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 15 studies were eligible for systematic review clinical trials (N = 3) and observational studies (N = 6) 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 = -0.91, 95% CI: -1.57, -0.25, P = 0.007). 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 = 0.07, 95%CI: -0.23, 0.38, P = 0.636), but individuals with higher acne severity had a diet with higher GL (Hedges’g = 0.64, 95%CI: 0.01, 1.26, P = 0.045). Conclusions: Diet, as a part of life style, 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.