Laboratory research equipment on a bench

Omega-3 Heart Rhythm Risk Reassessed in 35-Trial Review

A meta-analysis published in Circulation: Arrhythmia and Electrophysiology has re-examined whether omega-3 supplements supplements raise the risk of atrial fibrillation, an irregular heart rhythm. NutraIngredients reported on 4 August 2026 that the peer-reviewed paper pooled 35 randomised controlled trials covering 114,592 participants, making it several times larger than the earlier analyses that established the concern. Those earlier reviews drew on no more than eight trials. The work came from the Fatty Acid Research Institute and incorporated previously unpublished atrial fibrillation data from 15 trials, including studies where the condition was recorded as an adverse event rather than a planned outcome. The headline conclusion reported by the authors is that the increased risk seen in the earlier literature is concentrated in high-dose therapy given to high-risk cardiac patients, rather than in the doses found in ordinary retail fish oil and algal oil products.

The numbers, and who paid for them

The preprint version of the same analysis, posted to medRxiv in December 2025 with 34 trials and 114,326 people, reported that across all studies pooled together atrial fibrillation risk was significantly increased, by 14%. Splitting the data changed the picture: in high-risk patients on more than 1,500 mg a day of EPA and DHA the odds ratio was 1.48 (95% confidence interval 1.21 to 1.81), while the high-risk low-dose, low-risk high-dose and low-risk low-dose groups showed no statistically significant effect. The project was funded by the Global Organization of omega-3 supplements EPA and DHA, a trade body, and two authors disclosed commercial omega-3 interests. The authors also noted they could not guarantee capturing every unpublished trial.

What this means for your supplement routine

This is a safety analysis, not a benefit analysis, and it does not say anything about whether omega-3 helps anyone. What it changes is the reading of a headline you may have seen for the past few years. Senior author William S. Harris said the data should "provide reassurance that there is no meaningful increase in atrial fibrillation risk" for people taking nutritional doses. That is a claim from an industry-funded group and is worth weighing as such. Anyone taking omega-3 alongside prescribed heart medication, or at the doses used in cardiac trials, should be having that conversation with their own clinician rather than with a supplement retailer.

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This article reports published news and research and is for information only. Food supplements are not a substitute for a varied diet or medical care, and no product mentioned is intended to diagnose, treat, cure or prevent any disease. Speak to your GP or pharmacist before changing what you take, especially if you are pregnant, breastfeeding, or taking prescribed medicines.

Sources

Originally reported by NutraIngredients. This article has been reviewed by Dr Tosin.

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