Nutritional strategies for psoriasis Original paper

A variety of dietary recommendations have been developed that may improve psoriasis symptoms, but individual studies have produced mixed results. A review of the available research may identify nutritional strategies with good evidence.

This review examined the evidence for a variety of micro- and macronutrients, as well as diets intended to treat psoriasis.

The authors summarized their findings as follows:

• Obesity and metabolic syndrome frequently co-occur with psoriasis, and a low-energy diet has been found effective in reducing psoriasis symptoms in people with excess body weight.

• Excess consumption of simple sugars (glucose, fructose, and sucrose) has been reported to contribute to psoriasis symptom severity. Carbohydrates with dietary fiber and a low glycemic index, such as whole grains and unprocessed vegetables, may be preferable to simple sugars for people with psoriasis.

• Because inflammation is a central contributor to psoriasis, foods and supplements with antioxidant effects have been investigated. Polyunsaturated fatty acids from the omega−3 family have an anti-inflammatory effect, and excess consumption of omega−6s relative to omega−3s is associated with increased severity of psoriasis. The authors also recommend consumption of foods rich in antioxidants, such as carotenoids, flavonoids, selenium, and vitamins A, C, and E.

• Vitamin D deficiency is associated with an increased risk of psoriasis, and psoriasis symptoms often intensify in winter, when skin synthesis of vitamin D is reduced. Although the negative effects of vitamin D deficiency are compelling, intervention trials examining the effect of supplementation on psoriasis are needed.

• A gluten-free diet has been proposed for people with psoriasis. Celiac disease and psoriasis are both autoimmune diseases, and asymptomatic celiac disease is observed more frequently in people with psoriasis compared to the general population. Some reports suggest positive effects from a gluten-free diet, but it has not been clearly established whether gluten consumption can contribute to psoriasis.

• Although research into a strictly vegetarian diet is lacking, the authors suggest that a diet rich in fruit and vegetables may significantly contribute to improvements in psoriasis.

• A 2015 observational study^[1] found that psoriasis symptom severity was lower in participants with greater adherence to a Mediterranean diet, which is characterized by a high consumption of vegetables, cereals, legumes, fish, fruit, nuts, and extra virgin olive oil. People with psoriasis had higher fat mass percentages and lower adherence to a Mediterranean diet overall, which could mediate the association between the diet and reduced symptom severity.

• Some research suggests that a low-calorie ketogenic diet could lead to weight loss and a reduction in chronic inflammation, which could benefit people with psoriasis. The authors noted that further studies are needed to compare the effects of ketogenic and other diets on psoriasis symptoms.

This review did not have specific criteria for inclusion or exclusion of studies.