What You Need to Know About Omega-3 Fatty Acids

High doses may increase your risk of a heart condition.

Studies in the 1970s demonstrated very low coronary heart disease rates among Eskimos in Greenland who consumed large amounts of seafood. Since then, much research has focused on how long-chain omega-3 polyunsaturated fatty acids in fish oil, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are important contributors to these benefits.

I want to share with you some of my concerns. There appears to be a dose-related risk for a heart condition (atrial fibrillation, a condition characterized by an irregular and often rapid heartbeat) with omega-3 fatty acid intake, at least with high doses of the supplement.

There have been three historic (and one recent) randomized clinical trials that support the supplement and atrial fibrillation connection. The VITAL-RHYTHM study is the latest clinical trial to evaluate the association. Led by Christine M. Albert, MD, MPH of Cedars-Sinai Medical Center (Los Angeles), the research team discovered no effect of omega-3 fatty acid supplements on the risk of atrial fibrillation.

The researchers also believe the VITAL-RHYTHM study is the only randomized trial to assess the effect of vitamin D3 supplementation on atrial fibrillation risk. They found no connection of vitamin D with Afib.

Researchers recently published these findings online. As noted, the current study points to no omega-3 fatty acid/atrial fibrillation connection. Still, taken in concert with the other three randomized clinical trials, we get hints that there may be a dose-related effect of omega-3 fatty acids on atrial fibrillation risk.

In the previous STRENGTH and REDUCE-IT trials, both of which evaluated high doses (4 grams per day) of omega-3 fatty acids in patients with heart disease (or at high risk for it), there appeared to be an increase in risk for atrial fibrillation in the omega-3 groups (versus control) in both trials.

The takeaway message? If you choose to take omega-3 fatty acids in high doses, you may increase your risk of common and potentially hazardous heart rhythm abnormalities. Vitamin D3 at 2,000 IU appears not to increase risk.

Thank you for joining me today. As for me, I am off for a walk to use a truly safe way to decrease my risk of heart disease.


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This article lives here: NutritionWhat You Need to Know About Omega-3 Fatty Acids
Michael Hunter, MD
Michael Hunter, MD
I received an undergraduate degree from Harvard, a medical degree from Yale, and trained in radiation oncology at the University of Pennsylvania. I practice radiation oncology in the Seattle area.

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