But before you buy fish oil supplements from the local pharmacy, there are some things to be aware of.
The largest study to test vitamin D and omega-3 pills in healthy adults found they did little to prevent cardiovascular disease, but hinted at benefits for groups including African-Americans.
The results showed that people receiving the drug, 28% less likely to suffer from heart attacks than patients with placebo, and 8% less likely to develop cardiovascular diseases. She recommends that people talk to their health care provider before they start taking a fish oil supplement.
JoAnn Manson: We encourage people to eat fish and get these omega-3s in the diet.
Previous research suggests fish oil may have greater benefits for heart health than for reducing stroke, because there are some mechanisms - such as reducing irregular heart rhythm - which would be more important for heart attack than for stroke. However, the good news is that for those at higher risk due to elevated triglycerides the use of prescription medicines can be associated with a lower risk of heart attacks and strokes, albeit at a cost.
For the VITAL trial, almost 26,000 US men and women aged 50 and older were randomly assigned to take 1 gram of fish oil or 2,000 International Units of vitamin D daily, or a placebo.
Not everyone with heart disease would necessarily benefit from the supplements participants received in the trial. from shutterstock.com.
"The lower risk of heart attack was found particularly in those who have low fish consumption", Manson said. The study was a systematic review, which combined the results of ten trials testing fish oil supplements (at a lower dose than the REDUCE-IT trial), involving 77,917 older adults at high risk of cardiovascular disease. They reduce triglycerides (the type of fat that contributes to hardening of the arteries) and the risk of blood clots, and are anti-inflammatory. Instead, they looked at areas where vitamin D's benefits haven't been definitely proven, such as cancer and heart disease.
Dr. Satjit Bhusri is a cardiologist with Lenox Hill Hospital in New York City.
Although hundreds of studies of these supplements have been published over the years, the new clinical trial - a federally funded project involving almost 26,000 people - is the strongest and most definitive examination yet, said Dr. Clifford Rosen, a senior scientist at the Maine Medical Center Research Institute who was not involved in the research. "A reduction in heart attacks this profound has not seen been since in primary prevention since the early trials of aspirin therapy".
What about diet? Isn't that a better way to get omega-3 fatty acids? Those at risk had diabetes and at least one other risk factor.
There are many ways that omega-3 fatty acids could help heart health, Manson said.
People interested in taking fish oil supplements should discuss it with their doctor first, said Dr. Helene Glassberg, an associate professor of clinical cardiovascular medicine at the University of Pennsylvania's Penn Medicine. He had no role in the studies or ties to the companies involved.
"It does have a blood-thinning effect". You should eat two servings of fish every week.
For someone who's healthy but looking to prevent heart disease, "still at the top of my list is lifestyle", Glassberg said.
The evidence will evolve further but, in the meantime, and based on a recent evidence review, the National Heart Foundation recommendations don't advise health professionals to routinely recommend omega-3 supplements for heart health.