New study links long-term melatonin use to elevated risk of heart failure and mortality: Insights and implications

A comprehensive and recent study conducted by Dr. Ekenedilichukwu Nnadi and his team at SUNY Downstate Health Sciences University highlights a concerning association between long-term use of melatonin supplements and an increased risk of heart failure and death.

Analyzing electronic health records of over 130,000 adults diagnosed with insomnia, the study sheds light on potential cardiovascular risks linked to a widely used sleep aid.

The research is from an unpublished study set to be presented at the American Heart Association’s scientific conference in New Orleans next week, reported NYT.

Study methodology and key findings

The researchers focused on adults who had taken melatonin consistently for at least one year. They found that 4.6% of those on melatonin developed heart failure within five years, compared to 2.7% among those who never took melatonin.

This suggests a 90% increased risk associated with melatonin use. Melatonin users were also nearly 3.5 times as likely to be hospitalized for heart failure and twice as likely to die from any cause during the study period.

Expert analysis and limitations

Dr. Nnadi cautioned the public and media against interpreting these findings as causal, emphasizing this was an association study rather than proof that melatonin directly causes heart failure.

Importantly, the study cohort included only individuals with prescription-documented melatonin use, relevant because melatonin is prescribed in some countries but available over the counter in others, like the US. This limitation calls for further research to understand causality and the biological mechanisms if any.

Why it matters

Insomnia affects cardiovascular health through elevated blood pressure, increased stress hormones, and systemic inflammation. Melatonin, while popular for improving sleep, may indirectly mark underlying health issues or interact with cardiovascular risks in ways not fully understood.

Experts like Marie-Pierre St-Onge from Columbia University underscore the importance of caution, advising against chronic melatonin use without medical supervision.

Despite its reputation as a safe supplement, this study urges careful consideration, particularly among middle-aged and older adults or those with pre-existing heart conditions. Health professionals advocate consulting doctors before starting or continuing melatonin supplementation.

Ongoing and future research will be vital to clarify safe usage guidelines and understand long-term effects on heart health.

Melatonin remains useful for many, but this emerging evidence highlights the need for heightened awareness and prudence around its long-term use, especially regarding cardiovascular health.