Gluten sensitivity in non-celiacs is due in part to the nocebo effect or “negative anticipation”: in people who believe they are sensitive to this protein, the mere idea of ingesting it causes more symptoms, according to a study
Some people who are not celiac Neither those allergic to wheat reduce their intake of foods with gluten because they believe that this protein, present in the seeds of many cereals, causes certain gastrointestinal symptoms. A study published last Tuesday in the medical journal “The Lancet Gastroenterology & Hepatology” has observed that this sensitivity may be due in part to a nocebo effect: the negative anticipation of a substance or treatment, the opposite of the placebo effect. The mere idea of ingesting gluten causes more symptoms in those who have this sensitivity.
The scientists (Marlijne CG de Graaf et al.), from the field of psychology and medicine digestive systemand belonging to institutions in the Netherlands and the United Kingdom, investigated the effects of intake expectation versus Actual gluten intake on symptoms in people with non-celiac gluten sensitivity. The study was randomized, double-blind (neither the experimenter-observer nor the subject of the experiment knew the origin of the sample or the treatment during the experimentation) and with placebo control. It was carried out for three and a half years on 165 people.
As gluten doses were used four slices of bread in two meals. The expectation along with the intake of gluten were the main source of symptoms in the first 12 hours of gluten ingestion, and these symptoms were greater after lunch than after breakfast (at breakfast there was only exposure to gluten/nocebo, at lunch the previous stimulus was repeated breakfast for the second time in 8 hours).
“The combination of expectation and actual gluten intake had the greatest effect on gastrointestinal symptoms, reflecting a nocebo effect, although an additional effect of gluten cannot be ruled out,” the researchers explain in their interpretation of the study. Our results require further investigations into the possible involvement of gut-brain interaction in non-celiac gluten sensitivity,” they clarify.
Asked about this study, Javier Molinaassistant doctor of the Digestive System Service of the San Pedro de Alcántara Hospital (Cáceres), highlighted that this work complies with “it meets the highest quality standard and methodologically it is unquestionable.”
In statements to SMC, Molina recalls that “there is already cumulative evidence on the importance of the nocebo effect in food intolerances and in patients with disorders of the brain-gut axis,” such as irritable bowel syndromeand that the results of this study “are in line with this evidence, underlining the importance of the nocebo effect (negative expectations) as a co-cause of common symptoms in half of the patients with suspected food intolerances.”
“This study provides solid scientific evidence to support the psychological therapy with the intention of correcting wrong expectations and beliefs in the multidisciplinary treatment of disorders of the brain-gut axis,” summarizes the doctor.