Melatonin: Fascinating facts on the hormone that brings you the Zzzs

Last Updated December 20th, 2021

What is melatonin?

Melatonin is a hormone produced by the pineal gland present in the brain. It is also produced in the gut, bone marrow, and the eyes. As the day proceeds, the levels of melatonin from the pineal gland gradually spike up (after sunset). The levels of melatonin drop the moment the sun rises making you awake.

It helps you to sleep and often it is referred to as the sleep hormone. It does not blow you off completely into sleep, it just makes you aware that it is night time and you need to relax. Melatonin is involved in regulating the circadian rhythm (the body’s clock in terms of physical, mental and behavioral changes that take place during the day and the night).

It also regulates body temperature and blood pressure. Melatonin aids in various biochemical actions with respect to signaling the brain, reduced reactivity, enzymatic changes, and other mechanisms that promote vasodilation (dilation of the blood capillaries and better blood flow) and eventually brings down the blood pressure.

If your body is signaling you to relax, then it is because melatonin binds to certain sensors in the brain signaling the reduction in the nerve related activities. In the eyes, it helps in diminishing the dopamine levels. That is why you feel relaxed and might sleep to give your body its share of rest.

Melatonin does not make you feel sleepy. It aids in the biochemical and nerve impulse reactions that are involved in creating a sense of sleepiness. On the other hand, those who have inadequate melatonin production find it hard to sleep. The presence of light minimizes the melatonin levels and that is why you wake up and feel active.

Melatonin levels may decrease due to

  • Smoking
  • Shift work
  • Aging
  • Stress
  • Insufficient exposure to natural light during the day

Melatonin: An antioxidant

Oxidative stress is the major cause of many underlying genetic diseases, diabetes, cancer, etc. It is caused by reactive oxygen species (ROS). There is a generation of ROS due to factors like stress, pollution, smoking, consuming processed foods, etc. The processing of these harmful traits results in the generation of ROS.

ROS molecules are very unstable looting the molecules from cells, tissues and even DNA as a result of which there is damage. Antioxidants are those compounds that stabilize the instability of the ROS thereby protecting the cells, tissues, and even the DNA.

Melatonin protects the brain

The brain utilizes 20% of the oxygen in the body. So, it is more prone to ROS damage. Melatonin and its metabolites protect the brain cells from ROS damage. It also has anti-inflammatory properties. Inflammation is a result of an injury or an infection or a disorder that is characterized by pain, redness, and swelling.

Melatonin is known to suppress proteins, immune cells, and other factors that are involved in creating inflammation. It even contains the expression of the enzymes involved in inflammation. That is why even the management of neurodegenerative diseases like Alzheimer’s can be done by including melatonin.

Melatonin is also vital for wound healing in the brain or even for spinal cord injuries. Any such damage to cells (in this case, the brain and the spinal cord) impairs the homeostasis (a response to stabilize) in the cells. The calcium-potassium ion channel for nerve impulse conduction gets damaged. Melatonin helps in restoring the calcium signaling activities in injured nerve cells. This, in turn, helps in creating a long-range calcium signaling which expels the damaged brain cells and prevents the adjacent cells from further damage.

Melatonin and fat regulation

Leptin is a hormone that is secreted by the fat cells and this hormone signals to the brain that the body has consumed sufficient food. It helps regulate the energy balance by terminating hunger. Lower levels of leptin make you feel hungry. So when you consume a meal, there is an increase in the production in this hormone signaling your brain that you are full. Ghrelin is a hormone that induces hunger.

A study was done on 56 postmenopausal women and 25 women (aged 27 – 36 years). These women were given melatonin supplements for up to 24 weeks. Around 64.2% of the women had improved sleep. The insomnia severity index decreased from 14.53% to  9.8%  in postmenopausal women. The drop in the body mass index (a factor that determines the ideal weight according to the age and height) was from 30% to 28%  in obese women and this BMI reduction was seen even in normal weight women.

Melatonin is recommended for sleep disorders

It is suggested for treating the conditions of insomnia (a chronic state of sleeplessness). Even conditions of delayed sleep phase syndrome show a good response to melatonin. Children who have abrupt melatonin productions or very low levels of this hormone can benefit a great deal via melatonin supplements.

Some people take a long time to fall asleep, while others tend to frequently wake up suddenly in the night. Some even sleep inadequately beyond which they are unable to sleep. All these cases can be rewarded to betterment with melatonin supplements. Also, there are a few pieces of evidence on human subjects available. So, more work needs to be done on these areas just to confirm the results with safety. Melatonin does not extend the sleep. The dosage of melatonin supplements varies with the condition.

Side effects of melatonin supplements

Melatonin supplements come in tablet forms. They must be consumed 30 minutes before you go to sleep. Always begin with a small dosage and increase gradually. The following side effects have been reported so far:

  • Nausea
  • Irritability
  • Headaches
  • Drowsiness
  • Dizziness

The following side effects are reported in older adults:

  • Restless legs
  • Skin pigmentation
  • Thrombosis (blood clots) – melatonin increases the release of calcium which combines with fibrinogen protein to form blood clots.

Who must NOT consume melatonin supplements?

  • It is not advised for women who are pregnant or planning to become pregnant or breastfeeding women. It may be safe for children, but it is advisable to avoid as it may interfere with growth and development.
  • Melatonin might make bleeding more intense. So those with bleeding disorders must avoid taking it. If an individual has undergone a transplant then melatonin is not advisable because it enhances the immune functioning and this will intervene with the immunosuppressive drugs.
  • Melatonin interferes with medications related to blood thinning, blood pressure medication and antidepressants.
  • If you decide to take melatonin supplements, it is important to consult a doctor first.

Natural ways to maintain optimum melatonin levels

  • Warm almond milk before bedtime
  • Half a banana with a tablespoon of peanut butter
  • Including magnesium-rich foods in the diet like green leafy vegetables, almonds, pumpkin seeds, etc.
  • Lavender essential oil based aromatherapy
  • Exercise daily and don’t watch TV before you sleep

The bottom line…

Melatonin is important for regulation of sleep patterns. Any discrepancies associated with sleep like sleep apnea, insomnia, etc. This hormone does not make you sleepy but it regulates your body’s mechanisms that are involved in sleep.

On one hand, melatonin regulates cellular or gene related mechanisms to minimize injuries or cell death, and on the other, the antioxidant nature of melatonin helps in protecting the nerve cells from neuronal damage. Supplements of melatonin are beneficial to address all these factors, but it is not safe for pregnant women and those on certain medications. Consult your doctor before consuming any supplements.

Poor lifestyle patterns like abrupt sleep, too much smoking, stress, and aging contribute to reduced levels of melatonin. Instead, improve your lifestyle and opt for natural ways to induce your body to produce melatonin.



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