The three pillars for a long and healthy life are diet, exercise and sleep. While people must consume wholesome foods and engage in regular physical activity on their own, deep sleep at night is a component that is not only cultivated by individuals but is also controlled internally by a hormone known as melatonin. Melatonin is commonly called the “sleep hormone.”
Melatonin is a vital hormone secreted by the pineal gland – a small endocrine gland seated at the centre of the brain. The synthesis of melatonin takes place according to the circadian rhythm – an inherent natural internal sequence that facilitates the sleep-wake cycle and repeats every 24 hours. Maximum production and release of melatonin by the pineal glands occurs at night, from where it passes into the cerebrospinal fluid in the brain to help relay signals via the bloodstream to other organs in the body. The tissues in the system receive melatonin which indicates that it is night-time, thereby enabling uninterrupted sleep. Since melatonin formation is triggered in the pineal gland largely owing to dim surroundings, it is also referred to as the “hormone of darkness”.
However, the production of melatonin is hindered by the presence of excessive light, which leads to a drop in the hormone. Though low melatonin levels do not affect the person’s ability to fall asleep at night, sufficient and optimal amounts of melatonin foster uninterrupted deep sleep, prevent disorders like insomnia and promote better quality of rest in the nighttime.
Melatonin And Its Structure:
The discovery of melatonin was initially based on identifying a compound synthesized by the pineal gland that regulated skin complexion. Melatonin was first identified in humans in the year 1958 by Dr. Aaron Bunsen Lerner, a renowned physician, scientist and dermatology professor at Yale University, USA. While working on experiments to identify a component that could prove useful in treating pigmentation conditions like vitiligo, Dr. Aaron Lerner and his team found the hormone melatonin and isolated it from bovine pineal gland extracts.
With extensive research being carried out subsequently to decipher the functions of melatonin, Harry J. Lynch, a reputed American scientist, revealed that the compound was synthesized by the pineal gland in humans at a higher rate nocturnally i.e. at night or in dark environs and ascertained the key role of the hormone in connection with the circadian rhythm.
The biochemical structure of melatonin comprises carbon, hydrogen, oxygen and nitrogen molecules and the hormone belongs to the group of compounds known as acetamides. Melatonin has a molar mass of 232.283 g/mol (grams per mole), with the chemical formula C13H16N2O2.
Functions Of Melatonin:
Melatonin performs various crucial roles in the human system, such as:
- Synchronizing the circadian rhythm and regulating the sleep-wake cycle
- Fostering continuous peaceful sleep at night and ensuring ample rest for the body
- Maintaining an ideal low body temperature slightly below normal levels during the night
- Controlling blood pressure and preventing instances of hypertension
- Bolstering immunity and reducing the risk of chronic illnesses like diabetes, heart disease, as well as infections
- Enriching skin tone and texture and conferring uniform complexion
- Protecting internal cells, tissues, besides the brain, nerves, spinal cord from oxidative damage by harmful free radicals, thanks to its powerful antioxidant properties
Adverse Effects Of Hormonal Imbalance In Melatonin:
A dip in melatonin levels in the body makes it difficult to sleep at night but does not result in any other serious health complications. Moreover, melatonin levels tend to fluctuate in normal healthy individuals through the day, peaking during the night and decreasing in the daytime as light inhibits its synthesis. Melatonin production also reduces gradually with old age and so higher than average or low melatonin levels arising inherently in the body do not pose any severe health problems.
Melatonin triggers some discomforting signs only when the supplement is taken in very large doses. Melatonin supplements are often consumed by a considerable number of adults to sleep better at night, but care must be taken to ingest them only within the recommended dosage by the doctor. If taken in high doses, it leads to massive circulation of melatonin in the blood and induces fatigue, drowsiness, headaches and a very low body temperature.