BackgroundDietary fish is a rich source of Omega-3 poly-unsaturated fatty acids (PUFAs). These compounds may have protective effect against cardiovascular events possibly by modifying lipid profiles. Consequently, fish oil supplements are produced commercially to complement low fish intake. It is not clear if both interventions have similar effects. The aim of this trial was to compare the anti-hyperlipidemic effect of omega3 fatty acid supplements with fresh fish.MethodA total of 106 patients with hyperlipidemia were randomized. One group received 2 g/day of omega-3 capsules for a period of 8 weeks and the other group received a mean of 250 g trout fish twice weekly (for dinner and lunch) for the same time period. The effects of these diets on the lipid profile after the intervention were compared between the two groups.ResultsData from 48 patients in fish oil group and 47 patients from fish group was used for final analysis. In both groups, total cholesterol, non-HDL cholesterol, triglyceride (TG) levels, and Castelli I index (total cholesterol/HDL ratio) were reduced significantly following the treatment; however, dietary-fish intake had a more pronounced effect (−85.08 ± 74.82 vs. −30.75 ± 89.00, P < 0.001; 75.06 ± 35.43 vs. −16.93 ± 40.21, P < 0.001; −66.55 ± 30.79 vs. −12.7 ± 35.48, P = 0.003; and −0.77 ± 1.39 vs. −3.02 ± 1.85, P < 0.001; respectively). HDL level was increased in both groups with a higher effect in dietary fish group (4.47 ± 7.83 vs. 8.51 ± 8.79, P = 0.022). Atherogenic (Log [TG/HDL ratio]) and Castelli II (LDL/HDL ratio) indices did not change in fish oil group while were reduced significantly by fresh fish consumption (−0.04 ± 0.27 vs. −0.26 ± 0.17, P < 0.001; and 0.15 ± 0.7 vs. -1.32 ± 1.15, P < 0.001, respectively). LDL level was increased in the supplementation group, while it was significantly reduced in the dietary-fish group (+18.7 ± 24.97 vs. −22.75 ± 27.28, P < 0.001).ConclusionConsumption of fresh fish seems to be superior in positively modifying the lipid profiles which may have important translations in the occurrence of cardiovascular events.