Around 8.5 million people living in the UK are thought to be following a gluten-free diet. For some – around 1 in 100 people – removing gluten is necessary due to coeliac disease. Others, however, ditch a whole food group believing that it’s a healthy diet choice or they have ‘Non Coeliac Gluten Sensitivity’.
However, a new study suggests that a small fraction of the people who have ditched gluten may in fact be reacting to something else entirely: Fructan.
Not heard of it? That’s because it isn’t nearly as well known. Fructan is a type of carbohydrate that’s found in some wheat and vegetables – most notably onions – which, according to a new study, can cause similar symptoms to those experienced with ‘gluten sensitivity’. Here’s what you need to know.
The research
Scientists looked at a small sample of 59 individuals who already followed a gluten-free diet, despite being told they did not have coeliac disease. They were then assigned random diets that contained either gluten, fructan or a placebo, which they had to follow for a week.
The participants’ symptoms were then measured using a gastrointestinal symptom rating scale, which was originally designed to note IBS symptoms in patients. It was found that the fructan diet triggered 15% more bloating and a 13% increase in overall gastrointestinal symptoms, compared to the placebo alternative. Interestingly, the gluten diet had no effect.
According to the authors, this may explain why people with irritable bowels often improve on gluten-free diets but don’t make a full recovery. Study lead Peter Gibson, of Monash University in Australia, said:
‘Gluten was originally assumed to be the culprit because of coeliac disease, and the fact that people felt better when they stopped eating wheat… Now it seems like that initial assumption was wrong… Certainly the evidence points to fructans being more of a problem.’
These findings fit with previous trials, which showed that roughly 70% of people with IBS feel better when they cut out fructans and other nutrients from a food group known as FODMAPs. As a result, experts often recommend low-FODMAP diets to patients with stomach issues.
Speaking to New Scientist, gastroenterologist Katie Ellard explained: ‘Once coeliac disease has been ruled out, I still recommend knocking off wheat to see if that helps, but I explain that it’s to eliminate fructans not gluten from their diet.’
As well as onions, fructan most commonly occurs in some breads, barley and many common vegetables like cabbage and broccoli. So, although more research needs to be done, this is definitely something to bear in mind when trying to get to the bottom of your tummy troubles.
The study was published in the online journal Gastroenterology.
