Nutrient - Omega 3 fatty acids may help fight age-related loss of muscle mass and strength
Reputable studies from around the world are helping to uncover new details about how omega-3 fatty acids may help protect us from chronic disease. Now, researchers at Washington University School of Medicine have unearthed yet another possible benefit from taking these fatty acids – helping to combat age-related loss in muscle mass and strength.
As people age, muscle function can deteriorate. Muscle mass declines, and with it, muscle strength. Sarcopenia, a more debilitating loss of muscle function, affects 50% of men and 30% of women who are 80 years of age or older.
A key factor in sarcopenia is the rate of muscle protein production, which begins to slow down when people age. As muscle and it’s protein content diminish, strength also declines. This loss of strength makes it more difficult to successfully perform the normal physical tasks that are needed for daily living and that we take for granted, such as walking, showering, standing up from a chair, lifting light objects, and caring for one’s personal needs.
Muscle loss also slows down the body’s metabolism, increasing susceptibility to weight gain in the midsection. This type of weight gain is a major risk factor for insulin resistance, type-2 diabetes, hypertension and atherosclerosis.
Resistance exercise has been shown to be a powerful intervention in the fight against sarcopenia, by helping to prevent loss of muscle mass and improve muscle strength. Now, a new study reported in The American Journal of Clinical Nutrition, and funded by the National Institutes of Health, provides hope that high doses of long-chain omega-3 fatty acids may also help to counter sarcopenia.
Researchers at the Center for Human Nutrition at Washington University School of Medicine in St. Louis, randomly assigned healthy adults with an average age of 71, to receive either corn oil or 4 grams per day of fish oil (containing 1.86 grams EPA and 1.5 grams of DHA) for a period of 8 weeks.
Muscle protein is made of a rather small group of molecules, called amino acids, and insulin increases protein synthesis by facilitating the transport of amino acids into the muscle cell.
Study participants receiving the omega-3s saw an improvement in the rate of muscle protein synthesis in response to an increase in blood levels of amino acids and insulin. The researchers also showed that the omega-3 fatty acids resulted in a greater activation of a signal pathway called mTOR that is known to control protein synthesis and muscle mass.
While the exact mechanism by which the omega-3s exert their beneficial effects on muscle synthesis is still unclear, the researchers commented: “Dietary omega-3 fatty acid supplementation could potentially provide a safe, simple and low-cost intervention to combat sarcopenia.” The researchers plan to perform follow-up trials involving more subjects in the near future.
Smith GI, Atherton P, Reeds DN et al. Dietary omega-3 fatty acid supplementation increases the rate of muscle protein synthesis in older adults: a randomized controlled trial. Am J Clin Nutr 2011; 93:402-12.