Omega-3 index is directly associated with a healthy red blood cell distribution width

Prostaglandins Leukot Essent Fatty Acids. 2022 Jan:176:102376. doi: 10.1016/j.plefa.2021.102376. Epub 2021 Nov 22.


Low red blood cell (RBC) membrane content of EPA and DHA, i.e., the omega-3 index (O3I), and elevated RBC distribution width (RDW) are risk factors for all-cause mortality. O3I and RDW are related with membrane fluidity and deformability. Our objective was to determine if there is a relationship between O3I and RDW in healthy adults. Subjects without inflammation or anemia, and with values for O3I, RDW, high-sensitivity C-reactive protein (CRP), body mass index (BMI), age and sex were identified (n = 25,485) from a clinical laboratory dataset of > 45,000 individuals. RDW was inversely associated with O3I in both sexes before and after (both p < 0.00001) adjusting models for sex, age, BMI and CRP. Stratification by sex revealed a sex-O3I interaction with the RDW-O3I slope (p < 0.00066) being especially steep in females with O3I ≤ 5.6%. In healthy adults of both sexes, the data suggested that an O3I of > 5.6% may help maintain normal RBC structural and functional integrity.

Keywords: Docosahexaenoic acid; Eicosapentaenoic acid; Hematology; Omega-3 index; Red blood cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Body Mass Index
  • C-Reactive Protein / analysis
  • Cell Size*
  • Cross-Sectional Studies
  • Dietary Supplements
  • Docosahexaenoic Acids / blood*
  • Eicosapentaenoic Acid / blood*
  • Erythrocyte Membrane / chemistry*
  • Erythrocytes / ultrastructure*
  • Female
  • Health Status*
  • Healthy Volunteers
  • Humans
  • Male
  • Middle Aged
  • Risk Factors


  • Docosahexaenoic Acids
  • C-Reactive Protein
  • Eicosapentaenoic Acid