MUENSTER, Germany—Researchers found moderate amounts of omega-3 fatty acids are effective in improving lipid profiles of normolipidemic humans ( J Nutr. 2009;135(9):861-68).
A controlled parallel study was conducted in 74 healthy normolipidemic men and women aged 19 to 43 years. Participants were randomly assigned to one of three interventions and consumed a total intake of 4.4 g/d alpha-linolenic acid (ALA; ALA group), 2.2 g/d eicosapentaenoic acid (EPA; EPA group), and 2.3 g/d DHA docosahexaenoic acid (DHA; DHA group) for six weeks. Fatty acid ethyl esters were incorporated into margarines, which replaced the participant's normal spread.
The ALA, EPA or DHA intake led to a significant enrichment of the low-density lipoprotein (LDL) with the respective omega-3 fatty acid. In addition, LDL EPA contents in the ALA group increased by 36 percent (P<0.05) with no changes in LDL DHA. The EPA intervention led to an additional enrichment with DHA (24 percent; P<0.00), whereas the DHA intervention further increased the amount of EPA (249 percent; P<0.001). ALA, EPA or DHA intake did not affect fasting serum concentrations of total and LDL cholesterol, but fasting serum triacylglycerol concentrations significantly decreased in the EPA (–0.14 mmol/L) and DHA (–0.30 mmol/L) interventions and also in the ALA intervention (–0.17 mmol/L). DHA intake significantly increased serum HDL cholesterol, whereas no changes were found with ALA or EPA intake. Researchers concluded data supported the hypothesis that isolated dietary ALA, EPA and DHA intakes lead to differential enrichment in LDL due to interconversion.