Effect of omega‐3 fatty acid suplementation on Omega‐3 Index and red blood cell (RBC) membrane fatty acid composition

Abstract

Omega‐3 fatty acids (n‐3 FA) have been shown from epidemiological studies and clinical trials to lower incidence of cardiovascular disease (CVD) in patients with pre‐existing CVD as well as in healthy individuals. In randomized secondary prevention trials fish or fish oil have been shown to lower total and coronary heart disease (CHD) mortality at intakes of about 1 g/day. The Omega‐3 Index (EPA + DHA expressed as % of total FA) has been proposed as a physiologically relevant, modifiable, independent and graded risk factor for death from CHD. RBC membrane FA composition correlates well with biomarkers of n‐3 FA including serum EPA and DHA, whole blood EPA, DPA and DHA and FA composition of cardiac tissue. The present dietary intervention study investigates the effect of a fish‐oil based, n‐3 FA supplement on Omega‐3 Index and RBC membrane FA composition. Thirty healthy men and women consumed a supplement providing 1070 mg total n‐3 FA (460 mg DHA, 480 mg EPA, and 80 mg other n‐3 FA) daily for 4 wks. At the end of this period there was a significant 24% increase (p<0.01) in the Omega‐3 Index (Fig.1). While there were no significant changes in % linoleic, gamma linoleic, and alpha linolenic acid; EPA, DPA and DHA significantly (p<0.01) increased compared to baseline values (0.76% versus 1.4%, 2.30% versus 2.58% and 5.49% versus 6.60% respectively), and % arachidonic acid significantly decreased (19.58% versus 18.83%, p<0.05). This study shows that RBC membrane FA composition and so Omega‐3 Index can change in a short time using a fish‐oil based supplement.