The American Heart Association said Monday that researchers analyzing health data from thousands of adults suffering from chronic insomnia found that people who were prescribed melatonin for more than a year were more likely to develop heart failure within five years than individuals who did not use the supplement. The study also found that melatonin users were more likely to be hospitalized for heart failure and had a higher overall risk of death than non-users. Washington Post.
The study, which has not yet been peer-reviewed, has received mixed reactions from both sleep medicine experts and cardiologists. Experts are advising the public to remain calm, stressing the need for further research on the long-term use of melatonin.
“The findings are certainly provocative and deserve attention, especially given the widespread perception of melatonin as a gentle, ‘natural’ sleep aid,” said Muhammad Rishi, MD, associate professor of clinical medicine and spokesman for the American Academy of Sleep Medicine, who was not part of the research. He said the study is observational and relies on electronic health record data, which limits its ability to prove cause and effect.
The study used an international health records database and analyzed five years of data from more than 130,000 adults with insomnia.
Researchers identified nearly 65,000 participants who were prescribed melatonin at least once and reported using it for at least a year. Over five years, about 3,000 of those taking prescription melatonin experienced heart failure for the first time, while about 1,800 were classified as non-users.
Individuals were excluded from the study if they had a prior diagnosis of heart failure or were prescribed other sleep medications. Participants identified as melatonin users were matched with others in the database who also had insomnia but had no record of melatonin use. The researchers said they adjusted for a number of factors that can affect a person’s risk of heart failure, including other existing health conditions.
“Melatonin is also a well-known antioxidant,” said Onn-Hsiao, MD, associate professor of cardiovascular medicine at Yale School of Medicine, who was not involved in the research, and it may provide protective benefits against coronary artery disease, which can lead to heart failure. Some research also suggests that, when taken at the right time and dose, melatonin supplements may help control blood pressure. The report said the new study “appears to be the only one that says melatonin can cause heart failure.”
What is melatonin?
Melatonin is a hormone produced by the pineal gland in the brain in the evening, which signals the body that it is time to sleep. However, some physicians advise against using melatonin supplements for the management of chronic insomnia, citing limited and inconsistent evidence of their effectiveness and a lack of research on long-term safety.
Sleep experts commonly recommend small doses of melatonin to help correct disruptions in sleep timing, such as those caused by jet lag or shift work. Unlike some other countries, melatonin is available without a prescription in the United States.
While both prescription and over-the-counter forms contain the same active ingredient, prescription versions are usually subject to strict pharmaceutical regulations that ensure greater consistency in purity and dosage.
Akenedilichukwu Nnadi, lead author of the new report and chief resident in internal medicine at SUNY Downstate/Kings County Primary Care in Brooklyn, advised individuals who have been using melatonin for years to consult with their doctors, especially those with heart disease or risk factors.
“The point is not to say that melatonin is ‘bad’ or that everyone should stop taking it. The point is that we should not assume that something is risk-free just because it is natural or sold over the counter,” he said.
key takeaways
- Melatonin is a hormone produced by the pineal gland in the brain in the evening, which signals the body that it is time to sleep.
- The study, which has not been peer-reviewed, also found that melatonin users were more likely to be hospitalized for heart failure and had a higher overall risk of death than non-users.
