Fish oil which is considered beneficial for cardio patients, does not prove to be of help to arrhythmias patients.

Doctors recommend eating oily fish at least two to four times a week for patients after myocardial infarction. But according to the researchers there is no proper evidence to prove the claim. Only one trial conducted about ten years ago has led to the belief of the efficacy of fish oil.

Professor Ross Tsuyuki of the Epidemiology Coordinating and Research Centre in Edmonton, and colleagues, conducted random trials of fish oil supplements in the prevention of cardiac deaths and arrhythmias in more than 30,000 participants in 12 studies.

Out of these 3 studies studied the effect of fish oil supplements on the reduction in implantable cardiac defibrillator intervention. This study showed a neutral effect of fish oil. Six studies targeted on the effect of fish oil on sudden cardiac death. These six studies also showed no benefit for the patients. A further 11 studies showed a 20% reduction in deaths from heart problems.

"Until now, everyone had assumed that fish oils 'worked' by reducing arrhythmias," Dr. Tsuyuki said, noting that the reduction in mortality must be related to some other mechanism.

The researchers feel that the mechanism by which fish oil reduces deaths from cardiac causes still remain elusive but it is presumed that may be that it helps to stabilize atherosclerotic plaque due to its anti-inflammatory properties.