Comparison between plasma and erythrocyte fatty acid content as biomarkers of fatty acid intake in US women

Am J Clin Nutr. 2007 Jul;86(1):74-81. doi: 10.1093/ajcn/86.1.74.


Background: Erythrocyte fatty acids may be superior to plasma fatty acids for reflecting long-term fatty acid intake because of less sensitivity to recent intake and a slower turnover rate.

Objective: The objective was to compare the fatty acid content of erythrocytes with that of plasma with respect to their abilities to reflect usual fatty acid intake.

Design: Fatty acids in plasma and erythrocytes were measured by capillary gas-liquid chromatography in 306 US women aged 43-69 y. Fatty acid intake was assessed with a food-frequency questionnaire, which was validated for measuring intakes of various fatty acids.

Results: Docosahexaenoic acid (DHA, 22:6n-3) in erythrocytes and plasma provided the strongest correlations with its intake, but erythrocyte DHA concentrations [Spearman's partial correlation coefficient (r(s))=0.56] were better than plasma DHA concentrations (r(s)=0.48) as a biomarker. Total trans fatty acids (r(s)=0.43) and total 18:1 trans isomers (r(s)=0.42) in erythrocytes were also more strongly correlated with intake than were those in plasma (r(s)=0.30 and r(s)=0.29, respectively). Moderate correlations were observed for linoleic acid (18:2n-6; erythrocytes, r(s)=0.24; plasma, r(s)=0.25), alpha-linolenic acid (18:3n-3; erythrocytes, r(s)=0.18; plasma, r(s)=0.23), and eicosapentaenoic acid (20:5 n-3; erythrocytes, r(s)=0.38; plasma, r(s)=0.21). For polyunsaturated and trans fatty acids, correlations between intakes and biomarkers improved moderately when average intakes over previous years were used.

Conclusion: Erythrocyte n-3 fatty acids of marine origin and trans fatty acid content are suitable biomarkers for long-term intake.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biomarkers / blood
  • Cohort Studies
  • Diet Records
  • Dietary Fats / administration & dosage
  • Dietary Fats / blood*
  • Eating
  • Erythrocytes / metabolism*
  • Fatty Acids, Nonesterified / blood*
  • Female
  • Humans
  • Middle Aged
  • Plasma
  • Statistics, Nonparametric


  • Biomarkers
  • Dietary Fats
  • Fatty Acids, Nonesterified