Studies suggest that n-3 polyunsaturated (omega-3) fatty acids have beneficial effects on cardiovascular disorders including anti-inflammatory, antithrombotic, hypolipemic and vasodilatory effects and contribute to primary and secondary prevention of ischemic heart disease in the general population (Hirafuji et al. 2003; Simopoulos 1999). Omega-3 fatty acids are found primarily in fatty fish and in smaller amounts in flax, soy, canola, olive and wheat germ oils and black walnuts. Studies have also suggested that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation may result in changes in red blood cells (Andersson et al. 2002; Bruckner et al. 1987; Cartwright et al. 1985; Terano et al. 1983) which in turn may improve oxygen delivery to working muscles. Another study has shown that fish oil supplementation may facilitate fat oxidation (Delarue et al. 2003). Supplementation with EPA and DHA may improve VO2 max and aerobic performance.
Javierre et al. (2005) assessed the effects on lipid profile and fasting blood glucose in 19 adult males with SCI at 3 and 6 months following daily supplementation of 1.5 grams DHA and 0.75 grams of EPA. Despite significant increases in the plasma concentration of DHA and EPA, plasma concentrations of glucose, total cholesterol, HDL, LDL, very low density lipoprotein cholesterol (VLDL), and triglycerides did not show differences as the result of n-3 fatty acid supplementation.
In a follow-up study Javierre et al. (2006) determined whether omega-3 fatty acid supplementation contributed to improved muscle strength and endurance capacity in persons with SCI. Twenty-one males, 18 with paraplegia and three with tetraplegia, underwent global physical evaluations at baseline, three months and six months of receiving omega-3 fatty acid supplementation. Participants continued with their usual diet while taking 1.5 grams per day of DHA and 0.60 grams per day of EPA plus 9 mg of alpha tocopherol provided in capsules; two capsules at each of three meals were consumed. No adverse effects were observed during the supplementation period. Increases in the concentrations of plasma DHA and EPA were observed. Body weight of the participants was stable during the study. There was an observed improvement in the functional capacity of the neuromuscular system as shown in enhanced strength and endurance of the upper-body musculature in the tests performed by the subjects.
There is level 4 evidence (from one pre-post study: Javierre et al. 2005) that daily supplementation with DHA (1.5 g) and EPA (0.75 g) increases plasma DHA and EPA levels but does not alter total cholesterol, very low-, low-, or high-density lipoprotein, triglycerides, or glucose.
There is level 4 evidence (from one pre-post study: Javierre et al. 2006) that DHA and EPA supplementation increases upper body strength and endurance in persons with SCI.