The relationship between diet and inflammatory skin diseases is poorly understood. In atopic dermatitis (AD), commonly called eczema, new research suggests elimination diets do not impact disease for patients with no known food allergies.1 Despite limited research on the link between diet and diseases, like AD, patients often ask whether the foods they eat affect disease risk and severity.
A recent study, conducted by Aaron Drucker, MD, at the University of Toronto and colleagues with the department of dermatology at the Warren Alpert Medical School at Brown University, showed gluten consumption may not be associated with an increased risk for developing inflammatory diseases, including AD and psoriasis.2 In a prior study, Dr Drucker and his colleagues showed pro-inflammatory diets did not affect the risk for developing these same diseases.3 His latest study adds to the current body of literature that shows little to no correlation between diet and the risk for developing AD.
Dr Drucker, scientist with Women’s College Research Institute and assistant professor with the department of medicine at the University of Toronto in Toronto, ON, discussed his latest findings in an interview with The Dermatologist.
“When we see patients with psoriasis or AD, they often ask about the role diet, and sometimes specifically gluten, play in their disease,” said Dr Drucker. In the study, he and his colleagues used food frequency questionnaires to assess gluten consumption of participants from the Nurses’ Health Study II. Analysis for psoriatic diseases included data from 1991 to 2015, and analysis for AD included data from 1995 to 2013 for AD.
“Nurses’ Health Study II has high-quality data on participants’ diet over more than 2 decades and we have done many studies looking at psoriasis and eczema using that study,” said Dr Drucker. “Since the data available on diet were collected during adulthood, we focused on cases where the skin disease began in adulthood.”
Overall, 85,185 participants were included in the psoriasis analysis, 85,324 participants were included in the psoriatic arthritis analysis, and 63,443 participants were included in the AD analysis.
Dr Drucker et al found no association between increased gluten intake and any of the disease outcomes. Comparing the highest vs lowest gluten intake quintiles, the multivariable HRs were 1.15 for psoriasis, 1.12 for psoriatic arthritis, and 0.91 for AD.
“There is some previous evidence to suggest gluten may be involved with psoriasis, so we were surprised to find no association,” said Dr Drucker. However, no strong evidence had suggested a link between gluten and eczema, so this finding was not surprising, he added.
While the findings do not support gluten intake as a risk factor for inflammatory skin diseases, the study did not assess the impact of strictly-gluten free diets.
“For some relationships between food and disease, eating any of that food can have negative effects. For example, with celiac disease, eating any gluten, even a small amount, can be detrimental,” said Dr Drucker. “If there is a relationship between gluten and psoriasis or AD, and this relationship is similar to that for celiac disease, we would not have been able to detect that in this study, as the data we have on diet does not assess whether people eat zero gluten,” he added.
According to Dr Drucker, studies examining the impact of completely gluten-free diets on AD and psoriasis could further illuminate the relationship, or lack-there-of, between gluten intake and inflammatory skin diseases.
1. Lim NR, Lohman ME, Lio PA. The role of elimination diets in atopic dermatitis—a comprehensive review. Pediatr Dermatol. 2017;34(5):516-527. doi:10.1111/pde.13244.
2. Drucker AM, Qureshi AA, Thompson JM, Li T, Cho E. Gluten intake and risk of psoriasis, psoriatic arthritis and atopic dermatitis among US women [published online August 9, 2019]. J Am Acad Dermatol. doi:10.1016/j.jaad.2019.08.007
3. Bridgman AC, Qureshi A, Li T, Tabung FK, Cho E, Drucker AM. Inflammatory dietary pattern and incident psoriasis, psoriatic arthritis, and atopic dermatitis in women: A cohort study. J Am Acad Dermatol. 2019;80(6):1682-1690. doi:10.1016/j.jaad.2019.02.038