Justifiable desire
It is easy enough to understand the human desire for the sun. The need for sunlight laid genetically different peoples it completely different - the southern nations, it is undoubtedly much higher than in the northern. For example, the skin Southerner caught in the Far North, is experiencing the most severe stress, as shaped by generations of the need for solar radiation is not satisfied stingy northern sun.
Sunlight is involved in maintenance of insulin synthesis reactions (pancreas hormone) maintains a balance of skin microflora. But a positive impact on the human psyche is not disputed by physicians. Let us also remember that under ultraviolet light to produce vitamin D - an important regulator of calcium and phosphorus metabolism in the body - and serotonin - a substance (also known as "chemical messenger"), which controls impulses between nerve cells of the brain, under his "observation" that appetite, sleep, mood and emotions.
By reducing the production of serotonin marked depressive moods of the body, increasing sensitivity to pain, insomnia, migraine attacks. Serotonin is often called "happy hormone", as he joy moments produced in large quantities. For serotonin needs light, the lack of sunlight in winter is the reason for such a common seasonal depression. In addition, excess light inhibits the formation of another hormone - melatonin, which is important in the occurrence of depressive states.
What is the positive effect of losing sunlight? For each person has its own optimal "dosage" of sunlight, beyond which begin to show the negative effects are not always visible to the naked eye, but lead to devastating consequences.
Concealed danger
The most dangerous rays of the solar spectrum - UV-A and UV-B. They cause the instant formation of free radicals that trigger lipid peroxidation. Peroxidation called one of the causes of cancer. That is why doctors say it is about the maximum protection from the rays of the spectrum. By the way, not all free radicals are harmful, many of them operate in the body are many biochemical functions, and the harmful effects of these particles begins when the process gets out of control, what exactly happens when aggressive influence of solar radiation.
Protective systems
The natural defense system of the skin protects the body from the damaging effect of sunlight. These systems were selected and perfected in the course of evolution, and thanks to them we can find some time in the sun without compromising their health.
First, the skin produces melanin, and appears as a protective tan skin reaction to sunlight. But there is one very important point - this mechanism is fully switched on only after a week of daily exposure to the sun.
Secondly, there is a seal of the epidermis - the skin is trying to mechanical protection from the rays.
Third, antiradical activated enzyme systems.
Fourth, the substance in the body operate, regenerating damaged cells.
Fifth, skin urocanic acid is formed - in addition to melanin, which is formed in the tanning process, it is a natural absorber of UV radiation. But intense aggression radiation changes the chemical structure of urocanic acid, and the result of this process is the fact that the body loses its ability to reject cancer cells.
The degree of activity of these systems, different people have different and depends on the phototype man of his age and health. Resources are not unlimited photoprotection, and an overdose of UV radiation may occur malfunction of any links. To avoid this, you must not only carefully dosed sun exposure, but also actively help protect the skin against UV attack. For this purpose, a special sunscreen that allow more time in the sun.
Fitzpatrick skin types
I. Never tan, always burn (usually excessively white skin, blonde hair, blue or green eyes). "Unprotected" time in the sun - 5-10 minutes.
II. Sometimes it can get a tan, but most burn (fair skin, blond or brown hair, green or hazel eyes). "Unprotected" time - 10-20 minutes.
III. Often sunbathe, sometimes burn (average skin, brown hair, brown eyes). "Unprotected" time - 15-25 minutes.
IV. Always tan, never burn (olive skin, dark hair, dark eyes). "Unprotected" time - 20-30 minutes.
V. Never burn (dark brown skin, black hair, black eyes).
Professor Thomas Fitzpatrick skin types classified according to the degree of perception of ultraviolet radiation. This classification is useful for determining the degree of self-protection of the skin. "Unprotected" time - time to severe sunburn skin. For the calculation of safe exposure to sunlight is necessary to multiply the number of SPF (specified on a tube of sunscreen) for the duration of exposure to the sun to burn for your skin type.
Solar procedures - a very pleasant pastime. Until a few decades ago, doctors talked about balneology heliotherapy - treatment of sun. Heliotherapy was carried out in the form of solar-air baths, which were determined biodozy. This treatment helps to activate the mental and physical performance, strengthening of the autonomic nervous system, improve metabolism, blood, endocrine activity, increase adaptive capacity of the organism. On the other hand, when exposed to sunlight uncontrolled paradoxical effect observed decrease in immunity that persists for a long time after such a rest - up to a year.
Author: Olga Zorina