Taking Fish Oil Supplements Can Prevent Dangerous Arrhythmia

In a randomized, double blind, placebo-controlled study 65 patients with cardiac arrhythmias without coronary heart disease or heart failure were subdivided into 2 groups. 33 people were supplemented with encapsulated fish oil 3g/day totaling 1000 mg. EPA/DHA (n-3 PUFA) combined per day over 6 months. The other group (32 people) was given 3 g/day of olive oil as placebo.

Clinically, this editor is impressed with the results given the relatively low dose of EPA/DHA. This study used small 500-mg. capsules (18%EPA/12%DHA) either 2, tid or 3, bid. The equivalent dose of a common capsule of 300 EPA/200 DHA would be only 2 capsules per day! Even at this nominal dosage, the fish oil group experienced significant:

• Decrease of serum triglycerides
• Decrease of total cholesterol
• Decrease of LDL cholesterol
• Decrease of plasma free fatty acids and thromboxane B2
• An increase of HDL cholesterol
• Moreover, a reduced incidence of atrial and ventricular premature complexes, couplets and triplets were documented. Put more simply, severity of ventricular arrhythmia diminished significantly over the 6-months.

No changes were seen in the placebo (olive oil) group. Notably, olive oil does NOT appear to carry cardiovascular benefits like fish oil.

The researchers report that a recent trial Cardiac Arrhythmias Suppression Trial (CAST) “showed an even higher rate of death from arrhythmia in patients after myocardial infarction treated with antiarrhythmic drugs compared to patients assigned to placebo”. Therefore, with just 1 g/day of n-3 (EPA/DHA) PUFA supplementation, we can offer a reasonable regimen at low cost and little risk in clinical practice to our patients.

Singer P, Wirth M, “Can n-3 PUFA reduce cardiac arrhythmias? Results of a clinical trial” Prostaglandins, Leukotrienes and Essential Fatty Acids 71 (2004) 153–159.