Low Glycemic Load or Index Diet in Association with Acne Vulgaris: A Systematic Review and Meta-analysis

Background: Social life can be affected by skin condition. Acne Vulgaris (AV) is a multi-factorial skin disorder that affects many people. Several dietary factors are associated with AV.Objectives: Different findings on glycemic indices led us to investigate the effect of the dietary glycemic index (GI) and glycemic load (GL) on AV by a systematic review and meta-analysis.Methods: Observational studies and clinical trials were extracted from PubMed, EMBASE, Scopus, and Google Scholar. The mean ± Standard division (SD) for acne grading in clinical trials and the mean ± SD GI or GL of the diet for observational studies were used for meta-analysis.Results: We found that nine out of ۱۵ studies were eligible for systematic review clinical trials (N = ۳) and observational studies (N = ۶) designs. The meta-analysis of three studies clinically assessed the effect of GI/GL on acne and showed that a diet with lower GI/GL reduced the acne severity (Hedges’g = -۰.۹۱, ۹۵% CI: -۱.۵۷, -۰.۲۵, P = ۰.۰۰۷). The analysis of six observational studies showed that dietary habit with higher GI might not affect the acne severity in patients with AV (Hedges’g = ۰.۰۷, ۹۵%CI: -۰.۲۳, ۰.۳۸, P = ۰.۶۳۶), but individuals with higher acne severity had a diet with higher GL (Hedges’g = ۰.۶۴, ۹۵%CI: ۰.۰۱, ۱.۲۶, P = ۰.۰۴۵).Conclusions: Diet, as a part of lifestyle, is associated with AV. Adherence to lower GL diet may reduce the severity of AV. Further well-designed clinical trials are required to confirm these results.