Photo Credit: Lipowski

Researchers reviewed a host of studies investigating diet plans in an effort to guide evidence-based recommendations for patients with psoriasis.

Despite limited comprehensive evidence supporting the benefits of dietary intervention in treating psoriasis, studies have shown a promising correlation between restrictive diets and reduced symptoms. There are several diet plan options available that have shown promise in this capacity.

To develop an evidence-based foundation to inform dietary recommendations for patients with psoriasis, Xin Li, MM, and colleagues organized a narrative review of studies that addressed the viability of several diet plans that alleviate psoriasis symptoms. The findings were published in Clinical Nutrition.

Mediterranean Diet

Studies have found that the Mediterranean diet benefits patients with inflammation, cancer, and cardiovascular disease. The researchers noted that several studies have also shown improved results for patients with psoriasis who adhere to the diet.

Both Psoriasis Area and Severity Index (PASI) and C-reactive protein (CRP) scores were diminished in patients with psoriasis on the Mediterranean diet. This improvement was attributed to the following essential components of the nutritional plan:

• Use of extra virgin olive oil as the primary cooking lipid;
• At least three servings of fruit per day;
• Less than one serving of processed or red meat per day;
• At least three servings of legumes per week;
• At least three pescatarian meals per week; and
• At least three servings of tree nuts per week.

The results were replicated in several studies reviewed.

Gluten-free Diet

The elimination of gluten was also found to be beneficial to patients with psoriasis. Gluten restriction has been vital to the treatment of Celiac disease, and studies have shown that patients with Celiac and psoriasis have experienced a benefit in improved inflammatory status and reduced symptoms in both diseases when a gluten-free diet was used.

Studies also noted that, as a result of the diet, positive serum antibodies—including immunoglobulin A (IgA) tissue transglutaminase antibodies, IgA anti-gliadin antibodies, endomysial IgA antibodies, and immunoglobulin G anti-gliadin antibodies—were detected.

Calorie Reduction & Keto

The review also included a very low-calorie diet (VLCD) and a very low-calorie ketogenic diet (VLCKD), which is a more stringent version of VLCD. A case study documented a patient who experienced complete relief of psoriasis symptoms after adhering to a 300 calorie per day diet in which enteral nutrition, using a protein-based formula, was used to sustain her.

Another study introduced a low carbohydrate diet, with protein comprising 15% to 30% of total caloric intake, to 25 patients with psoriasis who were also treated with tumor necrosis factor alpha inhibitors. Compared to a control group receiving the biological therapy without dietary intervention, the restricted diet group experienced lower PASI scores.

Studies that examined patients using a VLCKD also found a reduction of symptoms and attributed this improvement to corrections in amino acid pathways.

n-3 Fatty Acid Enrichment

There were mixed results among several studies that observed the impact of n-3 fatty acid supplements. One study showed improved psoriatic skin lesions without an improved PASI score. Another study noted an improvement of plaque psoriasis symptoms and obesity with a diet rich in polyunsaturated fatty acids. It was hypothesized that the increase of n-3 fatty acids results in the modulation of inflammatory cytokine pathways, alleviating psoriasis symptoms.

Despite the mixed results, the researchers found enough benefits across the studies to consider this dietary intervention as an alternative or supplemental treatment option.

Additional Options

Other dietary interventions that positively affected psoriasis symptoms included probiotic and prebiotic supplementation, dietary and seaweed fiber, coffee consumption, a reduced-salt diet, and alcohol restriction. The studies also showed that antioxidant and vitamin D supplementation showed little success in reducing psoriasis symptoms.

“Although this is a relative scarcity of high-quality studies on the dietary treatment of psoriasis, the limited existing data substantiate that a healthy diet positively impacts psoriasis and represents a crucial nonpharmalogical approach to its management,” the researchers concluded.