Omega-3 Supplements Won't Fight Irregular
MONDAY, Nov. 15 (HealthDay News) -- Omega-3 fatty acid
supplements don't cut back on recurrences of atrial fibrillation, a
type of irregular heartbeat that can cause stroke, new research
"We now have definitive data that they don't work for most patients with AF [atrial fibrillation]," said Dr. Peter R. Kowey, lead author of a study appearing in the Dec. 1 issue of the Journal of the American Medical Association that is also
scheduled to be presented Monday at the American Heart
Association's annual meeting in Chicago. "Although we can't exclude
the possibility of efficacy in sicker AF patients, it would be hard
to believe that it would work in that population and not in
healthier patients. So for practical purposes, yes, [this is] the
end of the line in AF."
This study, the largest of its kind, looked at patients with AF
who were otherwise healthy.
"We cannot say there is any convincing evidence of a role for omega-3 in the prevention of atrial fibrillation," added Dr. Ranjit Suri, director of the Electrophysiology Service and Cardiac Arrhythmia Center at Lenox Hill Hospital in New York City, who was not involved with the trial.
The study was funded by GlaxoSmithKline.
Omega-3 fatty acids, which are found in fatty fish such as
salmon and albacore tuna, had showed some promise in preventing
heart disease in earlier trials.
Of the total 663 outpatient participants, 542 had paroxysmal
atrial fibrillation, which appears suddenly and resolves on its
own, and 121 had persistent atrial fibrillation, which needs
Participants were randomized to receive either a placebo or 8
grams of omega-3 supplements daily for the first week, followed by
4 grams a day for the remaining 23 weeks of the trial.
The doses used in the study are available only by prescription
and are "higher than doses previously published in studies," said
Dr. Robert Block, a cardiologist and assistant professor of
community and preventive medicine at the University of Rochester
At the end of six months, 46 percent of those in the placebo
group and 52 percent of those taking omega-3 supplements
The numbers of paroxysmal AF patients in the placebo and
treatment groups who had AF recurrences were about equal (48
percent and 52 percent, respectively), the investigators found.
In patients with persistent AF, more patients in the omega-3 arm
had recurrences than in the placebo group (50 percent and 33
But experts haven't ruled out a possible role for omega-3 in
other types of patients, such as those with heart failure.
"Our data do not speak to other cardiac indications," said Kowey, who is president of the Main Line Health Heart Center and a professor of medicine and clinical pharmacology at Jefferson Medical College in Philadelphia. "There has been conflicting data there as well and a clear need for definitive studies like ours in those indications."
"Omega-3 may be helpful in patients with high triglycerides and bad overall cholesterol profiles or people prone to electric storms in the heart who are at risk of sudden death," said Suri.
Block recommends that patients with cardiovascular disease eat
two servings of oily fish weekly, or three over-the-counter omega-3
capsules a day.
In those with no cardiovascular disease, "there is no practical
definitive benefit," but they still might also want to eat fish
regularly, he said.
Heart Rhythm Society has more on atrial
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