Omega-3s: Worth the Heart-Health Hype?

Interest in the potential health benefits of omega-3 polyunsaturated fatty acids began in the 1940s, when researchers noted that native populations in Greenland, who consumed a diet rich in oily fish, had a very low rate of heart disease.

In 1999, a landmark study that followed 11,000 patients over several years showed an overall 20% reduction in fatal heart attacks among people who consumed 1 gram of omega-3s daily. At that point, omega-3 supplements started showing up on store shelves, and fish was in vogue.

However, follow-up studies have been less consistent about the effectiveness of omega-3s, so some recent headlines have suggested that omega-3s don’t actually work. For those of us who want to improve our heart health, it’s natural to ask, “Now what?”

Is Fish a Good Omega-3 Food?

Jeremy Greenhaus, RD, a clinical dietitian at The University of Vermont Medical Center, has closely followed the research, and his takeaway is that omega-3s are still helpful and important.

Greenhaus points to several recent reviews of the last 20 years of research about the relationship between fish consumption and cardiovascular health. All conclude that fish consumption is associated with less heart disease and fewer fatal heart attacks, even if the numbers weren’t always as exciting as that first study. (His examples can be found here, here and here.) The sources of inconsistency, say the researchers, likely have to do with the cooking method, since too much fried fish may increase the risk of cardiovascular disease.

As we learn more about different sources of omega-3s, it turns out there is more nuance than initially thought. So we asked Greenhaus for a little guidance.

How Omega-3s Prevent Heart Disease

Omega-3s act on the anti-inflammatory pathways in our bodies, says Greenhaus. When there’s less inflammation in our heart and our arteries, we have lower blood pressure and we see less atherosclerosis, or hardening of the arteries – both of which are known precursors of heart attack and stroke.

The Best Sources of Omega-3s

The best source, by far, is fish – and specifically, oily or fatty fish, such as salmon, tuna, mackerel, sardines or shrimp. Greenhaus suggests eating these types of fish two to three times per week. Be careful, though, he says, because these foods are also high in cholesterol and sodium.

Vegetarians, vegans and those who don’t prefer fish can look to other foods, such as walnuts, flax seeds and wheat germ, for natural sources of omega-3s. But those aren’t likely to be enough to deliver the full recommended daily amount, says Greenhaus, so a supplement may be in order.

How to Choose Omega-3 Supplements 

When choosing an omega-3 supplement, pay attention to quantity and quality. Greenhaus recommends a total daily omega-3 consumption of 2 to 4 grams (or 2,000-4,000 mg). This includes all sources, both whole foods and supplements, so keep your diet in mind as you choose a supplement dosage. Usually, supplement tablets will come in increments of 1500-2000 mg, so don’t assume one pill will meet your needs; check the label.

When choosing a supplement, quality is just as important as quantity. Look for third-party seals on the bottle label, from either USP (United States Pharmacopeia) or NSF (National Sanitation Foundation). Since vitamins and supplements are not regulated by the Food and Drug Administration, these organizations offer independent verification, confirming that the reported dosage is accurate and that it only contains the ingredients noted on the label.

Greenhaus also suggests looking for a supplement with a 2:1 ratio of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to support anti-inflammation. There’s been lots of discussion and research on the proper balance of EPA and DHA, and Greenhaus points to these two studies (this NIH study and this review of various clinical trials) supporting that optimal two-to-one balance. 

Omega-3s vs. Triple Omegas

These aren’t quite the same thing, explains Greenhaus, and one gives you more “bang for your buck” when it comes specifically to heart health. While supplements offering “triple omegas” do contain omega-3s, they also contain omega-6 and omega-9, which are more effective at boosting our immune health than our cardiovascular health. Both omega-6 and omega-9 are helpful for boosting our body’s natural defense mechanisms against illnesses and other invaders, Greenhaus says, but we generally get enough of those in our diets, so supplementation isn’t necessary. It’s the omega-3s people are often short on, so these are the best to focus on if you’re looking for a supplement.

Omega-3s Risks, Benefits and Side Effects

According to Greenhaus, there aren’t any major risks with omega-3s, which means anyone can and should consider boosting them in their diets. “But again, if you choose a supplement, just make sure the one you choose is verified to contain just omega-3s,” he reminds us.

Even those who have already started experiencing symptoms of cardiovascular disease, such as high cholesterol or high blood pressure, can still benefit. “It’s not too late, especially if you have high triglycerides,” says Greenhaus, citing this NIH study suggesting that omega-3 fatty acids decrease the presence of free fatty acids in the bloodstream, which could contribute to high levels of triglyceride production in the liver. While there is still more research needed on the exact mechanisms behind this, Greenhaus says, research definitely supports the lowering of triglycerides with fish oil. 

As for side effects, the worst possible downside of omega-3 supplements is the possibility of a fishy aftertaste, or “fish burps.” “Since the primary ingredient is fish oil, you can sometimes get an unpleasant taste,” Greenhaus concedes. “If this is an issue, look for a flavored variety. There are several that are USP-designated and have a lemon flavoring to offset the fish taste.”