There are very few studies that have been done to characterize patients who avoid wheat and/or gluten (PWAWG) in the absence of celiac disease. In a recent study, this previously overlooked group was compared to celiac disease patients and the general public.
84 PWAWGs who had celiac disease ruled out as a diagnosis were examined and compared to 585 celiac disease patients and 2,686 patients who had participated in the National Health and Nutrition Examination Survey (NHANES). The authors found that PWAWGs shared a similar cardiovascular profile to patients diagnosed with celiac disease such as a lower body mass index (BMI), lower hemoglobin levels, and a lower rate of high blood pressure, compared to the NHANES group.
A potential explanation for these similarities is simply their shared gluten free diet. However, the authors noted that gluten has been shown to have a beneficial effect on high blood pressure in previous studies making a gluten free diet an unlikely explanation. The authors instead suggest another possibility. The PWAWGs and celiac disease patients had something else in common: 60% of the PWAWGs were positive for human leukocyte antigen (HLA)-DQ2/DQ8 haplotype which is found in 90% of celiac disease patients. This immune system link could be the reason behind the lower incidence of high blood pressure and possibly for other similarities between the PWAWG and celiac disease groups.
25 of the patients in the PWAWG group (30%) had an alternative diagnose, mostly small intestinal bacterial overgrowth (SIBO) and some fructose/lactose intolerance. This high percentage suggests that many people who have made the decision to avoid wheat and/or gluten could be symptomatic due to other dietary intolerances and more non-invasive diagnostic testing done at the outset of when symptoms present could spare these people from having to adhere to a strict gluten free diet.
The authors indicate that there were limitations in their study. Primarily that the number of patients in the PWAWG group was small (n=84) and the number of men in that group was even smaller (n=18). With these reservations, the authors conclude that because the PWAWG group is very diverse in terms of alternative diagnoses, more studies are needed to fully characterize it and to determine the cause for the similarities found between it and the CD group.