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MEL

Sleep hormone

Melatonin

Melatonin is often called the body's "sleep hormone" because it plays a crucial role in regulating our circadian rhythm and preparing the body for sleep. But melatonin's functions extend far beyond sleep – it is also a powerful antioxidant, affects the immune system, regulates hormone balance and helps protect the nervous system from damage and premature aging.

Contents

What is melatonin?

Melatonin is a hormone that is mainly produced in the pineal gland (epiphysis) in the brain. It is strongly linked to the body's circadian rhythm and helps regulate the sleep-wake cycle, which is why melatonin is often called the body's sleep hormone. Melatonin is produced from the amino acid tryptophan via serotonin and is released into the blood when light decreases, mainly in the evening and at night.

The production of melatonin is controlled by the biological clock in the brain, the so-called suprachiasmatic nucleus (SCN), which is affected by both light and darkness. When it gets dark, melatonin production increases and signals the body that it is time to rest. During daylight, melatonin levels decrease sharply.

What can an elevated melatonin level be due to?

Elevated melatonin levels are usually linked to normal physiological conditions and vary depending on the time of day. Here are some examples of factors that can affect melatonin levels:

Darkness: Natural exposure to darkness stimulates the pineal gland to produce more melatonin. This is a normal and desirable response to promote sleep.

Melatonin supplementation: Exogenous melatonin, used to treat sleep disorders, can temporarily increase melatonin levels in the blood.

Liver disease: In some liver problems, the breakdown of melatonin may be reduced, leading to higher levels in the blood.

Smoking: Studies have shown that smokers may have elevated levels of melatonin compared to non-smokers.

It is important to note that high melatonin levels at night are part of the body's normal rhythm.

Symptoms of high melatonin

  • increased sleepiness
  • decreased body temperature
  • low blood pressure
  • mood swings
  • fatigue during the day (with too high a dose of supplements)

Elevated melatonin levels due to natural circadian variation are usually not linked to negative symptoms. However, in case of an overdose of supplements, fatigue and reduced attention may occur.

What can a low melatonin value mean?

Low levels of melatonin can affect sleep quality and circadian rhythm. This may be due to several factors, including:

Light exposure at night: Light, especially blue light from screens, inhibits melatonin production and can lead to sleep difficulties.

Aging: Melatonin production naturally decreases with age, which can contribute to sleep disorders in the elderly.

Shift work and jet lag: Irregular sleep patterns and time changes can disrupt the body's melatonin production.

Neurological diseases: Conditions such as Alzheimer's and Parkinson's disease can negatively affect melatonin production.

Stress and lifestyle factors: Chronic stress and poor sleep habits can reduce melatonin levels.

Symptoms of melatonin deficiency

  • sleep disorders
  • difficulty falling asleep
  • impaired sleep quality
  • daytime fatigue
  • impaired concentration
  • depressed mood
  • shortened sleep time

Other effects of melatonin

Melatonin has more functions than just regulating sleep. It acts as a powerful antioxidant and protects the body's cells against oxidative stress. It has also been shown to have immunomodulatory effects and can affect female sex hormones, especially in regulating the menstrual cycle.

Research also suggests that melatonin may have a protective role in neurodegenerative diseases such as Alzheimer's and Parkinson's disease, by reducing inflammation and oxidative damage in the nervous system.

Reference range for melatonin

Night: 50 – 200 pg/ml

Day: <10 pg/ml

Diurnal variation

Melatonin follows a clear circadian rhythm. Low levels during the day and high levels at night are normal. If production is disrupted, e.g. by light exposure in the evening, sleep and health can be negatively affected.