title: Linoleic acid is associated with lower long-chain n-6 and n-3 fatty acids in red blood cell lipids of Canadian pregnant women.
abstract: BACKGROUND
  Arachidonic (ARA), eicosapentaenoic (EPA), and docosahexaenoic (DHA) acids are important in membrane glycerophospholipids. Higher maternal blood ARA, EPA, and DHA concentrations in gestation are associated with higher maternal-to-fetal transfer of ARA, EPA, and DHA, respectively, which emphasizes the importance of maternal fatty acid status in gestation. As in the brain, red blood cell (RBC) ethanolamine phosphoglycerides (EPGs) are high in plasmalogen, ARA, and DHA.
  
  
  OBJECTIVE
  We determined the relation between dietary n-6 (omega-6) and n-3 (omega-3) fatty acid intakes and n-6 and n-3 fatty acids in RBC EPGs and phosphatidylcholine in near-term pregnant women.
  
  
  METHODS
  The subjects were 105 healthy Canadian pregnant (36 wk gestation) women. Fatty acid intakes were estimated by food-frequency questionnaire, and fasting venous blood samples were collected.
  
  
  RESULTS
  DHA and EPA intakes were positively associated with RBC EPG and phosphatidylcholine concentrations of DHA (rho = 0.309 and 0.369, respectively; P < 0.001) and EPA (rho = 0.391 and 0.228, respectively; P < 0.001) and inversely associated with RBC EPG 22:4n-6 and 22:5n-6 (P < 0.001). In RBCs, concentrations of linoleic acid (LA, 18:2n-6) were inversely associated with DHA, EPA, and ARA, respectively, in EPGs (r = -0.432, P < 0.01; r = -0.201, P < 0.04; and r = -0.303, P < 0.01) and phosphatidylcholine (r = -0.460, -0.490, and -0.604; P < 0.01 for all).
  
  
  CONCLUSIONS
  Membrane fatty acids are influenced by the amount and balance of fatty acid substrates. Our results suggest the competitive interaction of LA with ARA, EPA, and DHA, with no evidence that higher LA increases ARA. Biochemical indicators to suggest that DHA is limiting are present in our population. This trial was registered at clinicaltrials.gov as NCT00620672.
authors.affiliation: Nutrition and Metabolism Program, Child and Family Research Institute, Department of Paediatrics, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
authors.forename: Russell W
authors.initials: RW
authors.lastname: Friesen
authors.forename: Sheila M
authors.initials: SM
authors.lastname: Innis
mesh_terms: D000328:Adult; D004041:Dietary Fats; D004912:Erythrocytes / Q000378:metabolism; D004983:Ethanolamines / Q000097:blood; D005227:Fatty Acids / Q000097:blood*; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D043371:Fatty Acids, Omega-6 / Q000097:blood*; D005260:Female; D020404:Glycerophospholipids / Q000097:blood; D006801:Humans; D054709:Lecithins / Q000097:blood; D019787:Linoleic Acid / Q000097:blood*; D008431:Maternal-Fetal Exchange / Q000502:physiology; D018579:Patient Selection; D011247:Pregnancy / Q000097:blood*; D011263:Pregnancy Trimester, Third; D055815:Young Adult
chemical_list: D004041:Dietary Fats; D004983:Ethanolamines; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D020404:Glycerophospholipids; D054709:Lecithins; D019787:Linoleic Acid