Harvard Health Blog
Why does hair turn gray?
By: Robert H. Shmerling, MD, Faculty Editor, Harvard Health Publications If you look at photos of President Obama taken before he ran for president and since he left office, youíll notice a distinct difference: where there used to be only dark brown hair, there is now far more gray than brown. It seems that the stress of running a country would turn any personís hair gray. But is stress really to blame? And why