SupplementsFatty acidsOmega-3Vegan
Flaxseed (linseed) oil is the richest plant source of the omega-3 ALA. The catch is biochemistry: the body converts only a little of it to the active EPA, and almost none to DHA.
Key takeaways
- Rich in alpha-linolenic acid (ALA), a plant omega-3.
- Conversion is poor: roughly 5–10% of ALA → EPA, and <0.5–5% → DHA.1
- It raises EPA a little but not DHA or the omega-3 index — for real EPA/DHA, use algae or fish oil.
- Fine as part of a healthy diet; it oxidises easily — keep refrigerated and don’t heat.
What it is
Cold-pressed oil from flax (linseed) seeds, very high in ALA. Whole ground flaxseed additionally provides fibre and lignans.
The evidence
Supplementing ALA modestly raises blood EPA but has little effect on DHA or the omega-3 index, because human conversion is inefficient (and lower in men).1 It contributes to a heart-healthy dietary fat profile, but isn’t a reliable EPA/DHA source.
Dose & storage
A tablespoon provides plenty of ALA. Buy small, dark bottles, refrigerate, and never cook with it (it goes rancid fast).
Who benefits
A useful dietary omega-3 fat for everyone, but vegans wanting EPA/DHA should choose algae oil instead.
References
Adult research summary for education, not a prescription.
- Efficiency of ALA conversion to EPA and DHA in humans — review. pmc.ncbi.nlm.nih.gov
This article summarises nutrition science for education. It is not a substitute for individual medical advice; consult a professional before starting a supplement, in pregnancy, or alongside medication.