Going ‘gluten free’ is one of the hottest dietary trends at the moment. Now a new study has cast further doubt into if self-diagnosed ‘gluten sensitivity’ is related to gluten at all.
Gluten-free diets are the cornerstone of managing the very real and serious autoimmune condition of coeliac disease. Putting coeliac disease aside, a person could be forgiven for thinking that we are now faced with an epidemic of self-diagnosed ‘gluten intolerance’ judging by the popularity of gluten-free diets.
The question of if non-coeliac gluten sensitivity (NCGS) is a real condition or not is a vexed one. Only a small amount of well-designed research has been conducted so far, with mixed results in reproducing symptoms of gluten intolerance in controlled dietary trials.
Leading researchers are now proposing that self-reported gluten sensitivity may just be a marker for dietary changes that reduce the amount of other food components that can cause gastrointestinal problems.
Called FODMAPs, these are different types of carbohydrates such as lactose, fructose, fructans and sugar alcohols that can cause irritable bowel syndrome (IBS) like symptoms in some people. Wheat contains FODMAPs, but so too do many other foods such as milk, pears, plums, onions, garlic, and legumes.
Adding another very small piece to the incomplete puzzle, a just published randomised-controlled trial looked further into NCGS. First thing to note is that NCGS is not a diagnosable condition like coeliac disease is. Diagnosis relies on self-reported symptoms such as abdominal pain, bloating, nausea, and fatigue experienced following the consumption of gluten-contain foods. But that does not prove that it is gluten causing the problems as there is more to cereal foods than just gluten.
In the latest study, 35 people who were clinically diagnosed as likely having NCGS and were already following a strict gluten-free diet were given a sachet of flour simply labelled as A or B. They were then asked to sprinkle it on soup or pasta for 10 days. One sachet had gluten in it, the other didn’t. After a two week break, each person commenced using the other sachet of flour.
Just one-third (12) of the participants managed to correctly identify which flour had gluten in it by the presence of symptoms following its ingestion. Half of those that thought the gluten-free flour had gluten in it said they experienced gastrointestinal symptoms after eating it, but not when they ate the flour that actually contained gluten.
What the results show is that while the sample size was small and the duration short, it was unlikely that it was gluten causing problems in most people. ‘Random chance’ seemed to have a large role to play. That doesn’t mean the symptoms experienced were not real, but IBS-like symptoms follow varying patterns of intensity over time so the study could have just been detecting that.
It could also be that it was the cereal flour in general that was causing the problems in some people, unrelated to gluten. So that still leaves FODMAPs as a potential culprit.
What it all means
The research into NCGS is beginning to mount a case that for many people who are following self-styled gluten-free diets for health reasons, gluten avoidance may have very little to do with any symptom improvements seen.