• Posted August 24, 2023

Do Fish Oil Supplements Really Boost Your Health?

Stroll past the supplements in any drugstore and you'll find broad claims about fish oil helping everything from heart and brain health, to joints, eyes and immune systems. But you just might be wasting your money, according to a new study.

“We know from recent large, randomized trials that fish oil supplements do not prevent heart disease in the general population, but yet they are one of the most common supplements taken, often by people who still believe they will benefit their heart,” said lead study author Joanna Assadourian, fourth-year medical student at UT Southwestern Medical School in Dallas.

The authors researched what these labels actually say, using data from labels of on-market fish oil supplements, to measure the frequency and types of health claims. They included both U.S. Food and Drug Administration-reviewed qualified health claims and those that made assertions about supporting structure or function in various organs.

The researchers also assessed the total daily doses of combined EPA and DHA, the omega-3 fatty acids found in fish oil, found in supplements from 16 leading manufacturers and retailers.

They found that 2,082 of the 2,819 analyzed made at least one health claim, which is nearly 74%. And of those, only 19% made an FDA-approved qualified health claim, which helps consumers understand any scientific uncertainty surrounding a claim. The others made general structure or function claims, such as “promotes heart health.”

The most common claims were assertions about promoting cardiovascular health.

The study also found a lot of variation in daily doses of EPA and DHA, with 9% of supplements among the 16 leading brands containing a daily dose of 2 grams or more of combined EPA and DHA. So far, experts have not established daily dietary recommendations for EPA and DHA, according to the Office of Dietary Supplements.

The study pointed out that 1 in 5 people over age 60 takes fish oil supplements, often for heart health.

You may be better off investing in fresh vegetables, a gym membership or medication to treat blood pressure or cholesterol, said co-author Dr. Ann Marie Navar, an associate professor of medicine, also at UT Southwestern.

“As a preventive cardiologist, I tell my patients that if they are taking fish oil to try to avoid heart disease then they can stop taking it because it's not helping them,” Navar said.

Patients should be talking to their doctors rather than taking advice from labels, Assadourian said. “Supplement labels can be confusing even for the most savvy of consumers,” she noted.

Study findings were published Aug. 23 in JAMA Cardiology.

Connie Diekman, a food and nutrition consultant and former president for the Academy of Nutrition and Dietetics, said the evidence on fish oil supplements is soft. While consuming seafood provides a health benefit, it's not clear that oil from the fish is the reason why.

It may be “the synergistic effect of everything in that food, as opposed to a single nutrient,” said Diekman, who was not involved in this research.

“I think the first thing that I would say, as a dietitian, is this is a conversation you should have with your physician to get a referral to a dietitian or you need to get on some reputable websites where dieticians are involved who can translate that for you because supplements, while there are laws regulating them, they're like everything else, companies market them and marketing is about selling a product,” Diekman said.

Fish, of course, is a source of protein. Compared to other meats, it is not high in saturated fats. It's also a source of omega-3 fatty acids.

The American Heart Association recommends consuming fish twice a week, particularly fatty fish.

But fish isn't appealing to everyone and some opt out because of allergies or dietary preferences.

To help with the fishy taste for those who want to add fish to their diet, Diekman suggests starting with a less-fatty fish that has a milder flavor.

Another option is to cook the fish then let it cool a little, so the flavor is mellower, Diekman said, sharing a tip from her fish market. It can also be served on top of pasta or mixed with vegetables so the fish is not the centerpiece, she suggested.

It's also important to read the list of ingredients on any supplements because they are likely to contain more than just the one ingredient a person is looking for, Diekman said.

“Look to be sure that you're actually getting what you want versus a lot of fillers,” Diekman said.

Navar noted that two ongoing placebo-controlled randomized trials, VITAL and the U.K.'s ASCEND, tested fish oil supplements for heart disease prevention and found no benefit.

“We need more research now on what consumers are inferring from vague statements like “promotes brain health” and what types of messaging can be used that will accurately convey what is known about the benefits [or lack of benefit] of fish oil supplements,” Navar said.

Researchers concluded that more regulation may be needed for dietary supplement labeling to prevent consumer misinformation.

More information

The U.S. Food and Drug Administration has more information on dietary supplements.

SOURCES: Ann Marie Navar MD, PhD, associate professor of medicine (cardiology), UT Southwestern Medical School, Dallas; Joanna Assadourian, BSA, fourth-year medical student, UT Southwestern Medical School, Dallas; Connie Diekman, MEd, RD, food and nutrition consultant and former president, Academy of Nutrition and Dietetics; JAMA Cardiology, Aug. 23, 2023