A comparison of Omega-3 Fatty Acids Intakes from Three Dietary Screening Tools

A newly developed omega-3 questionnaire (O3Q) designed to capture habitual intakes of omega-3 fatty acids was previously validated based on the whole blood levels of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and Omega-3 Index, but lacks comparison with existing "gold standard" dietary tools.

To compare the estimated habitual intakes of omega-3 fatty acids from three dietary assessment tools including O3Q and two other commonly used methods (24-hour recall and Diet History Questionnaire).

A correlational study of estimated omega-3 intakes from the O3Q, multiple 24-hour recalls, and Diet History Questionnaire collected from an observational study (n = 49) were compared to corresponding whole blood levels of EPA, DHA, and Omega-3 Index. The 49 participants included in this study completed the O3Q, Diet History Questionnaire, and at least one 24-hour recall during the observational study. Any incomplete data sets (missing one of the three kinds of dietary assessments) were excluded. Spearman's correlation evaluated the relationship between estimated omega-3 intake from each diet assessment method and biomarkers. Stepwise multiple linear regression examined associations of estimated dietary intakes of EPA+DHA from the three intake methods and the Omega-3 Index level.

The estimated intakes from the O3Q had higher correlation coefficients with the corresponding blood biomarkers (EPA, r_s=0.75; DHA, r_s=0.74; Omega-3 Index, r_s=0.77; p <0.001 for all) compared to the DHQ (EPA, r_s=0.53; DHA, r_s=0.41; Omega-3 Index, r_s=0.45; p <0.001 for all) and 24 hr diet recall (EPA, r_s=0.61; DHA, r_s=0.45; Omega-3 Index, r_s=0.55; p <0.001 for all). The regression analysis only demonstrated the O3Q as the significant dietary assessment predictor of the Omega 3-Index level (β = 0.66, p <0.001).

The O3Q is the preferred tool to evaluate habitual Omega-3 fatty acids intake and estimate Omega-3 index and outperforms using multiple 24-hour recalls or the Diet History Questionnaire for these specific dietary variables.