The Dermatology Blog

We know that ultraviolet light from the sun causes damage to your skin. That’s because ultraviolet light is a form of radiation. It damages the delicate DNA in your skin cells, leading to aged, damaged skin and to skin cancers. It also causes free radicals to develop in the skin, damaging fragile elastin and destroying collagen, leaving skin wrinkled, lax, and without elasticity. Although most of the damage is done by this high energy form of radiation, new research suggests that even low energy forms of radiation are harmful.

Although most of the energy from the sun is visible and ultraviolet light, about 30% of solar radiation is from infrared light. Infrared light is essentially heat from the sun. It’s what warms you up when you sit in that little spot of sunlight on your sofa in the winter and what makes you sweat when you lie out at the beach in the summer.

A study published in the Journal of Investigative Dermatology (a basic science journal of skin care) found that when researchers exposed volunteers to infrared light in doses similar to what they might get in a couple of hours sun exposure, their skin produced up to a 14 fold increase in collagen chopping enzymes. These enzymes, called matrix metallo-proteinae, are normally produced to break down collagen. Increased levels of MMPs can be seen in autoimmune diseases such as rheumatoid arthritis.

The study also found that health-promoting antioxidants in the skin were depleted following exposure to the infrared light.

Although more research is needed to confirm that infrared light exposure does lead to the type of damage that causes aging, the circumstantial evidence is strong that it does. Unfortunately, sunscreens do not protect against infrared light damage. Even broad spectrum sunscreens that protect against both UVB light (which is about 280 – 320 nm) and UVA (320 – 400), offer no protection for infrared light (760 -1440 nm).

Preventing photoaging (such as wrinkles, sagging, and sun spots) might be more difficult than we had realized. The best way to minimize aging from the sun is to avoid sun exposure during peak hours of 10 AM to 2 PM and to cover up with a hat and long sleeves if you are going to be in the sun all day.

Don’t forget, if you are committed to protecting yourself from sun exposure, then it is a good idea to supplement your diet with vitamin D. By taking 1,000 IU daily, you will keep your vitamin D stores high, and won’t need to worry about using the sun to get your daily vitamin D.

Photo: Greg Donikian