Can an EVOO-Rich Mediterranean Diet Calm Psoriasis — or Is That Too Good to Be True?

Study Overview

The study, “Mediterranean Diet and Patients With Psoriasis: The MEDIPSO Randomized Clinical Trial,” was published in JAMA Dermatology in 2025 by Perez-Bootello and colleagues. It was an open-label, single-center randomized clinical trial with blinded outcome evaluation, conducted at a dermatology referral clinic in Madrid, Spain, from February 2024 to March 2025.

The trial screened 45 people and randomized 38 adults with mild-to-moderate psoriasis, defined by a Psoriasis Area and Severity Index (PASI) score of 2 to 10. Participants were receiving stable topical therapy, which matters: the diet was being tested as an adjunct, not as a replacement for dermatologic care. Nineteen people were assigned to the intervention and nineteen to the control group; 37 of 38 participants completed the 16-week study.

The intervention was a dietitian-guided Mediterranean diet program with nutritional counseling, educational materials and weekly provision of extra virgin olive oil. The control group received standard low-fat dietary advice without the same intensive dietitian supervision. The primary endpoint was change in PASI at week 16. Secondary endpoints included Mediterranean diet adherence, anthropometric and metabolic markers, serum inflammatory cytokines and patient-reported outcomes.

Key Findings: The Actual Numbers

The primary result is not subtle. A 3.4-point PASI separation over 16 weeks is meaningful in a mild-to-moderate population, where baseline scores are not extremely high to begin with. The PASI 75 result is even easier to understand: almost half of the Mediterranean diet group achieved at least a 75% reduction in psoriasis severity, while no control participant did.

The HbA1c result also matters because psoriasis is not only a skin condition. It clusters with cardiometabolic risk, insulin resistance and systemic inflammation. A between-group HbA1c improvement of -4.1 mmol/mol, with a 95% confidence interval from -6.9 to -1.3 and P = .01, suggests the dietary intervention may have improved metabolic terrain alongside skin severity.

Mechanism: Why EVOO-Rich Mediterranean Eating Could Affect Skin

Psoriasis involves immune activation, especially inflammatory pathways connected to the IL-23/Th17 axis, TNF signaling, keratinocyte proliferation and vascular changes in the skin. Diet is not going to switch those pathways off like a biologic drug. But diet can influence the background inflammatory load those pathways sit inside.

Extra virgin olive oil contributes two relevant layers. First, it supplies oleic acid, a monounsaturated fat that can replace saturated fat and ultra-processed-food fats in the diet. That shift can improve postprandial lipid handling, endothelial function and insulin sensitivity. Second, high-quality EVOO contains phenolic compounds — hydroxytyrosol, tyrosol, oleocanthal, oleacein and oleuropein derivatives — that interact with oxidative-stress and inflammatory biology.

The likely mechanism is not “olive oil treats psoriasis.” It is more plausible that an EVOO-supported Mediterranean diet reduces dietary glycemic load, improves fat quality, increases fiber and polyphenol intake, changes gut-derived inflammatory signaling and lowers oxidative stress. That could reduce systemic inflammatory pressure enough for skin severity to improve in some patients, especially when conventional topical therapy is stable in the background.

Context: How This Fits the Wider Evidence

MEDIPSO lines up with the broader Mediterranean diet literature: the strongest results usually come from the whole pattern, not from isolating one heroic ingredient. PREDIMED and related trials made extra virgin olive oil central to a cardioprotective Mediterranean diet, while newer olive-oil studies show more targeted signals in blood pressure, oxidized LDL, insulin resistance, cognition and inflammatory markers.

What is new here is the clinical dermatology angle. Psoriasis nutrition research is often observational, underpowered or based on weight-loss interventions. MEDIPSO is still small, but it is randomized, has a blinded evaluator and reports a hard clinical severity endpoint. It does not prove that EVOO alone reduces plaques; it does strengthen the argument that food quality belongs in psoriasis care, especially for patients with metabolic risk.

Limitations

• • Small sample: only 38 participants were randomized, so the effect needs replication in larger multicenter trials.
• • Open-label design: participants knew whether they were receiving intensive dietitian support, which can influence behavior and patient-reported outcomes.
• • Not EVOO-isolated: weekly EVOO provision was part of a Mediterranean diet package, so the trial cannot identify the independent effect of extra virgin olive oil.
• • Control intensity mismatch: standard low-fat advice without dietitian supervision is not an equal-attention control.
• • Short duration: 16 weeks is enough to show a signal, but not enough to know durability, relapse risk or long-term medication-sparing effects.
• • Specialist setting: a Madrid dermatology referral clinic may not represent all psoriasis populations, diet cultures or healthcare systems.

Our Take

This is a genuinely useful trial, but it should be interpreted precisely. The strength is the clinical endpoint: PASI moved, PASI 75 appeared in nearly half the intervention group, and HbA1c improved. That is much more compelling than a vague biomarker-only nutrition study.

The weakness is attribution. The result belongs to a supported Mediterranean diet intervention, not to EVOO alone. Still, because extra virgin olive oil was actively provided and is a defining fat source of the pattern, the paper is relevant to olive-oil users. My read: not game-changing yet, but definitely practice-shaping. For psoriasis patients who also care about metabolic health, an EVOO-rich Mediterranean diet is one of the rare lifestyle interventions that is biologically plausible, broadly healthy and now backed by randomized clinical dermatology data.

Reference

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 Dermatology. 2025;161(12):1215-1223. doi: 10.1001/jamadermatol.2025.3410. PMID: 40991259.