The Medical Board of the National Psoriasis Foundation has recently published a systematic literature review in JAMA Dermatology, with findings that indicate the efficacy and benefits of dietary weight loss—coupled with a hypocaloric diet—for overweight and obese patients with psoriasis. The recommendations further suggest that overweight or obese patients with psoriatic arthritis may benefit from vitamin D diet supplementations, and weight loss.
Researchers from the University of Southern California Keck School of Medicine wrote, “Regardless of patients’ perspectives on established medical therapies, nearly all patients seek to understand how diet affects their psoriatic disease. Overall, there is a critical lack of evidence synthesis on the relationship between psoriatic diseases and diet. This literature gap speaks to the need for evidence-based dietary recommendations that are accessible to clinicians and patients.”
The evidence-based dietary recommendations stemmed from the review of published literature between January 1, 2014 and August 31, 2017. Researchers focused on observational and interventional studies of patients with psoriasis and PsA, and identified 55 papers and 77,557 unique patients that met the inclusion criteria. Members of the medical board voted on each recommendation, and issued strong recommendations for dietary weight loss with a low-calorie diet among overweight and obese patients with psoriasis.
Additionally, the board recommended a gluten-free diet in patients with serologic markers of sensitivity, as low-quality data asserts that select foods, nutrients, and dietary patterns may affect psoriasis—and patients with psoriasis have a twofold increased frequency of celiac disease, and more often have the markers of IgG tissue transglutaminase and IgA endomysial antibodies. In addition, high levels of these antibodies have been shown to correlate with worse skin disease.
Moreover, the researchers highlighted three ‘concepts’ for the interpretation of their recommendations: they stressed the importance of continuing regular medical therapy for psoriatic diseases, noting that dietary interventions cannot be the sole source of treatment. They also pointed to the fact that dietary interventions can sometimes be associated with contraindications and adverse affects. Lastly, the researchers wrote that the recommendations may have impacts beyond psoriatic disease, and could affect overall general health.
“Dietary interventions, when implemented, should be used in conjunction with standard medical therapies for psoriatic diseases,” Ford and colleagues wrote. “Based on low-quality data, select foods, nutrients, and dietary patterns may affect psoriasis. For patients with psoriatic arthritis, we weakly recommend vitamin D supplementation and dietary weight reduction with a hypocaloric diet in overweight and obese patients.”