WASHINGTON (AP) — Don't let headlines linking melatonin to heart failure keep you up.
That's the message after some scary-sounding reports about preliminary studies on sleep-related supplements. This study raised questions about the safety of long-term use of melatonin for insomnia.
Doctors have long known that too little or interrupted sleep increases the risk of heart disease. But heart experts say these types of so-called observational studies cannot prove that melatonin use plays any role in replacing the insomnia patients were trying to treat.
“We shouldn't sound the alarm and tell patients to stop taking melatonin altogether,” said Dr. Pratik Sandesara, an interventional cardiologist at Emory Healthcare who was not involved in the study.
Our bodies naturally produce melatonin, a hormone that regulates our sleep cycles. Levels usually rise as it gets darker in the evening, causing drowsiness.
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People sometimes take lab-generated melatonin to help them fall asleep and to adjust for jet lag and time changes.
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A new study used international electronic health records to track adults diagnosed with insomnia who received melatonin prescriptions, suggesting they use the supplement for at least a year.
Over five years, the researchers found that 4.6% of chronic melatonin users developed heart failure, compared with 2.7% of insomnia patients whose medical records did not indicate melatonin use. The study was presented at an American Heart Association meeting but has not been peer-reviewed.
However, prescription melatonin is only required in certain countries. Because the supplement is commercially available in the United States, Americans in the study may have used the supplement without being recorded, said Dr. Clyde Yancey, chief of cardiology at Northwestern University, who was not involved in the study. The study also did not give any dosage.
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Additionally, supplements in the United States do not require government approval, so ingredients may vary between brands. Researchers at Downstate Health Sciences University in New York characterized the finding as indicating the need for further research.
Meanwhile, Emory's Sandesara said patients with questions about melatonin should talk to their doctors. Doctors generally recommend short-term use, such as for jet lag.
Yancey noted that while this study does not prove any dangers from long-term use of melatonin, there is also no evidence that melatonin should be used indefinitely.
And one of the keys to getting better sleep is practicing better sleep hygiene, like keeping your room dark.
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“Exposure to blue light, especially at night, reduces melatonin levels. That's the science,” he says. Sleep problems are “more than just being sleepy and tired; you're putting yourself at risk.”
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This article has been corrected to show that Dr. Clyde Yancey, not Yancey, is Northwestern University's chief of cardiology.
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