Many people get sunburned every now and then, especially in summer. This still happens, even though there's actually a good protection against sun damage to the skin besides a hat and clothing: sunscreen.
But some people are skeptical about putting chemicals on their skin the form of cream or spray suncreens, and there are numerous claims circulating online.
Which of them are true and which are misleading or unproven?
Claim: "Sunscreens contain carcinogenic substances," says this TikTok user. This is all the more bizarre because sunscreens are supposed to protect us from skin cancer. The user adds that all chemical sunscreens are carcinogenic and says that because of this, people should only use so-called mineral sunscreens, which, she claims, are much healthier. Shortly afterwards, the woman posts a voucher code for a mineral sunscreen — in other words, she advertises it.
DW fact check: Unproven.
The user's statement cannot be proven. "Sun creams do not contain any carcinogenic substances," Dr. Uta Schlossberger, a dermatologist practicing in the western German city of Cologne, told DW.
US-based dermatologist Hope Mitchell agreed with Schlossberger: "There is no evidence whatsoever that sun creams cause cancer."
But then why do numerous social media users claim this at all?
In order to find out, we need to look at the details.
Differences between filters
The main difference between mineral and chemical filters is how they deal with the sun's rays.
Mineral sunscreens contain titanium dioxide or zinc oxide to form a barrier on the skin that reflects ultraviolet, or UV, light. They do not absorb into the skin and therefore often leave a chalky, white layer on the skin when applied.
Currently, there is no scientific evidence that mineral sunscreens contain carcinogenic substances.
However, many people prefer to use chemical sunscreens because they are almost invisible on the skin.
These creams need to be reapplied every few hours as they wear off more quickly.
They contain chemical substances that change their chemical structure and are absorbed by the skin, thus warding off sun damage.
Again, there is no scientific evidence that chemical sunscreens contain substances that are carcinogenic to humans.
Dermatologists recommend buying new sunscreen every year
However, some sunscreens contain the synthetic UV filter octocrylene. A study in 2021 found that octocrylene can decompose over time to become benzophenone.
In animals, benzophenone can cause damage, according to dermatologist Schlossberger. This has also been confirmed by the World Health Organization : The filter is considered carcinogenic in animals and "possibly carcinogenic" in humans. However, a carcinogenic effect in humans has not been scientifically proven.
Just in case, dermatologists recommend not to use an old chemical sunscreen from the previous year if it contains octocrylene, but to buy a new one every year.
But while there is no hard scientific evidence that chemical sunscreens cause cancer, in the past few years, scientists have raised concerns about the lack of existing data on some the active ingredients they commonly contain.
The US Food and Drug Administration , for example, asked for more data on a several ingredients that are absorbed into the body's bloodstream when sunscreen is used.
However, according to experts, the risk of cancer from sun exposure is much higher than the risk from using chemical sunscreens.
Does using sunscreen lead to vitamin D deficiency?
Claim: "Sunscreen leads to vitamin D deficiency." So many social media users are saying this that a number of dermatologists are publishing videos to debunk this myth: for example, this dermatologist on TikTok or this doctor from the United States.
DW fact check: False.
The consensus among experts is that sunscreens do not cause vitamin D deficiency. This scientific article, for example, says that sunscreens with a high sun protection factor (SPF) do filter out most of the sun's UVB radiation, and at the same time, UVB wavelengths are the ones that trigger vitamin D production in the skin.
"However, clinical studies have never shown that daily sunscreen use leads to vitamin D deficiency. In fact, the prevailing studies show that people who use sunscreen daily can still maintain their vitamin D levels."
Vitamin D is absorbed even with sunscreen on the skin
This study from King's College in London also concludes that even when a high SPF sunscreen is applied correctly, there is no vitamin D deficiency.
According to Schlossberger, the reason there is no vitamin D deficiency from sunscreen use is that it does not block 100% of UVB rays (see infographic, above). The remaining percentage that still gets through is enough to maintain vitamin D levels, she said.
Do Black people and people of color need sunscreen?
Claim: "Black people don't need sunscreen," says an influencer with more than 2 million followers on TikTok. The video in which he "teaches" his baby that Black people don't need sunscreen has more than 600,000 views.
DW fact check: False.
This claim is made over and over again on social media — but it's not true. People with darker skin types can stay in the sun a little longer without sunscreen without suffering skin damage, Schlossberger told interview.
However, no one has complete sun protection. Everyone can get sunburned.
Every skin type needs sun protection
Background: Dermatology distinguishes between six different skin types: Skin type one means, for example, that a person's skin is particularly sensitive to the sun. Skin type six, meanwhile, is described as "black skin" that is highly pigmented and significantly less sensitive. So the darker the skin type, the longer a person can stay in the sun without burning.
"We know that highly pigmented skin has a natural sun protection factor of about 13," dermatologist Hope Mitchell told DW. An additional sun protection factor of 30 keeps out a higher percentage of ultraviolet rays, she added.
Also, according to the American Academy of Dermatology, SPF 30 is the minimum that all people should apply, regardless of their skin tone.
Can a vegan diet really protect against sunburn?
Claim: Some TikTokers, such as this influencer with almost 30,000 followers, claim people don't need to apply sunscreen. In several videos, she explains that she and her baby don't use sunscreen because their vegan diet is protection enough.
DW fact check: False.
Experts vehemently disagree with this statement. "I think that's very dangerous," said Schlossberger. According to the dermatologist, one can achieve a better skin repair mechanism through a better diet — but not build up sun protection.
Carrots are said to have a positive effect. The consumer center in South Tyrol, Italy explains that beta-carotene contributes "as well as other carotenoids, vitamins (especially C and E) and trace elements (especially selenium), to prevent or repair skin damage by UV radiation."
However, "as a sole sunscreen, beta-carotene intake is far from sufficient and is not a substitute for sunscreen."
The German Cancer Society also confirms that although secondary plant compounds can contribute a little to sun protection, they are not recommended as sole protection.