Atrial Fibrillation: High Omega 3 Levels Reduce Risk by 29%
According to a study published in Circulation by a group of researchers led by Dariush Mozaffarian, an expert from the Harvard School of Public Health (Boston, USA), high blood levels of Omega 3 reduce the risk of atrial fibrillation by 29%. The greatest beneficial effect against this disorder appears to be from docosahexaenoic acid (DHA), one of the two forms of Omega 3 found in fish and, more generally, in marine sources of Omega 3.
Omega 3 for heart health
Atrial fibrillation is the most common form of cardiac arrhythmia: in Europe, over 6 million people suffer from it. Its incidence increases with age; other risk factors include high blood pressure, diabetes, heart ischemia, congestive heart failure, and left atrial hypertrophy (enlargement of the left atrium of the heart). It often appears after heart surgery.
Available therapies to tackle this issue are limited. Considering its widespread presence in increasingly older populations and its potential severe complications (such as stroke and heart failure), finding effective prevention strategies is particularly important.
Within this context, Mozaffarian and colleagues analyzed the potential of Omega 3 fatty acids, known as valuable allies for heart health. In particular, years of research have linked these fats to:
- the ability to control blood triglyceride levels;
- the ability to normalize blood pressure;
- antithrombotic and anti-inflammatory properties;
- reduction of cardiovascular event risk, such as heart attack.
Atrial fibrillation: Omega 3 fatty acids help regulate heart rhythm
The research involved analyzing data from 3,326 men and women aged 65 or older in the United States. At the start of the study, none of the participants had atrial fibrillation; during the study, 789 individuals developed the condition. It was found that participants with the highest blood levels of Omega 3 and DHA had about a 25% lower risk of developing atrial fibrillation.
Considering total Omega 3 levels only, the highest amounts were associated with a 29% risk reduction, and in terms of percentage of total fatty acids, each 1% increase in Omega 3 levels was linked to a 9% reduced risk of atrial fibrillation.
Focusing on individual Omega 3s, the association was specific for DHA, with a 23% risk reduction. Each 0.5% increase of DHA in total fatty acids was associated with a 6% lower risk of atrial fibrillation.
The other two Omega 3s studied – EPA (eicosapentaenoic acid) and DPA (docosapentaenoic acid) – were not associated with a reduced risk of atrial fibrillation.
Omega 3 for prevention of atrial fibrillation?
“Our results provide evidence that dietary Omega 3 fatty acids may protect against the development of atrial fibrillation in older age,” Mozaffarian and colleagues wrote in Circulation.
The primary source of these fats is fish. Additionally, the market offers a wide range of dietary supplements containing DHA, alone or combined with EPA; the possibility of using them not only as a preventive approach to cardiovascular diseases but also for atrial fibrillation prevention has generated strong interest in the medical-scientific community and would represent concrete benefits both for people's quality of life and economically.
Unfortunately, research results have been conflicting. In fact, larger and longer placebo-controlled studies have observed an increased incidence of atrial fibrillation dependent on the dose of Omega 3 consumed.
Omega 3 drugs and atrial fibrillation risk
Regarding drugs based on Omega 3 ethyl esters, prescribed to reduce blood triglycerides, the Italian Medicines Agency (AIFA) has issued a note agreed with European regulatory authorities to inform doctors about the association between their use and the risk of atrial fibrillation.
The note confirms that this association is dose-dependent and that the risk “was higher with a dose of 4 g/day [grams per day].” The risk was lower for smaller doses, down to 1 gram per day.
Furthermore, the note clarifies that the increased risk was observed “in patients with established cardiovascular disease or cardiovascular risk factors treated with medicinal products based on Omega-3 fatty acid ethyl esters,” without mentioning risks for healthy individuals or those without cardiovascular risk factors. The recommendation is to “consult a doctor if symptoms of atrial fibrillation develop” and, if so, to discontinue the treatment permanently.
It is important to remember that symptoms of atrial fibrillation include dizziness, fatigue, palpitations, and breathing difficulties, and that not all Omega supplements contain these fats in the form of ethyl esters; in fact, today the highest-quality products favor other more natural forms, particularly re-esterified triglycerides and phospholipids.
How to act?
Consuming adequate doses of Omega 3 sources, such as fatty fish, remains important to meet the body's needs, and Omega 3 supplements continue to be valuable allies for health when this is not possible or difficult to achieve (for example, due to selective eating, allergies, ethical choices, or increased needs).
It is important to keep in mind AIFA's indications regarding atrial fibrillation risk. From this perspective, choosing forms other than ethyl esters could be preferable. In any case, fortunately, it is often not necessary to reach doses associated with a significantly increased risk.
References:
Herrmann W, Herrmann M. n-3 fatty acids and the risk of atrial fibrillation, review. Diagnosis (Berl). 2024 May 9;11(4):345-352. doi: 10.1515/dx-2024-0077
IMPORTANT INFORMATION NOTE AGREED WITH EUROPEAN REGULATORY AUTHORITIES AND THE ITALIAN MEDICINES AGENCY (AIFA). November 8, 2023. https://www.aifa.gov.it/documents/20142/1804929/2023.11.08_NII_omega-3_IT.pdf
Wu JH, Lemaitre RN, King IB, Song X, Sacks FM, Rimm EB, Heckbert SR, Siscovick DS, Mozaffarian D. Association of plasma phospholipid long-chain ω-3 fatty acids with incident atrial fibrillation in older adults: the cardiovascular health study. Circulation. 2012 Mar 6;125(9):1084-93. doi: 10.1161/CIRCULATIONAHA.111.062653
