Effect of omega‐3 fatty acid supplementation on indicators of membrane fluidity

Abstract

Membrane fluidity is a central aspect of cell physiology that can be modulated by fatty acid (FA) intake. Increasing dietary omega‐3 fatty acids (n‐3 FA) increases n‐3 FA in membrane phospholipids, which in turn may influence the fluidity and permeability of the plasma membrane and mitochondrial bilayers. The altered membrane biodynamics may explain molecular mechanisms underlying health effects associated with n‐3 FA and may affect cellular energy production. We investigated the effect of low levels of marine‐sourced n‐3 FA supplementation on selected indicators of membrane fluidity in healthy volunteers. Specifically, we looked at the ratio of saturated to polyunsaturated FA, % saturated FA, % lignoceric and nervonic acids (C24:0 + 24:1 n‐9), % omega‐7 FA and % docosahexaenoic acid (DHA, C22:6 n3) in red blood cell (RBC) membranes. Thirty one men and women took a daily supplement providing 1070 mg total n‐3 FA, including 480 mg docosahexaenoic acid, for 8 weeks. Subjects were asked not to change their diet or exercise pattern. Results are shown below. Of the selected indicators of membrane fluidity measured, only % DHA in RBC was significantly higher after the eight weeks of supplementation (p<0.05). This study shows that supplementation with low levels of marine sourced n‐3 FA increases % DHA in RBC membranes. This increase may alter membrane fluidity and so enhance cellular energy output and affect vital membrane processes such as transport and signalling.