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 Feb;93(2):402-12. doi: 10.3945/ajcn.110.005611. Epub 2010 Dec 15.


Background: Loss of muscle mass with aging is a major public health concern. Omega-3 (n-3) fatty acids stimulate protein anabolism in animals and might therefore be useful for the treatment of sarcopenia. However, the effect of omega-3 fatty acids on human protein metabolism is unknown.

Objective: The objective of this study was to evaluate the effect of omega-3 fatty acid supplementation on the rate of muscle protein synthesis in older adults.

Design: Sixteen healthy, older adults were randomly assigned to receive either omega-3 fatty acids or corn oil for 8 wk. The rate of muscle protein synthesis and the phosphorylation of key elements of the anabolic signaling pathway were evaluated before and after supplementation during basal, postabsorptive conditions and during a hyperaminoacidemic-hyperinsulinemic clamp.

Results: Corn oil supplementation had no effect on the muscle protein synthesis rate and the extent of anabolic signaling element phosphorylation in muscle. Omega-3 fatty acid supplementation had no effect on the basal rate of muscle protein synthesis (mean ± SEM: 0.051 ± 0.005%/h compared with 0.053 ± 0.008%/h before and after supplementation, respectively; P = 0.80) but augmented the hyperaminoacidemia-hyperinsulinemia-induced increase in the rate of muscle protein synthesis (from 0.009 ± 0.005%/h above basal values to 0.031 ± 0.003%/h above basal values; P < 0.01), which was accompanied by greater increases in muscle mTOR(Ser2448) (P = 0.08) and p70s6k(Thr389) (P < 0.01) phosphorylation.

Conclusion: Omega-3 fatty acids stimulate muscle protein synthesis in older adults and may be useful for the prevention and treatment of sarcopenia. This trial was registered at clinical as NCT00794079.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Amino Acids / metabolism
  • Corn Oil / metabolism
  • Corn Oil / pharmacology
  • Dietary Fats / metabolism*
  • Dietary Supplements*
  • Fatty Acids, Omega-3 / metabolism
  • Fatty Acids, Omega-3 / pharmacology*
  • Female
  • Humans
  • Hyperinsulinism
  • Insulin / metabolism
  • Male
  • Muscle Proteins / biosynthesis*
  • Phosphorylation / drug effects
  • Protein Biosynthesis / drug effects
  • Sarcopenia / metabolism
  • Sarcopenia / physiopathology
  • Sarcopenia / prevention & control*
  • Signal Transduction / drug effects


  • Amino Acids
  • Dietary Fats
  • Fatty Acids, Omega-3
  • Insulin
  • Muscle Proteins
  • Corn Oil

Associated data