Omega-3 Fatty Acids and Muscle Protein Synthesis

• Evaluate the effect of omega-3 fatty acid supplementation on skeletal muscle protein synthesis rates both in the basal, postabsorptive state and in response to infusion of insulin and amino acids in young and older adults [ Time Frame: Measurements taken prior to and following 8 weeks of supplementation ] [ Designated as safety issue: No ]
  

• Evaluate the effect of omega-3 fatty acid supplementation on anabolic signaling pathways in skeletal muscle [ Time Frame: Measurements taken prior to and following 8 weeks of supplementation ] [ Designated as safety issue: No ]
  
• Evaluate the effect of omega-3 fatty acid supplementation on inflammatory cytokines in the systemic circulation and inflammatory signaling pathways in skeletal muscle [ Time Frame: Measurements taken prior to and following 8 weeks of supplementation ] [ Designated as safety issue: No ]
  
• Compare muscle protein synthesis rates between men and women in the basal, postabsorptive state and in response to insulin and amino acid infusion [ Time Frame: prior to supplementation only ] [ Designated as safety issue: No ]
  

Loss of muscle mass is a normal consequence of aging. The decline in muscle mass is estimated to be 0.2-0.5% per year from 60 years old onwards in healthy subjects with the decline worsened by chronic illness, poor appetite and diet, and reduced physical activity in the elderly. Increased morbidity is demonstrable with as little as a 5% loss of muscle mass - therefore, treatments that can prevent or slow the progression of muscle loss with aging are much desired.

A major cause for loss of muscle mass in advanced age appears to be an impaired ability to stimulate the synthesis of muscle protein in response to increased levels of amino acids (the building blocks of proteins) and insulin as occurs after eating because of low-grade inflammation and insulin resistance in muscle of old persons. We propose that long-chain omega-3 polyunsaturated fatty acids (fish oil) slow the loss of muscle mass because fish oil has anti-inflammatory properties and increases the sensitivity of muscle protein synthesis to insulin and amino acids. We will test this by studying the effect of fish oil supplementation on the muscle protein synthesis process in young and older adults.