“Preparing” your skin for the sun: many misconceptions and risks

"There is no way to prepare the skin for the effects of the sun," Professor Claude Linassier, director of the prevention, organization and care pathways division at the French National Cancer Institute (INCa), told AFP.

Each year in France, between 141,200 and 243,500 skin cancers are diagnosed, including 112,960 to 194,800 caused by excessive exposure to UV rays, according to Public Health France.

On social media, in magazines, and in the collective imagination, many misconceptions persist.

The most worrying: 20% of French people believe that sessions in artificial UV cabins before summer reduce the risk of getting sunburned, according to a 2023 Ipsos survey for the National Union of Dermatologists and Venereologists (SNDV).

However, "these practices considerably increase the risk of skin cancer," warns the union, while 33% of young people aged 25 to 34 resort to them.

"Twenty minutes of tanning in a booth is like a day of tropical sun on your skin! This practice is even more dangerous than unprotected sun exposure," Catherine Olivérès Ghouti, a member of the SNDV, told AFP.

Artificial UV radiation has been classified as "certainly carcinogenic to humans" by the International Agency for Research on Cancer (IARC) since 2009, and these booths are banned in several countries, such as Australia.

According to the French National Agency for Food, Environmental and Occupational Health and Safety (ANSES), people who have used tanning beds at least once before the age of 35 "increase their risk of developing skin melanoma by 59%."

Each year, around "380 new cases of melanoma" are linked to these self-tanning booths, adds Professor Linassier, who strongly advises against them.

"No healthy tan"

Another often-popular option: darken your skin tone before going out into the sun, by taking dietary supplements or using self-tanner, in order to be better protected.

Since dark skin produces more sun-protective melanin, the idea might seem tempting, but this shortcut is misleading.

Indeed, food supplements are often just "simple carotene-based colorants," which will give a tanned complexion, "but do not replace melanin and therefore do not provide any protection against ultraviolet rays," insists Professor Linassier.

In high doses, some beta-carotene-based dietary supplements even have a harmful effect on health, warns the oncologist, because they "represent an increased risk of lung cancer for smokers or ex-smokers, and people who have been exposed to asbestos."

By giving the illusion of already being tanned, these products can even encourage people to expose themselves to the sun for longer, or even without protection.

But, even in small doses, "there is no such thing as a healthy tan," reminds INCa.

"The latter constitutes an attack on the skin, a sign of a reaction that is triggered against the damage caused by UV rays, whether natural or artificial. Tanned skin therefore indicates that the DNA has suffered damage," the Institute emphasizes.

When exposed to the sun, the use of sunscreen is essential and should be reapplied every two hours, but even the most effective sunscreens - SPF 50 - do not filter out all UV rays.

Sun protection must therefore be multiple: wearing tightly woven or UV-treated clothing, a wide-brimmed hat, sunglasses and limiting exposure during the hottest hours.

And for those concerned about stocking up on vitamin D, just a few minutes of exposure are actually enough to cover physiological needs.

INCa therefore recommends exposing hands, forearms and face daily from April to September, "5 to 10 minutes for light skin and 15 to 30 minutes for dark or black skin."

For its part, the League Against Cancer launched a prevention campaign in mid-June calling for people not to "grill in the sun" this summer, because "we are not sausages," recalling that skin cancers are among the "40% of preventable cancers."