In a world where everything from baby formula to cleaning products gets a wellness autopsy, sunscreen inevitably gets dragged onto the table. Then, when unqualified influencers promote conflicting messages — and your own research turns up sunscreen ingredient names that look like someone head-butted their keyboard — confusion and mistrust are understandable.
So, I’ll clear things up for you. Does sunscreen cause cancer? No.
Across decades of intense scientific research, there’s no credible evidence of approved sunscreens causing cancer in humans. Organizations like the WHO, FDA and the American Academy of Dermatology recommend daily, broad-spectrum sunscreen use. The question then becomes: Where does the concern come from?
The most common health concerns people have about sunscreen surround its absorption into the blood. While small trials have linked chemical sunscreen ingredients to hormone problems and organ overgrowth in mice, these results cannot be applied to humans, as the mice were exposed to concentrations 277 times higher than those from normal sunscreen use.
Additionally, a recent study of the most common UV-blocking sunscreen ingredients found no evidence of DNA damage or increased cancer risk in humans. In fact, ingredient levels in the blood remained far below harmful thresholds.
Mineral sunscreen ingredients, like titanium dioxide and zinc oxide, are also considered by the FDA to be generally safe and effective. The hypothesized risks of sunscreens are far outweighed by the proven benefits of wearing them.
The concern over sunscreen takes away from the purpose it fulfills: protecting us from the sun. UV radiation emitted from the sun is directly linked to the development of skin cancer. It is estimated that 90% of melanoma cases in the U.S., the deadliest form of skin cancer, are due to UV radiation.
Scientific studies show that sunscreen reduces the incidence of skin cancer. A large randomized control trial in Australia showed that daily sunscreen use reduced melanoma incidence by 50%, and a Norwegian study found that using SPF 15+ sunscreen lowered melanoma risk by 30%.
When we do the risk assessment, UV exposure is the actual danger, and sunscreen is part of our defense.
Breaking down the science
Most of our sunscreens come in one of two types: chemical or mineral. Chemical sunscreens are small compounds absorbed into the skin, while mineral sunscreens are larger compounds that act as a physical barrier on top of the skin. Both work by absorbing UV rays from the sun and converting them into non-harmful heat.
Let’s get down to how sunscreen works.
Think about your skin as lots of cells each acting as a mini factory. Their job? Making umbrellas (melanin) to shield themselves from the sun’s UV rays. When exposed to these UV rays, those factories go into overdrive, rapidly producing these protective umbrellas.
Unfortunately, these cells are not perfect, and with rushed production comes mistakes: That’s cancer. Sunscreen is a roof over the factory, keeping the harshest rays out so normal production resumes without increased errors.
How to protect yourself
Which kind of sunscreen is best? No studies have proven a clear winner, but dermatologists recommend any broad-spectrum SPF 30+ sunscreen that you enjoy and will stick to using daily. Mineral sunscreens may be preferred for sensitive skin or for those concerned about ingredient absorption, but if untinted, some can leave a cast on darker skin tones. Chemical sunscreens, meanwhile, tend to be lightweight and easier to apply.
Whichever you choose, apply correctly with a quarter-sized amount per limb and an index and middle finger’s length on your face. Reapplying sunscreen every 90 minutes if you are wet or sweating and every two hours if dry is essential for protection.
Beyond sunscreen, the FDA recommends wearing ultraviolet protection factor 50+ clothing, protective accessories like a wide-brimmed hat or sunglasses, and seeking shade during peak sunlight hours of 10 a.m. to 2 p.m. to avoid harmful UV exposure.
Perform monthly skin self-exams and see a dermatologist yearly, especially if you have a family history of melanoma or personal history of skin cancer.
The evidence is clear: Sunscreen saves lives. It doesn’t endanger them. Choose a broad-spectrum SPF 30+ that you enjoy, and use it wisely. Protecting your skin today is an investment in your health tomorrow.
Grant DuVall is a UF College of Medicine Student.
