Fish Oil Supplements Do Not Reduce Atrial Fibrillation

A team of researchers has discovered that high dose of fish supplements have negligible effect on atrial fibrillation.

Atrial fibrillation (AF) is the most common abnormal heart rhythm in which the heart beats as fast as 150 beats a minute. It is strongly associated with other cardiovascular diseases like heart failure, coronary artery disease, hypertension, diabetes mellitus and valvular heart disease. It is known to affect more than 2.5 million American adults and the number is expected to increase as the population grows. It accounts for one-third of the hospitalizations for cardiac rhythm disturbances.

Eating oily fish like salmon and albacore tuna that is rich in omega-3 fatty acids have been shown to be good for heart health and people have been taking them even for atrial fibrillation. Smaller studies, focused at the intake of supplements in those with atrial fibrillation, have produced conflicting results.

In the latest study, researchers at Montreal Heart Institute have definitive evidence that high dose of fish oil supplements that is rich in omega-3 fatty acids do not prevent the recurrence of atrial fibrillation that can lead to stroke.

The study looked at 337 patients with AF who did not receive conventional antiarrhythmic therapy and were randomly given 4 grams of fish oil a day or a placebo for nearly 16 months. The researchers observed that 64.1 percent of the patients receiving fish oil had a recurrence of AF as compared to 63.2 percent of the participants taking placebo.

The study also concluded that fish oil supplements did not lower inflammation or oxidative stress markers that help explain the lack of efficacy.

"Fish oil has no role in the rhythm-control management of atrial fibrillation," said lead investigator Dr. Anil Nigam. "What is well-known and should be recommended to prevent heart disease and reduce blood pressure is a Mediterranean-type diet rich in natural omega-3 fats and other nutrients, including fresh fruits and veggies, legumes, olive oil, while lowering intake of red meat, trans fats and saturated fats. We believe that such a strategy might also be beneficial for the treatment of atrial fibrillation although more studies are required."

The finding was documented in the Journal of American College of Cardiology.