Higher omega-3 status linked to reduced risk of long-term cardiac events

The scientists previously evaluated the effect of six months of omega-3 treatment after a myocardial infarction. This study assesses what happened to participants over a six-year follow-up period.

“Even after two years the number of cardiac events was way lower in those who had been treated with omega-3 for just six months. That’s a very impressive finding,” said author on the paper William S. Harris, PhD, president of the Fatty Acid Research Institute (FARI); founder of OmegaQuant Analytics; and professor, department of internal medicine, Sanford School of Medicine, University of South Dakota.

However, the researchers demonstrated that the benefits of omega-3s coincided with the use of the Omega-3 Index. The Index, which was developed by OmegaQuant, is the measure of omega-3s eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) in a person’s blood. Studies show 8% is the optimal level of omega-3.

“We want to know the effects of taking omega-3 to raise the Index; not just the effects of being told to take omega-3,” Dr. Harris said. “It is one thing to take an omega-3 supplement, but it’s quite another to take enough to achieve a healthy target level in your own blood.”  

Study details​

Approximately 360 patients who had experienced heart attacks were admitted to three Boston hospitals. Six years after the initial admissions and study, the researchers sought to determine whether there was a difference in the rate of major adverse cardiac events (MACE) in the omega-3 group as compared to the placebo group and whether the participants experienced at least a 5% increased in the Omega-3 Index while they were on treatment.

Prior to treatment, researchers measured baseline red blood cell fatty acid levels, serum lipids and insulin resistance markers. Cardiac magnetic resonance (CMR) studies were conducted on patients at baseline and following the six months of initial study treatment.

Participants in the experimental group received 4 g daily of Lovaza (GlaxoSmithKline). Each omega-3 fatty acid (O3-FA) capsule contained EPA and DHA.

Researchers followed the patients at two-month intervals using scripted telephone interviews or questionnaires by mail during the six-month treatment period. When the treatment was completed, another outpatient visit was scheduled, and blood sampling and CMR were repeated. Afterward, patients were followed every six months for three years, then yearly.

“It’s not clear why some people did see an increase in their Omega-3 Index and others did not, but it appears that that’s what was most important in reducing their long-term risk for MACE,” Harris added.

The researchers chose a cutoff of a 5% increase of the Omega-3 Index as this change was associated with a lower rate of cardiac arrest in a prior study.

O3-FA for six months post-AMI did not reduce adverse cardiac events compared to placebo. However, patients treated with O3- FA and achieved a ≥ 5% rise in Omega-3 Index experienced a significant reduction of adverse cardiac events after a median follow up period of 6.6 years, the researchers wrote.

“I want people to realize that achieving a healthy blood level of omega-3 is not automatic if you’re taking an omega-3 supplement or drug (as in this study),” Dr. Harris said. “Achieving the optimal blood level is the primary goal, not just taking the pills.”

Source: International Journal of Cardiology
doi: 10.1016/j.ijcard.2023.1316​
“Effect of six months treatment with omega-3 acid ethyl esters on long-term outcomes after acute myocardial infarction: The OMEGA-REMODEL randomized clinical trial”
Authors: Benedikt Bernhard et al.