What are the best Vegetarian and Vegan Sources of Omega-3 Fatty Acids?

We have spent a generation arguing about fat, and the argument keeps changing sides. The fats your grandparents were told to fear are, in some cases, the ones nutrition science now treats as genuinely essential.

Chief among them are the omega oils: polyunsaturated fatty acids that your body cannot build on its own, which is exactly why they have to come from what you eat. If you are vegan, that “what you eat” question gets more interesting, and that is what this page is really about.

Are omega-3s found in plant foods?

Yes, but with a catch worth understanding before you build a diet around it. Plant omega-3 is almost all alpha-linolenic acid, or ALA. That is the short-chain form, and it is a precursor: a starting material your body has to convert into the longer-chain forms, EPA and DHA, which are the ones most studies actually look at.

So when you read that a seed is “high in omega-3”, check which omega-3. Most of the time it means ALA, and ALA is not the same thing your fish-eating friends are getting from their salmon.

How are plant-based omega-3 sources different from fish-based sources?

The short version: plants hand you ALA, fish hand you EPA and DHA ready to use. Flaxseeds and walnuts are ALA. Salmon and mackerel deliver EPA and DHA directly, no conversion required.

That conversion gap is the whole story. Your body can turn some ALA into EPA and DHA, but the rate is modest, so an ALA-rich diet is not a tidy swap for the long-chain forms. It is the one distinction I would not let a label gloss over.

Do people eating vegan and vegetarian diets have adequate omega-3 levels?

You can, but it takes a bit of planning rather than luck. Cut out fish and you cut out the main dietary source of EPA and DHA, which leaves you leaning on plant ALA and hoping your body converts enough of it.

Because that conversion is limited, you have two realistic options. Eat a lot more ALA-rich food, or go to an algae-based supplement that supplies EPA and DHA directly. If the long-chain forms are what you actually want, the second route skips the bottleneck. You can compare the algae options we stock in the Plankton for Health shop.

What are the 10 Best Plant Based Sources of Omega 3?

Here is the practical run-through. Read it as two groups: the algae that gives you EPA and DHA, and the rest, which are ALA sources worth eating but not interchangeable with the long-chain forms.

Algae

Algae is the one plant source that gives you EPA and DHA rather than just their precursor. That is what sets it apart from every seed on this list.

The reason is simple food-chain logic. Algae sits at the base of the marine chain: small fish eat it, bigger fish eat them, and the EPA and DHA you associate with fish started in the algae all along. Eat the algae and you go straight to the source instead of waiting for a fish to concentrate it for you.

Algae-based supplements concentrate those long-chain forms further than whole algae would, which is why they are the usual delivery format. Per serving the EPA on offer is modest, so treat it as a clean direct source rather than a megadose, and check the pack for the actual amount.

Set against a source that offers only ALA, such as flaxseed or chia, algae has the clear edge if EPA and DHA are your goal. The conversion route from ALA works, but slowly, and slower still for some people. It is why I keep coming back to algae: it lets you skip the argument.

Flax Seeds

Flax seeds, or linseeds (Linum usitatissimum), are one of the best plant sources of ALA you can buy (source). The catch is the one above: ALA, not EPA and DHA, so your body still has to do the conversion work.

To get the most out of them, a few habits help:

1. Grind them: whole flaxseeds are tough and tend to pass through largely undigested, so the goodness stays locked in the shell. A quick whizz in a coffee grinder or food processor fixes that.
2. Store them properly: the oils turn rancid over time. Keep them airtight in the fridge or freezer. Whole seeds last up to a year; ground flax is best used within a few weeks.
3. Eat them with other fats: pairing flax with nuts, avocado or olive oil helps your body take up the ALA and the other nutrients alongside it.

Walnuts

Walnuts are a solid plant source, with about 2.5 grams of ALA per ounce, the highest of any nut. You also get antioxidants and a useful mix of other nutrients in the bargain.

If you buy them whole, the freshness test is to crack one and look: the nutmeat should be plump, firm and creamy-coloured. Shrivelled or discoloured means it is past its best, and stale walnut oil is a flavour you will not forget in a hurry.

Rapeseed oil

Rapeseed oil, called canola in the US, carries about 1 gram of ALA per tablespoon. It is genuinely versatile, fine for cooking, baking or a dressing, and a sensible everyday oil to have in the cupboard.

Just do not file it next to algae. The ALA per tablespoon is small, and rapeseed is also high in omega-6. Most of us already get plenty of omega-6, so the practical point is balance: rapeseed is a fine cooking oil, not your omega-3 strategy.

Hemp Seeds

Hemp seeds bring about 1 gram of ALA per tablespoon, plus protein and fibre, which makes them an easy scatter over smoothies, salads or porridge. In their broader forms, hemp oil included, they slot just as easily into dressings or a protein boost. The omega-3 will not rival algae, but you would eat them for the rest of the package:

1. Good plant protein: hemp contains all nine essential amino acids, which is unusual for a plant food.
2. Rich in minerals: a useful source of magnesium, phosphorus, zinc and iron.
3. Fibre: a decent contribution to your daily fibre.
4. Skin nutrients: hemp supplies vitamin E and gamma-linolenic acid (GLA), which the skin draws on.
5. Nutrient-dense: a small serving delivers a broad spread of vitamins and minerals.

Edamame

Edamame, or boiled young soybeans, give you about 0.3 grams of ALA per half cup, alongside a good hit of protein and fibre. They make a filling snack or a quick addition to a salad, even if the omega-3 figure is a side benefit rather than the headline.

Kidney Beans

Kidney beans offer about 0.1 grams of ALA per half cup, so the omega-3 is minor here. You eat them for the fibre, protein and the rest, and the small ALA is a bonus on top of a soup or stew rather than a reason to buy them.

Chia Seeds

Chia is one of the heavier hitters here, with about 5 grams of ALA per ounce, plus fibre and protein. Stir it into a smoothie, soak it overnight in oats, or fold it into baking, and it disappears into the texture. Still ALA, though, so the conversion caveat applies.

Brussels Sprouts

Brussels sprouts carry a small amount of ALA, around 0.1 grams per half cup, alongside a generous load of fibre, vitamins and minerals. Nobody buys sprouts for the omega-3, and you needn’t either, but they earn their place on the plate regardless.

Perilla Oil

Perilla oil, pressed from the seeds of the perilla plant, is high in ALA and turns up in a lot of East Asian cooking and as a salad oil. It is one of the richer ALA oils, though it remains exactly that: ALA, with the usual conversion question attached.

Marine Phytoplankton: the Best Vegan form of Omega 3 EPA?

Ask why fish oil is the famous omega-3 source and the answer is almost circular: fish are rich in it because they eat algae. The fish are not the origin. They are the middleman.

Algae, and marine phytoplankton in particular, are the primary producers of omega-3 in the food chain. We can read the chain backwards from the species that feed on them: sardines, anchovies, salmon, tuna, mackerel. Phytoplankton makes up an enormous share of marine biomass and builds these fatty acids itself.

So eating phytoplankton takes you to the same original source the fish are drawing on, just without the fish in between. The per-serving EPA is modest, and I would rather say so plainly, but it is the real thing, in a plant form, and that is the fair way to put it.

Why Algae is the Best Vegan form of Omega 3 DHA

For DHA specifically, the workhorse is a marine microalga called Schizochytrium sp. It is what Phytality uses to produce a vegan DHA, and we have it as the core ingredient in the Clean Omega product. DHA is the omega-3 most associated with normal brain and vision function.

A few reasons it earns that role:

1. High DHA content: Schizochytrium can hold DHA at as much as 40% of its total lipid content, making it one of the most concentrated vegan DHA sources going.
2. Sustainable and renewable: it is grown in controlled conditions on renewable inputs, which keeps the environmental footprint of producing DHA down.
3. Cleaner sourcing: grown in a controlled environment rather than the open sea, it sidesteps the mercury, PCBs and dioxins that accumulate in fish, which matters if contaminant load is on your mind.
4. Fully vegan: it is wholly plant-based, so it suits vegans and vegetarians without the usual fine-print.

What to Look for in a Vegetarian and Vegan Omega-3 Supplement?

Start with where the oil comes from, because that is where the contaminant question lives. Mercury, lead and DDE, the breakdown product of the pesticide DDT, accumulate in fish, and PCBs, synthetic chemicals that build up in the food chain, are part of the same picture. It is a fair reason to look at how a supplement is sourced.

This is where phytoplankton grown in climate-controlled bioreactors, rather than harvested from the open ocean, has a clear advantage. You are tapping the primary source of EPA, and a closed system keeps contaminants low, with batches tested for heavy metals and pollutants rather than left to chance. You can see how we approach that in our testing and sourcing policy.

There is a fish-stocks argument too.

Over a million tonnes of salmon are farmed every year, and a good deal of that fish is fed on other wild-caught fish. As a rough rule, it takes around five pounds of caught fish to produce one pound of farmed fish, which strikes me as a strange sort of maths for a food meant to ease pressure on the seas.

It does not add up well. Researchers have also noted that even these intensively fed farmed fish are not as high in long-chain fatty acids as they once were. I read the wider picture as a food chain under strain, and that alone is a fair reason to look at a plant source instead.

Get your EPA from phytoplankton powder and you can leave fish off the plate while still drawing those long-chain fatty acids from a plant. Modest per serving, yes, but direct, and from a source you can actually account for.

Marine Phytoplankton vs Other Popular Vegan Omega-3 Supplements

Put marine phytoplankton next to the usual vegan shortlist: flax, hemp and sea buckthorn. The deciding question is always the same one, which form of omega-3 you are actually buying.

Of the three omega-3s, EPA, DHA and ALA, it is ALA that dominates the plant world. Flax, walnut and hemp are good ALA sources, and you will often hear that the body just converts ALA into EPA anyway. It does, but the rate is poor: estimates land somewhere between 8% and 20% efficiency.

None of this makes ALA pointless. It belongs in a good diet. But when I weigh the research on omega-3, it is EPA and DHA that draw most of the interest, and that is why I treat a source supplying them directly as worth distinguishing from one that only offers the precursor.

That is the long-standing case for fish oil over plant omega-3: it gives you EPA and DHA without the conversion tax. The snag is everything I set out above, the contaminant load and the sustainability strain that now come bundled with ocean-caught fish.

Marine phytoplankton is the way to keep the long-chain forms without the fish. As the one widely available plant source of long-chain omega-3, algae oil, with phytoplankton as its standout example for lipids, is where I would point a vegan who wants EPA and DHA from a plant. Browse the range in the Plankton for Health shop and check each pack for the per-serving amounts.

This article is for general information and is not medical advice. Food supplements are not a substitute for a varied, balanced diet and a healthy lifestyle. If you are pregnant, breastfeeding, taking medication or managing a health condition, speak to your GP or pharmacist before changing what you take. Last reviewed: June 2026.

Cara Hayes

Cara Hayes is an experienced natural health practitioner with a Masters in Clinical Nutrition & Dietetics from the University of Sydney. She has been writing for Plankton for Health since 2019 and contributes widely to many well-known health publications.