When we fall asleep, our body develops vigorous activity: it repairs, compensates, makes reserves for the coming day.
Chronobiology, the science that studies human biorhythms, has revealed to us that the human body is regulated by external factors, “synchronizers”, such as light and dark, heat and cold, day and night. During sleep, important processes take place in our body: the brain processes and sorts information, the synthesis of hormones starts, and the skin restores its resources.
Order in the head
If resting for 20 minutes with a good book or just relaxing in front of the TV is enough to eliminate muscle fatigue, then our brain needs proper sleep to truly rest. “When falling asleep, a person is between sleep and reality for several minutes, then the phase of slow sleep begins and lasts about 20 minutes. At this time, the cerebral cortex “stops communication” with other parts of the brain, explains somnologist Sergei Stebletsov. Then comes the deep sleep phase. Breathing and heart rate slow down, body and brain temperatures drop slightly. Paradoxically, after 20-30 minutes of deep sleep, the brain returns to the second phase, as if trying to wake up, but instead the next phase, called REM sleep, begins. It is so named because it has a rapid eye movement. It is during REM sleep that the most emotional and spectacular dreams occur. This phase is also called paradoxical sleep. Sleep phases make up one cycle and are repeated 4-6 times in the middle of the night.
For a long time it was believed that dreams generally occur only during paradoxical sleep, but in recent years it has been proven that visions come to us during non-REM sleep – they are shorter and less emotional. “In a dream, the information received is consolidated,” continues Sergey Stebletsov. – How does this happen? In the course of research, it turned out that during slow sleep in the hippocampus (this is one of the most ancient parts of the brain with many functions), the same groups of neurons are excited and in the same sequence as in the learning process that was carried out before falling asleep. That is, the hippocampus in a dream, like a diligent student, repeats the information received during the day, which contributes to better memorization. And during REM (paradoxical) sleep, emotional information is processed, mental balance is restored, and a program of behavior for tomorrow is laid down. If there is no REM phase with stormy dreams in a dream, then there will be no morning peak of attention and learning. By the way, people suffering from neurosis, increased anxiety and depression often say that they do not see dreams.
Hormone harmony
It is at night that the peak of hormone synthesis occurs – the body makes reserves of these substances so that they can be used during the day. For example, adrenaline, the “stress hormone”, is synthesized by the adrenal cortex – during sleep, a person almost does not need it, but it is simply necessary during stormy daytime activity. The adrenal glands also synthesize cortisol, which regulates metabolism and has an anti-inflammatory effect. Somatotropic hormone affects the growth processes and metabolic rate, promotes the restoration of bone tissue. Thyroid-stimulating hormone regulates the functioning of the thyroid gland, and it is one of the main regulators of metabolism. The synthesis of most of these hormones is triggered by the pituitary gland, an endocrine gland located at the base of the skull. “The time of active work of the pituitary gland is night. It is activated an hour after falling asleep, and by 3-4 hours there is a “hormonal reset”, and then the body is already completely ready for a new day, explains Sergey Stebletsov. – But the hormone melatonin, produced by the pineal gland, plays a crucial role in the regulation of the circadian rhythm, in the mechanism of sleep and adaptation to adverse environmental conditions. The maximum concentration of melatonin in the blood is observed between midnight and 4 o’clock in the morning. If the normal rhythm of hormone synthesis is disrupted as a result of prolonged insomnia, stress, this naturally entails various unpleasant consequences. For example, weight gain.
For the coming sleep
- Each cell or organ system has its own night watch schedule. This explains the recommendations regarding certain medicines and foods.
- At night, the pancreas secretes more insulin: sugars are stored in order to quickly and efficiently get energy from them the next morning. Unused sugars are transformed into fats – that is why it is recommended to limit sweet, fatty, alcohol before going to bed. The same feature is used in the creation of new anti-cellulite creams: the formulas of products that are applied before bedtime include active ingredients that “trap” sugars.
- At night, the liver works more actively, so for those who use choleretic drugs, it is better to drink them at night to prevent stagnation of bile.
- With stomach ulcers and gastritis, it is recommended to drink drugs at night that reduce the acidity of gastric juice.
- Hormonal anti-inflammatory drugs – corticoids – are not recommended to be taken at night to minimize their side effects.
- Antihistamines are best taken at bedtime to achieve the maximum anti-allergic effect.
Skin Resources
During the day, our skin exists in “protection mode” – to fight the aggression of the external environment. At night, it switches to “repair mode”. It produces collagen and elastin, compensates for the action of free radicals, recovers – all this requires large reserves of energy from it. The cells of the epidermis begin to intensively divide, restoring the stratum corneum of the skin – the peak of regeneration falls on the time between one and 3 o’clock in the morning. “The Chanel Research Center for Epidermis and Skin Sensitivity Research (CE.RIES) lab has been doing skin chronobiology research,” says Marie-Helene Lair, Chanel Brand Science Communications Officer. – By about 23 p.m., the tissues are best supplied with oxygen – this is the most suitable time for applying night products: the components penetrate the skin better and are absorbed by it as much as possible. At night, the phase of synthesis of fibroblasts and dermal fibers begins. These features are taken into account when developing night products, which include components that stimulate skin regeneration, such as Rectifiance intense, Ultra Correction.
“One of the biggest breakthroughs in science today is the value of calcium metabolism in the skin,” said Dr. Daniel Maes, Vice President of International Research and Development, Estée Lauder Corporation. – Calcium plays a very important role in triggering the skin’s natural repair mechanisms – this discovery was used to create Re-NutrivRe-Creation. At night, when the skin goes into self-healing mode, it is the movement of calcium molecules in the epidermis that triggers the production of lipids to eliminate dryness and compensate for the damage caused during the day. The restoration of the hydrolipidic barrier, in turn, leads to the fact that the skin can again effectively perform its main function – to protect our body from environmental aggression, ultraviolet radiation, invasion of bacteria and chemical agents. Stress and lack of sleep reduce the skin’s ability to recover – specially created products that take into account its chronobiological mechanisms, partly compensate for this, helping to maintain skin resources and maintain not only its beauty, but also its health.