The message has been clear for years: Ultraviolet radiation is a carcinogen, plain and simple. Its role as the No. 1 factor for skin cancer has been validated across the board, even by the World Health Organization. Yet, stunningly, studies have emerged throughout the years continuously suggesting that sun exposure, even the formation of skin cancer, can be beneficial. For example, one study found that those who get a nonmelanoma skin cancer, called a basal cell carcinoma, had a lower risk for developing Alzheimer's disease.
Adding fuel to the fire is a new study from Sweden released last week, which reported a lower death rate in individuals who reported increased sun exposure. Even more concerning, they suggested that sun avoidance was as dangerous as smoking. Let me repeat this in their words: "Nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking." Seriously?
Let's take a step back and consider what we are seeing in the data. Could it be that those with increased sun exposure over time are also more active, healthier, socially engaging then those who withdraw from going outside? Does it say anywhere anything about sun exposure and sun protection?
The authors also noted that one answer to longer life expectancy could be that more sun exposure results in more vitamin D production. While vitamin D has been the subject of great interest in many areas of medicine, currently the Institute of Medicine reports that there is not enough evidence to support the use of vitamin D for anything but bone health. That said, as a dermatologist I do believe that vitamin D is very important for many of our body's functions, but I know we don't need sun to get it.
What most people don't know is that we do not need to rely on vitamin D generated from UV exposure for our bone or whole body health. We certainly do know that unprotected UV exposure to the sun or indoor tanning devices is known risk factors for the development of skin cancer. As for vitamin D, adequate amounts of it can and should be obtained from a healthy diet that includes foods naturally rich in vitamin D, foods/beverages fortified with vitamin D, and/or vitamin D supplements. Vitamin D should not be obtained from unprotected exposure to ultraviolet (UV) radiation.
Let's address another myth. Many believe dermatologists want their patients to stay indoors and avoid sunlight even through windows. False. Who doesn't love a beautiful sunny day at the park, the beach, or ski slope? The misinterpretation here is that we do not advocate sun avoidance, but sun safety. Be my guest to enjoy the outdoors, but do so using a sun protective regimen including a broad spectrum sunscreen with a SPF 30 or higher; protective clothing including hats, sunglasses, and clothing; and seeking shade outdoors when possible. You can have your cake and eat it too.
All in all, studies like this need to be taken with some skepticism. I am not saying that this is "bad science," but that we need to be smart consumers of science and be sure to talk to your physicians and ask them questions. For certain and without a doubt, in this case, the last thing we all need is for people to believe that baking in the sun will prolong their lives.
Adam Friedman, MD, FAAD
Associate Professor of Dermatology
Residency Program Director
George Washington School of Medicine and Health Sciences
New York Academy of Medicine Fellow Ambassador