Dietary omega-3 fatty acid supplementation increases the rate of muscle protein synthesis in older adults: a randomized controlled trial.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 21159787 · doi:10.3945/ajcn.110.005611
What was done
Sixteen healthy older adults were randomly assigned to receive either dietary omega-3 fatty acids or corn oil (control) for 8 weeks. The rate of muscle protein synthesis and phosphorylation of anabolic signaling elements (mTOR Ser2448 and p70s6k Thr389) were evaluated before and after supplementation under basal postabsorptive conditions and during a hyperaminoacidemic-hyperinsulinemic clamp.
What was found
Corn oil supplementation had no effect on muscle protein synthesis rate or anabolic signaling phosphorylation. Omega-3 supplementation did not change basal muscle protein synthesis (0.051 ± 0.005%/h before vs. 0.053 ± 0.008%/h after; P = 0.80), but significantly augmented the hyperaminoacidemia-hyperinsulinemia-induced increase in muscle protein synthesis rate (from 0.009 ± 0.005%/h above basal to 0.031 ± 0.003%/h above basal; P < 0.01). This was accompanied by increased p70s6k(Thr389) phosphorylation (P < 0.01) and a trend toward increased mTOR(Ser2448) phosphorylation (P = 0.08).
Why it matters
Omega-3 supplementation enhances muscle protein synthesis sensitivity to hyperaminoacidemia and hyperinsulinemia in older adults, offering a potential nutritional strategy against sarcopenia.
Limits
The sample size was very small (n = 16). The trial assessed acute fractional synthesis rates under experimental clamp conditions rather than long-term functional endpoints such as muscle mass or physical strength, and specific supplement dosages were not reported in the abstract.
Cited by
- supports Studies by Bettina Mittendorfer's group showed that omega-3 fatty acid supplementation enhances the muscle protein synthetic response to amino acid infusion in both younger and older adults.
- supports Studies by Bettina Mittendorfer's group, led by Gordon Smith, demonstrated an enhanced muscle protein synthetic response to amino acid infusion following omega-3 supplementation in both younger and older adults.
- supports The enhanced muscle protein synthetic response to omega-3s in Gordon Smith and Bettina Mittendorfer's studies occurred without significant changes in circulating inflammatory markers.
- supports In animal and cell studies, as well as Bettina Mittendorfer's human studies, omega-3 potentiation of muscle protein synthesis is associated with activation of the mTOR-p70S6K signaling pathway.
- supports Acute studies demonstrate that omega-3 fatty acid intake has beneficial effects on muscle development, particularly in older adults.