New study shows effects of EPA and DHA may negate each other

The study measured omega-3 in participants’ blood and found that high levels of EPA were associated with a lower risk of cardiovascular events, while DHA appeared to counter the beneficial effects of EPA, the report said.

Conducted by researchers at the Intermountain Healthcare’s Heart Institute in Salt Lake City, Utah, the study’s results were presented at the American College of Cardiology’s virtual 2021 conference.

The researchers found that although high levels of EPA in the blood were associated with a reduced risk of major cardiac events and death, rising levels of DHA appeared to negate those benefits, Medical News Today wrote.

“The advice to take omega-3 for the good of your heart is pervasive, but previous studies have shown that science doesn’t really back this up for every single omega-3,” principal investigator Viet T Le, a cardiovascular physician assistant at the institute.

“Our findings show that not all omega-3s are alike and that EPA and DHA combined together, as they often are in supplements, may void the benefits that patients and their doctors hope to achieve,” he added.

In the study, the researchers used data from Intermountain Healthcare’s INSPIRE registry, which comprised about 35,000 blood samples from nearly 25,000 patients and their medical records, according to the report.

A random group of 987 individuals who had received a first heart scan at Intermountain Healthcare between 1994 and 2012 were selected and their plasma levels of EPA and DHA were measured, Medical News Today said.

The average age of those included was 61.5 years and at the time of their scan, 41% had obesity, and 42% had severe coronary artery disease.

During the following 10 years, 31.5% of all the patients had had a major adverse cardiovascular event, which the team had defined as all-cause death, heart attack, stroke, or heart failure, the report said.

Patients with the highest levels of EPA in their blood at the time of their first scan were less likely to experience a major cardiovascular event while rising levels of DHA appeared to lessen the beneficial effects of EPA, the study found.

Participants with more DHA than EPA in their blood had an increased risk of heart problems compared with those with higher levels of EPA, according to the report.

The findings remained after accounting for pre-existing illnesses, including severe coronary artery disease, chronic obstructive pulmonary disease (COPD), and heart failure, Medical News Today wrote.

“Based on these and other findings, we can still tell our patients to eat omega-3 rich foods, but we should not be recommending them in pill form as supplements or even as combined (EPA + DHA) prescription products,” Le concluded.

The Intermountain Healthcare Heart Institute’s research team has submitted the study for publication, according to Medical News Today.

However, a “large body of evidence” supported the benefits of both EPA and DHA for heart health, Medical News Today quoted Andrea Wong, senior vice president for scientific and regulatory affairs at the Council for Responsible Nutrition (CRN) – a trade association that represents the supplement industry – as saying.

Wong cited a recent study that had pooled data from 17 studies and had found that higher circulating levels of EPA and DHA, both taken separately and together, were associated with a lower risk of premature death and death from cardiovascular disease.

“Supplementing with EPA and DHA omega-3 fatty acids can contribute to heart health, but as one of many healthy habits to maintain a healthy heart. CRN recommends consumers at high risk or those with a history of cardiovascular disease talk with their cardiologist about what supplements are right for them,” Wong told Medical News Today.

EPA is an omega-3 fatty acid found in the flesh of cold water fish, including mackerel, herring, tuna, halibut, salmon, cod liver, whale blubber or seal blubber.

Also an omega-3 fatty acid, DHA can be synthesised from alpha-linolenic acid or obtained directly from breast milk, fish oil, or algae oil.