n-3 fatty acid effects on lipids, lipoproteins, and apolipoproteins at very low doses: results of a randomized controlled trial in hypertriglyceridemic subjects.

Although the hypotriglyceridemic effect of large doses of n-3 fatty acids (n-3 FAs) is well established, the effects of prolonged use of very low doses on lipids, lipoproteins, and apolipoproteins have not been clearly defined. This investigation compares the relative effects of very low, clinically practical doses of n-3 FAs on lipids, lipoproteins, and apolipoproteins in hypertriglyceridemic subjects. Ten subjects received 2.2 g n-3 FAs/d (group 1), seven received 1.1 g n-3 FAs/d (group 2), and eight received olive oil (group 3, placebo control) for 20-wk treatment period. In group 1, both low-density-lipoprotein cholesterol (LDL-C) and LDL-apolipoprotein B concentrations increased significantly from baseline values (28% and 23%, respectively; p less than 0.05) after treatment. Compared with the placebo group, the increase in LDL apolipoprotein B in both fish oil groups was statistically and clinically significant (p less than 0.05). Only minor changes in plasma triglyceride concentrations occurred. The data suggest that very low doses of n-3 FAs may cause potentially adverse increases in LDL-C and LDL-apolipoprotein B concentrations.