A pilot study to determine the short‐term effects of a low glycemic load diet on hormonal markers of acne: A nonrandomized, parallel, controlled feeding trial

Abstract

Observational evidence suggests that dietary glycemic load may be one environmental factor contributing to the variation in acne prevalence worldwide. To investigate the effect of a low glycemic load (LGL) diet on endocrine aspects of acne vulgaris, 12 male acne sufferers (17.0 ± 0.4 years) completed a parallel, controlled feeding trial involving a 7‐day admission to a housing facility. Subjects consumed either an LGL diet (n = 7; 25% energy from protein and 45% from carbohydrates) or a high glycemic load (HGL) diet (n = 5; 15% energy from protein, 55% energy from carbohydrate). Study outcomes included changes in the homeostasis model assessment of insulin resistance (HOMA‐IR), sex hormone binding globulin (SHBG), free androgen index (FAI), insulin‐like growth factor‐I (IGF‐I), and its binding proteins (IGFBP‐I and IGFBP‐3). Changes in HOMA‐IR were significantly different between groups at day 7 (–0.57 for LGL vs. 0.14 for HGL, p = 0.03). SHBG levels decreased significantly from baseline in the HGL group (p = 0.03), while IGFBP‐I and IGFBP‐3 significantly increased (p = 0.03 and 0.03, respectively) in the LGL group. These results suggest that increases in dietary glycemic load may augment the biological activity of sex hormones and IGF‐I, suggesting that these diets may aggravate potential factors involved in acne development.