For decades, doctors have been looking for a surefire way to prevent atrial fibrillation, an abnormal heart rhythm that can prove fatal. Now, a new, high-quality study has ruled out two potential competitors: vitamin D and fish oil supplements.
The study, called VITAL-Rhythm, was recently the focus of a virtual conference organized by the American Heart Association (AHA), the nation’s largest professional body of doctors who focus on the heart and cardiovascular system.
“Atrial fibrillation is a very common condition and difficult to treat,” said Dr. Christine Albert, the lead study author and Chair of the Department of Cardiology at the Smidt Heart Institute at Cedars-Sinai. “There are an estimated 33 million people in the world with atrial fibrillation.”
Doctors said it was a relief to see high quality evidence like this as they could focus on new research frontiers and avoid prescribing unnecessary pills to their patients.
Previous studies identified a possible link between these supplements and atrial fibrillation, but it wasn’t clear whether these differences were caused by the supplements themselves or by some other unexplained factor such as lifestyle choices.
Albert and her research team began an extensive study of 25,000 volunteers who were randomly selected to receive vitamin D, fish oil, or a placebo pill.
Dr. Erin Michos, director of women’s cardiovascular health and assistant director of preventive cardiology at the Ciccarone Center for Cardiovascular Disease Prevention at Johns Hopkins University Medical Center, said the study was recognized for being the case at this year’s American Heart Association conference was a high quality study that included various volunteers. This means that the results are applicable regardless of race or gender.
“They looked at vitamin D at 2000 IU per day versus placebo and at the same time 840 milligrams of marine omega-3 fatty acids per day versus placebo. This was a randomized clinical trial and blinded so participants didn’t know if they were taking a supplement ingestion or placebo, “said Michos.
In the past, large studies have suffered from underrepresentation and a lack of diversity, making it difficult for clinicians to apply these studies to their true patient population. This study, meanwhile, represented a larger population of African Americans and women.
An undated photo of fish oil supplements.
Michos said the importance of having strong African American representation in this process was critical. Many have lower levels of vitamin D in their blood due to the darker skin pigmentation, resulting in poor absorption of UVB light, which is required to produce active vitamin D and to reap its benefits.
“I applaud the study’s investigators for their diversity efforts in this study,” said Michos. “Twenty percent of blacks are over-represented for their proportion of the US population.”
Additionally, Michos said that women are often underrepresented in cardiovascular studies, which usually limits doctors’ understanding of whether a drug or treatment works as well in women as it does in men.
“However, this was not the case in the VITAL-Rhythm study,” said Michos. “51% of women took part in the VITAL study.”
In recent years, research has shown a behavioral change in some Americans towards an increase in the consumption of nutritional supplements: an estimated $ 120 billion industry.
However, researchers say the real health benefits of diet supplements are often overstated.
“The vast majority of dietary supplements seem to be of no use. Again, more is not better if you are not deficient in nutrients. Some high-dose dietary supplements can even cause harm,” said Michos.
There is growing evidence that dietary supplements fail to prevent primary or recurrent cardiovascular disease. Another debut study at AHA, the OMEMI study, showed no benefit in adding polyunsaturated marine n-3 fatty acids to prevent a second heart attack.
However, what has been shown repeatedly is the benefits of diet and exercise in preventing, or sometimes even reversing, conditions such as atrial fibrillation.
“We tend to look for the magic nutrient so we don’t have to eat well,” Albert said.
Albert said the most effective prevention is by maintaining a healthy weight, reducing alcohol consumption to 1-2 drinks a day, and maintaining healthy blood pressure.
Michos agreed, advising that a healthy lifestyle and eating habits can prevent not only atrial fibrillation but heart disease as a whole.
“Moderate exercise following a healthy diet and maintaining a normal weight can reduce the risk of atrial fibrillation. I think people would be better off saving their money on supplements that have not been shown to work and theirs instead Time and attention is focusing money on activities that promote healthy lifestyles, “she said.
Lily Nedda Dastmalchi, DO, MA, is an internal medicine-based physician at George Washington University and an employee of the ABC News Medical Unit.