For years, the American Heart Association has recommended eating two servings of fish a week. In 2017, the group also suggested that supplements might slightly lower the risk of death from heart failure or a recent heart attack, but also said the supplements did not prevent heart disease. A many people Take fish oil supplements, but some new studies discussed at the American Heart Association’s Scientific Sessions this weekend find that the supplement doesn’t really help improve heart health.
The first study, the longest and largest randomized study of its kind, looked at whether an omega-3 fatty acid supplement and / or a vitamin D supplement were useful in preventing atrial fibrillation.
Atrial fibrillation is a potentially serious heart rhythm disorder that affects more than 33 million people worldwide. The condition can affect a person’s quality of life. It also puts them at a much greater risk of stroke, heart failure, and even death.
Fish oil and vitamin D do not help A. Fib
In the first study presentation, almost 26,000 men and women who had no heart problems in the past received either 2000 IU of vitamin D3 and / or 840 mg of omega-3 fatty acids or a placebo olive oil or soybean oil. After five years there were almost 900 atrial fibrillation. That’s roughly 3.6% of the study population.
When comparing the results between the volunteers who took the placebo and those who received the vitamin supplements, the researchers found no statistically significant difference in the results.
These test results seem to be consistent with earlier short-term tests with both dietary supplements. Smaller or observational studies have produced conflicting data, but many have shown that there are no benefits from taking fish oil or vitamin D.
“Atrial fibrillation itself is a major problem affecting so many people by the age of 80 that around 10-15% of the population have atrial fibrillation,” said Dr. Christine Albert, Chair of the Department of Cardiology at the Smidt Heart Institute at Cedars-Sinai, who presented the results. “It can really affect the quality of life and it leads to a lot of adverse outcomes. I really hope this will spur others into doing primary prevention studies.”
Primary prevention steps she wants to explore next are some of the lifestyle interventions that appear to prevent atrial fibrillation incidents.
People who lose weight, control their blood pressure, and drink less alcohol seem to do better.
Fish oil does not reduce cardiovascular risk
In the second presentation, also published Sunday in the Journal of the American Medical Association, the researchers found that omega-3 fatty acid supplements do not reduce cardiovascular risk.
This was also a double-blind randomized study comparing the health of patients taking a high-dose omega-3 supplement with those taking a placebo made from corn oil.
The 13,078 patients in this study were treated with statins and were at high cardiovascular risk, high blood troglycerides, and low levels of the good cholesterol known as high-density lipoprotein cholesterol.
The volunteers were followed for more than two years between June 2017 and January 2020. The study was terminated prematurely. It found that the omega-3 fatty acids were unlikely to benefit.
In fact, there was a higher rate of gastrointestinal adverse events in the group taking the omega-3 supplement, more than 25%, compared to those taking the corn oil, which was just over 15%.
“Several studies now, with one major exception, have shown absolutely no effect of fish oil on cardiovascular outcomes,” said Dr. Steve Nissen, a cardiologist at Cleveland Clinic who worked on the study. “This study, known as REDUCE-IT, received a lot of attention. There was a lot of hype, including an FDA label that reduced cardiovascular risk.”
A purified form of EPA, one of the components in fish oil, was used in this experiment.
“The question is what’s going on here? What’s the difference between this study and ours, and I’ll be honest that another study used mineral oil as a placebo. We don’t think it was neutral,” said Nissen.
In other words, he believes the choice of mineral oil in the study skewed the results. Mineral oil is a form of liquid paraffin, a derivative of candle wax.
“If you take it regularly, mineral oil is bad for you,” said Nissen. “That’s why we think a study was cheap, not because fish oil was good.”
“In fact, both this and our study showed an increase in atrial fibrillation – a 69% increased risk – with fish oil in our study,” said Nissen. “So you can assume that fish oil may not be neutral. In some cases it can be harmful.”
This study is consistent with previous studies.
The US Food and Drug Administration approved the fish oil-based drug Vascepa in 2019 for the prevention of heart attacks and strokes.
Nissen hopes the FDA will take a look at these studies and reconsider this decision.
“But it’s hard to go back when the genie comes out of the bottle,” he said.
An editorial in the journal supporting the study by Dr. Gregory Curfman, assistant professor of medicine at Harvard Medical School, also suggested that the FDA conduct a post-marketing clinical trial of high-dose fish oil such as Vascepa vs. corn oil in patients at risk for cardiovascular events to “make this confusing.” further illuminate the clinical problem and the research question “.