The Gluten Debate Continues
There are only three published studies to refute or support the diagnosis of NCGS, Seidner says.
Italian doctors who published a study last year of 920 of their patients concluded that some people who don’t have celiac disease are indeed sensitive to wheat. But some were sensitive to multiple foods as well as wheat, the researchers said.
The two other studies were done by a team of Australian scientists. They reached two different conclusions.
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.