Mediterranean Diet as Adjunct Therapy in Psoriasis: Insights from the MEDIPSO Randomized Clinical Trial

Highlight

• The MEDIPSO trial demonstrated that a 16-week dietitian-supported Mediterranean diet significantly reduced psoriasis severity in patients with mild to moderate disease.
• Nearly half of the Mediterranean diet group achieved PASI 75, a substantial clinical improvement milestone, compared to none in the control group.
• Besides skin improvement, the Mediterranean diet intervention improved metabolic parameters, including a significant reduction in hemoglobin A1c.
• These results suggest dietary modification can serve as an effective adjunctive strategy for managing psoriasis alongside standard topical therapies.

Study Background and Disease Burden

Psoriasis is a chronic, immune-mediated inflammatory skin disease characterized by red, scaly plaques that significantly impair quality of life. In addition to cutaneous manifestations, patients often suffer from systemic inflammation and are at elevated risk for cardiometabolic comorbidities such as type 2 diabetes and cardiovascular disease. Conventional management relies largely on topical therapies for mild to moderate disease and systemic treatments for severe forms. However, as an immune-driven inflammatory disorder, modifiable lifestyle factors including diet may influence disease course.

The Mediterranean diet, rich in fruits, vegetables, whole grains, legumes, nuts, fish, and extra virgin olive oil, is renowned for its anti-inflammatory and cardiometabolic benefits. Observational studies have suggested an inverse association between Mediterranean diet adherence and psoriasis prevalence and severity, yet robust randomized clinical trial evidence has been lacking. MEDIPSO addresses this gap by evaluating whether a Mediterranean diet intervention can reduce psoriasis severity and improve metabolic parameters in patients receiving stable topical therapy.

Study Design

The MEDIPSO study was an open-label, single-center, single-blinded (evaluator) randomized clinical trial conducted at a dermatology referral clinic in Madrid, Spain, between February 2024 and March 2025. The trial enrolled 38 adult patients with mild to moderate psoriasis—defined by a Psoriasis Area and Severity Index (PASI) score ranging from 2 to 10—who were on stable topical treatments.

Participants were randomized 1:1 into two groups:

– Intervention Group: Received a 16-week dietitian-guided Mediterranean diet program, incorporating personalized nutritional counseling, educational materials about the diet, and weekly provisions of extra virgin olive oil.
– Control Group: Received standard low-fat dietary advice without any dietitian supervision.

The primary endpoint was the change in PASI score from baseline to week 16. Secondary outcomes included Mediterranean diet adherence, anthropometric indexes (such as weight and body mass index), metabolic parameters including glycated hemoglobin (hemoglobin A1c), serum inflammatory cytokines, and patient-reported outcomes related to quality of life.

Key Findings

Of the 45 patients screened, 38 were randomized, with 37 (97.4%) completing the study. The mean age was 46.4 years, and approximately two-thirds were male.

– Primary Outcome (PASI Change): The intervention group exhibited a mean PASI decrease of 3.4 points at 16 weeks (95% CI, -4.4 to -2.4), whereas the control group showed essentially no change (0.0; 95% CI, -1.0 to 1.0). The between-group difference was statistically significant at -3.4 (95% CI, -4.8 to -2.0; P < .001).

– PASI 75 Response: Nearly half (47.4%) of patients following the Mediterranean diet achieved PASI 75, indicating a 75% reduction in disease severity, whereas no patients in the control group reached this milestone.

– Metabolic Outcomes: The intervention group showed a significant reduction in hemoglobin A1c levels compared to controls (between-group difference of -4.1 mmol/mol; 95% CI, -6.9 to -1.3 mmol/mol; P = .01), suggesting improved glycemic control. Other metabolic and anthropometric outcomes trended favorably but were not highlighted as statistically significant.

– Inflammatory Markers & Patient-Reported Outcomes: The study also evaluated serum inflammatory cytokines and patient-reported quality of life parameters; however, detailed data on these secondary outcomes were not prominently reported.

– Safety: No adverse events related to the dietary intervention were reported, underscoring the safety and feasibility of Mediterranean diet implementation in this patient population.

Expert Commentary

The MEDIPSO trial provides pivotal randomized clinical evidence that diet modification, specifically a Mediterranean diet, can meaningfully reduce psoriasis severity when added to standard topical therapy. This aligns with mounting evidence implicating systemic inflammation and metabolic dysregulation in psoriasis pathophysiology.

The anti-inflammatory effects of the Mediterranean diet likely contribute to amelioration of psoriatic plaques and improvement in metabolic status, both of which have important clinical implications. Improvements in glycemic control reflected by reduced hemoglobin A1c underscore its cardiometabolic benefits, critical for a population at increased cardiovascular risk.

Nonetheless, some limitations exist. The open-label design with single evaluator blinding may introduce bias. The relatively small sample size and short duration necessitate validation in larger, longer-term trials to confirm sustained benefits and impact on systemic inflammation and comorbidities.

Despite these considerations, the findings reinforce current guideline recommendations emphasizing lifestyle optimization in psoriasis management. They also support integrating dietitians into multidisciplinary care teams to effectively implement evidence-based dietary strategies.

Conclusion

The MEDIPSO randomized clinical trial robustly demonstrates that a 16-week Mediterranean diet intervention substantially improves psoriasis severity among patients with mild to moderate disease receiving stable topical therapy. Alongside skin improvements, metabolic health benefits were also observed, reinforcing the diet’s systemic anti-inflammatory effects.

These findings advocate dietary counseling and Mediterranean diet adoption as feasible and beneficial adjuncts in psoriasis management. Dermatologists and clinicians should consider incorporating structured dietary interventions and professional nutritional support into comprehensive care frameworks for psoriasis patients, particularly those at cardiometabolic risk.

Future research should explore the long-term effects, mechanistic pathways, and impacts on comorbid conditions to optimize personalized integrative treatment strategies.

References

Perez-Bootello J, Berna-Rico E, Abbad-Jaime de Aragon C, et al. Mediterranean Diet and Patients With Psoriasis: The MEDIPSO Randomized Clinical Trial. JAMA Dermatol. 2025 Sep 24:e253410. doi: 10.1001/jamadermatol.2025.3410. Epub ahead of print. PMID: 40991259; PMCID: PMC12461594.

Additional relevant literature:

1. Boehncke WH, Schön MP. Psoriasis. Lancet. 2015 Sep 5;386(9997):983-94. doi: 10.1016/S0140-6736(14)61909-7.
2. Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med. 2013 Apr 4;368(14):1279-90. doi: 10.1056/NEJMoa1200303.
3. Barrea L, Balato N, Di Somma C, et al. Nutrition and psoriasis: is there any association between psoriasis and lifestyle nutritional habits? J Transl Med. 2015 Sep 29;13:13. doi: 10.1186/s12967-015-0659-1.

These studies contextualize the inflammatory and cardiometabolic links between diet and psoriasis.