The Effect of Transition from Traditional to Urban Life-Style on the Insulin Secretory Response in Australian Aborigines

Abstract

Recent epidemiologic studies have revealed a high prevalence of maturity-onset diabetes in certain populations that have undergone comparatively rapid urbanization. There is evidence suggesting that Australian Aborigines may respond to urbanization in this way. Thirteen full-blood Aborigines from the Mowanjum Community, Derby, Western Australia, cooperated in the present study. They spent 3 mo living in their traditional hunter-gatherer life-style, after which their insulin response to glucose was measured in a starch tolerance test. The findings were compared in follow-up studies conducted 3 mo after returning to their urban environment. Similar studies were conducted in Caucasians of comparable age and weight. Fasting glucose concentrations were lower in Aborigines than in Caucasians and were unaffected by life-style changes. Although basal insulin levels were similar in the three groups, there were striking intergroup differences in the insulin responses to glucose. The areas under the insulin curves in the first hour after starch ingestion were: urban Aborigines 4478 +/- 465 microU/ml-1/min, traditional Aborigines 2959 +/- 301 microU/ml-1/min, and Caucasians 2097 +/- 224 microU/ml-1/min. This appeared to reflect differences in the early rates of change of glucose concentrations. The data suggest that these Aborigines have an abnormally high insulin response to glucose, which is ameliorated, but not normalized, by reverting to their traditional life-style.

A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease

“…Both diet and physical activity changed markedly, which precludes evaluation about the isolated role of diet. In contrast, in a similar study on healthy Australian Aborigines by the same authors, the insulin response to 70 g of starch from white bread (and butter) was reduced, while the glucose response was not, after 10-12 weeks of reversion to a traditional lifestyle [50].…”

Animal foods in traditional Australian aboriginal diets: Polyunsaturated and low in fat

“…Although Australian Aborigines develop high frequencies of diabetes and diseases of the cardiovascular system when they are living in an urban environment (1)(2)(3), there is no evidence that they suffered from these conditions when living traditionally as hunter-gatherers. Indeed, we have shown that when urbanized Aborigines revert temporarily to their hunter-gatherer lifestyle, there are significant reductions in the risk factors for diabetes and heart disease in nondiabetic subjects (4,5) and marked improvement in the metabolic abnormalities associated with these diseases in diabetics (6).…”

The western diet and lifestyle and diseases of civilization

“…It has been argued that traditional populations may have been genetically protected against the chronic degenerative diseases that occur in industrialized countries, yet when non-westernized individuals adopt a more contemporary lifestyle, their risk for chronic degenerative diseases is similar or even increased compared with modern populations. 26,67,[78][79][80]108,109, Further, when they return to their original traditional lifestyle, many disease markers or symptoms return to normal. 81,145 These data demonstrate that the superior health markers, body composition, and physical fitness of hunter-gatherers and other populations minimally affected by modern habits are not due primarily to genetics but first and foremost to the environment.…”