The findings suggest that omega‐3 polyunsaturated fatty acid (PUFA)‐enriched fish oil (FO) capsules do not give the muscle-building advantage in the gym other studies have suggested.
The team from Sterling University in Scotland gathered 20 subjects, who weight-trained regularly, and gave them five grams of fish oil every day for eight weeks.
The weight lifters then ate a large breakfast before performing a number of leg presses and leg extensions, consuming 30 g of protein powder afterwards.
Muscle biopsies were taken before and after the trial to measure how much of the omega-3 fats were taken up by the muscle cells.
The results demonstrated that FO supplementation did not significantly enhance rates of muscle growth in response to ingestion of 30 g of whey protein in healthy, resistance‐trained young men.
Additionally, FO supplementation did not significantly enhance muscle growth rate when the consumption of 30 g of whey protein was preceded by a bout of high‐intensity resistance exercise.
Although there is growing evidence for the efficacy of FO supplementation to enhance muscle growth, previous studies that have demonstrated this have also included specific criteria in its methodology.
One study that administered amino acids through an intravenous infusion could not be considered a viable means for the general population to consume protein. Another study showed the metabolic response to infusion of amino acids differs from ingestion of an intact protein.
“Data from this study may suggest that FO supplementation alters anabolic signalling processes, without modulating rates of myofibrillar MPS (Muscle Protein Synthesis) in response to protein ingestion, or when resistance exercise precedes protein ingestion in healthy, resistance‐trained young males,” the study said.
The study also pointed toward research that demonstrated an oral 30 g dose of whey protein could maximally stimulate rates of myofibrillar MPS in young men.
“We propose it is possible that the ingestion of 30 g of whey protein in the current study maximised rates of myofibrillar MPS to the extent that FO supplementation would not have exerted a further anabolic influence or was undetectable.”
However, this finding has been contradicted in a study that supplemented elderly women with FO during 12 weeks of resistance exercise training. These women received enhanced skeletal muscle strength and functional capacity.
Even in the absence of resistance exercise one study demonstrated six months of FO supplementation improves muscle mass and function in elderly men.
The authors were quick to acknowledge that older individuals generally required a greater amount of protein to maximise rates of muscle growth compared to the young, yet they often failed to consume adequate amounts of protein throughout the day.
“Therefore, in studies in which protein intake was not controlled, and we speculate, suboptimal, it is plausible that feeding and exercise‐induced rates of MPS were also suboptimal, and thus a potentiation by FO supplementation on MPS and muscle mass was observed.”
Source: Physiological Reports
Published online ahead of print, DOI: 10.14814/phy2.12715
“Fish oil supplementation suppresses resistance exercise and feeding‐induced increases in anabolic signaling without affecting myofibrillar protein synthesis in young men.”
Authors: Chris McGlory, Sophie Wardle, Lindsay Macnaughton, Oliver Witard, Fraser Scott, James Dick, J. Gordon Bell, Stuart Phillips, Stuart Galloway, D. Lee Hamilton, Kevin Tipton