There were already several epidemiologic studies that showed eating fish frequently seemed to reduce deaths from coronary heart disease. There were also observational and clinical trials that more specifically showed that the reduction in cardiovascular deaths from eating fish was largely the result of the prevention of sudden cardiac death by n-3 polyunsaturated fatty acids in fish oil.

This led me to perform a clinical trial in which all subjects had an implanted cardioverter-defibrillator and were at very high risk of sudden cardiac death. The results of this study and the mechanisms by which n-3 fish oil fatty acids prevent fatal cardiac arrhythmias will be the subject of this review.