> Overall these theories provide a plausible and useful guide to the possible mechanisms by which a high-GI diet and dairy products can exert their effects in the pathogenesis of acne and can explain in part why people native to Papua New Guinea and Paraguay, living non-Westernized lifestyles, have no acne compared with more Westernized populations such as in Belgium (Table 2 and Table S1; see Supporting Information). However, they provide only the first step to understanding the link between diet and acne.

From http://onlinelibrary.wiley.com/doi/10.1111/bjd.13462/full