Predicting Who Is More Likely to Develop Irregular Heartbeat While Taking Concentrated Omega-3
This analysis revisited data from the STRENGTH trial, a large study that tested a concentrated omega-3 fatty acid supplement against a corn oil placebo in people with high cardiovascular risk. Earlier results from this and similar trials found that omega-3 supplementation was linked to a higher chance of developing atrial fibrillation (AF), an irregular heart rhythm. This sub-analysis aimed to figure out which patient characteristics made AF more likely.
Among 6,000 people taking the omega-3 supplement, 2.1% developed new AF during the study, compared to 1.2% of the 6,012 people taking placebo. Researchers found six factors independently linked to higher AF risk in the omega-3 group: older age, being male, higher body mass index, a history of heart failure, insulin-treated diabetes, and elevated levels of a blood marker for inflammation (high-sensitivity C-reactive protein).
Using these six factors, the researchers built a risk score that reasonably distinguished higher-risk from lower-risk patients, both in those taking the omega-3 supplement and in the placebo group. The authors describe this predictive ability as moderate and note that the score needs to be tested in other groups of patients before it could be used more broadly.
What this means for you
This research is specific to people at elevated cardiovascular risk taking a high-dose, concentrated omega-3 fatty acid supplement, not typical dietary fish oil doses. If you have several of the risk factors identified here—especially older age, higher body weight, heart failure history, insulin-dependent diabetes, or elevated inflammation markers—it may be worth discussing heart rhythm monitoring with your doctor if you’re considering high-dose omega-3 supplementation. This does not mean omega-3 supplements cause AF in everyone, and the findings need further validation before being used to guide individual decisions.
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Start the ALP ProtocolThis summary is for educational purposes only and is not medical advice. Always talk to your healthcare provider before making changes to your supplement routine.