Macronutrient intakes and associations with psoriasis severity: a cross-sectional analysis of the asking people with psoriasis about lifestyle and eating (APPLE) study

Nutrition in psoriasis management is an area of active research interest, but estimates of macronutrient intakes are lacking. The present study aimed to assess macronutrient intakes of people living with psoriasis in the UK and explore the relationship between their dietary sources and psoriasis severity. This was an online cross-sectional study collecting diet and psoriasis severity information from adults with psoriasis. Responses to a Food Frequency Questionnaire and the self-assessed Simplified Psoriasis Index were used to determine nutrient intakes and psoriasis severity. Relative to Dietary Reference Values, participants with psoriasis (n = 257) reported an overconsumption of % energy from free sugars (median 11.2%, IQR 2.6–37.6) and an underconsumption of fibre (20.2 g/day, IQR 5.9–44.0). Compared to participants in the lowest quartile of intake, those in the highest quartile of intake for % free sugars from beverages were more likely to report high psoriasis severity (adjusted Odds Ratio (OR) 3.85, 95% CI 1.507–9.831, P trend = 0.04), although Body Mass Index (BMI) attenuated this relationship. When fully adjusted, including BMI, elevated intakes of % protein from total meat was associated with increased odds of reporting high psoriasis severity (OR 2.47, CI 0.984–6.196), whilst % protein intakes from plant-based sources (OR 0.36, 0.140–0.915) was inversely associated with reporting high disease severity; P trends ≤ 0.05. Prioritising plant-based foods may be beneficial to people living with psoriasis, but this hypothesis needs confirmation from randomised controlled trials.