Hott Mama asks: With summer quickly approaching I’m worried about sun exposure on my hair. I know that sun makes my color fade faster, but is it doing any real damage to my hair? The Left Brain responds:
Dear Mother, yes sunlight can cause serious physical damage to hair. According to the International Journal of Cosmetic Science (2007 29. 143-146) the Textile Research Institute at Princeton University conducted a study in which they exposed hair of different ethnic types to natural environmental conditions in sunny (and hot) Arizona.
They found that the hair changed dramatically after extended exposure: the fibers became thinner and the cuticle scales fused together. The hair also became extremely brittle with numerous radial cracks and fractures. Perhaps most disturbingly the researchers said that “individual hair fibers fused together to form rod-like structures stuck together by solubilized, oozed out, gelled, and finally hardened proteins.” Whoa. Melted hair? One can only assume what kind of heat wave Arizona was having at the time of this study!
The good news is, they also found out that natural melanin pigment in the hair helped protect it from this environmental assault. Indian and Chinese hair, which have a higher melanin content, experienced less damage than European hair that had moderate, low or no melanin. (I guess that means if you have gray hair and you live in Arizona, you should never go outside.)
Please understand that this study was done under very extreme conditions. Under normal circumstances, hair recieves more damage from washing and drying and chemical processing than it does from sunlight. But it does make you stop and think about how to protect your hair. Since the Right Brain always makes fun of me for wearing a hat, I won’t suggest that as an option for you. But if you’re interested, you can read our previous post about sunscreen in hair care products.