,A five-year review of more than 130,000 adults with insomnia found that long-term melatonin use was associated with a higher risk of heart failure. That’s just one of the articles published this week by international news sites that have sparked fear among those using such a supplement.
What the unpublished study says
The preliminary study, to be presented at the American Heart Association meeting, analyzed data from 130,000 adults with chronic insomnia, dividing them into two groups: those who took melatonin supplements for at least a year and those who did not.
“Melatonin supplements may not be as harmless as commonly assumed. If our study is confirmed, this could influence how doctors prescribe supplements to patients with sleep problems.” said Ekenedilichukwu Nnadi, the study’s lead author and chief resident physician at a hospital in New York.
According to the research, people who used melatonin for more than a year had about a 90% higher risk of heart failure over five years compared to those with insomnia who did not use the supplement. At the same time, those who carried out the study say that the risk of hospitalization was almost 3.5 times higher in the case of those who took melatonin (19% compared to 6.6% in the case of those who did not use the supplement). And the risk of death would have been higher (7.8% in the case of those who used the supplement versus 4.3% in the case of the others).
“Melatonin supplements are generally considered a safe and natural option to support better sleep, so it was striking to see such significant increases in serious health problems.”said the author of the study. However, he also stated that additional research is needed.
What limitations does the current research have?
The research in question has not only been previously unpublished in any scientific journal, but it also has limitations and should be viewed with reasonable skepticism, experts say. In a New York Times review, sleep experts point out that we can’t draw any conclusions about melatonin from this study alone.
A more likely explanation, say those consulted by the publication, is that insomnia itself or a health problem that causes it (such as sleep apnea) could be to blame for the increased risk of developing heart complications. And melatonin would be just an “innocent witness”
One of the major limitations of the study is that melatonin use was only inferred based on analysis of medical prescriptions in electronic medical records. But in countries like the United States, melatonin can be taken without a prescription. Thus, those in the non-melatonin group may actually have been using it.
“There was also no information on melatonin dose and insomnia severity, said Dr. Phyllis C. Zee, a sleep specialist and researcher at Northwestern Medicine (who was not involved in the study). Both aspects could have influenced the risks for the heart. Dr. Sujay Kansagra also noted that the risk of heart failure was quite low in both groups.”says the New York Times analysis.
According to the same analysis, to understand whether melatonin increases the risk of heart failure, researchers should conduct controlled studies.
Experts admit the need for further studies
Beyond the limitations of the research, experts agreed that it’s a good reminder of how little we really know about supplement safety. Although melatonin supplements mimic a hormone that our bodies naturally produce, that doesn’t make them without health risks.
