Blood docosahexaenoic acid and eicosapentaenoic acid in vegans: Associations with age and gender and effects of an algal-derived omega-3 fatty acid supplement.
Level 4 - case-series / case-control
Cross-sectional analysis combined with an uncontrolled before-and-after interventional study.
PubMed 24679552 · doi:10.1016/j.clnu.2014.03.003
What was done
Researchers measured the red blood cell omega-3 index (eicosapentaenoic acid plus docosahexaenoic acid as a percentage of total fatty acids) using dried blood spot testing in 165 long-term vegans. A subset of 46 participants who had a baseline omega-3 index below 4% received an algal-derived vegetarian omega-3 supplement supplying 254 mg of docosahexaenoic plus eicosapentaenoic acids daily for 4 months and were retested at study completion.
What was found
Baseline mean ± SD omega-3 index across the cohort (n = 165) was 3.7 ± 1.0%. Female vegans had a significantly higher baseline index than males (3.9 ± 1.0% vs. 3.5 ± 1.0%; p = 0.026), and index values increased directly with age (p for trend = 0.009). In the interventional subset (n = 46), 4 months of supplementation significantly increased the omega-3 index from 3.1 ± 0.6% to 4.8 ± 0.8% (p = 0.009).
Why it matters
This study demonstrates that low baseline omega-3 levels in vegans can be meaningfully raised using a modest daily dose of plant-based algal EPA and DHA.
Limits
The intervention was open-label and lacked a control or placebo group. The supplementation sub-study had a small sample size (n = 46) selected specifically for an omega-3 index <4%, limiting generalizability to all vegans, and clinical health outcomes were not assessed.
Cited by
- supports Vegans and US military personnel have an average Omega-3 Index of around 3.5%.