For protection against heart disease, fish oil has long been a popular supplement — even if clinical trials didn’t show definite benefits. But here’s some encouraging news: A new trial found that large doses of a fatty acid found in fish oil can help prevent strokes and heart attacks in some patients.

In a large clinical trial, a prescription drug called Vascepa considerably reduced cardiovascular events in certain patients. The findings were presented at a recent American Heart Association meeting.

The trial involved more than 8,000 adults who were tracked for five years. It focused on people whose cholesterol levels were controlled with other medications but who also had high levels of blood fat known as triglycerides. The combination of fish oils and cholesterol-reducing drugs lowered the risk of strokes, heart attacks and other cardiac events by 25 percent compared with a group that received a placebo, the trial found.

But don’t run to the store for conventional fish oil just yet: Regular fish oil contains high levels of omega-3 fatty acids, most notably a blend of EPA and DHA, that can reduce fat in the blood and inflammation. The trial used highly purified EPA that is only available by prescription.

Still, researchers say the findings look promising for certain patients — those who have had heart attacks or strokes and have other cardiovascular risk factors such as high blood pressure, Type 2 diabetes and high levels of blood fat. While more study is needed, the findings suggest that those who take a cholesterol-reducing drug and still have elevated blood-fat levels, could someday see some benefits from a prescribed fish-oil based medication.