Which sun protection myths are really true?
Whoever lies in the sun should make sure to properly apply sunscreen beforehand. However, there are various claims and tips circulating about sunscreen protection - whether from a tube or through specific nutrition. Does pre-tanning in a tanning bed really help and does a day cream with LSF suffice? Fact check.
Summer, sun, beach or lawn: The hot days attract us outside. And every year, there are myths about sunscreen. Does a high sun protection factor (SPF) really make a difference? Does a vegan diet protect the skin? Does reapplying sunscreen extend its protective effect? This fact check shows what is true.
Claim: Reapplying sunscreen extends the sun protection.
Rating: False.
Facts: The German Federal Office for Radiation Protection advises applying sunscreen 20 to 30 minutes before sun exposure. To maintain the effectiveness of sunscreen, regular reapplication is important: "At least every two hours and especially after swimming and drying off." However, this only works if the sunscreen lasts that long.
Dr. Christoph Liebich, a dermatologist from Munich, explains that reapplying sunscreen does not actually extend the sun protection time. "For example, if I apply a factor ten sunscreen and have a protection time of ten minutes, it's over after 100 minutes. Then it doesn't matter if I apply ten or even fifty again." The sun's rays have already penetrated the skin, and the protection time has been used up. Nevertheless, reapplying sunscreen in these cases is still sensible to maintain the existing protection.
It is necessary to apply enough sunscreen from the start: According to the German Federal Office for Radiation Protection, the sun protection factor for a layer of sunscreen on the skin should be two milligrams per square centimeter. That is roughly equivalent to four heaped dessert spoons for the entire body of an adult.
Claim: A day cream is sufficient as a lighter sunscreen.
Rating: In some cases, correct.
Facts: For sun protection with a day cream, it is essential that it contains a UV filter. If this requirement is not met, there is no sun protection, as Kerstin Effers, consumer advisor for environmental and health protection at the North Rhine-Westphalia Consumer Center, points out. The sun protection factor should be indicated on the packaging. "Without this information, consumers cannot assess the protective effect for themselves," Effers says. Experts also recommend a high sun protection factor for day creams.
Additionally, it is just as important to use an adequate amount of day cream as with sunscreen. Dermatologist Liebich fears that some people may not apply enough day cream - after all, it is often a luxury product. "If the recommended amount is not applied, a lower protection factor offers even less protection," Liebich explains. Those who hesitate to use enough should opt for classic sunscreen instead.
Claim: Pre-tanning in a tanning bed protects the skin.
Rating: False.
Facts: When one lies in the sun or in a tanning bed, they receive ultraviolet radiation on their skin. In general, three types are distinguished: UVA, UVB, and UVC. UVA radiation is the part that penetrates into the leather skin (dermis). UVB rays, on the other hand, only affect the upper skin. UVC rays are so short-waved that they are already blocked by the ozone layer.
A tanning bed only causes a "dirty tan," which does not build a real protection, says dermatologist Liebich. The light used in tanning beds mainly consists of UVA rays, which cause a quick but not lasting tan. UVB rays are often filtered out. "We need UVB rays for protection build-up, but they are banned in tanning beds."
In general, tanning before sunbathing involves UV radiation exposure. This is why tanning beds are forbidden for people under 18 years old. "Any additional radiation is not good," emphasizes Liebich.
Claim: A vegan diet protects against sunburn.
Rating: False.
Facts: The idea that one can protect themselves from sunburn through a vegan diet is tempting. However, experts deny this. While the vitamins A and beta-carotene found in healthy food sources can help protect the skin - even from the sun - this is not enough to protect the skin from sunburn when the UV index is high.
Regarding beta-carotene, for example, fruits and vegetables are the most important sources for humans. Who eats a lot of it, gets "secondary plant pigments that then simply protect the skin from sunburn additionally," explains Liebich. However, the basis must always be sunscreen, as the diet alone does not build a real protection factor.
Claim: Sunscreen can expire.
Rating: True.
Facts: Sunscreen can also deteriorate. The reason not to leave cream and Co. on for too long has several reasons. The protection against UV light decreases over time, which can lead to sunburn in the short term and increase the long-term risk of skin cancer. That's why manufacturers indicate how many months a sunscreen should be used after opening. A label with an "12M," for example, means twelve months. A note with the opening date on the bottle can help.
Additionally, benzophenone, a potentially carcinogenic substance, forms in many sunscreens over time from octocrylene. Researchers have found this in a study for the "American Chemical Society." Benzophenone forms gradually from octocrylene. Many sunscreens contain this chemical because it protects against UVB rays. The researchers followed the aging of the product for a year in their experiment. An interesting finding and another reason to discard sunscreen from the previous year: Benzophenone can even form in unopened packaging.
Despite the common belief, pre-tanning in a tanning bed does not actually protect the skin from sunburn. In fact, tanning beds can only cause a "dirty tan" and do not provide a lasting or effective protection against UV rays.
Regarding sunscreen, it's important to remember that excessive sun exposure, even with proper sunscreen use, can still increase the risk of skin cancer over time. Therefore, it's essential to limit sun exposure and follow the recommended guidelines for sunscreen application and reapplication.
