Recent research presented at the American Heart Association scientific meetings has sparked concerns regarding the long-term use of melatonin, a widely prescribed sleep aid in the United Kingdom. The study indicates that individuals who use melatonin for extended periods may face an increased risk of heart failure, prompting calls for further investigation into its safety.
Melatonin, a synthetic version of the hormone naturally produced in the brain, has been prescribed in the UK for almost twenty years. Last year alone, over 2.5 million prescriptions were issued in England. Known as the “hormone of darkness,” melatonin helps regulate the sleep-wake cycle. Traditionally, it has been considered safe for short-term use in adults and, under specialist supervision, for children with conditions such as ADHD.
The study analyzed electronic health records of approximately 130,000 adults struggling with sleep issues over five years. Half of these individuals were melatonin users, while the other half did not take the supplement. The findings revealed that those who had taken melatonin for at least a year were about three times more likely to be hospitalized for heart failure—19 percent of melatonin users compared to 6.6 percent of non-users. Additionally, long-term users exhibited higher rates of heart failure diagnoses and mortality from all causes.
Despite these alarming statistics, researchers emphasize that the study only establishes an association, not causation. This distinction is crucial; correlation does not confirm that melatonin directly causes heart failure. The study currently exists only as a brief summary, lacking essential details such as melatonin dosage, the severity of insomnia, and lifestyle factors that could influence results.
Methodological concerns are also prominent. The study relied on electronic medical records rather than direct patient interviews, which can result in gaps in data. The research drew from the TriNetX Global Research Network, a large international database, but variations in healthcare practices and record-keeping across different locations could skew findings. In the UK, melatonin prescriptions are tightly regulated, while in the United States, it is available over the counter, often without any documentation in medical records. This lack of thorough tracking may lead to inaccuracies in categorizing users and non-users.
A critical aspect remains unanswered: why did certain individuals receive melatonin while others did not? It is possible that those prescribed the supplement experienced more severe sleep disturbances, which could indicate pre-existing health issues, including heart conditions. In such cases, melatonin may not be the cause of the heart problems but rather a marker of existing risks.
Interestingly, previous studies have suggested that melatonin might offer protective benefits for heart health, enhancing psychological well-being and improving heart function. Other research indicates it could alleviate symptoms for those already diagnosed with heart failure, potentially serving as a safe complementary therapy.
Since the findings are currently in abstract form and have yet to undergo peer review, the information remains limited. While the findings warrant attention and prompt discussions about the long-term risks of melatonin use, the conclusions drawn are not definitive. More comprehensive studies are necessary to determine the impact of prolonged melatonin use on heart health and, if so, to understand the underlying mechanisms.
As healthcare professionals navigate the complexities of sleep management, they must balance the benefits of treatment against potential risks. Poor sleep is linked to numerous health issues, including metabolic and mental health disorders. Typically, doctors encourage lifestyle modifications and cognitive behavioral therapy as first-line treatments. However, when these interventions do not yield results, short-term medication may be warranted to restore healthy sleep patterns and prevent further health complications.
The conversation around melatonin is ongoing, and until more robust evidence emerges, excessive concern may be unwarranted. Health experts like Heba Ghazal, a Senior Lecturer in Pharmacy at Kingston University, stress the importance of continued research to clarify these emerging risks associated with melatonin.
