Chocolate and acne

I found this article about diet and acne. It is based on the study below where researchers looked for a relationship between low-glycemic index foods and acne. It also addressed the popular association between acne and chocolate.

Smith RN, Mann NJ, Braue A, Mäkeläinen H, Varigos GA.A low-glycemic-load diet improves symptoms in acne vulgaris patients: a randomized controlled trial. Am J Clin Nutr. 2007 Jul;86(1):107-15.

This looked like a well-done study comparing a LGL (low glycemic load) diet group of 15-25 year old males with a normal diet group. The study was blinded to both the participants and the dermatologists who graded their acne. Of course, acne severity can be subjective, but the group also had independent raters who did sort of a quality control on the acne gradings.

The study addresses hyperinsulinemia, high androgen levels, acne, and the relationship to diet. The LGL diet group was given foods with a slower glucose release, like complex carbs, whole grains, and proteins. Not only was there a statistically significant difference in number of lesions and inflammatory response, but there was also a significant weight loss in the LGL diet group. The negatives of this study are that it was a relatively small sample group, unigender, and a narrow age range. But, for this population, acne severity was decreased by following the low glycemic load diet.

The basis for this is that high glucose levels in the blood cause a high insulin level. This was shown over time to decrease insulin sensitivity. Hyperinsulinemia is associated with increased androgen bioavailability and free concentrations of insulin-like growth factor I. So people gain weight and get acne.


Fulton J, Plewig G, Kligman A. Effect of chocolate on acne vulgaris. JAMA 1969;210:2071–4.

This is the study showing that acne and chocolate are not related. But the study design has been criticized because the placebo candy bar had similar nutritional contents to the chocolate bar.

My conclusion based on these studies is that maintaining a diet high in complex carbs and protein is good for weight, insulin resistance, and acne; but the exact mechanism of the effect on acne needs to be investigated further.