Doctors often recommend omega-3 fatty acids to help patients lower their cholesterol and improve heart health. Those omega-3 fatty acids can come from fatty fish such as salmon and mackerel, or supplements that often contain a combination of the acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Now, new research from the Intermountain Healthcare Heart Institute in Salt Lake City shows that only higher EPA blood levels lowered patients’ risk of serious cardiac events and death, while DHA attenuated the cardiovascular benefits of EPA.
Higher DHA levels at any level of EPA worsened health outcomes. The results of the Intermountain study, which examined nearly 1,000 patients over a 10-year period, will be presented virtually at the American College of Cardiology’s Scientific Session in 2021 on Monday, May 17.
“The advice to take omega-3s for the well-being of your heart is ubiquitous, but previous studies have shown that science doesn’t really support this for every omega-3,” said Viet T. Le, MPAS, PA, researcher and cardiovascular physician assistant at the Intermountain Heart Institute and principal investigator of the study.
“Our findings show that not all omega-3s are the same, and that combined EPA and DHA, as often in supplements, may offset the benefits patients and their doctors hope to achieve.
” In this study, Intermountain researchers used the INSPIRE registry, an Intermountain Healthcare database started in 1993 that contains more than 35,000 blood samples from nearly 25,000 patients.
Through INSPIRE, researchers identified 987 patients who underwent their first documented coronary angiographic study at Intermountain Healthcare between 1994 and 2012.
The circulating levels of EPA and DHA in their blood were measured from those blood samples. Researchers then followed those patients for 10 years, looking for serious cardiac side effects including heart attack, stroke, heart failure requiring hospitalization or death.
They found that patients with the highest levels of EPA had a reduced risk of serious heart disease. When they evaluated how EPA and DHA affect each other, they found that higher DHA diminishes the benefit of EPA.
In particular, they also found that those patients with higher DHA levels than EPA were more at risk for heart problems. Le said these results raise further concerns about the use of combined EPA / DHA, particularly through supplements.
“Based on these and other findings, we can still tell our patients to eat omega-3 rich foods, but we should not recommend them in pill form as a supplement or even as combined (EPA + DHA) prescription products,” he said .
“Our data reinforces the findings of the recent REDUCE-IT (2018) study that prescription-only products for EPA reduce heart disease.” Meeting: American College of Cardiology 2021 Other members of the research team include: