Skip to content
ZenBodyLove

Algal omega-3 EPA and DHA

Microalgae are a non-fish source of the long-chain omega-3 fats DHA and EPA. Adults following vegetarian and vegan diets take in less EPA and DHA and have lower blood levels than meat-eaters, and randomised trials show that algal-derived DHA supplements raise blood DHA and the omega-3 index in vegan, vegetarian and omnivorous adults, with algal-oil capsules delivering DHA as well as cooked salmon. Algal DHA lowered blood triglycerides in a meta-analysis of small trials, but no trials have tested algal omega-3 against hard health outcomes in vegans, and large trials of mostly fish-oil omega-3 found little or no effect on mortality or cardiovascular events.

  • Longevity
  • Vegan

Evidence retrieved up to

What the research shows

In adults without coronary heart disease, DHA from algal oil lowered blood triglycerides and raised both HDL and LDL cholesterol in randomised trials.

Moderate certaintyFurther research may change the size of the effect.
No known concerns at usual amountsBenefit

Who this is about

adults without coronary heart disease

Practical note

Graded moderate: a meta-analysis of 11 randomised trials (485 healthy participants) with a pooled triglyceride change of -0.20 mmol/L, downgraded for small trials and imprecision; the much larger Cochrane review of long-chain omega-3, mostly from capsules, found a triglyceride effect at high certainty. The median algal DHA dose in the trials was 1.68 g a day, well above the amounts in the vegan status trials.

Safety note

The same trials showed a small rise in LDL cholesterol alongside the fall in triglycerides.

Sources

In healthy adults, DHA from algal-oil capsules raised plasma and red blood cell DHA to the same extent as the same amount of DHA from cooked salmon.

Low certaintyFurther research is likely to change this.
No known concerns at usual amountsBenefit

Who this is about

healthy adults

Practical note

Graded low: a single small open-label randomised study (32 adults, 2 weeks) with a post-hoc bioequivalence analysis; downgraded for risk of bias and imprecision. The study gave 600 mg DHA a day.

Vegan note

Supports algal oil as a fish-free alternative source of DHA.

Sources

Algal-derived omega-3 supplements raise blood DHA and the omega-3 index in vegan, vegetarian and omnivorous adults, with the largest rises seen in vegans.

Moderate certaintyFurther research may change the size of the effect.
No known concerns at usual amountsBenefit

Who this is about

healthy adults, including adults following vegan or vegetarian diets

Practical note

Graded moderate: randomised placebo-controlled trials (116 adults, crossover; 72 vegans) and an uncontrolled vegan study agree, and the blood marker is the outcome itself, but trials were small and short (5 weeks to 4 months) and the vegan trial combined omega-3 with other nutrients. Trials used about 250 to 540 mg of DHA plus EPA a day. Proposed omega-3 index zones (under 4 percent, 4 to 8, over 8) are one researcher's proposal and describe a marker, not a health outcome.

Vegan note

Algal oil is the main vegan source of preformed DHA and EPA.

Sources

In adults at varying cardiovascular risk, increasing long-chain omega-3 intake, mostly from capsules, had little or no effect on all-cause mortality or cardiovascular events; no trials have tested algal omega-3 against these outcomes in people following vegan diets.

Moderate certaintyFurther research may change the size of the effect.
No known concerns at usual amountsNo clear effect

Who this is about

adults at varying cardiovascular risk

Practical note

The Cochrane review (86 trials, 162,796 participants) rated all-cause mortality and cardiovascular events high certainty; downgraded one level here for indirectness, because the trials were not of algal sources. The review also found low-certainty evidence of a slight reduction in coronary heart disease events.

Vegan note

Evidence on hard health outcomes comes from general-population trials not using algal sources; whether it transfers to vegans with low baseline status is untested.

Sources

Adults following vegetarian and vegan diets take in less EPA and DHA and have lower EPA and DHA status than meat-eaters; what this means for long-term health is not established, as these groups generally show favourable cardiometabolic profiles.

Moderate certaintyFurther research may change the size of the effect.
No known concerns at usual amountsUnclear

Who this is about

adults following vegetarian or vegan diets

Practical note

Graded moderate for the lower intake and status: consistent observational evidence across a 141-study systematic review (authors employed by a food company) and a 2026 review; the health consequence is not graded. One study of 165 long-term vegans found a mean omega-3 index of 3.7 percent, similar to a low-fish omnivore cohort rather than lower.

Vegan note

Vegan diets contain almost no preformed EPA or DHA unless algal sources are used, and conversion from plant ALA is limited.

Sources

In adults, long-term supplemental EPA and DHA within the ranges studied raised no safety concerns such as bleeding episodes in the evidence reviewed by the European Food Safety Authority, though most of that evidence came from fish oils.

Low certaintyFurther research is likely to change this.
No known concerns at usual amountsNo clear effect

Who this is about

adults

Practical note

Graded low: an expert opinion summarising mostly fish-oil studies, so indirect for algal oils. EFSA considered combined EPA and DHA up to 5 g a day, and DHA alone up to about 1 g a day for the general population, as raising no safety concerns, and cited European dietary recommendations of 250 to 500 mg a day.

Vegan note

Most safety data are from fish oils rather than algal oils.

Safety note

EFSA noted a rise in LDL cholesterol of about 3 percent with supplemental DHA at 2 to 4 g a day, and set no upper limit because data were insufficient.

Sources