During summer months, we spend every free moment outside, very often in the sun. The sun has a beneficial effect on our mood and immunity, enables the synthesis of vitamin D, strengthens the heart, bones and joints. In addition to the beneficial effect on our body, UV radiation of the solar spectrum is one of the leading causes of skin cancer and premature aging, so adequate protection is necessary.
The statistics of malignant melanoma and other skin cancers have increased in recent decades. The index of solar radiation is higher every year, so its impact on the skin is becoming more significant. This is the main reason for the constant appeal of doctors to protect ourselves when it comes to the sun exposure.
Sunburn
Burns and damage to the skin (even human DNA in cells) are caused by ultraviolet radiation, i.e. UVA and UVB rays. We should not forget UVC radiation, as the most dangerous, which is, fortunately, blocked by the Earth’s atmosphere, primarily the ozone layer.
UVA radiation makes up about 95% of the total solar radiation. UVA rays have the longest wavelength and penetrate almost the entire depth of the skin, to the dermis. At first it was thought that this radiation could not cause skin burns, only tanning. Tanning beds were formed on this delusion.
Over time, we realized that UVA radiation is significantly more dangerous than UVB radiation. By penetrating all skin structures, it causes changes in the genetic material of the cells and their mutation. Mutation of skin cells leads to the formation of precancerous lesions and cancers.
UVA rays are also the main culprit for collagen and elastin tearing, i.e. premature aging of the skin. Over time, the skin will weaken due to this negative effect, it will become thinner or very thickened, and wrinkles and hyperpigmentation will appear. Burns are also possible with UVA rays, but it takes a little longer than with UVB rays. UVA rays can penetrate clouds and glass.
The UVB spectrum has a slightly shorter wavelength. It stays in the more superficial layers of the skin and is the main cause of sunburn. It is especially intense when the index of solar radiation is high, between 10 and 16 hours, and glass and clouds mostly block it. All creams with SPF have protection focused on UVB rays, but only those creams where it is expressly specified have UVA protection.
The first response of the skin to excessive exposure to sunlight is inflammation, i.e. burns characterized by redness, swelling, pain and even blisters.
How does our body protect itself from dangerous radiation?
With the help of melanocytes, cells located in the epidermis, are responsible for the production of melanin – the pigment responsible for skin colour. It is composed of complex polymers that absorb almost all wavelengths of ultraviolet radiation. Melanin is our natural “sunscreen”.
Scientists from Lund University in Sweden recently explained the entire process. When ultraviolet light reaches melanin molecules, it releases a proton that converts that energy into harmless heat, which cannot damage DNA. It is fascinating that it happens in a thousandth of a billionth of a second.
Sun protection and tanning beds
Ultraviolet radiation is more important factor for skin aging than all the others we are exposed to together. It is also the biggest risk factor for skin cancer.
The matter is so serious that only one case of sunburn in childhood doubles the chances of developing melanoma later in life.
Between 10 am and 4 pm, the sun is the strongest and thus the UV radiation is more dangerous. Also, in our region the sun rays strike the Earth surface at the largest angle in June, when the day is the longest and then they are the most dangerous, although in Europe it is not the warmest period.
During this period, it is necessary to pay special attention to skin protection.
In the summer, we should wear long-sleeved clothing and socks that cover most of our body. Thin fabrics are equal to SPF 15, which is enough for running errands but not for the beach. That is why one burns very easily under a canvas umbrella, spending the day in its “shade”.
Gradual exposure to the sun is important to allow the skin to adapt to the increased radiation, but not in the tanning salons.
It is a great misconception that going to the tanning salon prepares the skin for sun exposure. Tanning beds use UVA radiation that penetrates deep into the skin, creating damage to the genetic structure of the skin and not creating protection from UVB radiation. Every exposure to this radiation accumulates over years and leads to the formation of various skin cancers, elastin damage and premature aging. The harm of tanning beds is so great that in most countries of the European Union, the use of tanning beds is prohibited for people under 18 without the consent of parents.
How much protection does a dark skin provide?
About the equivalent of SPF 3, which is not a lot.
The best protection is to avoid the sun when it is the strongest, and in the morning and afternoon the use of creams with an adequate SPF. The sun protection factor is a guide to how long you can stay in direct sunlight before your skin starts to burn. It is considered that the protection factor higher than 50 does not exist, although some creams are marked with up to SPF 90. When choosing a cream with SPF, it is necessary to choose one having both UVA and UVB protection.
When we are at seaside or in the mountains, the protection factor 30+ should be applied on the face every 2 hours.
Mandatory face protection with UVA/UVB SPF greater than 15 will protect permanently exposed facial skin from the harmful effects of sunlight. One should not forget sunglasses.
A significant intake of red and orange fruits and vegetables rich in beta carotene will make our skin more resistant to UV radiation and will make tanning easier. Vitamins C and E are also important to us as they are powerful antioxidants. It is believed that any tanning represents damage to the skin by UV radiation, and an adequate amount of vitamins will significantly help us fight this damage.
Unfortunately, the sun’s radiation is such that the skin recovers poorly from it. All our exposure to this kind of radiation over years accumulates leading to the premature skin aging, its thinning or thickening, wrinkling, as well as precancerous lesions and skin cancer.
Vitamin D
Vitamin D is a steroid hormone that has been associated primarily with bone growth and calcium deposition for years. Over the last ten years, its special role in the metabolism of the skin, brain, T and B lymphocytes, pancreas and cardiovascular system has become clearer. With vitamin D receptors on almost the entire surface of the intestine, it is one of the key elements of the immune response.
Vitamin D deficiency
It is estimated that about 50 percent of Europe’s population is deficient in this vitamin, of which 13 percent is severely deficient. Lifestyle changes as well as moving from the countryside to polluted cities are the main culprits for such a high deficiency of this vitamin.
Vitamin D is unique in that our body only produces it by exposing the skin to the sun. It exists in the form of Vitamin D3 which our bodies produce and Vitamin D2 which is found in the food we eat.
It takes between 1,000 and 1,500 hours of skin sun exposure annually with a minimum dose of redness to produce an adequate amount of vitamin D. Vitamin D formed in this way lasts 2 times longer in circulation than vitamin D which is ingested through food or supplements. Exposure of the body to sunlight until a minimum amount of mild redness appears on the skin allows the synthesis of vitamin D equal to the intake of 10,000 to 25,000 units of vitamin D.
Benefits of adequate amount of vitamin D
Benefits of adequate amount of vitamin D are numerous and the following are the most important:
It reduces the possibility of developing cancer because it prevents the rapid proliferation of cells as well as the formation of new blood vessels.
It provides heart muscle health through kidney metabolism as well as through receptors on blood vessels.
It reduces blood pressure.
Obesity is associated with vitamin D deficiency.
The risk of type 2 diabetes is reduced by taking 700 IU of vitamin D per day.
Depressed people who received 20 to 40 thousand units a week had better results in overcoming depression.
High levels of vitamin D reduce the risk of multiple sclerosis by 62%.
Vitamin D synthesis in humans
Several factors that affect the synthesis of vitamin D should be taken into account.
- Wearing SPF 30 reduces vitamin D synthesis by 95%.
- People with darker complexion have a more intense defense against UVB radiation and thus decreased vitamin D synthesis. They need 3 to 5 times longer sun exposure in order to produce the same amount of vitamin D as fair-skinned people.
- Obese people deposit vitamin D in adipose tissue, so they need a much larger amount for adequate blood circulation.
- Ageing of the skin reduces the ability to synthetize vitamin D.
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