Is sunscreen toxic? The UV truthers on the Internet sure think so.

Boston Globe

3 days ago

'They told us the sun was the threat,' another said. 'Not the corporations funding both the warning and the cure. I stopped burning when I stopped believing them.'
'People burn because of the seed oils in these processed foods,' read a third reply. 'If you eat clean, you'll be fine.'
Wait — what? Wasn't it just yesterday that we were supposed to feel guilty for
not
using sunscreen? Yes, but forget all that nonsense from your dermatologist. Now it's burn, baby burn.
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The social media doctors have weighed in, and now a serious portion of the public believes any or all of the following: Sunscreen doesn't prevent cancer, it causes it. Sunscreen is a ploy by big pharma to increase profits by making people sick. Use it, and you'll end up deficient in Vitamin D (most people reportedly don't put on enough for this to be a problem).
A 2024
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Brigham and Women's Hospital dermatologist
She learned that firsthand, in 2023, when she posted a TikTok video with what seemed like basic, if perhaps even dull, advice: wear sunscreen on exposed skin and reapply it regularly.
The vitriolic responses, and there were hundreds, had a theme: She was a shill for big pharma. She was propagating the lie that sunscreen protects against skin cancer. She was saying this to … somehow … get more patients.
'I had no idea that this was a public sentiment,' she said. 'It had never been discussed in medical school or any of my training.'
But the misconception that it's harmful is so common that even educated people believe it, she said. 'I went to play tennis yesterday, and my coach was like, 'I'm not putting chemicals on my body.' He's an engineer.'
The skepticism has its roots in reality, if only very tangentially, said Timothy Rebbeck, a professor of cancer prevention at Dana-Farber Cancer Institute, whose research focuses in part on false claims connected to cancer.
'This is a phenomenon we see in a lot of cancer misinformation,' he said. 'There is a kernel of truth to a story.'
For example, he said: a study is done in a test tube or an animal that shows a compound found in microscopic levels in sunscreen, when exposed to ultraviolet light, could cause DNA damage.
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That result, taken out of context, makes its way to social media, where it's sensationalized and amplified. 'By the time it gets to your social media feed, it doesn't resemble the original piece of information,' he said. 'No one goes back to the original paper and sees that it was in mice.'
Even if sunscreen raised your risk for skin cancer — which it doesn't, he emphasized — its well-established cancer-fighting benefits would outweigh any risk. 'If you're trying to make a choice, the choice is pretty clear.'
There are two types of sunscreens: physical blockers, which have zinc oxide or titanium dioxide and reflect ultraviolet rays from the sun; and chemical blockers, which contain chemicals that absorb the sun's ultraviolet rays.
Fernanda Duarte put sunscreen on Luisa Vilela, 10, of Watertown at the Artesani Playground in Brighton in 2021.
Christiana Botic for The Boston Globe
Rebbeck said that people who are concerned about the content of sunscreens should choose one that contains zinc oxide or titanium oxide, which are well established as safe and effective without any indication of carcinogenicity or other adverse health effects.
As Harvard Health Publishing explained in
'However, there has been no conclusive evidence that oxybenzone is harmful to humans,' it wrote. 'Organizations that have raised concerns about oxybenzone typically cite studies done in rats, where the rats were actually fed oxybenzone. It would take an individual 277 years of sunscreen use to achieve the equivalent systemic dose that produced effects in these rat studies…'
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But what's Harvard Health Publishing compared to the wisdom, or at least the reach, of social media star and
'Anytime I do an interview, I get a lot of s*** when I admit that I don't [wear sunscreen],' she said in a viral 2024 episode of her 'Let's Be Honest' podcast, before prompting her guest to talk 'about the health benefits of the sun and why we maybe don't need sunscreen.'
'We've literally spent our whole existence as humans under the sun all day, until the last, like, 100 years or so, and now we're like shut-ins … and that's really bad for a lot of reasons,' her guest replied.
At Castle Island on a recent weekday, the weather app was showing a UV rating of 5, high enough for the website of the National Weather Service to recommend use of a sunscreen of at least SPF-30.
But Catherine Civitella, who was hanging out with a friend from college, wasn't wearing any, as she considers it 'toxic.'
She formed that opinion from 'the internet,' she said, and also by observing people in Florida, where she used to live. There, she noticed that the better people ate, and the more time they spent in the sun, sans sunscreen, the better their skin looked.
'What you put in your body is more important than what you put on your body,' she said.
Over on the beach, Maria Turolska, a Dorchester grandmother watching her 18-month-old grandson, both fair-skinned, said she wouldn't use sunscreen on herself or the little boy, even though his parents wanted her to.
Asked if she thought sunscreen could cause cancer, she reflected the widespread skepticism about basically everything these days: 'The companies who sell the products want you to think this, but it's hard to know if it is good or not good.'
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Alas, as is too often the case, you may be doomed no matter what you do. Studies have found that people who use sunscreen tend to stay out in the sun longer, according to Harvard Health Publishing, 'and thus may actually increase their risk of skin cancer.'
Beth Teitell can be reached at