Though summer is becoming fall, don’t put down your sunscreen just yet. The sun is the most important cause of both skin cancer and wrinkles, and those of us in South Florida need extra protection due to our close proximity to the equator.
Some sunscreens are better than others for various reasons, and we’d like to discuss the two main types, chemical and physical sunscreens. Both types have been used for decades, with varying results.
When they were first manufactured, most sunscreens had a sun-protection factor (SPF) of 15. That means that if you’d normally burn with ten minutes of sun exposure, an SPF 15 would allow you to safely stay in the sun for 15 times longer than that, or 150 minutes. As more studies were done on ultraviolet light’s effect on the skin, researchers recognized the need for greater protection and better sunscreens were developed with SPF of 30 and above.
Chemical sunscreens can be great broad spectrum options. There has been some concern in media reports regarding the safety of one popular ingredient, oxybenzone, due to potential hormone disruption. This fear came from a study where rats were fed very high doses of oxybenzone. Importantly the ingredient has been studied in humans applying it topically and oxybenzone has never been found to cause hormonal changes.
The other main type of sunscreen is mineral-based (also known as physical blockers), composed of zinc oxide, titanium dioxide or a combination of both. Utilizing these crushed minerals, the sunscreen remains on top of the skin, forming a barrier against the sun’s rays. In the past, people wearing physical blocker sunscreen were quite noticeable on the beach due to the thick white coating on their skin. Newer generation physical blockers significantly improved this whitening problem by using minerals crushed into even smaller particles. Though there were some concerns about these smaller mineral nanoparticles getting absorbed into the skin, numerous human studies of zinc oxide for instance, have shown that this is not the case. Mineral sunscreens also are better tolerated by those with allergies, including people with sensitive skin.
If nanoparticles still concern you, you can look for zinc oxide or titanium dioxide sunscreens whose particles are “micronized,” that is, the minerals are crushed into larger sizes than those containing nanoparticles, but which are still transparent (or nearly so) on skin.
Both mineral-based and chemical-based sunscreens are great options, and we encourage you to choose the one that fits best with your lifestyle. Remember to look for a sunscreen that is labeled ‘broad spectrum,’ as it blocks both UVA and UVB rays. For sweating or water-based activities, look for a sunscreen that is labeled water resistant (effective for up to 40 minutes) or very water resisant (up to 80 minutes). For babies over 6 months, it is best to use sunscreens with physical blockers.
Although there is not one best sunscreen, some of our favorites include Elta MD UV Clear for daily face use and MDSolarSciences SPF50 mineral crème for face on the beach. We also like the Vertra sunscreen stick with tint for a dual purpose sunscreen/cover-up, great for touch-ups during the day. Most of these products are available at our on-site apothecary at Skin Associates of South Florida.
