03/01/2026
A neighbor told me that they take 1000mg of OTC «fish oil» supplements daily believing that it would help with their overall health and specifically reduce and prevent the ventricular heart rhythm disorder that they have.
My comments, based on my experience at the National Institutes of Health (working at NHLBI and with the Office of Dietary Supplements) is that taking 1000 mg of fish oil daily is generally safe and may have modest benefits on improving blood fats. But clinical research shows no consistent evidence that fish oil prevents or reduces serious heart rhythm problems, including PVCs or more life-threatening ventricular arrhythmias. Lifestyle factors —stress, sleep, caffeine, and electrolyte balance— usually have a much bigger impact. If the heart rhythm problems are frequent, new, or cause symptoms like dizziness, fainting, or chest pain, it’s best to see a physician for evaluation.
The clinical reality of testing the possible beneficial effects of «fish oil» on heart rhythm is that:
• Large, rigorous randomized clinical trials have NOT confirmed a clear preventive or protective effect
• Benefits appear small (or, more often, absent) in patients receiving optimal medical therapy
• Fish oil is NOT presently recommended as an anti-arrhythmic treatment.
So —bottom line— even though fish oil was once thought to be a natural “heart rhythm stabilizer,” randomized clinical trials have NOT shown that it prevents deadly heart rhythm disorders.
References.:
1. Leaf A, Albert CM, Josephson M, Steinhaus D, Kluger J, Kang JX, Cox B, Zhang H, Schoenfeld D, Fatty Acid Antiarrhythmia Trial Investigators. Prevention of fatal arrhythmias in high-risk subjects by fish oil n-3 fatty acid intake. Circulation. 2005 Nov 1;112(18):2762-8. doi: 10.1161
2. Raitt MH, Connor E, Morris C, Kron J, Halperin B, Chugh SS, McClelland J, Cook J, MacMurdy K, Swenson R, Connor SL, Gerhard, G, Kraemer DF, Oseran D, Marchant C, Calhoun D, Shnider R, McAnulty J. Fish oil supplementation and risk of ventricular tachycardia and ventricular fibrillation in patients with implantable defibrillators: a randomized controlled trial. JAMA : the journal of the American Medical Association. 2005. Jun 15; 293 (23) 2884-91
3. Brouwer IA, Zock PL, Camm AJ, Böcker D, Hauer RNW, Wever EFD, Dullemeijer C, Ronden JE, Katan MB, Lubinski A, Buschler H, Schouten EG, SOFA Study Group. Effect of fish oil on ventricular tachyarrhythmia and death in patients with implantable cardioverter defibrillators: the Study on Omega-3 Fatty Acids and Ventricular Arrhythmia (SOFA) randomized trial. JAMA. 2006 Jun 14;295(22):2613-9. doi: 10.1001
4. Matthan NR, Jordan H, Chung M, Lichtenstein AH, Lathrop DA, Lau J. A systematic review and meta-analysis of the impact of omega-3 fatty acids on selected arrhythmia outcomes in animal models. Metabolism. 2005 Dec;54(12):1557-65. doi: 10.1016
5. London B, Albert C, Anderson ME, Giles WR, Van Wagoner DR, Balk E, Billman GE, Chung M, Lands W, Leaf A, McAnulty J, Martens JR, Costello RB, Lathrop DA. Omega-3 fatty acids and cardiac arrhythmias: prior studies and recommendations for future research: a report from the National Heart, Lung, and Blood Institute and Office Of Dietary Supplements Omega-3 Fatty Acids and their Role in Cardiac Arrhythmogenesis Workshop. Circulation. 2007 Sep 4;116(10):e320-35. doi: 10.1161
