The skin goes through the aging process like other body parts. Since ancient times, man has sought to find the causes of aging and ways to delay it. Skin aging can be divided into two parts: aging caused by aging, and aging caused by sunlight
Aging caused by aging
Over time, many biochemical reactions occur in the human body, which gradually cause changes in the skin, for example, the cells of the epidermis (surface layer of the skin) do not shed easily and the collagen and elastin fibers also break. The skin is not able to maintain its moisture as before. Also, the skin’s ability to fight infections, understand emotions, and regulate body temperature decreases. “DNA” that controls the proliferation of cells may be damaged and this proliferation is out of control, leading to cancer.
The destruction of collagen and elastin and the force of gravity cause certain changes over time: fine lines appear around the eyes, lines around the mouth and on the forehead deepen, and the skin becomes loose and droopy. Nails gradually become more brittle and hair thins.
Aging caused by sunlight
The biggest factor that damages the skin is not aging but sunlight. Over the years and over time, the sunlight causes superficial and deep wrinkles in the skin, it makes the skin loose and swollen, giving it a dull and yellow color, the appearance of the skin becomes leathery and dry, and sometimes accompanied by peeling. The sun also increases the risk of skin cancer. Sunlight reduces collagen and causes the formation and increase of some moles and skin spots. You can see some of these changes in the photo below of a middle-aged woman:
How to distinguish aging caused by aging from aging caused by sunlight?
This is easily recognizable. Look at the lines and folds and wrinkles and consistency of the skin on your face and the back of your hand. Now compare it with a part of the skin that has not been exposed to much sun like your stomach area. You will see that there is a big difference.
How does sunlight damage the skin?
Sun damage is caused by the ultraviolet rays contained in it. There are different types of these rays in the sunlight, the degree of their penetration in the skin is different from each other. The wavelength of ultraviolet rays is between the wavelength of visible light and X-rays. Ultraviolet rays that reach the earth through sunlight have three main wavelengths:
“C” type ultraviolet rays:
It has the shortest wavelength and the highest energy level compared to the other two wavelengths, and therefore causes the most damage to the skin, but fortunately, it is usually absorbed by the ozone layer before reaching the earth’s surface and passing through the atmosphere. to be Of course, in areas like Australia where this layer has thinned, there is a possibility of severe skin damage due to this radiation.
Type “B” ultraviolet rays:
It has a shorter wavelength than type “C” and its energy is less, so it causes less damage to the skin. This radiation penetrates the epidermis and its effects can be seen in the form of sunburn. The more times you get sunburned, the more likely you are to develop skin cancer. Type “B” ultraviolet rays cause a kind of genetic mutation, after which the cells grow excessively and lead to cancer. More than 90% of squamous cell cancers have this mutation.
“E” type ultraviolet rays:
It has the longest wavelength and is caused by sunlight and aging Skin cancer plays a role. Due to its longer wavelength, this ray penetrates deeper into the dermis (deep layer of the skin). Only 10% of “B” type ultraviolet rays reach the skin, but this amount is 50% for “E” type. The amount of “E” ultraviolet rays in the light that reaches the earth from the sun is ten times that of “B” type ultraviolet rays.
All these facts show how important it is to avoid sunlight and use appropriate clothing, brimmed hats, gloves, and sunscreens in preventing premature aging of the skin and its diseases and malignancies.
Dr. Nima Torabi Golsfid