By Arthur W. Perry, MD, FACS Dr. Perry is a board certified plastic surgeon, an Adjunct Associate Professor at Columbia University, and a member of the Medical Advisory Board for The Dr. Oz Show.
Sunscreens have been around for nearly 100 years. The goal was to block ultraviolet (UV) light, the harmful rays of the sun. Sunscreens started out with pasty zinc oxide that no one would use. So scientists created sunscreens with clear chemicals that absorbed UV light. In 1944, Coppertone® became the first mass marketed sunscreen. Fast forward to now, when about a billion dollars worth of sunscreen are sold each year in the United States.
UV light causes skin cancer and prematurely ages the skin, and so it’s very important to protect our skin with sunscreen. We don’t want to block sunshine completely – about 20 minutes each day is good for us – it boosts our vitamin D and improves our mood. Beyond 20 minutes, however, and our immune system suffers. We either need to spend the rest of the day inside or protect our skin with sunscreen.
There are 17 individual sunscreen ingredients that are FDA approved: 15 of these are clear chemicals that absorb UV light and two are made of minerals that reflect UV light. Of these 15, nine are known endocrine disruptors. To be effective, chemical sunscreens need to be rubbed into their skin 20 minutes before sun exposure. They do a pretty good job at blocking UV light, but they actually get used up as the sun shines on them. In fact, some sunscreens lose as much as 90% of their effectiveness in just an hour, so they need to be reapplied often. This is not the case with zinc oxide and titanium dioxide, the two mineral, or physical, sunscreens. These two work very differently – they sit on the surface of the skin and physically block UV light.
Chemical sunscreens don’t sit on the surface of the skin – they soak into it and quickly find their way into the bloodstream. They scatter all over the body without being detoxified by the liver and can be detected in blood, urine, and breast milk for up to two days after a single application. That would be just fine if they were uniformly safe – but they’re not.
As I mentioned, nine of the 15 chemical sunscreens are considered endocrine disruptors. Those are chemicals that interfere with the normal function of hormones. The hormones most commonly disturbed are estrogen, progesterone, testosterone, and thyroid. Endocrine disruptors, like some ingredients in chemical sunscreens, can cause abnormal development of fetuses and growing children. They cause early puberty and premature breast development in girls, and small and undescended testicles in boys. They cause low sperm counts and infertility. Endocrine disruptors that act like estrogen can contribute to the development of breast and ovarian cancers in women, and other endocrine disruptors may increase the chance of prostate cancer in men.
Sounds pretty unsettling, doesn’t it? But there’s more. As I said earlier, chemical sunscreens function by absorbing UV light. In the process, some may get used up and mutate. Some generate DNA-damaging chemicals called “free radicals.” These may lead to cancers.
I’m pretty negative about chemical sunscreens, and while I do have to tell you that I believe they are not proven to cause cancer, as I said on The Dr. Oz Show, “Where there’s smoke, there’s fire.”
Poisoning that takes place over decades is difficult to study. Chemicals like arsenic and botulism make us sick very quickly, and so it was easy to figure out that they are toxins. Lead is a toxin that takes longer to cause illness, so it was many years before the government listened to scientists and restricted its use. And chemical sunscreens are even harder to study since their effects are subtle and take a long time to appear.
As you read this, you might be saying, “Why is this guy – a plastic surgeon – saying something I’ve never heard about before?” This information isn’t new for me. My patients know I’ve been talking about sunscreen and other cosmetic toxicity for about 15 years. But I’m just an interpreter of science. And experts agree with me.
R. Thomas Zoeller, MS, PhD, is a Professor of Biology at the University of Massachusetts. He’s an author of the Endocrine Society’s scientific statement about endocrine disrupting chemicals and their official representative. He said, “Dr. Perry makes an important point that sunscreens are applied to skin in a formulation that serves as a drug delivery system and that some sunscreens are known to interfere with hormone action. The way in which these chemicals can interact with hormone systems could plausibly increase the risk of various cancers as well as other endocrine disorders.”
If there were no good alternatives, we’d be in a pickle – we’d have to make some hard decisions whether or not to use sunscreen. But, fortunately, we have great alternatives.
Zinc oxide and titanium dioxide are rocks that are ground down to a fine consistency. They do a great job at blocking both UVA and UVB light. Zinc is less whitening on the skin and blocks nearly all dangerous UV light. Inexpensive versions of these sunscreens are gooey and while you might put them on your kid’s skin, most people don’t like them. But newer zinc oxide sunscreens contain particles so small that they are transparent. These sunscreens are called micronized and do a great job at protecting against UV radiation. Even newer sunscreens use rocks that are ground into smaller bits called nanoparticles. Nanoparticles have their own issues, and some people don’t consider them to be uniformly safe.
Some people may call me “self-serving” because I have my own skin care company and I produce a SPF 20 sunscreen with micronized zinc oxide. But I created this product because of my attitude toward sunscreens. I really do feel that people are poisoning themselves by putting ounce-quantities of chemical sunscreens on their bodies, and I cringe when I see women, particularly pregnant or breastfeeding women, and small children slathering that stuff on their skin.
Bottom line? Use a micronized zinc oxide containing SPF 15 broad-spectrum sunscreen every day of the year and an SPF 30 when you’re on the beach or working in the garden. How much should you use? An ounce spread over your whole body should do it. And reapply it every 2 hours or so. For more information, I’ve posted scientific references on the toxicity of sunscreens and cosmetics on PerryPlasticSurgery.com.