Diet and psoriasis

Background: Patients with psoriasis have a growing interest in managing their disease through diet. Objective: This review paper aims to analyze dietary interventions for psoriasis and their outcome. Methods: Terms "psoriasis AND diet" were used to search PubMed database and 63 articles describing dietary changes influencing psoriasis were selected. Results: Low calorie diet (LCD) improves Psoriasis Area and Severity Index (PASI) and Dermatology Life Quality Index (DLQI) in conjunction with topical or systemic therapy, although LCD was unsuccessful in maintaining disease remission when patients discontinued concomitant cyclosporine or methotrexate therapy. A fish oil diet improved baseline PASI of 7.7 to 5.3 at three months and 2.6 at 6 months compared to control (PASI: 8.9, 7.8, and 7.8, respectively). A randomized, double-blind, placebo-controlled study investigating selenium supplementation in psoriasis provided no PASI improvement. Zinc supplementation with concomitant betamethasone valerate 0.0025% ointment in a randomized, double-blind, placebo-controlled study provided a mean PASI of 11.2 in the intervention group and 8.0 in the control group with no significant difference between both arms. Gluten free diet and vitamin D supplementation were also efficacious dietary changes although results were mixed. Conclusions: Dietary changes alone do not cause a large effect in psoriasis but may become an important adjunct to current first line treatments.