For years, the American Heart Association has recommended eating two servings of fish a week. In 2017, the group also suggested that supplements could slightly lower the risk of dying 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 a couple of new studies discussed at the American Heart Association’s scientific sessions this weekend find that the supplement doesn’t really contribute to heart health.
The first study, the longest and largest randomized study of its kind, looked at whether a dietary supplement containing omega-3 fatty acids and / or a dietary supplement containing vitamin D had benefits 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 increases the risk of stroke, heart failure, and even death.
Fish oil and vitamin D don’t help A. Fib
In the first study presentation, almost 26,000 men and women who had no history of heart problems 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 is about 3.6% of the study participants.
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 study results appear to be consistent with previous short-term trials of both dietary supplements. Smaller or observational studies have produced conflicting data, but many have shown that there are no benefits from consuming fish oil or vitamin D.
“Atrial fibrillation itself is a huge problem that affects so many people that by the age of 80, around 10-15% of the population will 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 leads to a lot of negative outcomes. I really hope this inspires others to conduct primary prevention studies.”
The primary prevention steps she wants to explore next are some of the lifestyle interventions that appear to prevent atrial fibrillation.
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, researchers found that omega-3 fatty acid supplements did not reduce cardiovascular risk.
This was also a double-blind, randomized study that compared the health status of patients taking high-dose omega-3 supplements with those taking placebo with corn oil.
The 13,078 patients in this study were treated with statins and were at high cardiovascular risk, high blood glycerides, and low levels of good cholesterol, known as high-density lipoprotein cholesterol.
The subjects were observed for two years between June 2017 and January 2020. The study was terminated prematurely, it became clear that the likelihood of a benefit from the omega-3 fatty acids is low.
In fact, there was a higher rate of gastrointestinal side effects in the group taking the omega-3 supplement, more than 25%, compared to those taking the corn oil at 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 the Cleveland Clinic who contributed to the study. “This study, known as REDUCE-IT, got a lot of attention, there was a lot of hype, including an FDA label reducing cardiovascular risk.”
A purified form of EPA, one of the ingredients 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 this other 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.
“Mineral oil is bad if taken regularly,” said Nissen. “That’s why we think a study was cheap, not because fish oil was good.”
“In fact, both this study and our study showed an increase in atrial fibrillation – a 69% increased risk – with fish oil in our study,” said Nissen. “So you can argue that fish oil may not be neutral. It can be harmful in some cases.”
This study is consistent with previous studies.
The US Food and Drug Administration approved the fish oil-based drug Vascepa for the prevention of heart attacks and strokes in 2019.
Nissen hopes the FDA will look at these studies and reconsider this decision.
“But it’s hard to undo once the ghost 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 launch a clinical trial of a high-dose fish oil such as Vascepa vs. corn oil in patients at risk for cardiovascular events to “shed further light on.” throwing this confusing clinical problem and research question ”.