Legend has it that Marie Antoinette’s hair turned white the night before she was guillotined. Presumably the stress of impending decapitation caused her locks to lose color within hours. Can stress cause hair to turn grey? Did the stress of the Presidency cause Obama’s hair to grey as shown above?

Maybe, but probably not.

Hair is created in the follicles when hair cells are created, then dying and new new cells being created that force out the old cells.  The old, dead cells are the hair that we see.  Hair is colored because special cells in the follicle produce melanin in various shades – dark brown, black, yellow and red.  (Melanin is a pigment produced by cells.)  The combination of different colored melanin produced by the melanin producing cells that gives hair its color.  If the melanin cells stop working the dead hair cells are uncolored – either gray or white.

What causes melanin production to stop? For some reason, the hair producing cells work longer than the melanin producing cells in most people. The first gray or white hairs usually first begin at age 30 for men and age 35 for women. Some people may go gray in their 20’s and others don’t start till their 50’s.  More than 40% of Americans have some gray hair by their 40th birthday.

Research has found that graying is largely genetic, but other factors can play a role. The primary gene responsible for grey hair was identified about a year ago by European researchers.  Stress hormones may impact the survival and/or activity of melanin producing cells, but no clear link has been found between stress and gray hair.   Some hypothesize that graying could be a result of chronic free radical damage.  Poor nutrition can be a contributing factor as can some autoimmune diseases. Smoking has been shown to cause graying of hair.  Smokers are four times as likely to have premature gray hair.  Thus, genetics play the primary role, but other factors might be at play as well.

As for Marie Antoinette, scientists say it is extremely unlikely that her hair turned grey overnight.  Only encounters with Chuck Norris have been proven definitively to turn hair grey instantaneously.