Acne is the most common skin condition, affecting up to 50 million individuals annually. Self-esteem is affected, and scarring can result if left untreated or inadequately treated. Although still somewhat controversial in some circles, available data have linked acne to dairy products, refined sugar ingestion, and high glycemic loads.
Acne has been linked to insulin levels and insulin-like growth factor (IGF-1). Glycemic loads are associated with both insulin and IGF-1. Metformin reduces glucose release from the liver while increasing glucose uptake in muscles and adipocytes.
Dr. Jon O. Ebbert
So, can interventions that reduce glycemic load, such as diet and metformin, decrease the incidence of acne in patients among whom other standard interventions have been tried?
Gabriella Fabbrocini, MD, of the University of Naples, Italy, and her colleagues tested this hypothesis by conducting a randomized, clinical trial evaluating the impact of a low glycemic diet and metformin on acne (Clin Exp Dermatol. 2016 Jan;41[1]:38-42). Twenty males aged 17-24 years with acne for at least 1 year were randomized to either metformin 500 mg twice daily with a 1,500- to 2,000-kcal diet rich in fruits, vegetables, fish, and low carbohydrates with standard therapy; or standard therapy alone. Standard therapy consisted of a bland skin detergent and a sebostatic cream. Acne severity was rated by four observers.
Patients in the metformin group demonstrated a statistically significant improvement in acne severity, compared with patients in the standard care only group. No side effects were reported with metformin.
In this study, only patients with an “altered metabolic profile” were enrolled and randomized. An “altered metabolic profile” was defined as impaired fasting glucose, high total cholesterol or LDL, reduced HDL, and elevated waist circumference and body mass index. Results should be generalizable only to patients with these characteristics. The sample size in this study was small, but the included picture of acne resolution on one subject was indeed impressive.
For patients among whom traditional acne treatment approaches have not been effective, and knowing the tolerability and affordability of metformin, this may be a reasonable intervention.
Dr. Ebbert is professor of medicine, a general internist at the Mayo Clinic in Rochester, Minn., and a diplomate of the American Board of Addiction Medicine. The opinions expressed are those of the author and do not necessarily represent the views and opinions of the Mayo Clinic. The opinions expressed in this article should not be used to diagnose or treat any medical condition, nor should they be used as a substitute for medical advice from a qualified, board-certified practicing clinician. Dr. Ebbert has no relevant financial disclosures about this article.