The Case for and Against Taking Fish Oil Pills

Fish shape made out of fish oil vitamins
A large meta-analysis published in 2018 found that fish oil supplements weren't positively correlated with reductions in fatal or nonfatal coronary heart disease or any major vascular events for heart patients. So, does that mean people should still take them? It depends. JW LTD/Getty Images

Eggs at one time were considered awful for you. Cholesterol bombs. Heart killers. Dietary death. Now, even the American Heart Association says that a few eggs a week, no matter their high-flying cholesterol content, may be good for you and your ticker.

The story of fish oil supplements — officially, pills that contain omega-3 fatty acids, considered critically good fats to have in your diet — is similar, only reversed. At one time, regularly popping a fish oil pill was considered hugely beneficial for mental health, for cardiovascular health, for brain health and to aid in the health of unborn babies, among other benefits.


But earlier this year, a British meta-study that covered 77,917 heart patients was released, and it said that fish oil supplements "had no significant association with reductions in fatal or nonfatal coronary heart disease or any major vascular events."

In other words, the pills didn't do anything. Not for these heart patients in terms of heart attacks and strokes, anyway.

Suddenly, fish oil supplements weren't quite the magic pill that some took them to be.

What's a health-conscious consumer to think?

"I think the overall message is, when you look at the best evidence in the world, taken together, synthesized in this way," Dr. Hertzel Gerstein, a Canadian endocrinologist and one of the study's authors, says, "overall there's really no scientific justification to go out and buy omega-3 fatty acid supplements if you think you're going to be preventing heart attacks and strokes, because there's no evidence you will."

That study dealt, specifically, with dietary supplements. Many reputable places, including the National Institutes of Health, the Harvard School of Public Health and, yes, the American Heart Association, still tout the need for omega-3s.

Two problems exist in getting enough omega-3 fatty acids, though:

That is why many consider fish oil supplements a must.

Four sardines and fish hook
Sardines are an excellent source of omega-3s.
Envision/Corbis Documentary/Getty Images

According to the Council for Responsible Nutrition (CRN), some 16 percent of Americans adults take omega-3 fatty acids in supplement form. With tens of millions of Americans popping fish oil pills, spending millions of dollars, the manufacturers of these supplements aren't going to go quietly on suggestions that their products don't work.

"This study was about high-risk cardiovascular heart disease individuals, and determining if omega-3 fatty acids would act, essentially, like a drug, a nutritional drug, to help prevent future cardiac events," say Douglas "Duffy" MacKay, the senior vice president for scientific and regulatory affairs for the CRN, the leading trade association for the dietary supplement and functional food industry. "But the bottom line for the general population is, this is still an essential nutrient that plays incredibly important roles in human nutrition. Balancing inflammation. It's part of cell membranes. It's part of cells communicating with one another. And Americans just don't eat a lot of cold-water fatty fish that provide these important nutrients."

Thus, MacKay contends, if sardines and flaxseed aren't on your weekly shopping list, you ought to consider supplements. Even if they don't stop heart attacks in high-risk cardiovascular cases.

"When you ask people about what they eat, do they eat anchovies? Do they eat sardines? Do they eat wild-caught salmon on a regular basis? Typical Americans don't," he says. "So for a typical American, eating the standard American diet, supplementing with these important fatty acids is incredibly important to make sure you're getting what your body needs."

For his part, Gerstein, a professor in the department of medicine at McMaster University in Hamilton, Ontario, Canada, agrees that omega-3s are essential. A diet high in omega-3s indeed may be beneficial, he says, although science behind that is still unsettled.

"There is some evidence from the dietary literature that there may be a benefit to it. This research does not in any way refute that," Gerstein says. "When you think of the dietary literature, though ... if somebody decides that they're going to eat a diet high in omega-3 fatty acids, that means they're also reducing other things, such as maybe red meat and other things. So if there's a benefit, maybe it's because they're replacing harmful things [with the omega-3s]."

The main question comes down to whether people are getting enough omega-3s in their diets and what can be done about it if not.

MacKay says most people don't get enough and suggests supplements (in consultation with a doctor) as a possible answer. Gerstein says they do, and if they don't, it's something that should be discussed with a doctor.

The good news is that taking a regular fish oil pill as a supplement doesn't seem to do any harm. Except, Gerstein says, all those extra fatty acids, not to mention all the money spent, may end up, quite literally, down the drain.

"You're making expensive urine," Gerstein says.