title: Dietary omega-3 fatty acid supplementation increases the rate of muscle protein synthesis in older adults: a randomized controlled trial.
abstract: 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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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 trials.gov as NCT00794079.
authors.affiliation: Washington University School of Medicine, St Louis, MO 63110, USA.
authors.forename: Gordon I
authors.initials: GI
authors.lastname: Smith
authors.forename: Philip
authors.initials: P
authors.lastname: Atherton
authors.forename: Dominic N
authors.initials: DN
authors.lastname: Reeds
authors.forename: B Selma
authors.initials: BS
authors.lastname: Mohammed
authors.forename: Debbie
authors.initials: D
authors.lastname: Rankin
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Rennie
authors.forename: Bettina
authors.initials: B
authors.lastname: Mittendorfer
mesh_terms: D000368:Aged; D000596:Amino Acids / Q000378:metabolism; D003314:Corn Oil / Q000378:metabolism / Q000494:pharmacology; D004041:Dietary Fats / Q000378:metabolism*; D019587:Dietary Supplements; D015525:Fatty Acids, Omega-3 / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006946:Hyperinsulinism; D007328:Insulin / Q000378:metabolism; D008297:Male; D009124:Muscle Proteins / Q000096:biosynthesis*; D010766:Phosphorylation / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects; D055948:Sarcopenia / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000596:Amino Acids; D004041:Dietary Fats; D015525:Fatty Acids, Omega-3; D007328:Insulin; D009124:Muscle Proteins; D003314:Corn Oil