More Sunscreen, More Sunburns continued...
The study was designed to look at patterns, not to prove cause and effect.
It’s possible that people with the fairest, most easily burned skin are also simply the group most likely to use sunscreen.
But if that were the case, Linos says, she would have expected to see the same phenomenon across all the different groups. That is, frequent shade seekers and long-sleeve wearers would also report having more burns compared to those who rarely reported those tactics.
The more likely explanation, she thinks, is user error -- people simply aren’t applying as much sunscreen as often as they should.
Numerous studies have shown that most people, even after they’re carefully schooled in proper sunscreen application, still don’t get enough on.
One of the latest, from researchers in Brazil, asked study participants to cover both forearms with sunscreen, and 30 minutes later, to reapply the sunscreen to just one arm.
Researchers used tape strips to measure how thickly the lotion went on.
Sunscreen is tested to work at its SPF when it’s applied to a depth of at least 2 milligrams per square centimeter on the skin.
After the first application, study participants got only a quarter of that amount on. For the arm that got the second application, the depth of the sunscreen eventually reached half of what it should have been, suggesting that even people who remember to reapply aren’t being fully protected.
Shade, Hat, Sleeves
Another problem is that many people rely on sunscreen as their sole form of protection, when really, shade and protective clothing need to be part of a multi-pronged approach to avoiding sunburns, which increase the risk of skin cancer.
“There’s still a lot of work that we as physicians, especially dermatologists, need to do to educate individuals about proper photoprotection,” says Henry W. Lim, MD, chair of the department of dermatology at Henry Ford Health System in Detroit.
He says this study is consistent with previous research.
“It’s known that people use sunscreen, but they don’t use it at the appropriate amount and because of that, they have a false sense of a security,” says Lim, who was not involved in the research.
That false sense of security can lead people to stay in the sun longer than they safely should, leading to an increased risk of sunburns and greater UV exposure, which can cause skin cancer.
Sunscreen Prevents Cancer
Sunscreen use has been shown to reduce some kinds of skin cancers, however, and earlier this year, a prospective study, the first of its kind, found that regular sunscreen use in a group of 1,621 Australian adults cut their risk of melanoma by 50%.