Is Diet Quality Associated With Psoriasis Severity?

Aug 14, 2024

Photo Credit: Sefa Ozel

Diet quality is associated with psoriasis severity, so knowing current dietary guidelines and ongoing dietary research is critical for treating psoriasis.

Dietary guidelines for people with psoriasis are sparse, focusing primarily on managing their comorbid conditions. Prof. Wendy Hall, MSc, PhD, from King’s College London, in the U.K, presented current dietary guidelines and ongoing dietary research¹.

A systematic review of 55 trials totaling more than 4,500 participants with psoriasis concluded that a hypocaloric diet should be recommended in people with psoriasis who are overweight or obese². A gluten-free diet could be recommended in people who have concomitant confirmed Celiac disease or a positive serology for gluten sensitivity. Low-quality observational evidence also showed that Mediterranean diets could be effective, but well-designed clinical trials are needed to confirm this conclusion.

A more recent meta-analysis analyzed the effect of dietary interventions in participants with obesity on psoriasis outcomes, including six randomized-controlled trials³. Dietary intervention and strict caloric restriction, compared with usual care led to reductions in Psoriasis Area and Severity Index (PASI) scores at week 16 of a very-low quality intervention. In two of these trials, dietary intervention also improved quality-of-life of a moderate quality evidence. Furthermore, the combination of diet intervention plus exercise program compared with information only led to reductions in BMI and higher proportions of participants achieving greater than or equal to 50% reduction in PASI of a moderate quality evidence, but not with achieving greater than or equal to 75% reduction in PASI.

Prof. Hall continued by describing two studies that assess dietary associations with psoriasis¹. The APPLE study (NCT05448352) is an online, cross-sectional survey collecting data on psoriasis severity, diet, demographics, and lifestyle characteristics. Dietary intakes were measured using the EPIC Food Frequency Questionnaire. In total, 371 participants started the APPLE survey and 270 participants completed the study. The recruited population were mainly White, British, women, and non-smoking with a median age of 40 years. The dietary intake of fibres, fatty acids, and sugars was similar to the overall British population. Overall, 51% of participants were comorbid obese or overweight and 19% had cardiometabolic disease. Regression analyses showed that increasing diet scores were associated with lowered psoriasis severity (P<0.05). For the Mediterranean Diet Score, intake of meat and poultry were positive predictors for psoriasis severity (P<0.05) and intake of fruits, nuts, and legumes were negative predictors of severity (P<0.05).

The METRED-P (NCT05820698) study aims to evaluate the feasibility of implementing a Mediterranean-style diet and/or time-restricted eating as dietary patterns for individuals with psoriasis, with a BMI of 25–50 and not receiving phototherapy or systemic therapy. The trial will assess adherence to the dietary intervention as well as measures of psoriasis.

In summary, “diet quality is associated with psoriasis severity,” said Prof. Hall¹. “The work done so far will generate hypotheses for potential dietary targets, possibly including plant-based diets. Ultimately we hope this will lead to evidence-based dietary guidelines for psoriasis management.”