Doctors recently developed a definition for gluten sensitivity, but it's an ambiguous one. It's a label for people who suffer bloating and other celiac symptoms and seem to be helped by avoiding gluten, but don't actually have celiac disease. Celiac disease is diagnosed with blood testing, genetic testing, or biopsies of the small intestine.
The case for gluten sensitivity was bolstered last year by a very small but often-cited Australian study. Volunteers who had symptoms were put on a gluten-free diet or a regular diet for six weeks, and they weren't told which one. Those who didn't eat gluten had fewer problems with bloating, tiredness and irregular bowel movements.
Clearly, "there are patients who are gluten-sensitive," said Dr. Sheila Crowe, a San Diego-based physician on the board of the American Gastroenterological Association.
What is hotly debated is how many people have the problem, she added. It's impossible to know "because the definition is nebulous," she said.
One of the most widely cited estimates comes from Dr. Alessio Fasano, a University of Maryland researcher who led studies that changed the understanding of how common celiac disease is in the U.S.
Fasano believes 6 percent of U.S. adults have gluten sensitivity. But that's based on a review of patients at his clinic — hardly a representative sample of the general public.
Other estimates vary widely, he said. "There's a tremendous amount of confusion out there," Fasano said.
Whatever the number, marketing of foods without gluten has exploded. Those with celiac disease, of course, are grateful. Until only a few years ago, it was difficult to find grocery and dining options.
"It's a matter of keeping people safe," said Michelle Kelly, an Atlanta-area woman who started a gluten-free, dairy-free, soy-free, nut-free bakery in 2010 after her son was diagnosed with celiac disease. While conventional bakers use wheat flour, she uses such ingredients as millet flour, sorghum flour, brown rice flour and tapioca starch.
At one of Atlanta's largest and busiest health food stores, Return to Eden, manager Troy DeGroff said over a third of his customers come in for gluten-free products for themselves or their family.
"Thank you, Elisabeth Hasselbeck," he said, referring to one of the hosts of the daytime talk show "The View" who helped popularize gluten-free eating.
It's hard to say how many of his customers have a medical reason for skipping gluten. But "they're at least paying attention to what they're sticking in their mouth," he said.
On a recent Friday afternoon, several customers bought gluten-free, though none had been diagnosed with celiac disease or had digestive problems from eating wheat.
Julia White said she picks up gluten-free items when her granddaughters visit. They've been diagnosed with problems, she said. "They don't just make this up."
Another customer, Meagan Jain, said she made gluten-free cupcakes with a school friend and liked the taste. But she doesn't buy gluten-free often because "it's expensive."
For her, "It's a fad. It's part of the eclectic, alternative lifestyle."
Celiac disease: http://digestive.niddk.nih.gov/ddiseases/pubs/celiac/index.aspx