Effect of omega-3 fatty acids on cardiovascular outcomes: A systematic review and meta-analysis — Research

Safi U Khan, MD, Ahmad N Lone, MD, Muhammad Shahzeb Khan, MD, Salim S Virani, MD PhD, Roger S Blumenthal, MD, Khurram Nasir, MD MPH, Michael Miller, MD, Erin D Michos, MD MHS, Christie M Ballantyne, MD, William E Boden, MD, Deepak L Bhatt, MD MPH · Systematic review and meta-analysis

Omega-3s for the heart have produced a decade of contradictory trials. This large meta-analysis tries to resolve the mess by asking a sharper question: does it matter whether the supplement is pure EPA or a blend of EPA and DHA?

Pooling 38 randomized trials and nearly 150,000 participants, the authors found that omega-3s overall reduced cardiovascular mortality, heart attack, coronary events, and revascularization — but the benefit was concentrated in EPA monotherapy, which outperformed the EPA+DHA blends. The catch was safety: EPA monotherapy also carried higher rates of atrial fibrillation and bleeding.

The practical takeaway is that the form of omega-3 matters — purified EPA appears more cardioprotective than mixed formulations — but the decision must weigh a real increase in atrial fibrillation and bleeding. It’s a benefit-risk judgment, not a blanket endorsement.

We rate the evidence moderate-to-solid: a large, stratified meta-analysis, though weakened by heterogeneity between trials and notably extensive financial conflicts among senior authors with omega-3 industry ties — worth keeping in view when reading the EPA-favoring conclusion. Its clinical significance is meaningful, because the EPA-versus-blend distinction directly shapes which product to use, tempered by the safety signals.

BlueRipple Health provides consumer education and research synthesis for informed health advocacy. This is not medical advice. Discuss all health decisions with a qualified clinician.