31 January 2011
Dietary Omega-3 Fatty Acid Supplementation Increases the Rate of Muscle Protein Synthesis in Older Adults: a Randomized Controlled Trial
Smith, G. et al., Am. J. Clinical Nutr., 93: 402-412 , 2011
Division of Geriatrics and Nutritional Science, Washington University School of Medicine , Saint Louis, MO, USA
The primary purpose of this research trial was to determine if omega-3 fatty acids from marine sources (as DHA/EPA) could influence muscle protein synthesis in older adults. This group was chosen since the loss of muscle mass with aging is a major public health concern. For this purpose, elderly adults (average age of 71 years) were randomly assigned to receive either supplementary corn oil (control group) or omega-3 (1.5 gm DHA plus 1.9 gm EPA daily ) for 8 weeks. Muscle protein synthesis was measured under basal conditions or in response to amino acid and insulin infusion using tracer technology (labeled amino acid) and gas chromatographic-mass spectrometric analyses. Corn oil supplementation had no effect on either the basal muscle protein synthesis rate or on the increase in the rate of muscle synthesis in response to amino acid and insulin infusion. In contrast , omega-3 supplementation had no effect on basal rates of muscle protein synthesis but significantly increased the response to amino acid and insulin infusion such that the fractional muscle protein synthesis rate was increased by 71 %..
Dr. Holub’s Comments:
Age-related ‘sarcopenia’ is characterized by a progressive decrease in muscle mass which leads to overall weakness and fraility. It remains to be evaluated if DHA/EPA omega-3 fatty acid supplementation may offer a safe and cost-effective treatment for preventing or treating age-related sarcopenia. The cellular mechanisms which underlie the effects of omega-3 supplementation on muscle protein synthesis are worthy of future investigation.