Circulating Docosahexaenoic Acid and Risk of All-Cause and Cause-Specific Mortality.
Level 3 - non-randomized controlled study
Meta-analysis of prospective observational cohort studies
PubMed 38506781 · doi:10.1016/j.mayocp.2023.11.026
What was done
The authors analyzed 117,702 UK Biobank participants with baseline plasma docosahexaenoic acid (DHA) levels followed for 12.7 years (2007 to 2021) to assess associations with all-cause, cardiovascular, and cancer mortality across DHA quintiles. In a secondary analysis, they merged these data into a meta-analysis with 17 prospective cohorts from the Fatty Acid and Outcome Research Consortium (FORCE), comprising 160,404 individuals and 24,342 deaths over a median 14 years of follow-up.
What was found
In the UK Biobank, the highest versus lowest quintile of DHA showed a 21% lower risk of all-cause mortality (HR, 0.79; 95% CI, 0.74 to 0.85; P < .0001). In the pooled multivariable-adjusted meta-analysis of 160,404 individuals, comparing the highest to lowest quintile of DHA was associated with a 17% lower risk of all-cause mortality (95% CI, 0.79 to 0.87; P < .0001), a 21% lower risk of cardiovascular disease mortality (95% CI, 0.73 to 0.87; P < .001), a 17% lower risk of cancer mortality (95% CI, 0.77 to 0.89; P < .0001), and a 15% lower risk of all other mortality (95% CI, 0.79 to 0.91; P < .001).
Why it matters
This large-scale prospective biomarker analysis reinforces the link between higher circulating DHA levels and lower risks of major causes of death, supporting the role of marine omega-3 fatty acids in long-term health.
Limits
The observational cohort design cannot establish causality, leaving potential for residual confounding from general diet and lifestyle factors. DHA was assessed from circulating levels at a single baseline timepoint, which does not capture changes in intake over the 14-year follow-up period.
Cited by
- supports Reductions in all-cause mortality, cancer, dementia, and heart disease are associated with raising the red blood cell omega-3 index from 4% to 8%.