WOLLONGONG, Australia—Supplementation with fish oil may improve skeletal muscle function and recovery, according to a new study (Br J Nutr. ePub 9 Aug 2010. DOI: 10.1017/S0007114510002928). Researchers from the University of Wollongong, Australia, noted fish oil modulates the fatty acid composition of muscle membranes; such changes in heart membrane composition have been linked to enhanced mechanical performance and modulations in oxygen consumption. They sought to determine whether changing skeletal muscle membrane composition in the legs could impact muscle function.
In the eight-week animal trial, male Wistar rats were fed diets rich in saturated fat (SF), linoleic acid (an omega-6 polyunsaturated fatty acid) or fish oil (high in omega-3 polyunsaturated fatty acids). The hindlimb skeletal muscle perfused using the animal’s own blood was then stimulated via the sciatic nerve to contract in repeated 10 minute bouts.
Animals on the n-3 duet had markedly increased levels of docosahexaenoic acid (DHA) and total omega-3s and decreased the n-6:n-3 ratio in red and white skeletal muscle membranes. There was no difference among groups in initial twitch tension; however, the fish oil group maintained greater twitch tension within all contraction bouts and recovered better during rest to produce greater twitch tension throughout the final contraction bout. In addition, oxygen consumption of the hindlimb muscle during contraction was significantly lower in the omega-3 supplemented group compared with the SF group; the animals fed fish oil also had a higher O2 efficiency index than the other two groups. The team concluded membrane incorporation of DHA following fish oil feeding increased the efficiency of oxygen consumption in the muscles and promoted resistance to muscle fatigue.