The Gluten Debate Continues
Conflicting Findings continued...
The first study, published in 2011, looked at people who didn’t have celiac disease but controlled their digestive tract symptoms with a gluten-free diet. Participants were randomly divided into two groups and were told to stick with their usual gluten-free diet. The researchers also gave everyone two slices of bread and one muffin to eat every day for up to 6 weeks. One group got gluten-free bread and muffins; the other got them with gluten.
Within 1 week, the group that ate the bread and muffins containing gluten reported more symptoms, such as pain and bloating, than the other group. “’Non-celiac gluten intolerance’ may exist,” the scientists concluded, but they found no clues as to why.
The Australians’ second trial, published this past May, found that symptoms in people with NCGS were just as severe on a gluten-free diet as on a high-gluten diet. The researchers provided the participants with all of their meals and also restricted dairy products, which can cause digestive tract symptoms. One possible explanation for their mixed results could be that they more tightly controlled what participants ate in their second study, Seidner says.
“We’re sort of left with some conflicting results and a dearth of information,” he says.
People who think they have NCGS should get tested to make sure they don’t have celiac disease, according to the American College of Gastroenterology (ACG).
If they have the same fairly common genetic variations seen in celiac patients, they should take more tests to rule celiac disease out, starting with a blood test to look for elevated levels of certain antibodies, the ACG says. If the blood test and symptoms suggest celiac, the next step is a biopsy of their small intestine to confirm it, according to the college.
“If everything’s negative, they clearly don’t have celiac disease, but they may insist on staying on the diet,” Seidner says. He encourages such patients to talk to a dietitian.
Patients have to resume eating gluten for weeks before getting the blood test and biopsy, and some refuse, Charles Halsted, MD, said at the meeting. He specializes in intestinal and nutritional diseases at the University of California, Davis.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.