If you have trouble falling asleep, are a night shift worker, or just temporarily battling jet lag, melatonin supplements may help you get a better night’s rest.
The numbers are staggering — between 50 to 70 million adults in the United States have sleep or wakefulness disorders. About 2 percent of the population uses melatonin supplements for sleep regulation, yet researchers are still learning about the overall effects of this treatment and how best to use it.
Melatonin is a hormone secreted from the pineal gland, which is located just above the middle of the brain. As the sun sets, the pineal gland begins to produce melatonin, which then is released into the blood around 9 p.m., causing you to feel sleepy.
Nightly melatonin levels can vary, and at times, this may be related to your age. For example, children secrete more melatonin than adults. Strangely, at the other end of the age spectrum, older people with sleep or wakefulness disorders do not always have lower melatonin levels.
The Effects of More Melatonin
Melatonin is naturally secreted in dim light or darkness — even artificial light will suppress them, said Katherine Sharkey, MD, PhD, assistant professor of medicine at Brown University in Providence, R.I.
Dr. Sharkey explained that the people who may benefit the most from taking melatonin supplements are those who sleep at odd times, such as night shift workers or those with jet lag from travel to other time zones. Melatonin is also recommended for sleep-onset insomnia (trouble falling asleep); the most common dosage is 3 mg taken two hours before bedtime.
While a melatonin supplement may help you fall asleep a bit more quickly, its effects are not as strong as those from prescription medications, according to Helen J. Burgess, PhD, associate professor and director of the Biological Rhythms Research Laboratory at Rush University Medical Center in Chicago. Also, studies have not consistently shown whether melatonin supplements can help you get a better night’s sleep or lengthen your sleep, she added.
Melatonin supplements can also help shift your body clock, allowing you to fall asleep earlier. This can help with jet lag when you’re flying east, such as to Europe, said Dr. Burgess. “The tricky part is that you need to use a low dose, not a high dose.” Studies have shown a .5 mg dose of melatonin supplement taken 5 hours prior to regular bedtime can help adjust the body’s internal clock, Burgess added.
Be aware that certain medications can also suppress your body’s ability to create melatonin, such as non-steroidal anti-inflammatory drugs (NSAIDs) and beta-blockers. According to a study published in the journal Sleep and co-authored by Burgess, melatonin supplements restored sleep quality in people taking beta-blockers who experienced low melatonin secretion and worsened sleep.
The Melatonin-Diabetes Connection
A recent study of nocturnal melatonin secretion in women showed that those with the lowest levels had a two-fold higher risk of developing type 2 diabetes than those in the highest category of melatonin secretion. “When this finding is taken in the context of other research, which has shown that the melatonin receptors found on pancreatic islet cells are important in regulating glucose metabolism, it makes an argument that melatonin secretion may play a role in development of diabetes,” said lead study author Ciaran J. McMullan, MD, of Brigham and Women’s Hospital in Boston. “This deserves testing in further studies.”
Sleep duration is also a risk factor for type 2 diabetes, with people who sleep less than 6 hours being at increased risk, said Dr. McMullan. “Therefore, it is important to consider if the lower melatonin levels are simply a marker of individuals with short sleep duration.”
Based on the results of this study, it may be too soon to conclude that there is evidence of additional benefits of high melatonin levels beyond the benefits of adequate sleep alone.
“We are becoming increasingly aware that sleep is a complicated behavior. It has many characteristic features, which need to be measured to fully describe an individual’s sleeping pattern beyond simply measuring sleep duration and frequency of snoring,” said McMullan. “So there is a huge potential for low nocturnal melatonin secretion to be dependent on some other characteristic of sleep that we have not measured.
“When it comes to solving the conundrum of whether this is all due to sleep or some additional characteristic of melatonin secretion, it comes down to performing randomized placebo-controlled trials with melatonin in which the effect of increasing melatonin is studied on both sleep and glucose metabolism,” McMullan explained.
Talking to Your Doctor Before Taking Melatonin
According to the study in Sleep, less than half of those who take melatonin supplements consult a physician. This may be an unwise choice because of the risk of interactions between these supplements and prescription medications or even other over-the-counter dietary supplements. If you do take any herbal remedies or supplements, including melatonin, be sure to talk with your doctor about it.
Another consideration is that not all dietary supplements are made the same — the quality of melatonin formulations can vary. Because of this, Burgess recommended choosing melatonin supplements from manufacturers who participate in the USP Verified Program for Dietary Supplements.
By Myra Partridge