Fish oil not Good for Abnormal Heart Rhythms
Reported June 16, 2005
(Ivanhoe Newswire) — Fish oil may be good for the heart overall, but its not so good for people with abnormal heart rhythms.
According to a new study, fish oil — and the omega-3 polyunsaturated fatty acids it contains — may actually lead to more incidents of potentially life-threatening irregular heart rhythms in people with the condition.
The finding is based on a study that compared two groups of people with abnormal heart rhythms. All the participants had implantable cardioverter defibrillators (ICDs) to help bring their hearts back into rhythm during episodes of either ventricular tachycardia (VT) or ventricular fibrillation (VF) — two types of irregular heart rhythms that put people at increased risk for sudden death.
One of the groups received fish oil supplements while the other received a placebo supplement consisting of olive oil. Results show people receiving the fish oil had more incidents of VT and VF than those receiving the placebo — 46 percent vs. 36 percent. Those most affected were patients who were suffering from VT at the beginning of the study. Sixty-one percent of the participants in that group who took fish oil suffered an incident of VT or VF compared to 37 percent of those who took the placebo.
The authors believe fish oil still has benefits for people who have experienced a heart attack, but the benefits may not extend to all heart patients. They write, The lack of benefit and the suggestion that fish oil supplementation may increase the risk of VT or VF in some patients with ICDs can reasonably be interpreted as evidence that the routine use of fish oil supplementation in patients with ICDs and recurrent ventricular arrhythmias should be avoided.
SOURCE: The Journal of the American Medical Association, 2005;293:2884-2891