MELBOURNE, Australia— That lunchtime burger and fries may affect more than just waistlines. Two Australian studies found a low glycemic-load, high-protein diet may be linked to acne vulgaris. In the first study, 43 male patients with acne completed a 12-week, parallel, dietary intervention study with investigator-masked dermatology assessments. Primary outcomes measures were changes in lesion counts, sex hormone binding globulin, free androgen index, insulin-like growth factor-I and insulin-like growth factor binding proteins (J Am Acad Dermatol. 2007 Aug;57(2):247-56).
At 12 weeks, total lesion counts had decreased more in the experimental group (-21.9) compared with the control group (-13.8). The experimental diet also reduced weight (P=0.001), reduced the free androgen index (P=0.04) and increased insulin-like growth factor binding protein-1 (P=0.001) when compared with a high glycemic-load diet. The researchers did note they could not preclude the role of weight loss in the overall treatment effect.
The second study, 43 male acne patients aged 15 to 25 years were recruited for a 12-week, parallel design, dietary intervention incorporating investigator-blinded dermatology assessments (Am J Clin Nutr. 2007;86(1):107-115). The experimental treatment was a low-glycemic-load diet composed of 25-percent energy from protein and 45 percent from low-glycemic-index carbohydrates. In contrast, the control situation emphasized carbohydrate-dense foods without reference to the glycemic index (GI). Acne lesion counts and severity were assessed during monthly visits, and insulin sensitivity (using the homeostasis model assessment) was measured at baseline and 12 weeks.
At 12 weeks, mean (±SEM) total lesion counts had decreased more (P=0.03) in the low-glycemic-load group (–23.5 ± 3.9) than in the control group (–12.0 ± 3.5). The experimental diet also resulted in a greater reduction in weight (–2.9 ± 0.8 compared with 0.5 ± 0.3 kg; P<0.001) and body mass index (BMI) and a greater improvement in insulin sensitivity than did the control diet.
Researchers concluded the improvement in acne and insulin sensitivity after a low-glycemic-load diet suggests nutrition-related lifestyle factors may play a role in the pathogenesis of acne. However, further studies are needed to isolate the independent effects of weight loss and dietary intervention and to further elucidate the underlying pathophysiologic mechanisms.
Moral of the story? We really are what we eat. More fuel for the nutricosmetics fire.