The relation between the omega-3 index and arachidonic acid is bell shaped: Synergistic at low EPA plus DHA status and antagonistic at high EPA plus DHA status

Introduction: The relation between docosahexaenoic (DHA) and eicosapentaenoic (EPA) vs. arachidonic acid (AA) seems characterized by both synergism and antagonism. Materials and methods: Investigate the relation between EPA + DHA and AA in populations with a wide range of EPA + DHA status and across the life cycle. EPA + DHA and AA were determined in erythrocytes (RBC; n=1979), umbilical arteries (UA; n=789) and umbilical veins (UV; n=785). Results: In all compartments, notably RBC, the relation between EPA + DHA and AA appeared bell-shaped. Populations with low RBC-EPA + DHA ( <2 g%) exhibited positive relationships; those with high RBC-EPA+DHA ( > 8 g%) negative relationships. Antagonism in UA and UV could not be demonstrated. Conclusion: Both synergism and antagonism might aim at a balance between omega 6 and omega 3 long-chain polyunsaturated fatty acid (LCP) to maintain homeostasis. Synergism might be a feature of low LCP omega 3 status. AA becomes suppressed by antagonism from an RBC-EPA+DHA > 8 g%. (C) 2011 Elsevier Ltd. All rights reserved.