title: The relation between the omega-3 index and arachidonic acid is bell shaped: synergistic at low EPA+DHA status and antagonistic at high EPA+DHA status.
abstract: BACKGROUND
  The relation between docosahexaenoic (DHA) and eicosapentaenoic (EPA) vs. arachidonic acid (AA) seems characterized by both synergism and antagonism.
  
  
  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 (<2g%) exhibited positive relationships; those with high RBC-EPA+DHA (>8g%) negative relationships. Antagonism in UA and UV could not be demonstrated.
  
  
  CONCLUSIONS
  Both synergism and antagonism might aim at a balance between ω6 and ω3 long-chain polyunsaturated fatty acid (LCP) to maintain homeostasis. Synergism might be a feature of low LCPω3 status. AA becomes suppressed by antagonism from an RBC-EPA+DHA >8g%.
authors.affiliation: Laboratory Medicine, University Medical Center Groningen (UMCG), 9700 RB Groningen, The Netherlands. M.luxwolda@lc.umcg.nl
authors.forename: Martine F
authors.initials: MF
authors.lastname: Luxwolda
authors.forename: Remko S
authors.initials: RS
authors.lastname: Kuipers
authors.forename: Ella N
authors.initials: EN
authors.lastname: Smit
authors.forename: Francien V
authors.initials: FV
authors.lastname: Velzing-Aarts
authors.forename: D A Janneke
authors.initials: DA
authors.lastname: Dijck-Brouwer
authors.forename: Frits A J
authors.initials: FA
authors.lastname: Muskiet
mesh_terms: D000328:Adult; D016718:Arachidonic Acid / Q000097:blood* / Q000378:metabolism; D002675:Child, Preschool; D004032:Diet; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000097:blood* / Q000378:metabolism; D015118:Eicosapentaenoic Acid / Q000097:blood* / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009752:Nutritional Status; D011247:Pregnancy; D014469:Umbilical Arteries / Q000378:metabolism; D014470:Umbilical Cord / Q000098:blood supply / Q000378:metabolism; D055815:Young Adult
chemical_list: D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid; D015118:Eicosapentaenoic Acid