If you have been taking fish oil supplements in an effort to smooth out erratic heart beats caused by atrial fibrillation, you can save your money, researchers said Monday. The largest study of the supplements ever conducted showed that a prescription form of omega-3 polyunsaturated fatty acids called Lovaza is worthless for treating atrial fibrillation, providing no benefit whatsoever.
"This is data that we've needed sorely," Dr. Christine Albert of Brigham and Women's Hospital in Boston, who was not involved in the study, said at a news conference. "There are a lot of patients taking these supplements."
Atrial fibrillation, which affects an estimated 2.2 million Americans, occurs when the heart beats erratically, making it difficult to pump blood throughout the body. Blood can pool in the heart, forming clots that can travel to the brain and cause strokes. An estimated 15% of strokes are caused by atrial fibrillation.
Fish oil is thought to help heart disease, and many patients take it in an effort to help atrial fibrillation as well. Several small studies have produced conflicting results about its value. Dr. Peter R. Kowey of the Jefferson Medical College in Philadelphia and his colleagues studied 663 patients with atrial fibrillation but no substantial structural heart disease. Half were given daily Lovaza and half a placebo for six months. The endpoint was when the first recurrence of fibrillation happened.
The team reported at a Chicago meeting of the American Heart Assn. and online in the Journal of the American Medical Assn. that they observed no significant differences between the two groups. The drug was "extremely well tolerated," Kowey said, but it simply provided no benefit. "We have demonstrated incontrovertibly that patients who received the drug did no better than patients who received placebo."
If the prescription-strength capsules have no effect, experts said, it is unlikely that over-the-counter supplements will provide any benefit.