title: Erythrocyte cell membrane phospholipid levels compared against reported dietary intakes of polyunsaturated fatty acids in pregnant Mexican women.
abstract: OBJECTIVE
  To evaluate the validity of a food-frequency questionnaire (FFQ) for assessment of the dietary intakes of polyunsaturated fatty acids (PUFAs) against a biochemical marker of fat intake, erythrocyte cell membrane phospholipid levels, during pregnancy.
  
  
  METHODS
  Cross-sectional analysis.
  
  
  METHODS
  Developmental Neurobiology Department, National Institute of Perinatology, Mexico City.
  
  
  METHODS
  One hundred forty-six healthy pregnant women during the last trimester of pregnancy. Among women enrolled, the first 35 pregnant women (24%) had their erythrocytes analysed for fatty acid status.
  
  
  METHODS
  We administered an FFQ and compared intakes of PUFAs against their erythrocyte cell membrane concentrations, processed by gas chromatography.
  
  
  RESULTS
  Pearson correlation coefficients among alpha-linolenic acid (ALN), docosahexaenoic acid (DHA) and eicosapentaenoic acid in erythrocyte cell membranes against their crude dietary counterparts were 0.32, 0.35 and 0.36 (each P < 0.05). In a simple linear regression, erythrocyte DHA and arachidonic acid (AA) were significantly related to their respective dietary intakes (beta = 0.30, 95% confidence interval (CI): 0.007-0.60, P=0.045 for DHA; beta = 0.49, 95% CI: 0.010-0.98, P=0.044 for AA). Erythrocyte cell membrane ALN concentration (%/total) was only marginally related to ALN dietary intake (mg day-1) (beta = 0.52, 95% CI: -0.020-1.10, P=0.061). However, after adjustment for long-chain n-3 PUFA/AA, this association reached significance (beta = 0.44, 95% CI: 0.026-0.825, P=0.038). Main dietary sources for n-3 PUFAs were canned tuna fish and fresh catfish; for n-6 these were eggs and cow's milk. The use of this FFQ in these pregnant Mexican women provided estimates of average long-term intakes of PUFAs and correlated reasonably well with their erythrocyte cell membrane phospholipid status. However, we need to consider that, during pregnancy, there is a faster turnover of PUFAs from fat storage that may modify the profile of erythrocyte PUFAs and lower the correlation between dietary intake and erythrocyte PUFAs.
authors.affiliation: National Institute of Public Health Mexico, Ave. Universidad 655, Col. Sta. Ma. Ahuacatitlán, Cuernavaca 62508, Mexico. mparra@insp.mx
authors.forename: Maria-Socorro
authors.initials: MS
authors.lastname: Parra
authors.forename: Lourdes
authors.initials: L
authors.lastname: Schnaas
authors.forename: Mohsen
authors.initials: M
authors.lastname: Meydani
authors.forename: Estela
authors.initials: E
authors.lastname: Perroni
authors.forename: Sandra
authors.initials: S
authors.lastname: Martínez
authors.forename: Isabelle
authors.initials: I
authors.lastname: Romieu
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004034:Diet Surveys; D004910:Erythrocyte Membrane / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D008800:Mexico; D010743:Phospholipids / Q000378:metabolism*; D011247:Pregnancy
chemical_list: D005231:Fatty Acids, Unsaturated; D010743:Phospholipids