At her session, “Diet and Psoriasis,” April W Armstrong, MD, MPH, FAAD, dove into the research and literature surrounding the impact of diet in psoriasis treatment.

She opened her session with the 3 topic questions she’d be addressing:

• Are gluten-free diets helpful in psoriasis?
• What is the effect of dietary weight reduction in psoriasis?
• Are there any specific foods, nutrients or dietary patterns that could be helpful in psoriasis?

Dr Armstrong first focused on glutens impact on psoriasis by zeroing in on celiac disease. She noted that celiac disease is seen twice as frequently in patients with psoriasis. Additionally, patients with positive antibodies for gluten sensitivity has an increased rate in patients with psoriasis.

“Interestingly, higher antibody levels of gluten sensitivity are correlated with greater psoriasis severity,” Dr Armstrong shared.

She stated that patients who have had small intestine biopsy with confirmed celiac disease, would find that a gluten-free diet does seem to ameliorate not only the gastrointestinal symptoms, but also reduce psoriasis severity. She also added that patients who tested positive for the markers of gluten sensitivity have also been found to undergo improvements, but those who tested negative or serological markers of gluten sensitivity would find the gluten-free diet to be unhelpful.

As for the question on whether withholding gluten from the patient’s diet will decrease the likelihood of developing psoriasis, Dr Armstrong stressed that currently there's no evidence in supporting that.

Dr Armstrong then moved on to the topic of weight reduction in psoriasis. She shared that if patients can really stick to a restrictive hypo caloric diet, there can be improvements seen in psoriasis disease severity index, quality of life and weight loss. She added that the National Psoriasis Foundation recommended that dietary weight reduction with a hypo caloric diet should be used as an adjunct intervention.

“I did want to mention the word adjunctive because a lot of our patients think that dietary restrictions alone can help them improve their psoriasis symptoms,” she added. She suggested that physicians continue their standard of care medical therapies for psoriasis.

Finally, Dr Armstrong addressed the specific foods, nutrients, or dietary patterns that are helpful with psoriasis by stating that this topic is not exactly clear as the evidence on these is currently evolving.

She introduced omega-6 and omega-3 fatty acids that are specifically studied for psoriasis. The omega-6 fatty acids can be metabolized into inflammatory mediators and can be elevated in the psoriasis plaques. However, the omega-3 fatty acids tend to the metabolizable and oppose the actions of this pro inflammatory mediator. She did note that intravenous fish oil supplementation was shown to be beneficial in terms of reducing psoriasis severity, but that it was not recommended to use oral fish oil supplementation as a way of improving psoriasis as there's not enough evidence at this time.

She also addressed the relationship between Western diet and psoriasis. She stated that, epidemiologically, a Western diet can have a number of potentially adverse effects on psoriasis due to the sucrose or the sugar component that was found in a trial using mouse models. She also referenced another study elaborating that the Western diet adverse effects are done by promoting the accumulation of IL-17A producing Gamadelta T-cells. She added authors of the study saw an increasing IL-23 pathway and it may be implicated in the pathogenesis of Western diet associated psoriasis.

Dr Armstrong finished her session by looking at the ketogenic diet. Recent studies showed that patients who underwent the diet were shown to have decreased inflammatory markers, and reduction in PASI alongside the dermatology life quality index. They also saw some improvement in glucose and total cholesterol.

She concluded, “The main message is medical therapy remains to be the most important aspect in our recommendation.”

Reference
Armstrong A. Diet and psoriasis. Presented at: AAD Annual Meeting; March 25-28, 2022; Boston, MA.