Cordain L, Lindeberg S, Hurtado M, Hill K, Eaton S, Brand-MillerJ. Acne vulgaris: a disease of Western civilization. Arch Dermatol. 2004;140(6):696-701.
The article by Cordain and colleagues is an observational study that evaluates 2 isolated nonwesternized populations: the Kitavan Islanders of Papua New Guinea and the Ache hunter-gatherers of Paraguay, who have a lack of acne. Dietary limitations are the only control. The glycemic index of their diets is substantially lower than that of a Western diet. Their genetic backgrounds are similar to those of other South American Indians and Pacific Islanders, who live in more westernized settings and have a considerably higher incidence of acne.