At the risk of being a Grinch, the Christmas season is a pretty good time to consider the possibility that sugar is killing us. It is yet another holiday in which sweets play a primary role, with candy canes dangling on trees, cookies or Coca-Cola set aside for Santa and visions of sugar plums (which are not fruit but hard candies) dancing in children’s heads.

Many argue that sugar in moderation is benign, but that assumption has been up for debate for as long as we have added sugar to our diets. Anti-sugar forces (myself...