The Sugar Plum Fairy would be shocked. The diagnosis rate of celiac disease—an autoimmune disorder that causes the body to treat gluten as a toxin—has doubled in the U.S. since the 1980s, meaning more people than ever are celebrating a gluten-free holiday season in 2012.
What a pity. Gluten is a sticky protein found in wheat flour, an essential ingredient in traditional holiday recipes from thin, crispy pizzelle to butter-laden shortbreads. Even spices aren't safe: Ground spices have added gluten to keep from clumping in their canisters. That means even sweet potato and pecan pie fillings are a no-no, not just the flaky crust .
Bakers get big benefits from gluten. It helps create a smooth, fluffy texture, makes everything moister, and helps treats hold their shape. Dough mixes better and is more likely to stand up against a rolling pin. Morning doughnuts often have added gluten to make them plumper and better able to hold up against a gooey glazing. Store-bought products are especially susceptible to added gluten: Familiar-label baked goods have to be consistent, hold their shape, maintain their familiar taste, and not spoil too quickly. This means that many off-the-shelf gingerbread men, coffee shop sugar cookies, and gift-boxed panettone fall victim, too.
There's more gluten in our diet than in generations past, according to gastroenterologist Alessio Fasano, head of the Center for Celiac Research at the University of Maryland. "Your grandparents ate a lot less gluten, and it was only in bread, beer, and pasta," says Fasano.
To avoid hidden gluten at holiday tables: Stay away from lunchmeats and canned meats, which often have gluten added to bulk up protein content. Go easy on processed cheese—gluten is added to keep the products from sticking to plastic wrappings. And don't go nuts—gluten often coats dry roasted nuts, helping salt and other seasonings stick.
Even if you ate cookies by the dozen at grandma's house last year, that doesn't mean you'll be able to this yuletide, according to Mayo Clinic gastroenterologist Joseph Murray. "The assumption that celiac disease starts in childhood is not on as solid ground as we once thought. Adults that have tested negative can later test positive," says Murray. "You can be an adult without the disease and then get the disease."