Long-chain omega-3 fatty acid serum concentrations across life stages in the USA: an analysis of NHANES 2011-2012.
Level 4 - case-series / case-control
Cross-sectional population-based biomarker survey
PubMed 33972333 · doi:10.1136/bmjopen-2020-043301
What was done
Cross-sectional analysis of the 2011–2012 National Health and Nutrition Examination Survey (NHANES) to establish reference ranges for circulating long-chain (LC) omega-3 fatty acids in a representative US population. Serum eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) were measured as percentages of total fatty acids in 945 children (ages 3–19) and 1,316 adults (ages 20 and older), and compared against concentrations linked to Dietary Guidelines for Americans (DGA) recommendations and Omega-3 Index risk categories.
What was found
Mean (SE) serum concentrations of EPA, DHA, and total LC omega-3s were 0.28% (0.01), 1.07% (0.02), and 1.75% (0.03) in children, compared to 0.61% (0.02), 1.38% (0.05), and 2.43% (0.08) in adults (all p < 0.001). Pregnant and/or breastfeeding women had mean (SE) EPA of 0.34% (0.07), DHA of 1.52% (0.08), and LC omega-3 of 2.18% (0.15), not significantly different from women of childbearing age (p = 0.17, p = 0.10, p = 0.73). Over 95% of children and 68% of adults had LC omega-3 concentrations below DGA-recommended levels, and approximately 89% of adults had an Omega-3 Index in the high cardiovascular risk category.
Why it matters
This study provides nationally representative reference ranges showing that the vast majority of Americans across all age groups have circulating omega-3 levels below recommended intake thresholds.
Limits
The study is cross-sectional from a single survey cycle (2011–2012) and does not evaluate clinical outcomes directly. Serum fatty acid percentages reflect relatively recent dietary intake rather than long-term erythrocyte membrane incorporation, and subgroup sample sizes for pregnant/breastfeeding women were not specified in the abstract.
Cited by
- context Ninety percent of Americans are deficient in omega-3 fatty acids.