Human beings require sleep, and we all know how important it is to get a good night’s rest. Quality sleep plays a vital role in the majority of health processes. In a nutshell, sleep gives the brain and body time to recharge after each day. It’s important for brain function and emotional wellbeing, it aids in the repair and healing of heart and blood vessels, and it ensures that our daytime performance is at its best.

There are many things that go into getting quality sleep, and certain conditions can hinder one’s ability to get the shut-eye they need. Mental illness, diabetes, kidney disease, neurological disorders, and respiratory problems can all affect how well a person sleeps. There is one particular hormone that plays a role in quality sleep: melatonin. But how does melatonin regulate sleep? Read on to find out all you need to know about the role of melatonin production in sleep.

What is melatonin?

Melatonin, often called the “sleep hormone”, is a type of hormone released at night by the pineal gland – a small gland in the center of the brain that is tasked with receiving information regarding the light-dark cycle of the environment. The gland, historically regarded as the “Seat of the Soul,” also produces the neurotransmitter serotonin and neurosteroids. Serotonin is a precursor to melatonin, which means that serotonin is used to create melatonin. Other areas of the body can also house melatonin such as the gut, the bone marrow, and the eyes.

The release of this hormone lets you know that it’s time to head up to bed and is tasked with helping you fall asleep. Melatonin can also act as an antioxidant, which can help to balance levels of free radicals in the body and ward off chronic disease caused by oxidative stress.

Image by Ben Blennerhassett on Unsplash: Being exposed to darkness sets melatonin in motion.

What is the function of melatonin?

The main function of melatonin is to alert the brain to darkness. When it does this, the brain automatically assumes that it’ll soon be time to get some sleep. It works alongside the circadian rhythm, which is the body’s 24-hour internal clock that makes sure essential functions are continuing when they should. Your circadian rhythm tells you when you should eat, sleep, and wake up.

Melatonin has other functions within the body, too, such as regulation of temperature, blood pressure, and hormone release. Melatonin causes a slight drop in your basal body temperature to help you get to sleep. The same is true for blood pressure and hormone release at night. There are certain patterns and cycles that lead to good or poor sleep quality. Melatonin is released to ensure that these patterns are working as they should, and that you’re getting the proper sleep you need every night.

What triggers melatonin production?

The trigger for melatonin production is darkness. When light is introduced, it halts production of melatonin. This is why the hormone is thought to help keep the body’s circadian rhythm regulated so that the sleep-wake cycle is functioning as it should. During its release, melatonin also binds itself to certain receptors that lead to an overall feeling of relaxation. This helps to reduce nerve activity in the brain, which calms you into being ready for sleep.

Another hormone that melatonin affects is dopamine. Dopamine is a type of neurotransmitter tasked with helping the body stay awake via its many roles within the body. Dopamine has also been shown to be a part of your eyes’ day-night cycle.

In some instances, being exposed to too much light close to bedtime can hinder melatonin production, and people who fail to produce enough of it at night are often plagued with sleep disorders that make it difficult to fall asleep such as insomnia. Other things that can affect the triggering of melatonin production include stress, blue light exposure, not getting enough light during the day, aging, and shift work.

Does melatonin promote deep sleep?

Melatonin does signal to the body that it’s time to sleep and can even promote a sense of relaxation, but does it promote a deeper sleep? REM sleep is considered the deepest stage of sleep out of all four stages. The three others are classified as the light, lighter, and lightest stages of sleep. Getting all four stages in the sleep cycle is important and experts suggest that a person should experience at least four or five sleep cycles per night, each lasting roughly 90 minutes. 

Image by Somnox Sleep on Unsplash: Proper sleep is vital for overall health.

Research has shown that melatonin does in fact increase deep sleep and, thus, the quality of sleep that one gets each night. One particular study looked at melatonin supplementation as a way to promote deep sleep and found that participants who took melatonin had significantly higher amounts of rapid eye movement (REM) sleep than those who were given a placebo. This means that to get the proper amount of REM sleep and sleep cycles throughout the night, the body needs to produce the proper amount of melatonin. For those who don’t produce this amount, supplementation may be necessary to ensure the proper amount of sleep for overall health.

Melatonin may be important for sleep, but it’s important for other functions within the body too. If you think you may not be getting enough sleep, talk to your doctor about possible causes and whether melatonin deficiency may be to blame.

Featured image by Vladislav Muslakov on Unsplash