Melatonin Hormone Guide
What Is Melatonin?
Melatonin is a hormone that is released by the pineal gland which encourages sleep and helps to preserve the natural human circadian rhythm. Melatonin is also produced by animals and many plants.
Human beings are naturally designed to be awake during daylight and to become sleepy once the sun goes down. That is because we are diurnal creatures. Although the average person sleeps eight hours per night, we have just begun to really understand why we sleep, and the processes behind it, in recent years.
Although we have been keenly aware of the connection between light/dark and the sleep cycle, we are only now becoming aware of the mechanisms which promote this cycle, and melatonin is one of the keys to this cycle.
It used to be believed that Mmlatonin was the primary mechanism which controlled the circadian rhythm, but today it is clear that melatonin is a tool that the body uses to change the body’s physiological patterns to induce sleep, as controlled by the central nervous system.
How Do Light and Dark Promote Patterns of Wakefulness?
Our brains actually process the presence or absence of light through the eyes in order to send information to the brain regarding the sleep cycle. The eyes absorb light, and this information passes from the eyes to the hypothalamus. The hypothalamus has a particular region known as the suprachiasmic nucleus which reacts to sunlight and other factors in order to either promote a state of wakefulness or sleepiness by manipulating body temperature, hormone release, and other factors which promote a normal sleep cycle.
Think of the suprachiasmic nucleus as a clock. Under normal circumstances, human beings usually wake up around the same time each day, and the appearance of sunlight plays a central role in establishing that set pattern. For example, when the suprachiasmic nucleus senses sunlight, it responds by promoting the secretion of cortisol and increasing ambient body temperature. In addition to this, the suprachiasmic nucleus also suppresses the release of melatonin, a hormone which encourages the body to go into a sleep state. Once the sun goes down, the body stops suppressing melatonin release, which encourages sleepiness.
Melatonin is often taken as a supplement in order to help promote sleep. This can be effective for many patients, but should only be used for a brief period of time, because long-term use can affect the body’s hormone patterns.
Of course, anyone that experiences significant issues with sleep should talk to a professional in order to get the appropriate treatment, but for mild or temporary sleeplessness, melatonin is often a fine option.
Where Does the Body Make Melatonin?
Melatonin is produced by the pineal gland, which is about the size of a bean and is situated in the central portion of the brain. Under normal circumstances, the pineal gland does not produce Melatonin during the day, but as the sun goes down and the suprachiasmic nucleus no longer receives sufficient light signal, this causes the body to start producing Melatonin.
After the pineal gland produces melatonin, it immediately begins to circulate through the blood stream. For people with normal sleeping patterns, this generally happens at about nine o’clock at night. This is why, a couple of hours after the sun falls down, you naturally enter a state of sleepiness, which inhibits your alertness and causes you to seek out a comfortable place to rest.
Once the body starts to release melatonin, it will continue to do so until sunlight, when melatonin levels will drop, encouraging wakefulness, until around nine o’clock in the morning, when the pineal gland completely deactivates and melatonin production halts. During the day, the body produces almost no melatonin.
Of course, time is not the only factor with regard to melatonin, light is also important. If it is the appropriate time, but the body still senses bright light associated with daytime, then the pineal gland will be activated but will not produce melatonin. In many cases, light produced indoors, especially white light with a lot of blue waves, will be interpreted by the brain as sunlight. This is why it’s important to turn off computers and televisions about an hour before bed in order to promote a healthy sleep cycle.
Melatonin is processed by the liver, and is filtered quickly. Ninety percent of Melatonin is processed by the liver the first time it passes through the organ.
How Much Melatonin Does the Body Release at Night?
Dependent on a wide variety of factors, different people produce different levels of melatonin. There does appear to be a strong correlation between age and melatonin production, where children produce the greatest concentrations of melatonin, and older adults produce less over time. This is both why children tend to sleep longer and deeper, and why adults tend to sleep for shorter periods of time. Older adults that have issues sleeping produce less melatonin than their peers on average.
How Much Melatonin Should I Take To Sleep?
Melatonin is a common supplement, and is actually the only hormone in America that can be obtained without a prescription. Because melatonin is present in many animal and plant-based foods, it is considered a nutrient, rather than a hormone, and is not regulated under the same rules as pharmaceutical drugs and other Bio-Identical Hormones. Supplements do not require FDA-Approval, and are not subject to regulations which are as strict as those intended for medications.
For this reason, it is important to source melatonin responsibly. An issue with many over-the-counter melatonin products is that they often provide much more melatonin than the body naturally has the capability to producein some cases twenty times more than the pineal gland secretes to promote sleep!
A few noted side-effects of melatonin supplementation are depression, fatigue, and vivid dreaming.
There has been quite a bit of animal research conducted with regard to melatonin, and there is evidence that melatonin affects blood pressure, and long-term or heavy use can potentially affect fertility. Because of the potential impact of melatonin upon blood pressure, those that are at high risk of cardiovascular disease, heart disease, stroke, kidney disease, or hypertension should always talk to their doctor before using melatonin. Melatonin may also exacerbate sleep apnea.
The best way to use melatonin is to use it to establish a healthy and natural circadian rhythm. This means that it should be taken an hour or so before you are ready to go to bed, so that you can get comfortable and fall naturally to sleep. Also, it is important to take a physiologically natural dose of melatonin in order to prevent side-effects and help your body stay in a normal rhythm.
It is important to note that our knowledge of melatonin (as is true with many other hormones), is incomplete, and more potential treatments or more effective usage protocols may be adopted in the future.
Is Melatonin Dangerous?
Although there are potential concerns regarding melatonin’s effect upon mood and cardiovascular health, there has never been a case of melatonin overdose, and there is no evidence that Melatonin overdose produces any toxic effects.
Melatonin Research
Many people have taken melatonin and report that it does indeed help them sleep. It is unclear if melatonin is better than placebo at inducing sleep however. Some studies have shown that Melatonin is no more effective than sugar pill, but there is evidence that melatonin produces other benefits.
For example, melatonin does have the ability to help patients realign their circadian rhythm to a normal schedule. Continuing study needs to be performed, however, to compare the benefits of melatonin to sunlight exposure in promoting healthy sleep patterns. Even so, Melatonin can be very useful for individuals that are exposed to bright light, such as the light of a computer screen, after sundown.
Melatonin has been shown to be highly effective at restoring sleep patterns and promoting sleep both for individuals that work odd hours, and for people suffering from jet lag.
Melatonin does not seem to have an impact on average length of sleep, but it does appear to help patients sleep more soundly, and fall asleep more quickly. Patients that have trouble getting themselves in bed at night may find melatonin very effective. The jury is still out, however, as there are some studies that show otherwise.
The biggest benefit of Melatonin is that it can alter an individuals circadian rhythm, helping them to reset the clock when their bodies are out of sync with their lives. Supplemental melatonin provides this benefit for around six hours.
Individuals should not take Melatonin in the hours just after they have woken up, because it can lead to fatigue and cognitive disruption when taken during a period when the body has just had a large amount of sleep.
Melatonin for Insomnia
The body of research regarding Melatonin and Insomnia is small, and there have been mixed results. In one particular study of men and women over the age of fifty, melatonin appeared to improve both sleep quality and the time that it took to fall asleep. Other studies have shared the result of improved sleep onset, but melatonin did not help insomnia patients maintain energy levels in the daytime, and did not help patients stay asleep through the entire night.
Before more conclusive evidence can be drawn, more elaborate research will need to be performed in order to assess the effectiveness of melatonin as an insomnia treatment. Also, there are no set guidelines for how much melatonin to take to treat various conditions.
Melatonin and Jet Lag
Jet lag is a condition that occurs when an individual changes time zones rapidly, causing their normal sleep schedule, as governed by day-night cycles, to be disrupted. The more time zones that an individual travels, the more time that it will take to recover. As a result, people feel fatigued when they would normally be rested, and they also become hungry at off-times.
There are a number of things that can make jet lag worse. For example, many people don’t sleep well on planes. Also, caffeine and alcohol can further alter sleep cycle. The circadian rhythm is important, and when individuals with set rhythms become disrupted, it can completely change their ability to go about their day.
A recent survey of people that regularly travel on business showed that around 50% of these individuals routinely have jet lag as a result of long-distance flights. As a result of this jet lag, they claimed that their productivity and performance were directly impacted. For reasons that are unclear, women were more affected by jet lag than their male peers.
Perhaps because melatonin is available as a cheap over-the-counter supplement, there has not been extensive study regarding its benefits with regard to jet lag. However, studies conducted thus far have shown that melatonin is highly effective at mitigating or completely preventing jet lag. Traveling forward in time or traveling 5+ time zones in a trip were correlated with the greatest degree of benefit.
Melatonin and Delayed Sleep Phase Syndrome
There are other conditions which impact circadian rhythm as well. For example, Delayed Sleep Phase Syndrome is a condition in which patients have major issues falling asleep at normal times, sometimes unable to sleep before sunrise.
This condition affects people of all ages, but is most common among teens. Research shows that melatonin can be an effective method to treat this condition and promote healthy sleep, but for many patients, simply exposing oneself to bright light when one wishes to be awake is equally beneficial.
Melatonin and Libido
In animals, melatonin plays a role in sex drive. Melatonin has the ability to suppress both Follicle-Stimulating Hormone and Luteinizing Hormone, which are important for the maintenance of libido as well as the production of sperm. The way that a species responds to melatonin depends on whether they are sexually active during the day or at night.
Animals that mate at night breed better while melatonin levels are high and daytime breeders mate most effectively when melatonin levels are low. Taking melatonin can negatively affect fertility in some individuals, but there is also evidence that it can promote fertility and libido in others. More research needs to be done to more accurately show how melatonin affects human fertility and libido.
Melatonin and Leptin
Leptin is one of the hormones that controls our hunger. High levels of Leptin produce the sensation of satiety. Leptin levels are affected by melatonin in a complex way. Melatonin interacts with Leptin and Insulin, helping to reduce hunger during sleep. If Melatonin and Leptin interact outside of the presence of Insulin, this causes Leptin levels to decline, however.
Melatonin and the Immune System
In addition to sleep, sex drive, and hunger, melatonin also has an impact on the function of the immune system. The research is limited in this regard, but melatonin does seem to have antiinflammatory properties. Researchers are attempting to discover if melatonin can be used as a way to mitigate inflammation. It is believed that Melatonin promotes the synthesis of cytokines which limit inflammation. In the near future, melatonin may be an important part of fighting both viruses and bacterial infections, and it also may benefit many people with cancer.
Melatonin and Dreaming
In some cases, people that take melatonin supplements report intense dreams. Studies have shown that a 50 milligram dose of Melatonin appears to increase the number of dreams because it lengthens the period of time that an individual spends in REM-Sleep, the period where dreams are most common.
Melatonin and Autism
Melatonin is useful for patients with Aspergers and Autism, because it helps them sleep longer and deeper.
Melatonin and Aging
There is some evidence that suggests that melatonin may be a useful anti-aging tool. It has long been known that children produce higher levels of melatonin later in the night, and older individuals reach peak melatonin much earlier. It is hypothesized that this is one of the reasons why younger and older individuals often have such different sleeping habits. It is also hypothesized that this is why adults don’t sleep as long, and why they are more prone to sleep dysfunction.
Animal research studies have also shown that exposure to exogenous melatonin changes the expression of thirteen separate genes in geriatric mice, reverting their expression to those associated with youth. The antioxidant properties in melatonin also may have a neuroprotective effect, which promotes neurological health deeper in to the lifespan, while also reducing inflammation. Both of these aspects have a significant impact on longevity.
Melatonin and Diabetes
Diabetes and Melatonin Levels appear to be correlated. Individuals that produce less melatonin than their peers appear to be more likely to develop Type-Two Diabetes. This could be because people that produce enough melatonin have greater issues controlling insulin, and also because less melatonin means that the body doesn’t rest as well, which has a tremendous impact on hormone health.
Melatonin and ADHD Treatment
Research has shown that patients taking medications such as Adderall for ADHD find it easier to sleep at night if they take melatonin before bed. Preliminary studies have shown that this benefit of melatonin does not decrease over the course of three months of treatment.
References:
Is There a Connection Between Melatonin and Fertility?
http://www.wisegeekhealth.com/is-there-a-connection-between-melatonin-and-fertility.htm
Melatonin and Sleep
http://sleepfoundation.org/sleep-topics/melatonin-and-sleep
Wikipedia: Melatonin
http://en.wikipedia.org/wiki/Melatonin
Read more here:
Melatonin The Sleep Hormone How It Impacts Your Health
