Simple rules will help you get an excellent, even tan without unpleasant consequences.
As BBC notes, everyone is familiar with that unpleasant burning and itching that occurs after the first few hours of exposure to sunlight. Yes, at first glance it's not scary, and why not endure it, because the reward will be chocolate-colored skin (again, if you're lucky, and it doesn't peel off first, turning you into a not-so-elegant leopard).
Besides, they say sunbathing is beneficial, that ultraviolet kills germs, helps the body produce vitamin D, and regulates circadian rhythms. All true, but it's not called radiation for nothing. In fact, it's nothing more than a sunburn, which causes enormous harm to the body at the cellular level.
A Hot Hello from Space
Sunlight is electromagnetic waves, and after they travel through space and the Earth's atmosphere, we ultimately get two types of ultraviolet radiation: near UV-A (UVA) and medium UV-B (UVB). There is also far and extreme ultraviolet, but these rays are almost completely blocked by the atmosphere.
UVA rays are unlikely to cause a burn, but they penetrate deep into the skin, and over time, such exposure will have a cumulative effect in the form of sagging skin.
UVB rays carry more energy, and their effects will appear immediately as redness and itching.
Feel It in Every Cell
Overall, ultraviolet radiation damages the skin, striking DNA molecules, proteins, fats, and so on. When these molecules absorb too much solar energy, intramolecular bonds are broken, molecular structure changes, and previously stable cells, where molecules had a specific shape and performed specific tasks, go haywire. This can lead to DNA code breaking and essential proteins no longer being produced.
Fortunately, each cell has an army of auto-correcting molecules that can intervene and repair the damaged DNA section. Unfortunately, with active irradiation of the entire skin surface, the auto-correctors physically cannot keep up with damage on such a scale.
If cell damage becomes critical, it triggers apoptosis, or suicide. Sounds harsh, but without it, too many crippled cells would accumulate in your skin, and the skin would stop performing its functions – with very sad consequences for the entire body.
This creates a kind of vicious circle: the self-destruct code is embedded in your DNA, but if that particular DNA section is damaged or escapes repair, apoptosis will not be triggered, and the cell will begin to grow uncontrollably. This is often how cancerous growths – carcinomas – arise.
A Natural Reaction
You've probably noticed that inflammation and itching don't occur immediately, but a couple of hours after sun exposure. This happens because the suicide process of damaged cells doesn't start right away: first they accumulate in your skin, then the immune system kicks in, but then...
White blood cells rush to the areas of skin where dead and dying cells have accumulated, and they begin to actively cleanse the body of fragments of dead cells. Your capillaries dilate, start leaking fluid through their walls: this is a natural process, but your skin turns red, itches, and hurts.
A few hours pass, the cleanup ends, and everything returns to normal, except that your skin starts producing melanin – the pigment that blocks ultraviolet rays and gives your skin that desired tan.
How to Tan Properly
Of course, a sunburn won't kill you, at least not immediately. But every time you get sunburned, your cells suffer serious damage from solar radiation, at the DNA level, and sooner or later this can lead to cancer.
So, should you not tan at all? No, why not, just do everything in moderation. If you know you burn quickly in the sun, or have just arrived at a resort and are scaring others with your pale body, in the first few days try to wear a long-sleeved shirt or dress, sunglasses, and a wide-brimmed hat.
Of course, you won't be able to completely hide from the sun, and you don't need to, because there are also sunscreens. They are usually divided by SPF factors from 15 to 50 or even 75, protecting the skin by 95-99.5% for at least half an hour from both types of ultraviolet rays.
At the same time, of course, you need to thoroughly cover the entire skin surface with cream, wait for it to absorb well, reapply every two hours, and if you decide to swim (many note that in water, the tan catches you stronger and faster), make sure your cream is water-resistant.
If you follow all these generally simple requirements, you will most likely get an excellent, even tan without unpleasant side effects and, most importantly, without long-term health damage.