Some British researchers at the University of Bradford, who were looking into why patches of skin had no pigmentation, have thrown new light on why hair goes gray. And as the nation swings its attention from the First Lady's arms to the President's newly acquired smattering of salt & pepper in his coif, it behooves us to get to the root of it all.

Graying hair starts when there is a dip in levels of an enzyme called catalase. This enzyme is super useful in that it is the catalyst that turns hydrogen peroxide into water and oxygen, which is naturally occurring but builds up over time. If there is insufficient catalase to do its job then the accumulation of hydrogen peroxide turns the hairs gray.

Unfortunately, the solution remains a gray area. Should we look for products that strip out the excess hydrogen peroxide, or for something that can replenish catalase? There are catalase supplements, but they are unlikely to get much further than the intestine, where they will be digested before doing any good. Nonetheless, at least scientists now have a good starting point from which to nail a solution. In the meantime, colorists will still find plenty of work.