Gray hair is nothing to be ashamed of. In fact, according to a new study by researchers in Japan, the presence of gray hair may be a good sign that your body is naturally protecting itself from cancer . A series of mouse experiments suggests we've evolved to let go of cells that are at risk of generating tumors at the expense of a little color. Our cells are routinely subjected to a barrage of 'genotoxic insults,' or DNA damage wrought by a wide variety of environmental factors. Skin cells bear

Tag-uri: DNA