Psoriasis is a chronic inflammatory disease that affects the skin. Red, thick patches with silvery scales develop, and these plaques that form cause the area to itch or become sore. This is the effect of new cells rapidly turning over and accumulating on the skin's surface.
Psoriasis can occur anywhere on the skin, but some of the most commonly affected areas include the scalp, face, elbows and knees.
As with other autoimmune diseases, the exact cause of psoriasis is not known, but in many cases, it appears to be influenced by genetics and environmental aspects. Additional risk factors for individuals with psoriasis include psoriatic arthritis, an elevated body mass index and co-morbidities, such as metabolic syndrome and cardiovascular disease.
According to research, carrying excess body weight is associated with more severe psoriasis symptoms and a decreased response to medication and other treatments. A 2018 systematic review, published in JAMA Dermatology, looked at several diet-related factors and how they impact psoriasis severity. They found that weight loss among individuals with a BMI in the overweight or obese range was associated with improved psoriasis symptoms, specifically when following a hypocaloric diet. And, despite an increased risk of celiac disease among individuals with psoriasis, evidence did not support the use of a gluten-free diet for controlling psoriasis severity among these individuals without confirmed celiac disease or gluten sensitivity.
Some studies have found that foods with anti-inflammatory properties may help in the management of psoriasis severity. Obtaining the recommended amount of omega-3 fatty acids has been considered beneficial; however, results have been mixed when evaluating the effectiveness of oral fish oil supplements and psoriasis severity, so obtaining them through dietary sources is encouraged. Additional studies, but with low quality evidence, have investigated the effect of a Mediterranean dietary pattern in patients with psoriasis, therefore a trial of this type of eating style may be considered along with conventional treatment. Additionally, vitamin D has been found to be a nutrient of interest, as a deficient state is associated with increased severity of symptoms. However, studies have not found vitamin D supplementation to be helpful in managing psoriasis in the absence of a deficiency.
Another area of interest is the use of a very low-calorie ketogenic diet (VLCKD) as a treatment for psoriasis due to its potential to decrease visceral adipose tissue and inflammation. However, there are currently few studies looking at VLCKD in managing this condition, and the research thus far has not determined whether the reduction in psoriasis severity was a result of the dietary intervention or due to overall weight loss. As with other diets and psoriasis, more research is needed.
Although there are no evidenced-based nutrition guidelines or therapeutic diets currently available for psoriasis, registered dietitian nutritionists can assist patients and clients with lifestyle interventions to help lessen its severity, including weight loss, when warranted and addressing any potential nutrient deficiencies, along with the appropriateness of dietary supplements.
- National Institute of Arthritis and Musculoskeletal and Skin Diseases. Psoriasis. Accessed August 3, 2022.
- Ford AR, Siegel M, Bagel J, et al. Dietary Recommendations for Adults With Psoriasis or Psoriatic Arthritis From the Medical Board of the National Psoriasis Foundation: A Systematic Review . JAMA Dermatol. 2018;154(8):934–950.
- Barrea L, Megna M, Cacciapuoti S, et al. Very low-calorie ketogenic diet (VLCKD) in patients with psoriasis and obesity: an update for dermatologists and nutritionists. Crit Rev Food Sci Nutr. 2022;62(2):398-414.
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