Low-Dose Omega-3 Intake Doesn’t Raise Atrial Fibrillation Risk: Study

Following years of mixed results surrounding omega-3 supplementation’s potential impact on atrial fibrillation (AFib) risk, a meta-analysis led by researchers from the Fatty Acid Research Institute (FARI) found that a modest AFib risk is limited only to high-dose prescription omega-3 therapies in high-risk patients. The findings were published in Circulation: Arrhythmia and Electrophysiology.

The study, led by Nada Abuknesha, PhD, associate scientist at FARI, analyzed data from 35 randomized controlled trials involving 114,592 participants, which is more than four times the number of studies included in previous meta-analyses.

Key Findings

Low-dose omega-3 supplementation, defined as less than 1,500 mg of combined EPA+DHA per day, was not associated with an increased AFib risk even among individuals characterized as having an elevated cardiovascular risk.

Only in the setting of high-dose (>1,500 mg per day) omega-3 therapy, used in patients with established cardiovascular disease, was AFib risk modestly increased. The absolute risk increase was 0.8%.

Over the past several years, meta-analyses suggested that omega-3 supplements may increase the risk of AFib. However, those reviews were significantly smaller, focused primarily on cardiovascular outcome studies, and didn’t account for several eligible trials where AFib data were available but unpublished. The study incorporated 15 trials that contained previously unpublished AFib data, including studies that reported zero AFib events to reduce publication bias. The study also was unique in how it evaluated risk based on dose and underlying cardiovascular conditions, FARI noted.

“Our findings show that the relationship between omega-3s and atrial fibrillation is much more nuanced than previous headlines suggested,” said William S. Harris, PhD, president of FARI and senior author on the study. “For the vast majority of people taking nutritional doses of omega-3s, these data should provide reassurance that there is no meaningful increase in atrial fibrillation risk.”

Providing Context

Even in high-risk cardiovascular patients receiving prescription-level omega-3 doses, the observed increase in AFib should be weighed against respective cardiovascular benefits from supplementation, the authors noted, such as reductions in the risk of heart attacks, stroke, and other major cardiovascular events.

“The decision to take or discontinue omega-3 supplements should be a discussion between a patient and his or her healthcare provider,” said Harris. “What this study does is provide clinicians with better guidance on which patients may benefit from closer monitoring when using high-dose omega-3 therapies while reassuring consumers that it is safe to consume omega-3 fatty acids from foods and dietary supplements.”

Based on the findings, AFib risk should be assessed differently based on whether it’s a nutritional omega-3 supplement dosed at 500-1,000 mg per day, versus pharmacological omega-3 therapy, which typically falls between 2 and 4 grams per day, prescribed for people with elevated triglycerides or established cardiovascular disease.