The effect of sunlight on health: avoiding it can also be bad

If we talk about ultraviolet rays, especially in summer, it is inevitable that the excesses of this exposure to the sun can cause fatal diseases such as Cancer. There is no doubt, it is so. But there is an American dermatologist who has come out to defend the supposed benefits of this sun exposure in general health. His name is Matt Zirwas, and has ignited the debate by publishing a study in which it investigates this hypothesis.

It all starts about 15 years ago, when the medical specialist witnessed a fact that drew his attention to the patients at his clinic in Ohio. Those who had received a lot of sunlight damage to the point of being diagnosed with skin cancer were the ones that seemed more robust and full of energy. "Despite the severity of their illness, they were in an excellent state of health and they hardly took medication ", says the dermatologist. "Then, however, I saw many people with beautiful skin, no cancer, but yes, with very little energy, vitality and taking all kinds of drugs to treat other health problems. "

Exposure to sunlight causes the release of nitric oxide into the blood, a chemical that keeps blood vessels "soft and flexible."

As a good scientist, Zirwas began to investigate. The first thing he wondered is what the history books said about ultraviolet light, doing a kind of medical archeology like Foucault did with the words. Finally, in 2014 he published a study in which he examined the medical data of about 30,000 women Swedish over 20 years about their sun habits, if they were smokers, consumed alcohol, were overweight, their level of education or income. The work, published in the 'Journal of Internal Medicine', showed that the risk of mortality doubled in those who tended to avoid the sun compared to others who received greater exposure to UVA rays.

The most curious thing is that the more amount of sun one of these women received, less likely to die. Zirwas thus began to suspect that exposure to the sun achieved a kind of protective effect. "If this were truly true, protecting yourself from ultraviolet light could have the same effect on the chances of death as deciding to smoke a pack of cigarettes a day ". Obviously, it seems like an exaggeration or madness. Therefore, the dermatologist continued investigating.

Good for the heart

For decades, as journalist Markham Heid says in 'Medium', researchers around the world have established links between sun exposure and its benefits in heart health. A curious phenomenon called as "winter cardiovascular disease", whereby both in the United States and in Europe, deaths related to cardiac pathologies reach their peak in this season. Therefore, many experts have argued that the absence or presence of ultraviolet light could be related. But they also offer other explanations: cold temperatures constrict blood vessels, So heart attacks may be more frequent.

Not leaving much of the house and being protected from the sun all the time means that we cannot generate vitamin D through our skin

But in recent years, several studies argue that a deficit of sunlight can aggravate the symptoms of heart disease, because UVA rays have the ability to stimulate the creation of vitamin D, which causes a drop in blood pressure . James O'Keefe, American expert cardiologist, one hundred percent agree with this idea. His research has shown that exposure to ultraviolet light causes the release of nitric oxide in the blood, a chemical compound that keeps blood vessels "soft and flexible," creating a surface "similar to Teflon so that platelets do not stick ". When the skin is exposed to sunlight, it is released into the bloodstream in amounts "so big".

"A very surprising fact of modern life is that most of us spend most of our time indoors, and when we go out, many of us protect ourselves from the sun," he says. Nina Jablonski, biologist anthropologist at Penn State University. A reality very different from that of our closest ancestors, since even 100 years ago, many people were engaged in agriculture or worked outdoors. "Therefore," he adds, "not leaving home much and being protected from the sun all the time means that we cannot generate vitamin D through our skin."

It is a fact that the skin of the human being has adapted to radiation levels and at different latitudes. "While more northern people with pale skin tend to suffer serious skin damage, including cancer, if they live in places near Ecuador, southern people develop health problems if they move to regions where there is no so much sun, "says Jablonski. "I think dermatologists want people to enjoy healthy skin and cancer-free for as long as possible, but most do not look beyond the skin, they do not think about the general well-being of their patients. "

Although it is one of the main factors that promote the creation of vitamin D, sunlight has beneficial effects that science has not yet been able to discover. "The standard advice of dermatologists is to avoid sunlight and take supplements of this vitamin, but probably there are many other ways by which the sun exerts positive effects ", admits Richard Weller, dermatologist at the University of Edinburgh.

The state of mind

Obviously, the light of our star king also exerts a great influence on our moods. Doctors associate a low exposure with a higher probability of suffering depression, for example. Further, "people who spend more time outdoors tend to be physically active, which holds health benefits, "he says Jo ann manson, specialist in Preventive Medicine in Boston. "But it is still very difficult to separate the positive effects of a fair exposure to UVA rays with the negative ones, since they can be very bad if there is excess."

He also believes that treating the sun as an enemy to avoid may be worrisome. "I am sure that a moderate exposure is perfectly compatible with a healthy lifestyle," says Manson. In short, as Aristotle said, virtue is in the middle. Little is bad, and too much is worse. The main thing is to take precautions but not to fall into the obsessive paranoia of believing that by sunbathing with relative frequency you will already develop diseases as terrible as cancer.