UV Light Spectrums
The dangers of UVA light and the importance of broad spectrum protection are becoming understood and labelling requirements reflect this new understanding in Canada. Recent research is finding that the more ubiquitous rays—visible light and infrared light may also be damaging the skin.
The focus of research in photo aging and sun damage has been about UV (ultraviolet) radiation—UVA and UVB rays. UVB rays cause sunburns and increase certain skin cancers. UVA rays cause symptoms of premature aging such as fine lines, wrinkles, and skin laxity. Recent research has indicated, however, that infrared light may also play a role in sun damage. As traditional sunscreens only protect the skin from the UV spectra of light, this may trigger new research into the effects of visible and infrared light. Given that UV light accounts for only 7% of solar energy at the earth’s surface (39% visible light and 54% infrared light), findings about the effects of visible light and infrared light may have a significant impact on the next generation sunscreens. In particular, infrared light A is getting attention as a possible cause for larger scale oxidative damage in or on the skin.1
The science of sun damage has been focused on the effects of UV light, and the findings of the effects of visible light and infrared light are still relatively new. In the meantime current sunscreens do not block off visible or infrared light. How should you protect yourself? First, use common sense. While sunscreens play an important role in sun protection, it is not the be all and end all. Simply avoiding or minimizing exposure is by far the most effective way to prevent sun damage. This may seem like common sense, but making sun conscious decisions like staying in the shade, wearing longer sleeve shirts and staying indoors when the sun is at its strongest are some of the best ways to prevent exposure to all spectra of sunlight. The second line of defense is to treat the skin with antioxidants which may be able to reverse some of the free radical damage that is caused by exposure to various light spectra. While the science of topical antioxidants is still relatively new, its future prospects look bright, and is an exciting area of research.
There are already some new generation sunscreens that are attacking the potential problems of infrared light. Although the research is still very new, it may be that there is more to worry about from UV exposure than previously thought--which is scary, given how much we already do know about how it can age us faster, and cause DNA damage, leading to various skin cancers.
1 A study into the mechanisms of Infrared A light on skin-aging. http://www.ncbi.nlm.nih.gov/pubmed/20130591