Five theses, five answers - Sunscreen myths in check: What is really true?
Summer, Sun, Beach: The hot days attract us outside. And every year, myths surface about sunscreen sales. Does a high sun protection factor really make a difference? Does a vegan diet protect the skin? Does aftersun prolong sunscreen protection? This fact-check shows what is true.
Claim
Aftersun prolongs sunscreen 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 necessary: "At least every two hours and especially after swimming and drying off." However, this only works if the sunscreen actually lasts that long.
Dermatologist Christoph Liebich from Munich explains that reapplying sunscreen does not extend the sun exposure time. "For example, if I apply a factor 10 sunscreen and have a personal protection time of ten minutes, it's over after 100 minutes. It doesn't matter if I then apply the factor 10 or even the factor 50." The radiation has 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 also 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 of skin. This corresponds to approximately four heaped teaspoons for the entire body of an adult.
Claim
A daily cream is sufficient as a lighter sunscreen.
Rating
True in some cases.
Facts
For sun protection with a daily 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-Westphalian Consumer Center, points out. The sun protection factor should be indicated on the packaging. "Without this information, the protective effect for consumers cannot be evaluated," Effers says. Experts also recommend a high sun protection factor for daily creams.
Additionally, it is just as important for daily creams as for sunscreen to use an adequate amount. Dermatologist Liebich fears that some people may not apply enough of the expensive creams - after all, they are often considered 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
Tanning in the sun or solarium protects the skin.
Rating
False.
Facts
When we expose ourselves to the sun or a solarium, we receive ultraviolet radiation on our skin. In general, ultraviolet radiation is divided into three types: UVA, UVB, and UVC. UVA radiation penetrates into the leather layer of the skin (dermis). UVB radiation, on the other hand, only affects the upper layer. UVC radiation is so short-waved that it is absorbed by the ozone layer.
Claim
A vegan diet protects from sunburn.
Rating
False.
Facts
The idea that sun protection can be achieved through a vegan diet is appealing. However, experts deny this. While the vitamin A and beta-carotene found in healthy food sources can provide a natural protection for the skin, including from the sun, this is not sufficient on its own to protect the skin from sunburn at high UV indices.
Beta-carotene, for example, is primarily found in fruits and vegetables. Those who consume a lot of these foods receive "secondary plant pigments that simply additional protect the skin from sunburn," explains Liebich. However, the basis must always be sunscreen, as nutrition alone does not build up a real protective factor.
Claim
Sunscreen expires.
Rating
True.
Facts
Sunscreen can also deteriorate. The reason not to leave cream and the like 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 risk of skin cancer in the long term. Therefore, manufacturers indicate how many months the sunscreen should be used after opening. This is indicated by a symbol with a number and an "M". For example, "12M" means twelve months. A note with the opening date on the bottle can help.
Additionally, benzophenone, which may be carcinogenic, forms in many sunscreens over time from octocrylene. Researchers have studied the aging of the product for a year 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 observed the product aging in the experiment. Interestingly, and another reason to discard sunscreen from the previous year: Benzophenone can even form in unopened packages.
Consumer Center on the use of sunscreenFederal Office for Consumer Protection on sunscreenUV-Protection tips from the German Weather Service (DWD)Consumer Center on the use of beta-carotene capsulesFederal Office for Radiation Protection on light protection factor
- The German Federal Office for Radiation Protection emphasizes the importance of regularly applying sunscreen, recommending reapplication every two hours and after swimming or drying off to maintain its effectiveness.
- In Germany, dermatologist Christoph Liebich from Munich explains that reapplying sunscreen does not extend the sun exposure time, as the radiation has already penetrated the skin and the protection time has been used up.
- According to the German Federal Office for Radiation Protection, an adequate amount of sunscreen should contain a UV filter and have a sun protection factor of two milligrams per square centimeter of skin, which is equivalent to about four heaped teaspoons for an adult's entire body.
- Kerstin Effers, consumer advisor for environmental and health protection at the North Rhine-Westphalian Consumer Center, stresses that for sun protection with a daily cream, it is essential that it contains a UV filter and has a sun protection factor indicated on the packaging.
- In Berlin, Effers further advises that even daily creams should have a high sun protection factor to ensure adequate protection, and warns that some people may not apply enough of the expensive creams due to considering them as luxury products.
- Liebich, the dermatologist from Munich, suggests that those who hesitate to use enough sunscreen should opt for classic sunscreen instead, emphasizing that the recommended amount should be applied to ensure the sun protection factor's full effectiveness.
- Environmental and health protection consumer advisor Effers also points out that a vegan diet does not provide sufficient sun protection on its own, even with the presence of vitamin A and beta-carotene found in healthy food sources, as nutrition alone does not build up a real protective factor against sunburn at high UV indices.
