Rheumatoid arthritis is a chronic, degenerative, autoimmune disease that mainly affects the joints and causes pain, inflammation, and stiffness. In search of improvement, many patients resort to fad or "miracle" diets, and seek to avoid foods such as those containing wheat; however, there is no scientific support for such a measure.
To obtain his master's degree in science at the Center for Research in Food and Development (CIAD), Diego Javier Brambila López, under the academic direction of Professor Ana María Calderón de la Barca, conducted a study on wheat in the diet and rheumatoid arthritis. The objective was to evaluate the immune response to wheat proteins, as well as the rate of disease activity, after a wheat-free diet and its reintroduction, in patients with rheumatoid arthritis, but without celiac disease.
The study involved people with rheumatoid arthritis, whose medical history was consulted and who were evaluated for joint and non-joint symptoms. Intestinal permeability and fecal microbiota were also analyzed, looking for bacteria that have been found to change in patients with rheumatoid arthritis (Prevotella copri and Bacteroides spp).
Participants were assigned a wheat-free diet for four weeks, with the reintroduction of wheat for at least three days. Throughout that period, as well as at the end, joint symptoms were assessed via RADAI-5 (rheumatoid arthritis disease activity index), as well as non-joint symptoms. Finally, their immune cells were challenged ex vivo with wheat gluten peptides to evaluate inflammatory response by cytokine production.
The patients did not have celiac disease (wheat intolerance) nor did they have impaired intestinal permeability, which could be a cause of the symptoms due to wheat consumption. It was identified that most of the patients had more than 40% of Bacteroides, but none had Prevotella copri. Such a microbiota profile does not coincide with that found in studies of patients with rheumatoid arthritis in other parts of the world.
Perhaps this is because in the patients in the study of the now, master of science, Diego Brambila, rheumatoid arthritis had several years of evolution. In addition, in our population, those suffering from other autoimmune diseases present a similar profile in the microbiota, with a high proportion of Bacteroides.
As a result of the challenge with wheat gluten proteins to the immune cells, the response was null, so it was decided to evaluate another wheat component such as fructans. In this evaluation of fructan intolerance by exhaled breath, there were no intolerants, but some patients did present intestinal symptoms, which could be due to visceral hypersensitivity.
Although no results were found in the immune response with the tool used, in one patient there was a clear decrease in joint and non-joint symptoms in the wheat-free diet and its increase when wheat was reintroduced, as evaluated with the RADAI-5 index. Some of the patients reported during the wheat-free diet to feel less morning stiffness, better mood, decreased intestinal symptoms, and improvement in their general health.
In conclusion, wheat could influence joint symptoms in some patients with rheumatoid arthritis, although not in all, but not necessarily through an immune-inflammatory response, but through hypersensitivity focused on the intestinal mucosa with signaling to the nervous system, as in irritable bowel syndrome.
To better understand the effect of wheat on patients with rheumatoid arthritis, Brambila López commented that the next stage of research is needed to evaluate the impact of other wheat proteins other than gluten. In addition, he added, it would also be necessary to analyze the composition and impact of the microbiota most representative of rheumatoid arthritis in our population and to consider other aspects such as the different stages of the disease, pharmacotherapy, and diet in general.
Collaboration of Diego Javier Brambila López, Master of Science student, and Ana María Calderón de la Barca, researcher of the Nutrition Coordination of CIAD.