Fish Oil May Prevent Sudden Cardiac Death

Category: Conditions of the Circulatory System

Fish oil contains n-3 polyunsaturated fatty acids (PUFA) which may reduce inflammation and the risk of coronary heart disease. Now research reports that n-3 fatty acids in fish oil may also reduce the risk of sudden cardiac death.

The placebo-controlled, double-blind study, published in the American Journal of Clinical Nutrition (2005, vol 81, issue 2), found that fish oil supplements significantly decreased heart rate by 2.1 beats/minute, which predicts a reduced risk of sudden cardiac death. Scientists at the Wageningen Centre for Food Sciences and Division of Human Nutrition, Wageningen University, in Wageningen, Netherlands, administered a daily 3.5gm dose of either fish oil or placebo oil (high-oleic acid sunflower oil) to 85 patients with a history of frequent premature ventricular complexes (PVCs). The daily dose of fish oil provided 700mg eicosapentaenoic acid (EPA), 560mg docosahexaenoic acid (DHA), and 260mg of other n-3 fatty acids. The researchers measured heart rate changes with two 24-hour Holter recordings at the beginning of the study and the end of the study.

At the end of the study (14 weeks), researchers found that fish oil supplementation did not significantly affect the number of PVCs, although the number was decreased by a mean of 6 percent more in the fish-oil group than the placebo group. "PVCs are a common form of arrhythmia that may trigger arrhythmias that are more life-threatening and are independent predictors of sudden cardiac death and mortality in patients with a history of myocardial infarction (MI), significant left ventricular (LV) dysfunction, or both," write the study authors. "These results indicate that n-3 fatty acids from fish are not very effective in the treatment of PVCs in this study."

However, twenty-four hour heart rate was significantly decreased in the fish-oil group by a mean of 2.1 beats per minute more than the placebo group, which predicts a lower risk of sudden death. According to the researchers, "increased heart rate is an independent risk factor for sudden death but not for fatal MI in middle-aged men free of known cardiovascular disease."

Posted by on December 28, 2008 10:00 AM