What dietary recommendations should be given to an adult patient with psoriasis to reduce inflammation, control weight, and lower cardiovascular risk?

Dietary Recommendations for Adults with Psoriasis

All overweight or obese adults with psoriasis should implement an 800-1000 kcal/day hypocaloric diet for the first 8 weeks, targeting a BMI <25 kg/m², as this produces clinically significant reductions in psoriasis severity and addresses the inflammatory cycle driven by excess adiposity. 1

Weight Reduction as Primary Intervention

Weight loss is the single most evidence-based dietary intervention for psoriasis patients with elevated BMI. The mechanism is clear: adipose tissue functions as an endocrine organ releasing pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) that directly worsen psoriasis, while suppressing anti-inflammatory adiponectin. 2, 1 This creates a bidirectional cycle where obesity worsens psoriasis and psoriasis-driven inflammation promotes metabolic dysfunction. 1

Specific Weight Loss Protocol

• Start with 800-1000 kcal/day for 8 weeks in overweight/obese patients, which yields approximately 15 kg weight loss and produces measurable PASI score reductions. 2, 1, 3
• Target BMI <25 kg/m² as the therapeutic endpoint, based on metabolic syndrome management guidelines. 1
• Focus on reducing visceral (central) obesity specifically, as this shows the strongest correlation with psoriasis severity and subclinical vascular disease. 2, 1
• Consider bariatric surgery (gastric bypass) for patients with BMI ≥40 kg/m² who fail conventional weight-loss programs, as case series demonstrate psoriasis remission following surgery. 1

The strength of this recommendation is particularly robust because obesity is both a risk factor for developing psoriasis (OR 1.66 for all patients, OR 2.23 for moderate-to-severe disease) and directly correlates with disease severity. 2

Critical Lifestyle Modifications

Smoking Cessation (Mandatory)

• Smoking cessation is non-negotiable, as smoking prevalence in psoriasis patients (37%) far exceeds the general population (13-20%), and smoking directly aggravates disease severity. 1, 4
• Cessation leads to progressive decline in psoriasis severity over time, making this intervention both disease-modifying and cardiovascular risk-reducing. 1
• Smoking is particularly associated with pustular psoriasis variants and increases cardiovascular mortality risk in this already high-risk population. 1, 4

Alcohol Limitation

• Limit alcohol to ≤2 drinks per day, as consumption above this threshold increases psoriasis severity, limits systemic treatment options, and reduces treatment efficacy. 1

Specific Dietary Modifications

Omega-3 Fatty Acid Supplementation

• Add omega-3 fatty acids (fish oil) as adjunctive therapy to topical, systemic, or phototherapy treatments, but not as monotherapy. 1, 5
• Replace saturated fatty acids with omega-3 polyunsaturated fatty acids, which have direct anti-inflammatory effects on the TNF-α/IL-23/IL-17 pathway. 6, 5
• Patient-reported outcomes show 44.6% of patients report skin improvement with fish oil/omega-3 supplementation. 7

Gluten-Free Diet (Selective Use Only)

• Implement a gluten-free diet ONLY in patients with confirmed celiac disease or positive celiac antibodies (anti-gliadin IgA/IgG, anti-endomysial, or anti-tissue transglutaminase antibodies). 1, 3
• Do not recommend gluten-free diets universally, as evidence supports benefit only in the subset with documented gluten sensitivity. 1, 3
• Among patients with gluten sensitivity, 53.4% report skin improvement with gluten elimination. 7

Antioxidant-Rich Foods

• Increase intake of fruits, vegetables, and legumes, which provide antioxidants (vitamins A, C, E, carotenoids, flavonoids, selenium) that counter oxidative stress in psoriasis. 6
• Patient surveys show 42.5% report skin improvement with increased vegetable consumption. 7

Vitamin D Supplementation

• Supplement with vitamin D, as psoriasis patients frequently have deficiency and supplementation shows benefit, particularly for those with psoriatic arthritis. 3, 6, 5
• Oral vitamin D supplementation yields 41% patient-reported skin improvement. 7

Foods to Reduce or Avoid

• Reduce simple sugars and saturated fatty acids, which activate inflammatory pathways (NLRP3 inflammasome, TNF-α/IL-23/IL-17 axis) and worsen psoriasis. 6, 5
• Limit red meat consumption, as it exacerbates inflammation through multiple mechanisms including reactive oxygen species and prostanoid/leukotriene production. 5
• Reduce nightshade vegetables if individual patients report worsening, as 52.1% of those eliminating nightshades report improvement. 7

Dietary Patterns with Evidence

While individual nutrient modifications are important, certain dietary patterns show promise:

• Mediterranean diet is being actively studied for psoriasis management and aligns with anti-inflammatory principles (high omega-3, antioxidants, fiber). 8
• Patient-reported outcomes favor Pagano diet (72.2% improvement), vegan diet (70% improvement), and Paleolithic diet (68.9% improvement), though these lack rigorous clinical trial data. 7

Cardiovascular Risk Management Through Diet

Dietary interventions must address cardiovascular risk, as psoriasis itself is an independent risk factor for myocardial infarction. 2, 9

Screening and Risk Stratification

• Apply a 1.5 multiplication factor to standard cardiovascular risk scores for patients with ≥10% body surface area involvement or those receiving systemic/phototherapy. 2, 1, 9
• Screen all patients for metabolic syndrome using ATP III criteria (≥3 of: waist ≥102 cm men/≥88 cm women, BP ≥130/85 mmHg, triglycerides ≥150 mg/dL, HDL <40 mg/dL men/<50 mg/dL women, fasting glucose ≥100 mg/dL). 2, 1
• Screen for hypertension yearly in patients ≥40 years or those overweight/obese. 2
• Screen for diabetes every 3 years in adults aged 40-70 with BMI ≥25 kg/m². 2

Dietary Management of Comorbidities

• Follow national guidelines for hypertension and dyslipidemia management, with targets based on the 1.5-multiplied cardiovascular risk calculation. 2, 9
• Dietary modifications for cardiovascular risk are particularly important because lifestyle changes can modify the excess risk conferred by psoriasis itself. 2, 9

Common Pitfalls to Avoid

• Do not recommend restrictive diets without evidence: Only gluten-free diets in serologically confirmed gluten sensitivity have strong support. 1, 3
• Do not use dietary interventions as monotherapy: Always combine with standard medical therapies for psoriasis. 3
• Do not overlook the bidirectional relationship: Obesity worsens psoriasis AND psoriasis promotes metabolic dysfunction, requiring aggressive intervention on both fronts. 2, 1
• Do not assume behavioral risk factors developed after psoriasis onset: The majority of risk factors (smoking, obesity) precede disease development and represent true causal relationships. 4

Integration with Pharmacologic Treatment

• Supplement folic acid in patients taking methotrexate as part of dietary management. 6
• Monitor for non-alcoholic fatty liver disease (NAFLD) with alanine aminotransferase every 2-3 years in overweight/obese patients, as this affects treatment choices. 1
• Weight loss improves response to systemic therapies, making dietary intervention synergistic with pharmacologic management. 2, 1