In westernized societies, acne vulgaris is a nearly universal skin disease afflicting 79% to 95% of the adolescent population. In men and women older than 25 years, 40% to 54% have some degree of facial acne, and clinical facial acne persists into middle age in 12% of women and 3% of men. Epidemiological evidence suggests that acne incidence rates are considerably lower in nonwesternized societies. Herein we report the prevalence of acne in 2 nonwesternized populations: the Kitavan Islanders of Papua New Guinea and the Aché hunter-gatherers of Paraguay. Additionally, we analyze how elements in nonwesternized environments may influence the development of acne.
Tubers, fruit, fish, and coconut represent the dietary mainstays in Kitava. Dietary habits are virtually uninfluenced by Western foods in most households. The intake of dairy products, alcohol, coffee, and tea was close to nil, and that of oils, margarine, cereals, sugar, and salt was negligible. Estimated carbohydrate intake was high, almost 70% of daily energy, while total fat intake was low (20% of daily energy). Virtually all of the dietary carbohydrate intake was in the form of low–glycemic load tubers, fruits, and vegetables.
The Aché diet contains wild, foraged foods, locally cultivated foods, and Western foods obtained from external sources. By energy, their diet consists of 69% cultigens, 17% wild game, 8% Western foods, 3% domestic meat, and 3% collected forest products. The cultigens consist mainly of sweet manioc, followed by peanuts, maize, and rice, whereas the Western goods are mainly pasta, flour, sugar, yerba tea, and bread.
Both the Aché and Kitavan diets are composed of minimally processed plant and animal foods and are virtually devoid of typical Western carbohydrates that yield high glycemic loads that may acutely or chronically elevate insulin levels (Table 1). Recently acculturated hunter-gatherer populations who have adopted Western diets frequently are hyperinsulinemic and insulin resistant and have high rates of type 2 diabetes, whereas hunter-gatherer and less westernized populations living in their native environments rarely exhibit these symptoms, including other unacculturated South American Indian tribes. Neither the Kitavan islanders nor the Aché hunter-gatherers manifest the classic symptoms of insulin resistance. The Kitavans are not overweight or hypertensive, and they maintain low serum concentrations of insulin, plasminogen activator inhibitor 1, and leptin, which are indicators of high insulin sensitivity.
Dietary interventions using low–glycemic load carbohydrates may have therapeutic potential in the treatment of acne because of the beneficial endocrine effects of these diets. Low–glycemic load diets are associated with a reduced risk for type 2 diabetes and dietary interventions using low–glycemic load carbohydrates improve insulin sensitivity. Furthermore, a large-scale intervention has demonstrated that diets rich in low–glycemic load foods reduced serum testosterone and fasting glucose levels while improving insulin metabolism and increasing concentrations of SHBG. These endocrine changes are consistent with those known to promote normal follicular cell proliferation and to reduce sebum production. It is possible that low–glycemic load diets may have therapeutic potential in reducing symptoms of acne, a disease virtually unknown to the Aché and Kitavans.
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https://jamanetwork.com/journals/jamadermatology/fullarticle/479093