Can you get omega-3 (EPA and DHA) without fish?
Short answer: Yes. Algae oil delivers the same EPA and DHA as fish oil with non-inferior bioavailability, fish only get it from algae too.
GMR of 100% would mean identical; the confidence interval stayed within the non-inferiority bound.
Randomised crossover bioavailability trial (2024)
The objection
“Fish is the only real source of EPA and DHA. The plant version doesn’t convert, so vegans are starved of the omega-3s the brain needs.”
The answer
The biochemistry behind this objection is real, which is why it’s worth answering properly rather than waving away.
Plant foods like flaxseed, chia and walnuts supply ALA, a short-chain omega-3. The body can convert ALA into the long-chain forms, EPA and DHA, that matter most for the brain and heart, but the conversion is inefficient, often only a few per cent. So the critic is right that leaning on flaxseed alone is a weak strategy. This site won’t pretend otherwise.
You can skip the conversion entirely, though. Fish don’t manufacture EPA and DHA; algae do, and fish accumulate them by eating it. Take the omega-3 from the original source and you get the identical molecules without the fish. A 2024 randomised crossover trial found the bioavailability of DHA and EPA from microalgal oil was statistically non-inferior to fish oil, with blood levels marginally higher if anything. Earlier work found algal DHA bioequivalent to eating cooked salmon.
So the practical position is to eat ALA-rich foods like ground flax and walnuts, and if you want guaranteed long-chain coverage, take a low-dose algae oil supplement. It’s the same EPA and DHA as fish oil, cutting out the middle-fish.
One honest caveat. Routine omega-3 supplements have not been shown to prevent heart attacks or strokes in the general population, on any diet. The claim that holds up is a narrow one: algae lets a vegan obtain EPA and DHA directly, with no nutritional disadvantage versus fish.