Acne: the role of medical nutrition therapy.
Acne is a common disease in Westernized nations, particularly among adolescents and young adults. Acne has substantial effects on quality of life, making treatment essential. Medical nutrition therapy as a potential treatment for acne is not new, although the literature examining diet and acne during the past 100 years is mixed. During the late 1800s and early 1900s, diet was commonly used as an adjunct treatment for acne. During the 1960s, however, the diet-acne connection fell out of favor. In recent years, dermatologists and registered dietitians have revisited the idea and become increasingly interested in the role of medical nutrition therapy in acne treatment. This article reviews the history and existing literature examining the association between diet and acne. Although the total number of studies conducted within the past 40 years is relatively small, the growing body of epidemiologic and experimental evidence suggests a relationship between diet and acne. Compared with other dietary factors, more research examines dietary glycemic load. The evidence is more convincing for high glycemic load diets, compared with other dietary factors. To date there are no randomized controlled trials investigating the relationship between frequent dairy or milk consumption and acne. Similarly, the number of research studies examining the relationship between dietary fat and/or n-3 fatty acids is sparse and the evidence is less robust. Taken together, several methodologic limitations need to be addressed, and additional research, preferably randomized controlled trials, is warranted before comprehensive evidence-based guidelines can be established. While dermatologists and registered dietitians continue to debate and research the potential relationship between diet and acne, the best dietary approach is to address each acne patient individually, carefully considering the possibility of dietary counseling.