07/31/2012 02:35 EDT | Updated 09/30/2012 05:12 EDT

News Summary: Explosion in gluten-free foods has some wondering whether fad is in full force

THE NEWS: Gluten-free products are flying off grocery shelves as cases of the once rare celiac disease increase, but some estimate that more than half of consumers buying the products don't react to gluten.

WHAT IS GLUTEN?: In the worst cases, the protein found in wheat, rye and barley triggers celiac disease, which causes abdominal pain, bloating and intermittent diarrhea. Those with the ailment don't absorb nutrients well and can suffer weight loss, fatigue, rashes and other problems.

FAD OR NOT?: Scientists say there may be more celiac disease now because people eat more processed wheat products like pastas. Gluten helps dough rise and gives baked goods structure and texture.