/find/tellmeabout/nutrients.html.
Combaret L, Dardevet D, Rieu I, et al. A leucine-supplemented diet restores the defective postprandial inhibition of proteasome-dependent proteolysis in aged rat skeletal muscle. Journal of Physiology, December 2005;569:489-499.