Melatonin is believed to work wonders: a few drops, tablets or even jelly beans for children - and you sleep better, longer and deeper. It is sold everywhere, it is even called the “sleep hormone”. But what seems like a harmless help can also be a serious threat.
A new study from the US warns: those who take melatonin for a long time are at higher risk of heart failure and premature death. Heart failure is a chronic disease in which the heart is no longer able to provide the body with enough blood and oxygen, leading to complaints such as shortness of breath, decreased performance and fluid retention.
The researchers emphasize that a cause-and-effect relationship has not yet been proven, but they define the results as an important indication that long-term use of melatonin may have an adverse effect, in addition to helping you fall asleep.
Science under the microscope: new studies, new warnings
The new data comes from a large-scale study presented to the American Heart Association. For this purpose, data on more than 130,000 adults with chronic insomnia were studied. For five years, comparisons were made between people who took melatonin for at least a year and others who did not use it. The result: the so-called “melatonin group“ had about a 90 percent increased risk of developing heart failure. The risk of being treated in hospital for this disease was 3.5 times higher. And the mortality rate was even twice as high.
However, these results should be considered inconclusive. Meanwhile, criticisms of the conclusions have also been made: it is claimed that a direct link between melatonin intake and an increased risk of heart failure has not been proven.
How does melatonin affect heart rhythm
Melatonin is actually not a “sleep hormone“, but a “darkness hormone“: it does not cause drowsiness, but signals the body that it is time to adjust to night mode. This hormone is produced in the pineal gland in the brain. With the onset of dusk, the level of melatonin in the blood increases, which is a signal to the body to calm down. Melatonin is the hormone that controls the interaction between sleep and wakefulness.
Daylight and blue-light screens (such as those on smartphones) suppress its release. That's why many who have trouble falling asleep at night turn to synthetic versions of melatonin, which are biochemically identical to the natural hormone.
Studies conducted so far have indeed shown that in certain cases - for example, after a long flight - melatonin can help stabilize sleep rhythms. But the trend of taking it daily has long since reached a scale that worries doctors.
In the United States, melatonin is among the best-selling dietary supplements, often in dosages that exceed the body's own levels by a hundred times. Moreover, unlike medications, the preparations are not subject to strict control. The differences in the substances they contain can vary greatly - even within the same brand.
What do melatonin preparations mean for the youngest?
Children's development is particularly critical. There are videos on social media in which parents recommend “jelly candies for sleep”. In the US, sales of jelly candies for children that contain melatonin have exploded in just a few years. Many products contain too much of it - up to three milligrams per candy, which is three times more than the human body produces.
According to American health services, the number of children's melatonin poisonings has increased dramatically in recent years. In Germany, pediatricians are also reporting more and more cases of overdose and night sickness.
There is another problem: someone who takes melatonin for months may later be unable to fall asleep at all without a tablet. Because the body is signaled that it can reduce its own production, and this further disrupts the natural regulation of sleep.
Why rituals help more than jelly candies
The psychological balance of the sleep system is very delicate. Melatonin takes an active part in it, and those who constantly perform manipulations in this area risk much more than just one restless night.
Therefore, it is recommended to be cautious: until the long-term consequences are better studied, melatonin should be perceived as what it is: an effective hormonal intervention - but not a pill for a good night's sleep.
And children don't need chemicals to fall asleep - they need rituals, darkness and peace much more, experts say. Reaching for melatonin gummy bears may be tempting, but it undermines the mechanism of sleep: a faculty that is usually best mastered by the body - if it is allowed to.
Author: Alexander Freund