N-3 fatty acids have several beneficial effects on dyslipidemia and diabetes, conditions which are prevalent in the elderly. This study assessed the effects of low-dose n-3 fatty acids on serum lipid profile, lipoprotein(a), apolipoprotein B, fasting glucose, insulin, and insulin resistance in a group of elderly Iranians.

A 6-month randomized, double-blind placebo-controlled clinical trial was carried out in 124 elderly residents of Kahrizak Charity Foundation aged >or= 65. The intervention group was supplemented with 1 g/day fish oil capsule (with 180 mg eicosapentaenoic acid, EPA; and 120 mg docosahexaenoic acid, DHA; a total of 300 mg n-3 fatty acids as effective constituents). Fasting blood samples were collected at baseline and after 6 months of the trial.

There were no significant effects of fish oil on the studied variables in the intervention group. In the placebo group, serum triglyceride significantly increased and high-density lipoprotein cholesterol significantly decreased (p = 0.01 and p = 0.009, respectively). By repeated measurement analysis after adjustments, the overall decrease in serum triglycerides compared with placebo was significant (p = 0.04).

Supplementation with low dose n-3 fatty acids for 6 months could significantly protect elderly Iranians from a rise in serum triglycerides.