How Do You Get Enough Omega-3 on a Vegan Diet? ALA, Algal EPA and DHA

A vegan diet supplies the essential omega-3, ALA, without trying: a tablespoon of ground flaxseed, 25 g of chia or walnuts, or a tablespoon of flaxseed oil each reaches or passes the 2 g a day at which the register's ALA wording applies. What it does not supply is EPA and DHA, because most adults convert only 5 to 10% of ALA to EPA and almost none to DHA. The direct route is algal oil, the same DHA molecule the fish got from algae: 600 mg of algal DHA a day raised blood DHA as much as the same amount from cooked salmon.^{1, 2} On a vegan label, read milligrams of DHA per daily serving against 250 mg.

• ALA: flaxseed, chia, walnuts, hemp, rapeseed oil and soya; 2 g a day from one or two servings
• EPA and DHA: 5 to 10% and under 1% of ALA becomes them; algal oil supplies them ready-made
• The yardstick: 250 mg EPA+DHA (heart), 250 mg DHA (brain, vision), 200 mg more DHA in pregnancy

How do vegans get omega-3?

By two routes, because omega-3 is three fats. Alpha-linolenic acid (ALA) is the plant omega-3 and the only one the body strictly cannot make; the NHS vegan diet page lists ground linseed (flaxseed), rapeseed oil, chia seeds, shelled hemp seeds and walnuts as its sources.³ EPA and DHA are made by marine algae and concentrated into oily fish; algal oil takes them straight from the algae. The Wellgard omega-3 guide explains what each fat does.

How much flaxseed, chia or walnut gives the ALA I need?

The register's wording, that ALA contributes to the maintenance of normal blood cholesterol levels, applies at 2 g a day.⁴ Approximate ALA per portion:⁵

Whole flaxseed passes through undigested, so grind it or buy it milled. Does flaxseed oil contain omega-3, 6 and 9 covers the oil; what foods are high in omega-3, 6 and 9 has more.

Does ALA convert to EPA and DHA?

A little to EPA, almost none to DHA, and women convert more than men. In tracer studies, young women turned about a fifth of a labelled ALA dose into EPA and up to 9% into DHA; young men made EPA and no detectable DHA; the reading across studies is 5 to 10% to EPA and under 1% to DHA.^{2, 6} In a feeding study, 2.4 to 3.6 g of flaxseed oil a day raised red-cell EPA and no dose raised DHA.⁷ The linoleic acid that vegan diets are rich in competes for the same enzymes and lowers conversion further.⁵ So ALA is not "the useless omega-3", and flaxseed is not "as good as fish oil" for DHA: nothing but DHA is.

Why do vegans have a lower omega-3 index, and does it matter?

The omega-3 index is EPA plus DHA as a percentage of red-cell fatty acids; its authors proposed 8% or more as the band with the lowest coronary death rate and 4% or less as the highest.⁸ In 165 long-term vegans the mean was 3.7%, the same as omnivores who ate little fish.⁹ In 14,422 people in Norfolk, non-fish-eaters' blood levels sat much closer to fish-eaters' than their intakes predicted, with higher estimated conversion in women and non-fish-eaters.¹⁰ The index is an association from general populations; no study has shown vegans coming to harm from theirs, and the NHS states there is no strong evidence of adverse effects from the lower intake.¹¹ A low index is a reason to add DHA, not an emergency.

Do vegan omega-3 supplements work?

Algal ones do, measurably. In 32 adults, 600 mg of DHA a day from algal-oil capsules for two weeks raised plasma phospholipid DHA by about 80% and red-cell DHA by about 25%, matching cooked salmon.¹ A systematic review found algal DHA raised blood DHA and the omega-3 index in vegetarians and vegans in every one of its six studies.¹² In the vegan study above, 254 mg of algal EPA and DHA a day for four months lifted the index from 3.1% to 4.8%.⁹ A flaxseed-based "vegan omega-3" raises EPA a little and DHA not at all, so read which omega-3 a product contains.

How much algal DHA should a vegan take?

Use the register's thresholds as the yardstick: 250 mg of EPA and DHA a day for the normal function of the heart; 250 mg of DHA for normal brain function and normal vision; 200 mg of DHA on top in pregnancy and breastfeeding.⁴ SACN's UK figure is 450 mg a day, what two portions of fish a week supply, and EFSA found no safety concern at up to 5 g a day.^{13, 14} More is not better, though: in the large trials the risk of new atrial fibrillation rose about 50% above 1 g a day and about 12% at 1 g or less, so keep to label doses unless a doctor says otherwise; why is fish oil no longer recommended sets that out.¹⁵ Read milligrams of DHA per serving on the back of the pack, not milligrams of oil: a "500 mg algal oil" capsule may carry anything from 100 to 250 mg of DHA, and some algal oils add EPA while others are DHA only; how much omega 3-6-9 do I need daily has worked examples.

What is the best vegan omega-3?

The one whose label answers five questions, rather than any brand. Milligrams of DHA per daily serving, against 250 mg. Whether EPA is included. The capsule shell, since some vegan oils come in gelatine. Freshness: a strong fishy or paint-like taste in an algal product is oxidation and a reason to return it. And vitamin A, if you are pregnant or buying for a child. Compare prices per 250 mg of DHA.

What is vegan omega 3-6-9?

Flaxseed oil in a capsule, so a plant ALA supplement. Wellgard Vegan Omega 3 6 9 supplies 692 mg of ALA per two capsules, against the 2 g a day at which the register's ALA cholesterol wording applies, with 152 mg of linoleic acid, 152 mg of oleic acid and 10 mg of vitamin E, which contributes to the protection of cells from oxidative stress; it contains no EPA or DHA, so it sits alongside, not instead of, an algal source. For the vegan reader who wants the DHA itself, Wellgard Vegan Omega 3 Gummies supply 50 mg of algal DHA and 50 mg of ALA per two gummies, against the 250 mg of DHA behind the register's brain and vision wording, with vitamin D at 100% of the NRV, which contributes to the maintenance of normal bones and teeth, vitamin A and vitamin C, which contribute to the normal function of the immune system, and vitamin E, which contributes to the protection of cells from oxidative stress; keep to the two-gummy serving, especially for children, because of the vitamin A. Is it better to take omega-3 or omega 3-6-9 compares them.

Vegan omega-3 in pregnancy and childhood

The register's maternal wording, that DHA intake contributes to the normal brain and eye development of the foetus and breastfed infant, applies at 200 mg of DHA a day on top of the adult 250 mg.⁴ In the Cochrane review of 70 trials, omega-3 in pregnancy reduced early preterm birth from 4.6% to 2.7%, and a later analysis found the benefit concentrated in women with low omega-3 status, which describes most vegans.^{16, 17} The NHS page for vegetarian and vegan pregnancy says DHA is important for the baby's brain and eyes, that algae-based supplements are a vegan source, and to check that any supplement contains no vitamin A and is suitable for pregnancy; a plain algal DHA oil meets that.¹¹ For children, the NHS notes that under-twos have different needs and points to specialist guidance for under-fives; the practical version is ALA foods daily and, for DHA, an algal product labelled for the child's age, at the label dose.³

Frequently asked questions

How can I increase my omega-3 without eating fish?

Add 2 g of ALA a day from the table above, and add DHA from algal oil, which skips the fish.^{1, 7}

Are there any vegan omega-3 supplements available?

Two kinds: algal oils and gummies supplying DHA (sometimes EPA), and flaxseed oils and 3-6-9 capsules supplying ALA.

What is vegan omega-3 good for?

The register answers by amount: 250 mg of EPA and DHA for normal heart function, 250 mg of DHA for normal brain function and vision, 2 g of ALA for normal blood cholesterol.⁴

Can I take vegan omega-3 every day?

Yes, with a meal; every trial dosed daily, and EFSA set 5 g of EPA and DHA a day as the level that raises no safety concern.¹⁴

Sources

1. Arterburn LM. Algal-oil capsules and cooked salmon: nutritionally equivalent sources of docosahexaenoic acid. 2008. PubMed 18589030.
2. Plourde M, Cunnane SC. Extremely limited synthesis of long chain polyunsaturates in adults. 2007. PubMed 17622276.
3. NHS. The vegan diet. nhs.uk.
4. Great Britain nutrition and health claims (NHC) register. gov.uk.
5. Burns-Whitmore B. Alpha-linolenic and linoleic fatty acids in the vegan diet. 2019. PubMed 31590264.
6. Burdge GC, Calder PC. Conversion of alpha-linolenic acid to longer-chain polyunsaturated fatty acids in human adults. 2005. PubMed 16188209.
7. Barceló-Coblijn G. Flaxseed oil and fish-oil capsule consumption alters human red blood cell n-3 fatty acid composition. 2008. PubMed 18779299.
8. Harris WS, von Schacky C. The Omega-3 Index: a new risk factor for death from coronary heart disease? 2004. PubMed 15208005.
9. Sarter B. Blood docosahexaenoic acid and eicosapentaenoic acid in vegans: effects of an algal-derived omega-3 supplement. 2015. PubMed 24679552.
10. Welch AA. Dietary intake and status of n-3 polyunsaturated fatty acids in fish-eating and non-fish-eating meat-eaters, vegetarians, and vegans (EPIC-Norfolk). 2010. PubMed 20861171.
11. NHS. Vegetarian or vegan and pregnant. nhs.uk.
12. Craddock JC. Algal supplementation of vegetarian eating patterns improves plasma and serum DHA concentrations and omega-3 indices: a systematic review. 2017. PubMed 28417511.
13. SACN. Advice on fish consumption: benefits and risks, 2004. gov.uk.
14. EFSA. EFSA assesses safety of long-chain omega-3 fatty acids, 2012. efsa.europa.eu.
15. Gencer B. Marine omega-3 supplementation and the risk of atrial fibrillation: meta-analysis of cardiovascular outcome trials. 2021. PubMed 34612056.
16. Middleton P. Omega-3 fatty acid addition during pregnancy. Cochrane, 2018. PubMed 30480773.
17. Simmonds LA. Omega-3 fatty acid supplementation in pregnancy: baseline omega-3 status and early preterm birth. 2020. PubMed 32034969.

This article is general information, not medical advice. If you are pregnant, breastfeeding, choosing a supplement for a child or take an anticoagulant, speak to your GP, midwife or pharmacist before adding an omega-3 supplement.