Tanning 101

Do you know what humans, seals, sea otters and walruses have in common? They’re the only mammals that purposely spend time in the sun. And those non-humans do it to warm up so they don’t have to consume as many fish in order to maintain their body temperatures in the cold ocean. Those marine mammals have specially adapted dark skin that absorbs heat rays but protects against ultraviolet rays.

Posted on | Arthur Perry, MD, FACS | Comments ()

Do you know what humans, seals, sea otters and walruses have in common? They’re the only mammals that purposely spend time in the sun. And those non-humans do it to warm up so they don’t have to consume as many fish in order to maintain their body temperatures in the cold ocean.  Those marine mammals have specially adapted dark skin that absorbs heat rays but protects against ultraviolet rays.

And other mammals? Just watch your dog and see what it does on a hot sunny day. Fido crawls under a nice cool shrub. But humans? Slather on that baby oil and park yourself square on the beach to get as deep a tan as possible. Sun tanning seems to be a national pastime, right up there with baseball.

But tanning doesn’t just make your skin look darker; it is the #1 cause of premature skin aging (unless you smoke – and that makes you look decades older by age 50.) It’s really not the tan that does the damage – it’s the sun exposure. And more specifically, it’s exposure to ultraviolet light.  The tan is your body’s response to the injury caused by the sun.

I’m certainly not saying that you can’t go out in the sun. In fact, we need the sun. Without it we would all be vitamin D deficient. Sun exposure is a natural mood elevator – think how depressing winters can be.) And there may be other things the sun does for us that we don’t even understand yet.

So, 20 minutes a day in the sun and you will feel and look better. But that’s it. Lather up with zinc oxide containing sunscreen after 20 minutes. It will block both types of UV light that are harmful and zinc oxide will not get absorbed into your body like the chemical (clear) sunscreens. Use a lot of that sunscreen – it takes a full ounce to cover your body. And reapply it after swimming.

Use one of those new UV detectors to help you decide whether you need sunscreen. Or check your local TV station; if the UV index is 2 or under, apply at least a 15 SPF sunscreen, and if it is over 5, use a 30 SPF if you are going to be in the sun more than 20 minutes.

And take a lesson from those other mammals – when you feel hot and lousy (which occurs after about 20 minutes in the sun), find some shade.

Blog written by Arthur Perry, MD, FACS
Dr. Perry has over 2 decades of experience as a clinical surgeon and has been named to the “Best Doctors in the NY Area” book...