Melatonin is a hormone naturally produced by the pineal gland in our body, playing a key role in regulating the sleep-wake cycle. Melatonin supplements, widely used to help with insomnia or jet lag, have been considered relatively safe. However, a recently published research abstract suggests a link between long-term use of melatonin and an increased risk of heart failure, sparking new discussions about heart health. In particular, these preliminary research findings, which will be unveiled at the American Heart Association (AHA)'s 'Scientific Sessions 2025' annual conference in early November 2025, emphasize the need for a cautious approach to using melatonin supplements.
Many previous studies have indicated that melatonin may have a positive impact on cardiovascular health, due to its strong antioxidant and anti-inflammatory properties. Studies have shown that melatonin neutralizes harmful free radicals, improves mitochondrial function, and may help regulate blood pressure. In fact, some studies on animals and humans have shown that melatonin has heart-protective activity, and can particularly lower blood pressure in patients with hypertension. Furthermore, there have been cohort studies showing that melatonin supplements do not increase the risk of cardiovascular disease and type 2 diabetes. These results raised expectations that melatonin could be beneficial for heart health.
However, preliminary research to be presented at the American Heart Association (AHA) is now raising important questions about these existing perspectives. The study analyzed the medical records of over 130,000 adults diagnosed with chronic insomnia for five years, and found that those who took melatonin long-term for more than a year were about 90% more likely to be newly diagnosed with heart failure than those who did not. In addition, melatonin users were nearly 3.5 times more likely to be hospitalized for heart failure, and the mortality rate from all causes within five years was also nearly twice as high. While melatonin supplements are often considered harmless, the study suggests that this may not be the case in reality, urging caution from experts.
These results are shocking, but the research team emphasized that the study revealed an 'association' rather than proving a 'causal relationship'. In other words, there is no evidence that melatonin directly causes heart failure. The limitations of the study include the possibility that other risk factors, such as more severe insomnia, depression, or anxiety, may have affected both melatonin use and heart risk. It was also pointed out that there may be cases of misclassification of non-users in countries like the United States where melatonin is available without a prescription. Therefore, further, more precise studies, such as additional randomized controlled trials, are urgently required to clearly assess the cardiac safety of melatonin.
These latest research findings make us reconsider our perception of melatonin supplements. We need to be aware that even melatonin, which is generally considered safe, can lead to unexpected health risks when taken for a long time. In particular, if you have existing heart disease or are considering long-term melatonin use, you must consult with your doctor or pharmacist. Experts advise against assuming that melatonin is safe simply because it is a 'natural' ingredient or can be purchased without a prescription. It is important to prioritize non-drug treatments, such as improving sleep hygiene and changing lifestyle habits, rather than relying on melatonin to solve sleep problems.
This study on the association between melatonin and heart failure reminds us of the importance of scientific exploration. In the future, further follow-up research, especially randomized controlled clinical trials, should clearly define the long-term cardiovascular safety of melatonin. It is important to clarify the exact mechanism of melatonin's effects on heart health, safe dosages, and benefits in specific patient groups. Heart health should be managed holistically through overall lifestyle improvements, such as a balanced diet, regular exercise, stress management, and sufficient sleep, rather than relying on a single supplement. If you have any questions, you should always consult with an expert to find the best health management method for you.
Q1: What does the recent melatonin research results mean?
A1: According to preliminary research to be presented at the American Heart Association (AHA), there has been a reported association that chronic insomnia patients who take melatonin long-term for more than a year may have an increased risk of heart failure incidence, hospitalization, and death.
Q2: Should I stop taking melatonin?
A2: This study revealed an 'association' and did not prove a 'causal relationship'. However, as it suggests potential risks with long-term use, if you are currently taking or considering taking melatonin, it is important to consult with your doctor or pharmacist to make a decision that suits your personal health condition.
Q3: Is melatonin always harmful to heart health?
A3: In the past, there have been research results that the antioxidant and anti-inflammatory effects of melatonin could help protect the heart. However, the latest research raises that there may be unexpected risks with long-term use, so the impact of melatonin on heart health is still complex and requires further research.
Q4: Is it safe for heart failure patients to take melatonin?
A4: In the case of heart failure patients, more caution should be exercised when taking melatonin. Since the new research results suggest an association with an increased risk of heart failure, you must consult with your doctor to determine whether to take it.
References:
* American Heart Association (AHA) Official Website: https://www.heart.org/
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