Fish oil supplements – also called omega-3 fatty acids – are among the top five best-selling supplements in America. Evidence suggests that fish oil supports childhood brain development and decreases joint inflammation, and it has been proven to lower triglycerides.
But if you’re taking fish oil supplements to prevent a heart attack, that may be wishful thinking. Most recent studies have not shown fish oil supplements to prevent heart attacks.
What caused misconceptions about fish oil?
The confusion about omega-3s started in the 1970s. Researchers observed Inuits in Greenland who had low rates of heart disease despite other unhealthy behaviors. The study concluded the Inuits’ diet – which includes fatty fish – kept their hearts healthy. Current reviews of the study, however, suggest their rates of heart disease were underestimated.
Another study in the 1990s compared vitamin E and omega-3 supplements among heart attack survivors. Results suggested the patients who took 1 gram of omega-3 per day had lower rates of sudden death. However, a subsequent study looking specifically at life-threatening heart rhythm abnormalities did not show any benefit of omega-3s. (An important side note: Patients who already have heart disease, as was the case with the subjects in this latter study, are quite different from those who have never had heart problems.)
The two studies caused a lot of excitement when they were published. In the last 15 years, however, the majority of studies have suggested omega-3 supplements have no effect on preventing a heart attack.
What’s your goal?
When patients ask me whether they should take fish oil, I ask, “What’s your goal?” Their goals generally fall into one of three categories:
- Improve overall health: Some people have no immediate heart health concerns. They eat right and exercise regularly but take omega-3 supplements as an add-on. I explain the pros and cons of omega-3s to this group, and let them decide if it is worthwhile to continue with these supplements.
- Lower triglycerides: Studies have proven omega-3s effectively lower triglycerides – the fat in your blood – but it takes 3 to 4 grams of EPA and DHA omega-3s every day to do so. Over-the-counter forms of the supplement are fine, but they often require taking up to 12 capsules a day to get that much EPA and DHA, depending on the strength. Prescription forms are more concentrated, requiring taking only three to four capsules a day to get the same EPA and DHA levels. But one tablet a day of either form will have little effect.
- Prevent a heart attack: Many patients have never had a heart attack but want to prevent one. I don’t usually recommend omega-3 supplements for that goal. There are very few fish oil side effects, and it likely won’t hurt you. But there is not good evidence to show that they prevent heart attacks either. There are a few ongoing studies that may give us a more definitive answer in the next few years about the role of omega-3 supplements and heart disease prevention. In the meanwhile, however, eating fatty fish twice a week is still a reasonable target and may have health benefits that are different from taking omega-3 supplements.
How can you prevent a heart attack?
Preventive therapies are much better today than they were 20 years ago. We’ve learned that statin medications are highly effective at decreasing the risk of first-time and recurrent heart attacks. Once you’ve had a heart attack, your risk for another skyrockets – it becomes greater than a one in four chance that you’ll have another in the next 10 years. If you are at high risk for a heart attack, you should be on a statin medication.
Good exercise habits are also incredibly important. Strive for 30 minutes of aerobic exercise five days per week. Even very busy people can make time. Take a brisk, 10-minute walk in the morning, another at lunch, and another after dinner – there’s your 30 minutes.
A healthy diet can also help decrease your heart attack risk. A recent study of 7,000 people who followed a Mediterranean diet – a plant-based diet that includes healthy fats – showed a 30 percent reduction in heart attacks and strokes.
The American Heart Association recommends eating fatty fish – salmon, mackerel, herring, anchovies, and tuna, which are all high in omega-3s – twice a week. Remember, it doesn’t count if you fry it, put it on a high-sodium white bun, and coat it with tartar sauce. That’s no healthier than a greasy cheeseburger.
Unfortunately, there’s no miracle pill to prevent a heart attack. The best approach is to be proactive by eating a heart-healthy diet, exercising, and, when necessary, working with your physician on a more intensive plan.
To schedule an appointment with a UT Southwestern preventive cardiologist, call 214-645-8300.