Everyone knows you’ll significantly lower the odds of contracting lung cancer if you don’t smoke.
Well, to prevent skin cancer, slather on the sunscreen when you spend time outdoors. But which one should you use? As it turns out, not all sunscreens are created equal, and some may actually be detrimental to your overall health.
Several ingredients commonly used in commercial sunscreens have fallen under scrutiny, as they could cause allergic reactions, hormonal disruptions, aging and other undesirable side effects for both humans and the environment.
Here is a list of some of the ingredients in question, courtesy of the Environmental Working Group, a consumer advocacy organization:
Oxybenzone: Used to help sunscreens penetrate the skin, oxybenzone has been known to affect animal sperm production and is linked to endometriosis in women. It also contributes to coral bleaching, a syndrome that damages and kills coral reefs. More and more coastal communities around the globe are banning its use.
Retinal palmitate: This antioxidant, a form of vitamin A, is used to counteract the aging effects of sun exposure. In animal studies, retinal palmitate is linked to the accelerated growth of cancerous tumors and lesions when applied to the skin in direct sunlight.
Octinoxate: In animal studies, octinoxate is tied to hormonal, thyroid and behavioral changes. It can also produce free radicals that damage cells and cause skin to age prematurely.
Octocrylene: Used to boost the performance of other UV absorbers, octocrylene can produce dangerous free radicals when exposed to sun. It is also a common skin allergen.
Homosalate: This ingredient absorbs UV rays but can accumulate in the body, leading to possible hormonal disruption.
These ingredients are widely found in a category of sunscreens called organic or chemical blockers. These carbon-based products work by absorbing UV rays before they can damage the skin.
“All of these chemicals can enter your bloodstream to different degrees — it’s important that consumers know this,” says Dr. Denis Dudley, a retired Ottawa-based obstetrician and reproductive endocrinologist who now manufactures his own line of sunscreens that are free of these ingredients.
Dudley believes organic/chemical sunscreens are geared toward warding off cancer-causing UVB rays; however, UVA rays are known to cause premature aging, and evidence is mounting that they also cause cancer.
Bounce the Rays Away
The other major sunscreen category is inorganic or physical blockers, which reflect and scatter UV light away from the skin. Made with minerals such as titanium dioxide and zinc oxide, these products are effective at protecting against UV rays without the risks of chemical sunscreens. However, they are less popular because they give skin a white hue.
“As dermatologists, we like these physical blockers,” says Dr. Laura Ferris, associate professor of dermatology at the University of Pittsburgh. “They do a better job, they are less likely to break down, and we also think you get better broad-spectrum protection with them. That is what I use personally.”
While Dudley agrees that mineral-based inorganic sunscreens are a much safer alternative, he raises a word of caution. Titanium dioxide and zinc oxide often need to be pulverized to tiny particles in order to boost effectiveness, and these nanoparticles can be absorbed through the skin. Dudley would like to see U.S. sunscreen manufacturers label products that contain nanoparticles.
Dr. David J. Leffell, a Yale School of Medicine dermatology professor, sees sunscreen as just one aspect of an overall skin protection regimen, which includes sun-protective clothing and shade during the peak UV hours of 10 a.m. to 4 p.m.
“What’s that saying?” he asks. “Only mad dogs and Englishmen go out in the noon-day sun.”