afd112b5_il___Cod_Liver_Oil__EPA___DHA___Why
[Used for] 2 Stars Cardiac Arrhythmia Do not take, or take only with a doctor's supervision, if there is a history of sustained ventricular tachycardia or ventricular fibrillation [Why] 
Fish oil has been shown to reduce the frequency of abnormal heartbeats in some trials. In a double-blind trial, people with a type of arrhythmia known as ventricular premature complexes were supplemented for 16 weeks with either 15 ml (1 tbsp) per day of fish oil or a similar amount of safflower oil as placebo. Patients taking the fish oil had a significantly reduced frequency of abnormal heartbeats compared with those receiving placebo, and 44% of those receiving fish oil experienced at least a 70% reduction in the frequency of abnormal beats.57 In a separate study, however, men given 20 ml (4 tsp) of cod liver oil per day for six weeks, beginning one week after a heart attack , had the same frequency of irregular heart beats as did men given no supplemental oil.58 In a double-blind study, people who had a history of certain potentially life-threatening arrhythmias—sustained ventricular tachycardia or ventricular fibrillation—had an increase in the recurrence rate of these arrhythmias when they took fish oil.59 A similar study found no adverse effect of fish oil supplements in people with these serious arrhythmias.60 Because of these conflicting findings, people with a history of either of these arrhythmias should consult a doctor before taking fish oil.
Fish Oil & Cod Liver Oil (EPA & DHA)