Omega-3 polyunsaturated fatty acids augment the muscle protein anabolic response to hyperinsulinaemia-hyperaminoacidaemia in healthy young and middle-aged men and women.
Level 4 - case-series / case-control
Prospective uncontrolled before-and-after interventional study
PubMed 21501117 · doi:10.1042/CS20100597
What was done
Nine healthy adults aged 25–45 years received 8 weeks of long-chain omega-3 polyunsaturated fatty acid supplementation (4 g/day of Lovaza). Researchers measured muscle protein fractional synthesis rates using stable isotope-labeled tracer techniques, mTOR/p70S6K signaling pathway phosphorylation, and muscle protein, RNA, and DNA concentrations during basal post-absorptive conditions and during a hyperinsulinemic-hyperaminoacidemic clamp before and after the intervention.
What was found
Basal muscle protein fractional synthesis rate and basal signaling element phosphorylation did not change after supplementation. During the hyperinsulinemic-hyperaminoacidemic clamp, omega-3 supplementation increased the muscle protein fractional synthesis rate from 0.062 ± 0.004 to 0.083 ± 0.007%/h (P < 0.05) and phospho-mTOR (Ser2448) and phospho-p70S6K (Thr389) levels by ~50% (P < 0.05). Muscle protein concentration and the protein/DNA ratio were also significantly greater after supplementation (P < 0.05).
Why it matters
This study suggests that long-chain omega-3 fatty acids can enhance the anabolic response of skeletal muscle to hyperaminoacidemia and hyperinsulinemia in healthy young and middle-aged adults, extending findings previously seen only in aging or cachexia.
Limits
The sample size was very small (n = 9) and lacked a placebo or parallel control group, leaving open the possibility of time-dependent confounding. The anabolic stimulus evaluated was an intravenous clamp rather than standard oral protein intake or physical exercise.
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.
- context Acute studies demonstrate that omega-3 fatty acid intake has beneficial effects on muscle development, particularly in older adults.