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Epidemiology

The pressure of modern life

Urbanization upsets health of the inhabitants of the interior of the Amazonia

HILTON SILVA / UFRJTypical house of the inhabitants of the Caxiuanã National Forest: rare contacts with Belém, the nearest city, a two day boat trip awayHILTON SILVA / UFRJ

Even if it increases comfort, the consequences of going into modern life – with readymade food, television, telephones and the washing machine – are no good at all for health. Hilton Pereira da Silva, a physician and anthropologist with the National Museum, linked to the Federal University do Rio de Janeiro (UFRJ), found a high level of arterial hypertension in the population of three rural communities in Pará that have gradually left gathering and collecting behind and started to use typically urban consumer goods.

In these populations from the interior of Amazonia, which the researcher from Pará has been accompanying since 1996, the level of hypertension is today equivalent to that found in those living in medium to large sized cities. Contrary to what happens in the urban centers, it is more frequent in women than in men. On average, on the basis of a sample of 348 adults, 25% of the women and 20% of the men showed high blood pressure, a risk factor for heart attacks and strokes. In the adult urban population, the levels of hypertension vary from 22% to 44%, depending on the ethnic and social groups, and the problem afflicts men more, some times twice as much as women.

Aracampina, the largest community studied, located on the island of Ituqui, on the banks of the Amazon River, has some 600 inhabitants. There were 460 seven years ago, when Hilton Silva arrived there for the first time and noted that life was changing quickly – a consequence of being close to Santarém, four hours away by boat. “When there is a transition to the modern and urban lifestyle, the first change is the diet”, he says. “There is an increase in the consumption of salt, canned goods and industrialized food, full of chemical products.”

On the first few times he was there, the researcher noted that the native “caboclos” (the term refers to mixed Indian and European or African Origin) used to fish intensely. They would complete their diet with cassava flour, fruit, beans and corn. “Today, the caboclos have left gathering and collecting behind, they are working in industrial fishing, in the sawmills or on farms, and they eat preserved meat, sugar, coffee and cookies”, he describes. “The changes in diet and living habits are causing a gradual change in the physiology of the organism that leads to hypertension.”

There is still no running water in Aracampina, but the caboclos now have electric light, thanks to the diesel generator, gas stoves, televisions connected to car batteries, and radio telephones. As a consequence, there has been a reduction in physical activity, which helps to control blood pressure. “Having access to gas stoves, they no longer look for firewood in the forest”, is one example given by Hilton Silva. “And they are now using disposable diapers, which also reduces the women’s work.” But other sources of stress are appearing, such as the need to earn more money to buy food, watches, bicycles and hi-fi equipment.

The results: in Aracampina, 44% of the women and 20% of the men have high blood pressure. “Apparently”, he says, “women’s physiology is responding more rapidly than men’s to cultural changes.” Another problem detected and not fully quantified is the increase in the number of cavities, lost teeth and obesity. On the same island, the community of Santana, with some 550 inhabitants, is experiencing a similar process of urbanization, but the shock to its health is less: 20% of the women and 17% of the men have hypertension, “perhaps because they have already adapted to the changes”, the researcher ponders. The analysis of the data was carried out with anthropologists Gary James, from the State University of New York, and Douglas Crews, from Ohio State University, both in the United States, and it will be published shortly in the American Journal of Physical Anthropology.

The third community studied is even smaller. It consists of about 200 individuals who lived scattered over the Caxiuanã National Forest, on the banks of the Anapu River, in houses that are separated from each other by distances that vary from 500 meters to 20 kilometers. Electric light, television and telephones are things they have merely heard about. Of the three groups, it is the most isolated: it is only reached after a two day journey by boat from Belém. The inhabitants of Caxiuanã are still collectors and feed themselves chiefly on game and cassava, and their crops of corn and beans. Even so, for reasons that are still being investigated, 11% of the women and 22% of the men have hypertension. They are high levels if compared with traditional indigenous groups in Amazonia or in other parts of the world, where the percentage is close to zero.

Prevention
Hilton Silva was in Aracampina, Santana and Caxiuanã in December, to announce the results that he had arrived at and to plan with the community leaders and teachers how to motivate the population to take better care of their health in general. “We cannot deny them the right to having consumer goods, but we must show the benefits and the risks of the changes in lifestyles.”

Homo sapiens himself underwent a similar situation some 10,000 years ago, when he ceased to be a nomad and a hunter to settle in a territory and to develop agriculture. It was a remarkable moment: to start with, our ancestors lost musculature and gained caries, and started to die younger, even though they had increased the fertility rate and reduced infant mortality. “The quantity of food increased, but its variety decreased, creating protein deficiencies”, he says. In those days too there was a choice between eating a little and well or a lot and not so well.

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