For years, dermatologists have cautioned the public of the perils of ultraviolet radiation on carcinogenesis and accelerated photoaging. Study after study has shown that UVB and UVA can make our patients look older and present with all nature of cancers that fill our schedules. And despite the Vitamin D controversy, we feel that the newer broad-spectrum sunscreens have helped our patients. So, we have set up our Maginot Line at the UV-visible spectrum border, confident that the "enemy" can be contained.

In March, while attending the 25th Dermatology Update in Montreal, Quebec, I learned of a small study by Dr. Schroeder et al, published in the October 2008 Journal of Investigative Dermatology where he and his team looked at the effects of near infrared radiation (between 700 - 1440 nm) on the skin. Schroeder and his team illustrated that the induction of collagenase and other metalloproteinases was as much as is seen with UVA. This was seen in both in vitro and in vivo human studies.

While it may be difficult to extrapolate from one small study, the concept that infrared radiation can be just as damaging as ultraviolet was a revelation for me. It was also disheartening for those of us who exchange our cold and snowy winters for the warmth of southern latitudes each year. How can I go home and tell my patients that applying new-fangled broad-spectrum sunscreens will be sufficient to halt the leathering of their skin? Furthermore, while I can recommend a sunscreen to protect against ultraviolet damage, what kind of defense can I provide against infrared radiation?

Dr. Schroeder has thrown us a lifeline that may become a major advance, if the research proves to be true. Their study showed that the major trigger for the metalloproteinase formation was oxidative stress within mitochondria in the dermis. They then tested the ability of current topical antioxidants to protect against the photoaging effects of infrared radiation.

What they found was fascinating. Some of the topical antioxidants, such as the polyphenols and Vitamin C, were very effective in blocking the effect. However, Vitamin E did not. What was not tested was the longevity of the protective effect, and whether it was necessary to reapply the antioxidants in order to maintain protection.

We are a very long way away from any standards or recommendations. However, it does give one pause to consider that maybe all the hype about antioxidants in cosmetics may not be so much hype after all. Also, one may envision a future where a patient will go to the pharmacy and select their sunscreen based on the SFP, UVA protection and IRA protection.

However, for our patients who are interested in forstalling their photoaging, perhaps we should start talking about the type of antioxidants in their moisturizers.

At least that's the way it looks from up here...