The case for physical sunscreen

Dr. Cohen

The following is a response to an article published in our July issue entitled, "Studies don't change suncreen guidance."

Unfortunately the message that many people heard from the May JAMA article about CHEMICAL sunscreen leading to higher bloodstream absorption of specific chemical ingredients than originally thought - seems to have led to many misperceptions. And the public simply does not realize that this does not apply to all sunscreens, specifically it does not apply to PHYSICAL BLOCK MINERAL sunscreens - that are regarded as safe and effective.

PHYSICAL BLOCK sunscreens, like zinc oxide and titanium dioxide, are specifically regarded by the FDA as generally safe and effective. The ingredients in the serum-level study, however, are all chemical sunscreens, and some of these are now under greater scrutiny, such as oxybenzone - according to the recent FDA guidance.

View recent FDA proposed sunscreen regulations here.

I have always preferred physical sunscreens for me, my family, and my patients. And my pediatrician wife feels the same way. There is a great deal of literature on the safety and efficacy of zinc oxide and titanium dioxide, as well as the fact that they cover a more broad spectrum of UVA sun exposure than the chemical ingredients. And physical sunscreens have definitely become much more cosmetically elegant and rub in very well - no longer looking like lifeguard toothpaste.

Physical block sunscreens also have the advantage of working right away, as soon as they are applied to the skin (vs chemical sunscreens that need about 20 minutes before they are more effective, as they actually work more like a sponge to absorb ultraviolet rays).

Having said that, applying chemical sunscreen in this study amount of 2 mg/cm² to 75% of body surface area and repeated application is really not consistent with typical sunscreen use among my patients, family, friends - even among my extremely diligent skin cancer patients. If we’re fortunate enough to get patients to embrace sun protection, then they often apply sunscreen, at best, to their face, neck, and hands (as the more exposed skin) routinely for most activities - and we recommend that they cover other areas such as the trunk (chest and back) with sun-protective long sleeve shirts, beach rash-guards or long sleeve biking and fishing shirts etc., specifically with UPF rating (ultraviolet protection factor). In addition, the chemical sunscreen article conclusion that serum levels of absorption were higher than originally thought does NOT equate to these serum levels being known to be harmful. These products have been used for many years, and that next step of saying these chemical sunscreen serum levels are indeed harmful has yet to be proven or even evaluated.

PHYSICAL BLOCK SUNSCREENS are what I recommended to my patients, family and friends. And it is what I personally use every day.

All of us dermatology and pediatrician parents (and every parent really) have rubbed zinc oxide onto our kids with diaper rash, including when almost no barrier of the skin is even apparent, and never worried about absorption nor have we seen any related sequelae. Further, the history of using zinc oxide on skin apparently dates back to ancient India in around 500 BC, with use for burns, wounds and significant skin irritations.

Remember to reapply physical sun-BLOCK every two hours - and more frequently if sweating, swimming, or toweling off. And don’t forgot to always wear a wide-brim hat as well as UPF long sleeve shirts. ƒ

Share this easy-to-digest summary of the FDA's proposed regulations with curious patients.

About this author:Joel Cohen, M.D., is an internationally-recognized expert on aesthetics and skin cancer. He is the Director of AboutSkin Dermatology (Greenwood Village and Lone Tree, Colorado) and also serves on the dermatology teaching faculty of the University of California at Irvine as an Associate Clinical Professor. He is Board-Certified by the American Board of Dermatology, and Fellowship-trained in aesthetic dermatology and dermatologic surgery. Dr. Cohen has published over 237 scientific articles and book chapters, and has co-authored 3 academic textbooks. He is the Co-Director of the ASDS Cosmetic Dermatology Fellowship in Colorado. He has also been a recipient of the ASDS Public Service Award, the ASCDAS Distinguished Service Award, and the ASDS Excellence in Education Award. In 2018, he received the Melanoma Research Foundation Humanitarian of the year Award. Dr. Cohen has lectured all over the world, appeared on many TV shows including Emmy Award-Winning The Doctors, and has also been interviewed in many magazines and newspapers including: Glamour, Vogue, New York Times, Allure, Shape, Marie Claire, TIME, Allure, InStyle, MORE, USA Today, US News and World Report, and Consumer Reports.