Study: melatonin deficiency accelerates aging and increases cancer risk

As we age, we begin to experience a deficiency of melatonin. This important hormone is synthesised in the epiphysis, a small endocrine gland (also called the pineal gland), which is located in the centre of the brain between the hemispheres.

The pineal gland only produces melatonin in the dark. If we are regularly exposed to light at night, over time this depletes the melatonin-producing function of the epiphysis, and this leads to accelerated aging, increases the risk of age-related diseases, including cancer, and ultimately shortens life expectancy.

The Laboratory of Cell Pathology at the Research Institute of Human Morphology of the B.V. Petrovsky Russian Scientific Centre for Human Morphology carries out complex studies devoted to the investigation of the influence of melatonin on the rate of aging, peculiarities of changes in organs and organ systems during aging, both in the norm and in age-associated socially significant pathologies. One of the key directions in research is prevention and treatment of malignant tumours, including melanoma.

This direction is due to the fact that melatonin is a hormone that has the widest range of biological effects. It regulates our biorhythms, affects the synthesis of sex hormones, immunity, has antioxidant properties, slows down aging, protects against stressors, weakens the manifestation of some diseases. Interestingly, this hormone, originally found in mammals, has in recent years been found in plants, and it also has a beneficial effect on them. For example, pre-sowing treatment of seeds with this hormone increases their resistance to unfavourable factors and germination.

Melatonin is synthesised only in the dark and is destroyed in the light. With age, its secretion sharply decreases, this process begins during puberty. But in modern conditions, we are all, and primarily residents of large cities, are exposed to light at night and often even sleep in partial darkness. This leads to a decrease in melatonin secretion, and people suffer from a lack of melatonin. At even higher risk are those 20% of the working age population who work in shifts and are often exposed to light around the clock. It is also important that most of the territory of our country is located in high latitudes. White nights and polar summers are, of course, romantic and beautiful. But it is an additional risk factor for all people who live and work in the zone of such territories.

In the laboratory of cell pathology conducted a series of studies aimed at identifying the role of melatonin in the development of experimental melanoma. At the first stage, they found that under constant illumination, that is, in conditions of melatonin deficiency, the tumour grows faster, metastasises more aggressively, and life expectancy decreases in experimental animals.

At the same time, laboratory rodents with the same melanoma, but in constant darkness, showed lower melanoma growth rates, fewer metastases, and significantly increased life expectancy. Thus, it was possible to confirm the dependence of the course of the disease on the body's supply of melatonin.

At the second stage, scientists tested the direct effect of melatonin on the development of melanoma. Mice were given this hormone together with water for drinking. Scientists were able to obtain very encouraging results. Namely: tumour growth was slowed down by almost 30%, its size was significantly reduced, and we saw foci of destruction in the tumour itself. That is, under the influence of melatonin the tumour began to be destroyed, and besides, it became less aggressive: the rate of its cell division decreased, the number of newly formed tumour cells decreased. On the background of the increase in the life expectancy of animals by 12-18%, there was a sharp decrease in distant metastasis. If in ordinary animals in almost 100% of cases we observed melanoma metastasis to the lungs and liver, in experimental animals receiving melatonin, metastasis occurred only in every third case, and only in the lungs.

Thus, the scientists concluded that melatonin may have a therapeutic effect against tumours. Of course, so far this effect has been recorded under experimental conditions - on laboratory rodents. In order to apply the same conclusions to humans, additional studies are needed.

In no case should you rush to the pharmacy and buy melatonin preparations. You should always remember that this is a hormone that can only be used on the prescription of a doctor. Self-use of it can lead to serious disturbances of biorhythms and provoke the development of a number of serious, including cancer, diseases, - warns the doctor.

Tips

As methods to prevent a decrease in your own melatonin production, you can follow some simple rules:

• lengthen the night to 8-10 hours by using shading lampshades and thick curtains on the windows in the bedroom;

• avoid even short-term exposure to light at night: switch off lamps, TV and computer during sleep, do not use gadgets;

• if necessary, use dim red light at night, which practically does not disturb melatonin synthesis;

• do not take melatonin without a doctor's prescription.