But instead of applying “too much” sunscreen, Sass follows the recommendations of the Food and Drug Administration. guidelines to test for sun protection factor (SPF), which means many of your sunscreen review followers are probably applying too little.
Skin cancer It is the most common form of cancer in the United States (nearly 100,000 people in the United States are expected to be diagnosed with melanoma this year), and sunscreen has been shown to help prevent the early signs of aging and the damage that it can lead to skin cancer, but that’s only if you apply it correctly and reapply it often.
“When a sunscreen brand does a photo shoot and uses a drop amount [of sunscreen] on a model’s cheek, people think that’s the amount they should use and end up getting sunburned,” said Sass, a doctoral candidate in biomathematics and statistics at North Carolina State University who maintains a database of Free data on over 200 sunscreens.
Evidence shows that people tend to use less than half the recommended amount of sunscreen (the same study showed that it’s common for people to get sunburn from “missing a spot” and waiting to apply sunscreen until they’re outside).
An application of sunscreen doesn’t give you “carte blanche to sit in the sun for eight hours,” said Jennifer Lin, a dermatologist and co-director of the Melanoma Risk and Prevention Clinic at Brigham and Women’s Hospital in Boston and an assistant professor. at Harvard Medical School.
How often should you reapply?
The American Academy of Dermatology recommends reapply sunscreen of at least 30 SPF every two hours outdoors, though Lin said it could be more frequent if you spend a lot of time outdoors.
“Think of your sunscreen as a constantly diminishing force field, particularly chemical [nonmineral] sunscreens,” Lin said. When it absorbs ultraviolet (UV) radiation, the chemical is extinguished; is no longer present. You walk outside with 100 percent coverage, and over the course of two hours, your coverage can drop to almost 0 percent, Lin added.
There are three types of skin cancer: basal cell and squamous cell carcinoma are the two most common; melanoma is not so common but it is much more dangerous. Research shows that intermittent high doses of UV radiation can cause melanoma, while cumulative daily exposure is associated with carcinoma.
“The science is very strong that prolonged sun exposure causes skin damage,” said Henry Lim, a Detroit-based dermatologist and specialist in dermatologic immunology. This ranges from precancerous wrinkles and roughness to the development of skin cancer. “We also know that with proper photoprotection, we can decrease the likelihood of sun damage.”
Sunscreen should be combined with seeking shade and wearing sun-protective clothing, sunglasses and a hat, said Ranella Hirsch, a dermatologist in Cambridge, Massachusetts. “Sunscreen was not meant to be the only warrior in this battle.”
Hirsch’s warrior of choice for kids is a sunscreen stick. “He makes things neat and easy.” Hirsch trained his children in the use of a stick when they were preschool children. She recommends swiping three or four strokes on each exposed body part with a 25 percent overlap.
One reason skin cancer is so common in the United States, Hirsch said, is because our fundamental approach to sun protection differs from that of other countries. “Americans think of sunscreen more like ‘I’m going to the beach, so I’ll throw my sunscreen in the bag,’ rather than applying it every day like in Asia and Australia.”
And, despite the overwhelming evidence for sun caution, Gen Z still wants to get a tan. On TikTok, #tan it had garnered 2.7 billion views as of last week and included videos of young people showing off their tan lines, advertising sun-amplifying products and posing inside tanning beds. (Strong evidence There is evidence that indoor tanning increases the risk of melanoma and non-melanoma skin cancers).
“Any type of tan is an indication that the skin is suffering from damage,” Lim said.
He also advises against substituting coconut oil for sun protection. “No data shows that coconut oil can protect the skin,” Lim said. “Because coconut oil is moisturizing, it could improve the penetration of UV rays into the skin.”
Jennifer Bowers, a cancer prevention fellow and psychologist in the Basic Psychological and Biobehavioral Sciences Branch at the National Cancer Institute, focuses her research on tanning behaviors in college students, who are considered a high-risk population because they spend more time under the sun than older people. .
One of Bowers’ main areas of research is unintentional tanning in youth. “We found that indoor tanning has decreased in recent years, but melanoma rates they keep increasing,” she said, prompting her to dig deeper into unintentional tanning. “I heard from participants in my studies that they could get a tan walking around campus or running errands and things like that.”
Bowers recommended setting reminders to reapply sunscreen. “It’s about creating a habit to protect yourself.”
Experts agree that the best sunscreen is the one you will use consistently.
“Ultraviolet radiation is getting stronger because the ozone layer it’s getting thinner,” Lin said. “So, if anything, sun protection is going to be increasingly relevant to us as a species.”
Janna Mandell is a freelance reporter based in the San Francisco Bay Area.