Effect of the Glycemic Index of Carbohydrates on Acne vulgaris

Rebecca C Reynolds,Jennie C Brand-Miller,Fiona S Atkinson,Karola S Stockmann,Peter Petocz,James Y J Choi,Stephen Lee

doi:10.3390/nu2101060

Rebecca C Reynolds, Jennie C Brand-Miller + Show 5 more

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https://doi.org/10.3390/nu2101060

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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/m2) 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.

Highlights

Acne vulgaris is a prevalent skin disorder with substantial physical and psychological morbidity
Twelve subjects discontinued because they were unwilling to adhere to the diet and three subjects were omitted from data analysis due to missing acne gradings
At baseline, DHEA-S was higher in those allocated to the low glycemic index (GI) diet (p = 0.04)

Summary

Introduction

Acne vulgaris (acne) is a prevalent skin disorder with substantial physical and psychological morbidity. Dietary factors have long been considered unimportant, insulin resistance (IR) and dietary carbohydrates have recently been implicated in the etiology of acne [1,2]. The glycemic index (GI) of meals has been directly correlated to insulin response [3] and low GI diets have been shown to decrease IR [4]. High insulin concentrations in the fasting and/or postprandial state may exacerbate acne by increasing the proliferation of basal keratinocytes. Insulin stimulates the synthesis of androgens leading to high sebum production, a recognized correlate of acne severity [5]. IR could increase inflammatory responses within and adjacent to the comedo [6]

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