Do yourself and your skin a favor and wear sunscreen.
There are two types of sunscreens, chemical blockers and physical blockers. Chemical blockers absorb UV radiation and then become inactive. Physical blockers (zinc oxide and titanium dioxide) reflect and scatter the UV radiation before it gets to your skin. There are pros and cons to each type.
Chemical sunscreens usually go on easier and feel nicer on your skin, while physical blockers tend to be a little thicker and most go on more white. Chemical blockers can cause an allergic reaction and physical blockers do not. Physical blockers last as long as they are on your skin, while chemical blockers have a shorter period of effectiveness.
Both types of sunscreens block UV radiation (UVR). There are two types of UVR, UVB and UVA. Protecting yourself from both types is important. Physical blockers protect against both UVA and UVB. Chemical blockers all block UVB and have varying levels of UVA protection. Why do dermatologists care so much about protecting your skin from UV radiation? There are three main reasons: DNA damage, photoaging and cutaneous immunosuppression.
UVR is a known carcinogen for skin cells and causes abnormal linkages and structural changes in your DNA. Indeed, sunburns are not caused by heat from the sun’s rays but by your body’s response to damage in your skin’s DNA. UVR also degrades the skin’s collagen and elastic tissue, leading to premature aging and wrinkling of the skin. UVR also causes pigmentation alterations known as solar lentigines and poikiloderma.
UVR also causes the immune cells living in your skin to become reduced. These cells have the job of looking for damaged DNA and fixing it and killing precancerous and cancerous cells as they form. When this system is suppressed, you are more likely to develop skin cancers. This is the main reason that starting a sunscreen routine is always the right answer. Even if you are 90 and have never used sunscreen, it is still the right answer.
Now, let’s answer the sunscreen questions mentioned above. The sunscreen you should buy is the one you will use regularly. If you polled all of the dermatologists in our group, you would get many different answers as to our individually recommended sunscreen brands. All of the sunscreens have similar ingredients. The differences lie in the other ingredients, known as the vehicle. Find a sunscreen you like that has both chemical and physical blockers and use it.
As far as SPF is concerned, you should use sunscreen with at least 30 SPF. SPF values cannot be compared one to one. A 30 SPF sunscreen blocks approximately 97 percent UVR. A 50 SPF sunscreen blocks 98 percent of UVR. A 100 SPF sunscreen blocks 99 percent of UVR. A 1000 SPF, if it existed, would block 99.9 percent of UVR. As a comparison, a white t-shirt, SPF 7, blocks roughly 85 percent of UVR. If this t-shirt gets wet, the SPF drops to 3 and it now blocks 67 percent of UVR.
The safety of sunscreens has come to the forefront of late and usually focuses on two questions, the safety of chemical sunscreens after they have been broken down by UV radiation and the safety of micronized zinc and titanium. I don’t want to minimize anyone’s health concern but there are no scientific studies to date definitively linking sunscreen to increased cancer rates or systemic toxicity. On the other hand, there are numerous studies linking sunscreen use to decreased rates of melanoma, basal cell carcinoma and squamous cell carcinoma.
Do yourself and your skin a favor and wear sunscreen. Apply it every two hours and immediately after sweating or swimming and you should be able to safely enjoy an active outdoor lifestyle. FBN
By Jordan Miller, M.D., FAAD
Jordan Miller, M.D., FAAD, was raised in Joseph City, a small Northern Arizona town east of Flagstaff. He received his medical degree from The Medical College of Wisconsin, in Milwaukee. He completed his transitional years at St. Luke’s Regional Medical Center, also in Milwaukee. He completed his dermatology residency at the Medical College of Wisconsin, participating in the care of dermatology patients at Froedert Memorial Lutheran Hospital; Children’s Hospital of Wisconsin and the VA Hospital. His residency included dedicated pediatric dermatology. After his residency, in 2009, he joined Northern Arizona Dermatology Center, practicing medical and surgical dermatology and seeing patients in Flagstaff and Sedona. Dr. Miller also works as the senior medical director of dermatology for a successful medical software company, Modernizing Medicine, located in Southern Florida. Dr. Miller and his wife, Elizabeth, have three children.
For more information, contact
Northern Arizona Dermatology Center, PC
1490 N Turquoise Dr, Flagstaff, AZ 86001
928-774-5074