If You Take This Popular Supplement, Your Heart May Be at Risk, Study Says

Zachary Mack
·4 min read

Millions of people use dietary supplements for their purported health benefits, constituting a nearly $37 billion industry in the U.S. as of 2021, IBISWorld reports. But one popular daily pill could be creating serious problems for people who may not even be aware of the danger. According to a new study out of the University of Georgia, fish oil may increase the risk of heart disease in some, depending on their genetic makeup. Read on to see what this could mean for you, and for more on supplements you should avoid, check out This Is the One Vitamin You Should Never Take, Doctors Say.

The study found that your genes determine whether or not fish oil supplements pose a risk to your heart health.

A team of scientists from the University of Georgia set out to determine the effects of fish oil on heart health by examining four fats found in the blood: total cholesterol, high-density lipoprotein, low-density lipoprotein, and triglycerides. To do this, they used data on 70,000 patients, dividing them into two groups: those who did take fish oil supplements (about 11,000 patients) versus those who did not. Then, they conducted a genome-wide scan.

The results, which were published in the journal PLOS Genetics, showed that after 64 million tests, a "significant variation" existed at gene GJB2. For those with the AG genotype, taking fish oil decreased triglycerides, while patients with the AA genotype who took fish oil saw their triglyceride levels slightly increase. "High triglycerides may contribute to hardening of the arteries or thickening of the artery walls (arteriosclerosis)—which increases the risk of stroke, heart attack, and heart disease," the Mayo Clinic explains.

And for those who are worried about their tickers, check out If You Can't Do This in 90 Seconds, Your Heart Is in Danger, Study Says.

The study proves that "fish oil supplementation is not good for everyone."

Researchers say the results raise questions about the traditional daily use of fish oils—which contain the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid—that have long been considered helpful in maintaining a healthy heart.

“We’ve known for a few decades that a higher level of omega-3 fatty acids in the blood is associated with a lower risk of heart disease,” Kaixiong Ye, PhD, the study's author, said in a statement. “What we found is that fish oil supplementation is not good for everyone; it depends on your genotype. If you have a specific genetic background, then fish oil supplementation will help lower your triglycerides. But if you do not have that right genotype, taking a fish oil supplement actually increases your triglycerides.” And for more important updates on pills, check out The FDA Just Issued a New Warning About These OTC Pain Meds.

The results also help explain why some studies have doubted fish oil's effectiveness in the past.

While the results showed that some people won't reap health benefits from taking daily fish oil, the researchers point out that the findings also shed a new light on previous studies that found omega-3 fatty acids to be ineffective at promoting heart health. “One possible explanation is that those clinical trials didn’t consider the genotypes of the participants,” Ye explained in a statement. “Some participants may benefit, and some may not, so if you mix them together and do the analysis, you do not see the impact.”

And for more health tips and news delivered right to your inbox, sign up for our daily newsletter.

Future use of the supplement could come down to personalizing it for each person.

Fortunately, figuring out whether or not you have the right genetic makeup to benefit from a fish oil regimen isn't as difficult as it may sound. The study authors point out that results from readily available genome testing companies can make the raw data available to customers, and, while the specific variant isn't already included in most reports, you can search for the genotype with variant ID rs112803755 (A>G).

“Personalizing and optimizing fish oil supplementation recommendations based on a person’s unique genetic composition can improve our understanding of nutrition and lead to significant improvements in human health and well-being,” Ye concluded. And for more on other ways daily pills could be affecting your health, check out If You Can't Sleep, This Common Medication Could Be Why, Study Says.