People without celiac who blame the pain on gluten are more likely troubled by something else in wheat, according to research at Oslo University Hospital in Norway. In 59 volunteers who had chosen a gluten-free diet because it made them feel better, researchers found most of them experienced discomfort after consuming fructan, not gluten.
Fructan is a carbohydrate found in wheat and some vegetables, such as onions, garlic, broccoli, cabbage and asparagus. It can affect irritable bowel syndrome (IBS), which is often reversible on a low-FODMAP diet.
In the study, participants ate muesli bars once a day. The bars were originally gluten free and low-FODMAP, but some had been laced with either the gluten or fructan equivalent content of four slices of sandwich bread. The bars appeared indistinguishable.
Each volunteer underwent three different challenges that lasted a week in randomly assigned order: eating gluten, fructan or a placebo bar containing neither. Between challenges, participants had at least a week or as long as needed for digestive problems to stop before proceeding to the next one. After each test, volunteers rated their discomfort on a scale to assess symptoms of IBS including pain, bloating, constipation, diarrhea and fullness.
The group reported significantly higher overall symptoms during the fructan challenge than on gluten or placebo. Fructan also scored highest for bloating alone. There was no difference in scores between gluten and placebo challenges.
The worst symptoms were reported on gluten, fructan and placebo by 13, 24 and 22 patients, respectively. Even in the most gluten-sensitive group, only four scored high enough versus the placebo to be diagnosed with non-celiac gluten sensitivity.
What does it mean?
While the study is small and does not rule out gluten sensitivity in some cases, it raises questions about how the condition has been studied, diagnosed and treated. The authors express doubt that non-celiac gluten sensitivity should be distinguished from IBS.
Skodje GI, Sarna VK, Minelle IH, Rolfsen KL, Muir JG, Gibson PR, Veierød MB, Henriksen C, Lundin KEA. “Fructan, rather than gluten, induces symptoms in patients with self-reported non-celiac gluten sensitivity,” Gastroenterology 2017;Nov 1, doi:10.1053/j.gastro.2017.10.040 [Epub ahead of print].
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