Modernization and population health: A natural experimental model of health transition in Vanuatu, South Pacific

Developing countries around the world are experiencing increasing prevalence of chronic diseases and obesity, particularly as lifestyles become more "Westernized" with modernization. Unfortunately, many developing countries lack the resources to treat costly chronic diseases, along with continuing infectious diseases and undernutrition, and psychosocial illnesses that accompany rapid cultural change. This combined disease burden is characteristic of the early stages of health transition, which encompasses the shift from infectious to chronic diseases (epidemiological transition), changing dietary patterns and decreased physical activity levels (nutrition and physical activity transitions), and changing public health focus and technologies. The South Pacific archipelago of Vanuatu exhibits varying rates of economic development, infectious disease patterns, and chronic disease risk across islands, and provides an excellent natural experimental model of health transition. We completed a cross-sectional anthropometric, dietary, and physical activity survey among adults and children on three islands in Vanuatu varying in degree of economic development, and compared these patterns to past studies of health. We analyzed behavioral differences among islands to identify behavioral changes associated with modernization; differences in chronic disease risk measures (such as obesity and central obesity) among islands; and associations among behaviors, environmental factors, and chronic disease risk. Among adults, chronic disease prevalence increased with level of economic development, and lifestyle factors such as consuming processed foods contributed to risk of overweight, obesity, and central obesity. Risk among children was complicated by early growth patterns. Most anthropometric patterns were similar among rural and suburban children, but we observed increased risk of central obesity among adolescent girls on a rural island where malaria was recently eradicated and increased tourism has contributed to rapid and recent lifestyle changes. Stunting in infancy followed by rapid catch-up growth is associated with increased chronic disease risk, and might contribute to these patterns observed in Vanuatu. This research indicates some possible focus areas for chronic disease prevention programs in Vanuatu and in other developing countries, and for interventions in developed countries where chronic diseases are already prevalent. If implemented early, prevention efforts might help developing countries avoid some of the health costs associated with modernization.