Are We Still Taking Fish Oil Pills or What?

Fish oil pills were once a buzzy supplement, but recent research has suggested that they may not be as good for your health as we once thought. Still, plenty of people believe that these supplements can be a vital tool in boosting heart health and reducing inflammation. The reality is, it's complicated.

Nearly 8% of American adults take a fish oil supplement, even though data shows that a lot of the claims around these pills are untested. That doesn't mean there's no value in taking fish oil pills — they just aren't a gateway to good health for everyone.

So, who should take fish oil pills and why? Cardiologists and a nutritionist explain.

Yu-Ming Ni, MD, is a a cardiologist and lipidologist at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, CA.

Joy Gelbman, MD, is a cardiologist at NewYork-Presbyterian and Weill Cornell Medicine.

Jessica Cording, MS, RD, is author of "The Little Book of Game Changers: 50 Health Habits for Managing Stress and Anxiety".

"This is not an easy question to answer," says Yu-Ming Ni, MD, a cardiologist and lipidologist at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, CA. "There is a lot of uncertainty about fish oil."

Joy Gelbman, MD, a cardiologist at NewYork-Presbyterian and Weill Cornell Medicine, agrees. "Randomized controlled studies looking at the effects of fish oil on cardiovascular outcomes have yielded mixed results, so it's hard to say definitively for all patients," she says.

The big potential benefit of taking fish oil pills centers around inflammation and heart disease and, again, the data has been mixed. A 2011 scientific analysis of 17 studies found that people who eat fish and shellfish — which is rich in omega-3 fatty acids — one to four times a week are less likely to die of heart disease than those who rarely or never eat seafood. "From there, people started focusing on fish oil," Dr. Ni says.

Since then, the data has been mixed. The National Institutes of Health (NIH) points out that a 2018 analysis of 10 major omega-3 supplementation studies found no evidence that omega-3s could reduce the risk of fatal or nonfatal coronary heart disease. Several placebo-controlled randomized trials also haven't shown any benefit for most people to take fish oil to prevent heart disease. But some other analyses show that it could be helpful.

To further complicate things, supplements are a largely unregulated industry in the US. While they're technically subject to oversight by the Food and Drug Administration (FDA), companies are merely expected to adhere to FDA guidelines vs. needing to go through a series of testing before their products hit the market. A study published last year found that there is a wide variety of amounts of omega-3 fatty acids found in fish oil supplements, regardless of what is on the label.

Fish oil pills can be helpful for some people—just not all, Dr. Gelbman tells PS. There are a few potential benefits to keep in mind.

Potential fish oil benefits for women are similar to those of men. However, Cording points out that expectant moms may benefit from taking a fish oil supplement or prenatal supplement that contains DHA, a type of omega-3 fatty acid. Research has linked these supplements in pregnancy to slightly higher birth weights and longer pregnancies.

While generally considered safe, there are a few potential side effects to keep in mind when considering fish oil pills, per Cording and Dr. Gelbman, including:

Fish oil pills can also thin your blood, which can create an issue if you're already on blood-thinning medications, Cording says. "You definitely want to be cautious with potential interactions," she tells PS.

Dr. Ni suggests doing your best to eat fish instead. "I recommend having two to three servings a week of fatty fishes like salmon, mackerel, and tuna," he says. "These are relatively high in omega-3 fatty acids and you're getting that same fish oil in the fish itself."

Ultimately, the decision of whether or not to take fish oil pills is a conversation to have with your doctor. "Consult with your physician before starting fish oil pills," Dr. Gelbman says. Dr. Ni also recommends keeping in mind that the data on fish oil pill benefits isn't strong to support their use. "The data is pretty unclear on potential benefits for the heart," he explains. "I don't see too many harms in taking them, but I don't really recommend them."

Korin Miller is a writer specializing in general wellness, health, and lifestyle trends. Her work has appeared in Women's Health, Self, Health, Forbes, and more.