Wednesday, March 8, 2017
Wisdom Wednesday: Sunscreens
I have just finished three months of intense lab review. From December through February, we reduce out lab fees to encourage our patients to perform yearly blood and urine analysis. This year the response was great and I’ve been looking a test results night and day.
For the past few years testing vitamin D levels has been standard practice in my office. Initially I was shocked at the number of patients we found that were deficient in vitamin D. After all, I practice in South Florida where the sun shines about 362 days a year.
In Michigan the deficiency is from the lack of sun, in Florida, we hide from the sun. We wear protective clothing, avoid the noon day sun and wear lots of sunscreen.
I don’t always wear sunscreen. If I have a tennis match at 8 AM or run the beach early in the morning, I want that sunlight striking my skin converting cholesterol to vitamin D3.
However, if I am going out on the boat or any outdoor activity during the late morning or afternoon, I want protection from the UVA and UVB rays.
My preference is clothing. I wear a hat with a wide brim and a long sleeved shirt with a rated SPF (sun protection factor). That lets me avoid all those chemicals on my skin.
For my face and hands or any other exposed skin I have to use sunscreen.
There are two basic types of sunscreen – physical and chemical. Physical sunscreens generally contain titanium dioxide or zinc oxide. They sit on top of your skin to deflect UV rays from penetrating and doing damage. They are often thicker, greasy, and less comfortable. They need total coverage in order for form a shield from the sun. But they last a long time and continue to protect as long as they sit on top of your skin.
Chemical sunscreens contain organic compounds (oxybenzone, octinoxate, octisalate, and avobenzone) that are able to convert UV rays into heat. The heat is then released from your skin and you are protected. They are usually thinner and more comfortable. Less is required since a physical barrier is not needed. But they typically need 20 minutes on your skin before they work. They can cause some skin irritation. And because they are consumed through the UV conversion, you have to apply more if you’re in the sun.
It’s also important to recognize that over-exposure to chemicals absorbed by your skin might also create a risk. So it’s imperative that you look into the sunscreen you’re selecting and make sure that the chemical makeup isn’t putting you in contact with substances that are more dangerous than the sun.
Most people use the chemical sunscreens, overlooking the potential health risk from the chemicals. I actually had a chemical sunscreen on my face that dissolved the nose piece to my sunglasses. I don’t want to think about what that might do to my body.
I now use the physical sunscreens exclusively. But if you are interested, check out the Environmental Working Group at www.ewg.org/sunscreen/. They test nearly all sunscreens on the market and produce a yearly report about their findings.
The Bottom Line:
Skin cancer can be serious and you need to be proactive. However, vitamin D is vital to the immune system and even has a role in skin cancer prevention. Protect yourself from the sun, but be smart about it. And ask your PCP to measure your vitamin D levels.