Health effects of melatonin levels on the body

Health effects of melatonin levels on the bodyA large part of falling asleep at night has to do with the melatonin hormone which is made from the pineal gland. Our bodies know when it is time to fall asleep and when to wake up because of our own natural clock. This natural clock also controls melatonin levels which rise mid to late evening and fall come morning.

Melatonin is not just a sleep hormone though; it plays many roles in the body as well. Melatonin has been associated with jet lag, the immune system, age-related disorders and sleep disorders. Although melatonin can be taken in supplement form as a means to improve such conditions, there are side effects like drowsiness and slower reaction time, which can increase the risk of injury if taken during the day.


Even though melatonin is a natural part of the body, taking it in supplement form is still a new concept and much is still unknown. Melatonin can be used to treat ailments like seasonal affective disorder (SAD) and depression because melatonin relies on light, and such mental disorders occur in darker environments – winter months, at night, etc.

With aging we lose melatonin, which can impede on our sleep as well as our mood. Here is what you need to know about the role and effects of melatonin levels in the body.

Effects of melatonin on sleep

Effects of melatonin on sleepSleep cycles can be disrupted by exposure to light. Because melatonin production is affected by light, too much or too little light can alter melatonin levels. When we take melatonin it can promote drowsiness and sleep, so it is not advised to take melatonin too early before your allotted sleep time because it can affect your wakening hours.

When melatonin levels are low we may find it difficult to sleep, so if melatonin levels do not rise prior to sleep it can be challenging or near impossible to fall asleep. Melatonin is at its highest around 2 a.m. when it begins to decrease until sunrise.

Melatonin levels and sleep disorders

Melatonin levels and sleep disordersIt is common for the elderly to experience sleep disorders as melatonin levels decrease with aging. For this reason, many seniors may opt for melatonin supplements as a means to treat their sleep disorders.

In a randomized, double-blind, crossover study researchers aimed to regulate the sleep of 12 seniors. Some participants received 2 mg of melatonin and others were given a placebo for three weeks. For those taking the melatonin, the time to fall asleep reduced dramatically. Awakening time was also reduced. Quality of sleep also greatly improved in the melatonin group compared to those who received a placebo. All the participants were deemed to have a melatonin deficiency. The researchers believe their findings support that seniors should be supplemented with low dosages of melatonin in order to combat sleep disorders.

In another study conducted on healthy males, those who received dosages of melatonin fell asleep at least 40 minutes sooner than those who took a placebo. Moreover, the level of dosage did not seem to make a difference – low to high dosages of melatonin produced the same effects. Researchers concluded the ideal time to take melatonin is one hour prior to sleep. Additionally, participants did not experience any adverse affects.

Working closely with melatonin is serotonin, which can also play a role in sleep disorders. Many sleep disorders are thought to be brought on by low levels of serotonin converting into melatonin. Serotonin is high during the waking hours, and at night these levels drop in order for melatonin levels to rise. In the morning when melatonin drops, serotonin rises once again.

Serotonin deficiencies can contribute to sleep disorders because it does not allow for melatonin levels to rise. This can lead to insomnia – a condition where sleep is disturbed. Symptoms of insomnia include daytime fatigue, lack of focus, irritability and ongoing sleep worries. Long-term insomnia can have negative side effects on the body as the body cannot restore itself during sleeping hours.

Melatonin levels and age-related disorders

As we know, melatonin levels decrease through aging, so it can also lead to age-related disorders. Decreased melatonin levels have been linked with Alzheimer’s disease, glucose intolerance, impaired immune function and cancer.

In studies conducted on rats, melatonin levels increased their life span by 20 percent. Other effects melatonin has against age-related disorders include:

  • It may combat free radical damage while you sleep – Free radicals can speed up aging and impair functions like vision.
  • It may protect you from cardiovascular disease.
  • It may help regulate the immune system to better help you fight off infections.
  • It may protect against diabetic complications.
  • It may help delay Alzheimer’s disease.
  • It may help combat obesity.
  • It may help prevent osteoporosis.

Effects of melatonin levels on the immune system

Effects of melatonin levels on the immune systemAs mentioned, melatonin can help regulate the immune system, primarily because it allows us to sleep. When we sleep the body resets and recharges, which is important to our health and immune system.

The digestive system is often thought of as our second brain because it is able to produce neurotransmitters. Melatonin plays an important role in our digestive system. In fact, the digestive system produces 400 times more melatonin than the pineal gland. Melatonin helps regulate motility and inflammation in the gut. It also has powerful antioxidant functions which control free radicals. Lastly, it influences gut intestinal bacteria and help T-helper cells form, which are used to balance the immune system and regulate inflammation.

When we sleep our body goes through sleep cycles, and our digestion is a part of those cycles. Continuous nights of poor sleep can result in digestive issues.

How melatonin levels influence multiple sclerosis

A recent study found that melatonin may have an effect on multiple sclerosis as well. Multiple sclerosis is an autoimmune disease, which can be affected by environmental factors. The researchers of the study uncovered that in the winter months – where there is reduced sunlight – multiple sclerosis symptoms worsened. They concluded that low melatonin levels, due to lack of sunlight, affect symptoms of melatonin.

Researchers then tested their findings on mouse and human models and found that melatonin triggers an immune response, which plays a role in multiple sclerosis.

Although researchers are hesitant to recommend melatonin as treatment for those with multiple sclerosis, the study also shows the importance of sunlight. Therefore, the researchers suggest getting adequate light – especially throughout the winter months.

As you can see, melatonin can have many effects on the human body. If you suffer from sleep disorders or are concerned about your melatonin levels, speak with your doctor before supplementing melatonin.

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