What’s Hot in Hyperpigmentation?
For years, we have known about the damaging effects of ultraviolet light (UVA and UVB) from the sun’s harmful rays. Now we are learning that some forms of heat can be just as damaging as UV. Doris Day MD, a clinical associate professor of dermatology at NYU has determined that “we used to think that UV rays were the only external cause of skin damage, but a growing body of research tells us that’s not true. Some forms of heat are proving to be just as damaging as UV.” Infrared rays travel deep into skin, causing free radicals that further accelerate skin aging. Day has found that “spin instructors and women who were taking hot yoga upwards of five times a week were getting more discoloration and persistent redness than other patients.” Although the occasional hot yoga class will not cause significant damage, it may not take much more to cause pigment changes. Besides the sun, which is the source of about 50% of infrared radiation, these rays can come from less-obvious places. Your skin is exposed to infrared rays when you blow-dry your hair, bake or even get a gel manicure.
According to a study from Seoul National University College of Medicine, just 30 minutes of heat exposure three times a week for six weeks can cause antioxidant levels in the skin to drop and create proteins that destroy collagen and cause wrinkles. Zoe Diana Draelos MD, a consulting professor of dermatology at Duke University has found that, “heat triggers melanocytes, the pigment-producing cells within our skin, to create pigment that causes age spots as a defense mechanism. Melanocytes react when they’re injured, and heat is a form of injury.” Those with naturally darker skin are more likely to develop heat-induced dark spots, since they are more susceptible to hyperpigmentation.
Now that we know infrared heat can age the skin, we can learn how to combat it. One of the best defenses is a sunscreen that contains zinc dioxide and titanium dioxide. These ingredients act as physical blocks against infrared heat from the sun. However, sunscreens with infrared (IR) protection contain antioxidants like vitamins A, C and E that can counteract free radicals and keep skin looking young. Look for a sunscreen with Broad Spectrum UVA and UVB plus IR protection such as SkinMedica Total Defense + Repair SPF 34, Obagi Sun Shield in Warm SPF 50 or Silverberg Antioxidant Sunscreen Moisturizer SPF 50+. It is recommended that you also include an antioxidant rich product such as Skinceuticals C E Ferulic, SkinMedica TNS Essential Serum or Silverberg Redness Reduction Advanced Antioxidant Serum, which help defend the skin against environmental free radicals.