1.4 Million Americans Have Celiac Disease And Don't Know It

Perhaps Domino's, and every other chain jumping on the gluten-free bandwagon, has it right; researchers from the Mayo Clinic estimate that about 1.8 million Americans have celiac disease. Unfortunately, about 1.4 million of them don't know it.

Examining blood tests and interviews from the Centers for Disease Control and Prevention nationwide sample, researchers suggest that celiac disease is more common than previously thought.

"If you detect one person for every five or six (who have it), we aren't doing a very good job detecting celiac disease," study co-author Joseph Murray said in a statement. Celiac disease is a disorder where the body can't break down gluten (so wheat, rye, and barley are out of the question).

The study, published in the American Journal of Gastoenterology, also estimates that about 1.6 million Americans are on a gluten-free diet, 80 percent of whom haven't been diagnosed (celebrity Miley Cyrus is just one).

While some gluten-free advocates say the diet is helpful for weight loss, "It is important if someone thinks they might have celiac disease that they be tested first before they go on the diet," Murray said. Read about the pros and cons of a gluten-free diet here.