A 16-week Mediterranean diet program may reduce psoriasis severity compared with standard low-fat dietary advice.
In a randomized clinical MEDIPSO trial, researchers found that the patients who were assigned to follow the Mediterranean diet had greater reductions in Psoriasis Area and Severity Index (PASI) scores, with nearly half reaching PASI 75, whereas no patients in the control group achieved this outcome.
Nine of the 19 patients in the Mediterranean diet group achieved PASI 75, five achieved PASI 90, and two achieved complete clearance. Thirteen reached PASI 50 compared with two in the control group. The mean change in PASI was −3.4 points for the intervention group and 0.0 for the control group.
Patient-reported outcomes also improved among those who received the intervention. These patients reported an improved quality of life and sleep as well as lower anxiety scores compared with controls. Depressive symptoms didn't change significantly.
Metabolic results were mixed. The intervention didn't produce differences in weight, waist circumference, cholesterol, or apolipoproteins. However, patients assigned to the Mediterranean diet had reductions in lipoprotein(a) and hemoglobin A1c compared with controls. Mild infections occurred in both groups but weren't linked to diet, and no hospitalizations were reported.
“The Mediterranean diet may exert beneficial effects in psoriasis through multiple metabolic and molecular pathways relevant to chronic inflammation,” said senior study author Álvaro Gonzalez-Cantero, MD, PhD, of the Hospital Universitario Ramón y Cajal in Madrid, and colleagues.
The researchers enrolled 38 adult patients with mild to moderate psoriasis on stable topical therapy. The mean age was 46 years, and 25 of the patients were male. The patients were randomly assigned 1:1 to follow either a structured Mediterranean diet program or low-fat dietary advice. The intervention included counseling with a dietitian, educational materials, and a weekly provision of extra virgin olive oil. Controls received standard advice without counseling. Thirty-seven patients completed the study. The trial was conducted at a dermatology referral clinic in Spain between February 2024 and March 2025. The design was open-label with blinded evaluators.
Adherence to the Mediterranean diet increased in the intervention group. Scores on the er-MEDAS adherence scale rose more than six points higher compared with those of the control group. Greater adherence correlated with greater improvement in PASI, suggesting a dose-response relationship.
The researchers acknowledged several limitations. The small sample size limited the ability to assess subgroup effects or detect rare outcomes. The study was conducted at a single center, which may have reduced generalizability. The 16-week follow-up period didn't capture long-term adherence or durability of improvements. Because the participants knew their group assignment, self-reported outcomes may have been influenced by bias.
Full disclosures can be found in the study.
Source: JAMA Dermatology
