November 13, 2018
By: Michelle Iannacchino
Diet and Dermatology: What is the Role for Medical Nutrition Therapy?
Date: Sunday, October 21st
Speakers: Kathleen Woolf, PhD, RDN, FACSM, Jennifer Burris PhD, RD, CNSC, CSSD, CSG, CDE
Session Description: Acne and psoriasis are two common chronic skin conditions affecting millions of Americans in the United States. Treatments have typically consisted of expensive medications that often come with serious and undesirable side effects. However, over the last decade, there has been a significant increase in research examining the relationship between diet and dermatology, providing an alternative route through lifestyle changes. This talk provided literature examining the role of medical nutrition therapy in aggravating, preventing, and treating acne and psoriasis along with the limitations and gaps that need further research.
- The Diet-Acne Hypothesis targets a handful of dietary factors that have recently been tied to potentially causing and inflaming acne. Dietary factors discussed included: Glycemic Index (GI) or Glycemic Load (GL), Dairy/Milk, Omega-3 Fatty Acids, and Chocolate.
- Glycemic Index/Load - Foods with a high GI are rapidly digested and absorbed causing hyperglycemia and reactive hyperinsulinemia. Foods with a low GI have a more gradual response, which has been observed to reduce some factors associated with acne.
- Dairy/Milk - Dairy contains carbohydrate that may increase acne through diet-induced hyperinsulinemia, which increases insulin-like growth factor 1 (IGF-1) concentrations. This pathway is similar to that described for high GI/GL diets. Among a variety of studies, it was observed that participants that consumed milk had a 16% increased risk of acne compared to those that did not drink milk.
- Omega-3 Fatty Acids - Omega-3 fatty acids are hypothesized to reduce acne severity primarily by suppressing inflammatory mediators. It may also diminish acne by decreasing insulin and IGF-1 concentrations.
- Chocolate - There has been very little research examining the relationship between chocolate and acne and no significant findings.
- Psoriasis is a chronic, inflammatory, autoimmune skin condition with underlying cellular changes. Common symptoms include scaling, itching, redness, and burning. Developing psoriasis is multi-factorial and involves genetic, immunological, and environmental factors. Various medical therapies for psoriasis consist of topical agents, phototherapy, oral medications, and biologics. Unfortunately, dietary interventions are rarely discussed due to lack of knowledge by physicians.
- The factors addressed with the Diet-Psoriasis Hypothesis included weight reduction diet, gluten-free diet, Mediterranean diet, and dietary supplementation.
- Weight Reduction Diet – Obesity and increased body weight leads to an increase in psoriasis incidence and severity and a decrease in effective treatments. Psoriasis may be mediated by the pro-inflammatory effects of adipose tissue. The Psoriasis Area and Severity Index (PASI) score, which measures the degree of a patient’s psoriasis, was known to decline once BMI decreased.
- Mediterranean Diet – This diet is characterized by a high proportion of fruits, vegetables, legumes, cereals, bread, fish, nuts and extra virgin olive oil. Anti-inflammatory properties of the dietary fibers, antioxidants, and polyphenols may help reduce chronic, systemic inflammation. Participants in a study who followed this diet for two years had a significant improvement in their psoriasis compared to the ones who did not adhere to the diet.
- Gluten-free Diet – The gluten-free diet has been suggested as being helpful for select patients with psoriasis. This diet has been shown to improve clinical psoriasis severity and skin biopsy findings for those with serological markers of gluten sensitivity.
- Dietary Supplementation (vitamin D and omega-3 fatty acids) – Poor vitamin D levels are very common in patients with psoriasis and have been associated with the severity. While topical vitamin D has been found to be an effective treatment option, the benefit of oral supplementation is less certain. Regarding omega-3 fatty acids, studies evaluating the use of oral fish oil supplementation in psoriasis show conflicting results and need further research.