Should You Be Taking Fish Oil? What a Cardiologist Tells His Patients

You may have heard that it’s a good idea to take fish oil or another kind of omega-3 supplement for heart health. Many people do – about 20 million people in the US take omega-3 supplements, mostly with the goal of preventing heart attacks and strokes. The question is, are they wasting their money, or getting essential health benefits? The answer may depend on which type of omega-3 they are taking.

Are Fish Oil Supplements Good for Your Heart?

The story of fish oil and heart health started with the observation that several populations (like the Inuit in arctic regions) who had a high intake of fatty fish also had low rates of heart attack and stroke. Since these diets are high in polyunsaturated fats or omega-3 fatty acids, this led to the hypothesis that these fats may be useful for heart health.

A large Italian study published over 20 years ago showed that heart attack survivors who took omega-3 or “fish oil” supplements had a reduction in death, heart attack, and stroke compared to those who did not receive the supplement. These results prompted the American Heart Association to recommend fish oil supplements to patients with heart disease, and many cardiologists followed suit. It wasn’t long before the benefits of fish oil were being touted even for people without heart disease. However, since then, several more rigorous studies (such as the VITAL study) failed to show a heart benefit from fish oil supplements.

What Does the Evidence Say?

Most doctors haven been in agreement that high-dose (3-4 grams per day) omega-3 is helpful in selected patients to lower triglycerides. But when it came to heart attack prevention, because of the conflicting study results, cardiologists were split into two camps. Some cardiologists still advocated for omega-3 supplements in high-risk patients, and some did not.

Then came the study that changed everything.

The REDUCE-IT trial studied high-dose pure EPA (a type of omega-3), called icosapent ethyl, in people with either established heart disease or at high-risk who were taking a statin medication and had elevated triglycerides. And the results were remarkable.

Those who were taking the omega-3 supplement had a 25% reduction in heart disease and stroke and a 20% reduction in death from heart disease. Why did this study have such a positive outcome when previous studies were either negative or weakly positive? Possible reasons include the higher dose used (4 grams per day), or that the omega-3 was pure EPA (and not the usual mix of EPA and DHA in most omega-3 supplements). The truth is, we don’t know why REDUCE-IT was such a positive study. Yet, multiple national and international medical societies now recommend icosapent ethyl in high-risk patients who are taking a statin and have elevated triglyceride levels.

Should You Take Omega-3 Supplements?

The answer depends on who you ask. Here is what I tell my patients about omega-3 supplements:

If there is a benefit to low-dose (1 gram per day) fish oil supplements, it is likely small. A better way to get omega-3 fatty acids is to eat fatty fish such as sardines, herring, albacore tuna, and salmon, among others. The American Heart Association recommends fish (particularly fatty fish) at least twice a week. High dose (4 grams per day) of omega-3 can be effective in lowering high triglycerides. If you do decide to take an omega-3 supplement, find a high-quality supplement manufactured from a reputable company.

Icosapent ethyl is reasonable for those at high-risk for heart disease and have elevated triglyceride levels who are taking a statin. I’m still reluctant to make a strong recommendation based on a single study, especially when that study is not consistent with other similar studies. Be aware there may be risks to omega-3 supplements as well. There is a small increase in bleeding (which is why I generally don’t recommend omega-3 for my patients on strong blood thinner medication), and an increase in Afib was seen in the REDUCE-IT trial. The story of omega-3 and heart health is a complex one, and it is not complete.