Diet plays little part in IBS flare ups - new research suggests

Author(s): Jesslyn Thay , Date: 05 January 2022

New research by teams in Sweden has shown that diet is less important than expected when managing Irritable Bowel Syndrome (IBS), and that excluding gluten may not always be necessary to reduce symptoms.

The findings, published in The American Journal of Clinical Nutrition, surprised researchers, as it has long been thought that gluten heavy diets increased IBS symptoms, but this is not always the case. IBS remains an exceedingly complex condition despite how common it is.

While the researchers did find that a certain type of carbohydrate diet –‘FODMAP’ can aggravate IBS symptoms, diet did not have such a big influence on the condition as previously thought.

The research conducted by Chalmers University of Technology and Uppsala University, studied 110 IBS sufferers and their symptom reactions to prepared rice pudding.

Three types of rice pudding were given to participants in the double-blind study. They included a rice pudding high in gluten, a rice pudding containing large amounts of FODMAP carbohydrate and a placebo rice pudding.

While the FODMAP puddings did increase the participants IBS symptoms, it was not the extent anticipated by the scientists, with expectations based on previous research.

Interestingly, there were no reported negative effects when participants consumed the gluten rich rice pudding – ruling out gluten as an aggravator for the condition in the participants.

Researchers were keen to point out that IBS is a very individual condition, and while diet did play a very small part in the study findings, this not always the case with every IBS sufferer.

They also stressed the study findings reaffirmed how much the condition is shaped by psychological factors and how many IBS symptoms can linked to an individual’s mental health.

"IBS is a very complex disease involving many factors, but our results indicate that the effects of specific diets are not as great as previously thought," explains Elise Nordin, PhD student in Food Science at Chalmers and lead author of the scientific article.

While Per Hellström, Professor of Gastroenterology at Uppsala University who held medical responsibility for the study, added: "Our results are important and indicate that the psychological factor is probably very important. IBS has previously been shown to be linked to mental health. Simply the awareness that one is being tested in a study can reduce the burden of symptoms".

FODMAP foods are foodstuffs high in fermentable carbohydrates, typically polymers of fructose/lactose and sugar alcohols. FODMAPs are found in a variety of foods including dairy, cereals, mushrooms, fruits and vegetables, and sweeteners such as xylitol.

• Elise Nordin, Carl Brunius, Rikard Landberg, Per M Hellström. Fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs), but not gluten, elicit modest symptoms of irritable bowel syndrome: a double-blind, placebo-controlled, randomized three-way crossover trial. The American Journal of Clinical Nutrition, 2021; DOI: 10.1093/ajcn/nqab337