How Sunscreen Works to Protect Your Skin
- Posted on: Aug 30 2017
At Romeo & Juliette, of course, we’re all about using the most technologically sophisticated lasers to get rid of unwanted hair permanently. But we also want to give our patients tips on how to keep their skin looking great. Sunscreen is obviously one of the key elements in fighting sun damage, one of the main factors in premature skin aging.
Sunscreens are ubiquitous these days, helping us ward off the damaging effects of the sun’s rays. If we’re headed to the Bahamas or the Jersey Shore, or a round of golf at Bethpage, putting on sunscreen is just as important as remembering your towel or lob wedge.
Younger people have never known a time without sunscreen, but if you’re in your upper 50s or 60s now, you probably remember when the first sunscreens were introduced. The first true sunscreen was called Glacier Cream and later became Piz Buin (which still makes sunscreen lotions today), and it was developed in 1946 by a Swiss chemist. But when Coppertone (the name says it all) came on the market in the 50s, sunscreen lotion began to grow. Of course, it’s estimated now that the early Glacier Cream and Coppertone products had an SPF of 2! Not much protection there.
Today’s sunscreens form a far more effective barrier against the sun. Now they’re waterproof (for awhile) with effective SPF of 50 (it’s thought that any SPF over that number doesn’t provide any more protection).
Inorganic versus organic
Sunscreens come in sprays, lotions, gels, or waxes, and are made of a mix of chemicals. There are inorganic and organic sunscreens, but they’re not categorized in the same way as organic food at a boutique grocery store. Inorganic chemicals in sunscreen can reflect or scatter the light away from the skin. Organic (carbon-based) chemicals can absorb UV rays so that your skin doesn’t.
Some of the early inorganic chemicals included minerals such as zinc oxide and titanium dioxide, and they acted as physical sunblocks. To be effective, they had to be covering the skin. That’s why the lifeguard at the county pool always had the white nose in the 80s and 90s. The minerals reflected the sun’s UV rays back off the skin just as white paint reflects light. Today’s inorganic particles are much smaller, so users don’t have to look as if they’re covered with white frosting.
Organic chemicals used in sunscreens have names such as avobenzone and oxybenzone. These chemicals don’t reflect or deflect the UV rays; they absorb them. They do this with chemical bonds. As the bonds absorb UV radiation, the components of the sunscreen slowly break down and release heat. This is why these sunscreens have an effective time limit at which point the user would need to reapply.
Two UV types
It took a long time for the scientific community to turn its eye to the mystery of the sun and what it does to our skin. Remember the “healthy glow” references and all? Sounds somewhat like cigarette ads in the 60s with “doctor recommended” and the like.
Now we know that there are two types of ultraviolet rays, UVA, and UVB. UVB rays cause sunburns. Originally, because the reddened skin from sunburns was so obvious, UVB rays were all anyone worried about. UVB rays affect the epidermis, the skin’s outer layer.
More recently, various research studies have brought the effects of UVA rays into a focus. UVA rays penetrate the epidermis into the dermis, the skin’s second layer. It’s thought that UVA rays damage the skin longer term with premature wrinkling, age spots, and other issues. UVA rays don’t cause sunburn, though, so they’re not as obvious. But a growing amount of research points to possible links between UVA rays and the development of melanoma, the most dangerous form of skin cancer.
What is SPF?
SPF is how you can judge the protection level of a sunscreen. It stands for Sun Protection Factor, and it refers to how well the sunscreen protects the user against UVB rays. Obviously, SPF came before UVA rays were understood. Now, any sunscreen worth a thing is labeled “broad spectrum,” and it protects against both UVB and UVA rays.
It’s recommended to use a broad-spectrum sunscreen with SPF between 15 and 50. To protect your skin, anything less than SPF 15 should be avoided altogether. A sunscreen with SPF 15 protects against about 93 percent of the sun’s UVB rays; SPF 30 blocks 97 percent. No sunscreen provides a 100 percent block, despite claims of SPF 100 and such. They are just taking your money!
Now you’re a sunscreen pro. When you’re on the beach or the links, don’t forget to wear your sunscreen of choice. And to look great in that swimsuit, don’t forget Romeo & Juliette to laser away all of your unwanted hair. Call us at 212-750-2000 for an appointment.
Posted in: Skin Care