Over Half of the United States Population Had an Undesirably Low Omega-3 Index Based on Erythrocyte Membrane Measurements: Results From the Cross-Sectional NHANES From August 2021 to August 2023.
Level 4 - case-series / case-control
Cross-sectional survey (NHANES 2021-2023)
PubMed 42291144 · doi:10.1016/j.cdnut.2026.107715
What was done
Researchers evaluated red blood cell membrane concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to determine the Omega-3 Index (O3I) across the United States population aged 6 years and older (n = 7,213) using cross-sectional data from NHANES (August 2021 to August 2023). They categorized O3I as undesirable (<4%), intermediate (4%–8%), or optimal (>8%) and analyzed associations with sociodemographic, lifestyle, dietary intake, and health characteristics among adults aged 20 and older (n = 5,721).
What was found
Across the US population aged 6 and older, 54% had an undesirable O3I (<4%), and the overall mean O3I was 4.12%, with values increasing with age. Among adults aged 20 and older, higher O3I values were observed in females, non-Hispanic Asians, individuals above the poverty line, those with education beyond high school, nonsmokers, polyunsaturated fatty acid (PUFA) supplement users, cholesterol-lowering drug users, individuals with a healthy weight, and those with certain heart health conditions.
Why it matters
These findings provide the first nationally representative baseline showing that over half of the US population falls below recommended target levels for red blood cell omega-3 fatty acids, indicating widespread suboptimal intake.
Limits
The cross-sectional design precludes establishing causality between identified correlates and omega-3 status. Specific numerical breakdowns for the intermediate and optimal categories, exact subgroup values, and clinical outcome event rates were not reported in the abstract.
Cited by
- context Ninety percent of Americans are deficient in omega-3 fatty acids.