Omega 3 fatty acids-supplementation to competition athletes: impact on the biochemical indicators related to the lipid metabolism*

Purpose: To assess the effects of omega 3 fatty acid supplementation to swimmers on biochemical indicators. Methods: Male elite swimmers (n = 14) were assessed in a placebo-controlled randomized study over a 6-week (45-day) experimental period. The placebo group (GP) received mineral oil (n = 6) and the supplemented group (GOP) received fish oil (n = 8) containing a total of 950 mg of eicosapentaenoic acid and 500 mg of docosapentaenoic acid. Immediately before starting the supplementation (T0), as well as 15 (T15), 30 (T30) and 45 (T45) days after that point, blood samples were collected and analyzed by gas chromatography for fatty acids composition, and by specific commercial kits for plasmatic lipoproteins. Results: The results showed that the diets of the swimmers were unbalanced regarding the macronutrient ingestion/body weight ratio (g/kg). The analysis of the consumption frequency questionnaire showed that (1) the swimmers have not regularly ingested omega 3 dietary sources and (2) the fish consumption was below once a week for 85% of the sample. The plasmatic fatty acids profile presented an increase in omega 3 polyunsaturated fatty acids (p < 0.05) and decrease in arachidonic fatty acid in the supplemented group (p < 0.05). The fish oil supplementation led to a hypocholesterolemic effect, with a decrease in VLDL, LDL and total cholesterol blood levels. The HDL levels presented no significant differences between the groups in any moment of the study (p > 0.05). Conclusion: N-3 fatty acids supplementation to swimmers alters the biochemical indicators of the lipid metabolism, with an influence in the decrease of the cholesterol-rich plasmatic lipoproteins, so preventing cardiovascular diseases.