Many people find that wheat or gluten cause them to react in some way: Some people have a wheat allergy, some have the autoimmune condition celiac disease, but the have some sort of intolerance or sensitivity to wheat and gluten.
This is because there still aren’t any reliable biomarkers to confirm gluten or wheat sensitivity, and clinicians typically rely on patient self-reports.
In irritable bowel syndrome (IBS), patients experience gastrointestinal symptoms without any visible damage to the digestive tract. Many patients with IBS believe that specific foods, like gluten or wheat, trigger their symptoms, prompting them to exclude these foods from their diets without consulting a dietitian or their doctor.
Unsurprisingly, about a third of IBS patients develop disordered eating habits and perceptions about food that may cause symptoms in and of themselves, such as orthorexia, or an unhealthy preoccupation with healthy eating. This may cause a “nocebo effect,” where patients experience symptoms due to their beliefs and expectations about a substance they assume is causing their issues but is actually inert — a “nocebo.”
As a nutrition researcher at McMaster University’s , I’m a member of a team that ran a to find out whether wheat, gluten or a gluten-free nocebo caused symptoms in IBS. And the results were surprising: even though some patients experienced worse symptoms from gluten or wheat, they weren’t very different from the nocebo, with similar proportions of patients reacting to each.
These results are similar to other published studies. Identifying the true sensitivities for patients with IBS is a controversial research area, with some studies finding gluten versus others finding it to have .
Researchers from the published an innovative study from the Lancet medical journal. Patients with reported gluten sensitivity were divided into four groups: Two groups were given gluten-free bread, but one of these groups was told it contained gluten and one was told it didn’t. Two other groups were given bread that did contain gluten, with one group believing it was gluten-free and the other believing it contained gluten.
The results showed that the patients who ate gluten and were also told they were eating gluten had significantly worse symptoms than the other three groups.
Why are people concerned about gluten?
Given the controversial evidence that not only gluten, but like fermentable carbohydrates or immune-stimulating proteins, , it’s possible for this hot topic to get blown out of proportion or taken out of context, contributing to .
All of these factors — that it is often diagnosed by excluding all other options, the significant psychological component, the division in the scientific community and clinicians who often discount patients’ experiences — make treatment difficult for patients with this disorder.
As a result, patients with IBS are often left to navigate conflicting online resources and test new diets to treat their symptoms.
How patients respond to evidence
When researchers challenge patients with gluten, wheat or a nocebo, they rarely report the personalized results back to the patients and see how this information impacts patient behaviour.
At , we wanted to see how presenting personalized nutrition information would affect our patients. After providing them with personal results about their gluten and wheat reactions, we followed up with patients after six months or more to see how this impacted their beliefs, behaviours and symptoms.
Again, we were in for a surprise! Patients largely kept similar beliefs about gluten, maintained a gluten-free diet and had consistent symptoms even after learning that most of them did not react to gluten or wheat. This begs the question: when people more generally learn new information that conflicts with an existing belief, what may help them to change accordingly?
The role of psychology in treating IBS
IBS has been long understood as a disorder of the gut-brain interaction. Psychological treatments are being increasingly investigated to minimize patient fears of foods, or nocebo effects, and to treat IBS symptoms more generally. At Harvard, found that exposure-based cognitive behavioural therapy (CBT) showed promise to improve IBS symptoms in five sessions with a nurse practitioner.
Similarly, , or gut bacteria, that were also correlated with improvements in gastrointestinal symptoms. At the , virtually delivered yoga was highly feasible and helped improve symptoms for patients with IBS.
However, IBS is a complex disorder which may be exacerbated due to many different causes, and psychological treatment will likely be only one component of an effective treatment plan for many patients.
Diet plays an important role in human health, but how it does so — especially among those with gastrointestinal diseases — becomes complicated by the emotional aspects of eating and the real needs for people to have nutritious, well-balanced diets without risking malnutrition. If you have concerns that certain foods, like gluten, trigger your symptoms, it’s a good idea to consult your doctor or a registered dietitian.
Caroline Seiler receives funding from the Canadian Institutes of Health Research.
