title: Effect of the glycemic index of carbohydrates on Acne vulgaris.
abstract: Acne vulgaris may be improved by dietary factors that increase insulin sensitivity. We hypothesized that a low-glycemic index diet would improve facial acne severity and insulin sensitivity. Fifty-eight adolescent males (mean age ± standard deviation 16.5 ± 1.0 y and body mass index 23.1 ± 3.5 kg/m(2)) were alternately allocated to high or low glycemic index diets. Severity of inflammatory lesions on the face, insulin sensitivity (homeostasis modeling assessment of insulin resistance), androgens and insulin-like growth factor-1 and its binding proteins were assessed at baseline and at eight weeks, a period corresponding to the school term. Forty-three subjects (n = 23 low glycemic index and n = 20 high glycemic index) completed the study. Diets differed significantly in glycemic index (mean ± standard error of the mean, low glycemic index 51 ± 1 vs. high glycemic index 61 ± 2, p = 0.0002), but not in macronutrient distribution or fiber content. Facial acne improved on both diets (low glycemic index -26 ± 6%, p = 0.0004 and high glycemic index -16 ± 7%, p = 0.01), but differences between diets did not reach significance. Change in insulin sensitivity was not different between diets (low glycemic index 0.2 ± 0.1 and high glycemic index 0.1 ± 0.1, p = 0.60) and did not correlate with change in acne severity (Pearson correlation r = -0.196, p = 0.244). Longer time frames, greater reductions in glycemic load or/and weight loss may be necessary to detect improvements in acne among adolescent boys.
authors.affiliation: Human Nutrition Unit, School of Molecular Bioscience G08, The University of Sydney, NSW 2006, Australia. r.reynolds@usyd.edu.au
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Reynolds
authors.forename: Stephen
authors.initials: S
authors.lastname: Lee
authors.forename: James Y J
authors.initials: JY
authors.lastname: Choi
authors.forename: Fiona S
authors.initials: FS
authors.lastname: Atkinson
authors.forename: Karola S
authors.initials: KS
authors.lastname: Stockmann
authors.forename: Peter
authors.initials: P
authors.lastname: Petocz
authors.forename: Jennie C
authors.initials: JC
authors.lastname: Brand-Miller
mesh_terms: D000152:Acne Vulgaris / Q000178:diet therapy*; D000293:Adolescent; D004032:Diet; D004040:Dietary Carbohydrates / Q000378:metabolism*; D038321:Glycemic Index; D006801:Humans; D007333:Insulin Resistance; D008297:Male
chemical_list: D004040:Dietary Carbohydrates