The Dangers of Melatonin in Children: A Problem of Overuse by Parents
By Stuart H. Ditchek,MD,FAAP
Throughout all of my years as a pediatrician, I have never witnessed the extensive abuse and overuse of any drug or therapy as widespread as what is happening with the current overuse of melatonin in children in the community in which I practice. I suspect and have very firm reason to believe that the overuse is in no way limited to this community alone. The issue is complex but it comes down to a basic tenet of pediatrics and parenting; “physician do no harm,” I would add in this case; “parents do no harm”. Melatonin has become a mainstay of parenting in certain communities in recent years.
I would start this article with the confession that I am amongst the strongest advocates for the safe use of herbals, vitamins and nutraceuticals in children. I have spent many years studying the subject and have written two books on this approach to parenting. I have spent time learning from one of the leading integrative medicine authorities in the United States, Dr. Andrew Weil who wrote the forward to both of my books. In the past, I owned a company that manufactured child friendly vitamins that were manufactured under my guidance. While that company no longer produces these products, I have continued advising patients on the proper use of these products. I am not coming from a position of intolerance to these therapies. Quite the opposite, I simply advocate for their safe use recognizing that before using a therapy on any child, it must be shown to be safe or have a very high likelihood of being safe.
I am going to address in a comprehensive fashion all of the issues regarding melatonin use in children including the parents responsibility, the pediatricians role, the manufacturers role an the regulatory issues.
Melatonin is a neruhormone produced in the pineal gland of mammals. This gland lies at the base of the human brain. The primary effect of this neurohormone is to regulate sleep-wake patterns and allow an individual to relax and fall asleep. The hormone is naturally secreted in a circadian fashion. This means that it peaks cyclically in the late evening and drops dramatically in the early morning. The drop of melatonin levels accounts for the arousal that occurs naturally in the morning. There are only two forms of naturally occurring melatonin. The mammalian form is produced in the brain of all mammals and in the past has been isolated and purified for supplementation. This form was derived from cows (bovine) and years ago was sold as a supplement for occasional sleep aid. The bovine form was discontinued several years ago, as mad cow disease virus become an issue and the risk of infection from cow’s brains was considered dangerous. In response, certain nutraceutical manufacturers then switched to a plant based product which had to be chemically modified to mimic naturally occurring mammalian melatonin hormone. This chemically manufactured product is what is being sold today in the United States. While it currently has gone under the radar of the Food and Drug Administration (FDA) as it is being marketed as a supplement, this will very likely change as we learn more about it’s risks and potential long-term negative effects.
In Europe where the use of herbals and nutraceuticals are far more regulated, melatonin is available only by prescription from a physician. The Europeans recognized many years ago that the potential for abuse in many herbal remedies was great and that side effects or unintended effects are not rare. In past years, melatonin was used for the occasional jet lagged traveler or shift workers who stayed up all night on jobs and needed to sleep during the day. Neither was ever intended for daily use. I fear that the trend in the community here in the New York area is rapidly becoming more common.
So what does melatonin have to do with anything other than sleep and why should parents be concerned?
In 2000, two researchers, one based in University of California in Berkley and another in Japan discovered a new neuropeptide, not previously described, called Gonadotropin Inhibitory Hormone (GnIH). This new neurohormone was discovered through studies in birds and was found to have a direct opposing effect on Gonadotropin Releasing Hormone (GnRH). GnRH is a critical peptide in humans and all mammals needed for the development of normal puberty and successful fertility. All neuropeptides produced in mammalian brains have effects on end organs and all end organs regulate their production by a complex feed back mechanism. Researchers Bentley and Tsutsui discovered and isolated the GnIH neuropeptide. It is now known that GnIH has a negative effect on GnRH which then has a negative effect on the end organs, in this case the testes and ovaries. The researchers discovered that GnIH binds to sites in the brain that produces normal GnRH and blocks it’s production leading to testes and ovaries that actually shrink and have decreased function.
In describing his research on melatonin Bentley is quoted stating; “It is a powerful hormone and yet people don’t realize that it’s as powerful as any steroid. I’m sure that many people who take it wouldn’t take steroids glibly. It could have a multitude of effects on the underlying physiology of an organism but we know so little about how it interacts with other hormone systems”. Bentley and Tsutsui have presented their important research on GnIH at the prestigious National Academy of Sciences and have followed up with a number of studies and publications confirming these complex interactions and risks. Since the discovery of GnIH in 2000 of this “new hormone”, the reproduction puzzle has been brought one step closer to being solved. We now know that GnRH “switches on gonads” and GnIH “switches off gonads”. Melatonin increases the production of GnIH. In a recent study by the research team, birds given injected melatonin had triple the levels of GnIH in their body as a result. Genetic models involving melatonin’s effects confirms that melatonin increases the messenger RNA needed to produce GnIH. The studies in bird mammalian models confirmed that melatonin binds directly to neurons in the hypothalamus brain tissue which resulted in increased production of GnIH. The end effect was a decrease in size and function of the testes and ovaries.
In a 2012 study by Tsutsui he wrote; “The discovery of GnIH has fundamentally changed our understanding of hypothalamic control of reproduction”. What is even more troublesome is the recognition that these receptors which are responsible for transporting peptides in the hypothalamus have fibers branching to multiple areas of the human brain. These areas are involved in basically every physiological and behavioral process imaginable. Thus melatonin will likely be found in the future to affect a multitude of physiological systems other than just reproduction via the GnIH mechanism, some positive and some negative.
In the past year, I have been asked by large numbers of parents whether I thought that the daily use of melatonin is safe. This interest has peaked as local manufacturers and health food stores have been advising its use to get children to sleep efficiently. The parents have almost unanimously stated that melatonin works beautifully. And they are correct, it does work beautifully, thus my serious concern.
I have been told that currently there are large numbers of families in the community lining their children up at bedtime and having them take nightly melatonin. Last year when a regional community family magazine wrote a piece on my integrative approaches in pediatric practice it included a bolded box on my early views on melatonin. The angry responses from parents who were clearly abusing this neurohormone was overwhelming. One parent described in great detail that she has nine children and gives all of them nightly melatonin. The answer that I consistently hear from parents is that it’s “natural” and thus must be harmless. This could not be further from the truth. Firstly, natural does not mean safe. Secondly, the commercially produced melatonin is not “natural”. While it is manufactured from a plant molecule, it is chemically modified in the lab to function efficiently and get absorbed quickly into the brain. I have no doubt that the melatonin neurohormone being sold works. However, just as it is mimicking the natural hormone, it is also likely getting into the brain and binding at the GnIH sites in the hypothalamus. Would any parent knowingly give their child a daily hormone or steroid without proper medical supervision and concern for potential toxicities? Of course not and neither should they in the case of melatonin.
The other issue that parents should consider is the impact of lessons being taught from the youngest age as to a child’s perception and training. Those who are giving their children nightly or frequent melatonin are sending a very direct message to children that a pill or a drug is needed to succeed or accomplish a task that should come naturally. This is a bad habit to imprint in a child’s impressionable mind and one that could have negative impacts in the future as the child enters adolescence. Teaching a child that a pill can easily replace a discipline is just plain bad parenting. It should not come as a surprise if the children being acclimated to daily melatonin today will become the narcotic sleep aid dependent adult of the future.
This brings me to my next criticism. I have been told that some pediatricians have given their unofficial stamp of approval to the daily use of melatonin. While I admire their patients for seeking the advice of their doctor, the pediatrician needs to do the proper research before approving such a serious hormone-mimicking agent such as melatonin. As an advocate for the safe use of herbals, nutraceuticals and vitamins, I fully recognize the need to look into the safety and long-term effects of any of these products. Pediatricians need to heed the newest research and look back at their suggestion that melatonin on a daily basis is safe. It is only a matter of time that a child or young adult will suffer a long-term complication such as gonadal dysfunction or infertility. This is not based on a hunch but real and growing data and research into this subject.
Parents should recognize that children have been raised for thousands of years without the need to receive nightly neurohormones or hormone mimicking agents. The current generation of parents is the first that I have seen use this approach and it is not a good practice. Teaching children proper sleep habits and the importance of schedule is the key. Obviously the parents who choose to use nightly melatonin on their children have chosen the easier path to sleep but one that will likely carry great risk throughout the life of that child as they approach puberty or the fertility years.
The manufacturers and health food stores recommending the nightly kids friendly melatonin carry a great responsibility here. While I recognize their position that they will sell whatever they can market to large numbers of families, they must draw a line in this case especially when there is clear and recent data on the science and the risks. I was told by a parent recently that they have repeatedly asked one of the major suppliers and retailers in the community if it is safe to be used daily and they respond with great confidence that it is. The fact is they do not know it is safe at all and they are clearly self-interested. Furthermore, they are not in a position to advise as they are not generally medically trained nor do they follow the much needed research.
The good news is that the growing crisis is getting much needed attention of the FDA and regulators will be taking a close look at the data. The likelihood is that like other problematic “natural” therapies, the FDA will likely take a very hard line as the risks are clear and the science is solid.
In the interim, lets stop the madness and immediately cease giving nightly melatonin to your children. The occasional use is likely fine but never for more than seven to ten days at a time and never with a greater frequency than two or three times a year. Even that frequency might not be completely safe but future research will tell. The local manufacturers and health food stores encouraging these melatonin products should cease advising parents immediately on the safety of its nightly use. I would go as far as to say that they should consider pro-actively removing these kids friendly melatonin products from their shelves until the safety issue can be established or denied. While I do not expect them to comply, I would strongly suggest that they take these steps in view of the serious possibilities for future reproductive issues.
While I recognize that my views on this issue will not be well received by those who manufacture and sell these products as well as parents who have come to rely on them, it does not change my resolve. As a pediatrician, I have the responsibility to always protect children and advise parents on risks and dangers. Anything less than that concern would be inappropriate and an abandonment of my responsibility and others like me. Parents need to do the right thing and take a critical look at this very potent supplement and its potential effects on their children.
Stuart H. Ditchek, MD, FAAP
Author, Healthy Child Whole Child (Harper Collins 2001,2009)
Clinical Assistant Professor of Pediatrics
New York University School of Medicine
Medical Director and co-founder, Kids of Courage
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