Effects of stearidonic acid on serum triacylglycerol concentrations in overweight and obese subjects: a randomized controlled trial

Background/objectives:Eicosapentaenoic acid (EPA), which may reduce the coronary heart disease (CHD), can be synthesized at low rates from alpha-linolenic acid (ALA). The rate-limiting step for this conversion Delta6-desaturation of ALA into stearidonic acid (SDA). Thus providing in SDA may increase endogenous synthesis of EPA, which may subsequently serum triacylglycerol concentrations, an effect frequently observed supplementation. We therefore studied the effects of Echium oil on serum triacylglycerol concentrations and the omega-3 index, which correlate with the risk for CHD.Subjects/methods:A randomized, double-blind, placebo-controlled crossover trial was conducted, in which 36 healthy and slightly obese subjects daily received 10 g of Echium oil (providing SDA) or a high oleic acid sunflower oil (HOSO) as control for 6 weeks, washout period of at least 14 days. Four subjects dropped out. between periods were tested for statistical significance (P<0.05) using t-test.Results:Serum triacylglycerol and other lipid concentrations were significantly affected by consumption of Echium oil compared with HOSO. oil significantly increased percentage of EPA in red blood cell (RBC) with 0.14+/-0.25% (mean+/-s.d.) compared with HOSO (P=0.02). No effects on docosahexaenoic acid in RBC membranes or on the omega-3 index found.Conclusions:In healthy overweight and slightly obese subjects, an intake of SDA from Echium oil does not lower serum triacylglycerol concentrations. Despite an increase in the percentage of EPA in RBC the omega-3 index was not changed.European Journal of Clinical Nutrition online publication, 17 September 2014; doi:10.1038/ejcn.2014.193.