Effects of duration of treatment and dosage of eicosapentaenoic acid and stearidonic acid on red blood cell eicosapentaenoic acid content.

Abstract Objective The purpose of this randomized, controlled, parallel group study was to characterize the relationships between dosages of stearidonic acid (SDA) and eicosapentaenoic acid (EPA), and incorporation of EPA into red blood cell (RBC) membranes over time. Methods Healthy subjects ( n =131) received capsules with placebo (safflower oil), SDA (0.43, 1.3, 2.6, or 5.2g/d) or EPA (0.44, 1.3, or 2.7g/d) for 12 weeks. RBC fatty acids were analyzed biweekly. Results RBC %EPA increased in all EPA and SDA groups ( p p =0.187). For theoretical intakes of EPA of 0.25, 0.5, and 0.89g/d, the amounts of SDA needed to achieve equivalent RBC EPA enrichment were 0.61, 1.89, and 5.32g/d (conversion efficiencies of 41%, 26%, and 17%), respectively. Conclusions SDA increased RBC %EPA in a dosage and time-dependent manner at intakes as low as 1.3g/d.