"It is currently more difficult to show additional benefit when patients are treated aggressively with everything else," said Dr. Chip Lavie, medical director of cardiac rehabilitation and prevention at the John Ochsner Heart and Vascular Institute in New Orleans.
Lavie also noted that many of the trials evaluated in the analysis gave such small doses of fish oil to patients that it's not hard to understand why they got few benefits from the supplement.
"The very best studies in my opinion still show some benefits," he said.
Still, many experts say the best way to get fish oil is just to eat fish. The American Heart Association currently recommends that people get their dose of omega-3 fatty acids from eating two servings of fatty fish, such as salmon, mackeral, tuna, sardines, per week. For the fish-averse, a slightly different kind of omega-3 fatty acid can be found in flaxseed, walnuts soybeans and canola oils.
"Supplements will never be a replacement for a healthy dietary pattern," Manson said.