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Chickens along the River Solimões

River dwellers change a diet of fish with manioc flour for frozen poultry

Eduardo CesarLike a visitor from the South or the Southeast who came from afar to stay, food from the supermarket embarked in one of the deepest corners of Brazil. Residents of small riverside communities on the banks of the Solimões River, in central-western part of the state of Amazonas, are exchanging a low calorie diet, historically based on local fish and manioc flour, for a more fast food kind of diet, with the availability of frozen chicken, cookies, and soft drinks. Typical of urban centers, this dietary transition had already been observed in cities of all sizes in the Northern Region of Brazil, such as the large city of Manaus, with 1.8 million inhabitants, the average-sized city of Santarém, in the state of Pará, and much smaller cities with just a few thousand residents. Now these changes in eating habits have arrived in rural villages with anywhere between 80 and 250 people. Many of these locations are virtually unknown and only accessible by boat after swirling around on the river for hours, sometimes days.

A progressive replacement of the old items on regional menus in these remote points of the Amazon was found in a multidisciplinary study coordinated by the agronomist Luiz Antonio Martinelli of the Center for Nuclear Energy in Agriculture (CENA) at the University of São Paulo (USP) in Piracicaba. Through the analysis of finger nail samples from 431 inhabitants from eight villages and four cities in the state of Amazonas, which stores useful information to reconstruct the diet of an individual over the last six months, the work shows that groups of river dwellers from the Upper and Middle Solimões River are eating processed foods with increasing frequency. “They are transitioning from a diet in which most of the food is locally produced to one consisting of industrialized food items purchased away from home,” says Martinelli. To confirm the story suggested by the fingernail samples, residents also underwent interviews and completed questionnaires regarding the products they consume at meals. The study results appeared in an article in the May 31st online version of the American Journal of Human Biology.

In these rural villages there is no supermarket, sometimes not even a tiny convenience store. Such junk food items typically arrive in these remote locations by way of hucksters using boats known as regatões, which come from Manaus and other cities, carrying passengers on the top deck and goods down below. These boats, laden with food items, have frequent power outages. On such occasions, interuptions in the cold storage system often causes chicken to thaw to the point of spoiling. “When this occurs, many people have diarrhea the next day,” said Martinelli.

Carbon and nitrogen
The entry of chicken and processed foods into the diets of a population changes the proportion of stable isotopes and two chemical elements that are present in fingernails, carbon and nitrogen. Isotopes are heavier or lighter forms of the same chemical element, whose distinction is defined by the number of neutrons in its nucleus. From the human tissue samples, the researchers determined two isotopic ratios, delta carbon 13 and delta 15 nitrogen. The first index reflects the ratio between two distinct forms of carbon atoms, rare and heavy 13C and light and abundant 12C. The second index records the ratio of two forms of nitrogen, the uncommon 15N and the common 14N. “The isotopic information clearly shows an increase in the consumption of frozen chicken and foods with sugar in riverside populations,” says biologist Gabriela Nardoto, another author of the study, who was at Cena when the study was conducted, but is now working at the University of Brasilia (UNB). Although there are many cattle in the Amazon, beef is still too expensive to feature in the diets of poorer residents.

Eduardo CesarConsumption of fresh fish in the Amazon fellEduardo Cesar

With respect to the type of food consumed, the indices fall within a certain range of values. A diet rich in fish and manioc flour should result in delta carbon 13 values between -26 and -32 ‰ (the result of the count is negative and expressed in parts per thousand). A menu with processed food and beef or chicken gives values in the range of -11 to -14 ‰. Results between these two indices indicate that the population analyzed consumes foods with a variety of origins, coming as much from the supermarket culture as from more regional cuisine.

This is exactly the case for the eight communities located on the Solimões River (Capacete, Novo São Francisco, Terezinha III, Boa Esperança, Jarauá, Nova Jerusalém, Santa Maria do Cururu, and São Francisco do Cururu). The average delta carbon 13 value for people from these communities was -23.4 ‰. In the two mid-sized cities with about 15,000 residents, Alvarães and Novo Airão (located on the Lower Negro River), the index was -20.2 ‰. In the capital city of Amazonas (Manaus) and Tefé (a municipality of 60,000 inhabitants), where there are abundant supermarkets, the value was -17.4 ‰. “The popularity of frozen chicken has become so great that some residents of rural villages who do not have refrigerators, do have a freezer just to store the product,” says Gabriela. The isotopic analyses of delta 15 nitrogen, which indicates the trophic level of food and the amount of fertilizer used to grow vegetables that were consumed, follow the same trends. They also suggest an increasing standardization in the tastes of Brazilians at the dinner table, even in the most inaccessible parts of the country.

Recent data from the Brazilian Institute of Geography and Statistics (IBGE) indicates that over the past decade, the consumption of fresh fish and manioc flour has declined by almost half in the state of Amazonas, while the consumption of rice, grains and meat only increased. With the improvement of the Brazilian economy and the spread of social programs for income distribution to the poorest citizens, there is more paper money circulating among the hands of river people. When there is extra money to spend, families of these rural villages, just like a good part of the more urban population of Brazil, decide to leave their former eating habits behind. “In some parts of the year, especially during the rainy season, it’s cheaper and more practical to buy frozen chicken than it is to go fishing,” says economist Tatiana Schor, of the Department of Geography at the Federal University of Amazonas (Ufam), who participated in the part of the study focusing on villages on the Solimões and Negro Rivers. “Furthermore, many women complain that fish are too much work in the kitchen, mostly because they have to be cleaned, and they don’t like that it makes their hands smelly.”

Urban culture
The desire to imitate the food preferences of urban residents is also motivated by a cultural component. Many riverside people have a television in their home and this type of cultural influence makes them want to consume the products they see are valued by residents from coastal urban centers, instead of the regional cuisine they are accustomed to. “They have a very positive view of the meat, especially of beef, and prefer to eat canned foods instead of fish with manioc flour,” explains Maria Elisa Garavello, an expert in nutritional anthropology at the Luiz de Queiroz College of Agriculture (ESALQ) at USP, and another author of the current study.

Nobody is opposed to improving the living conditions of populations living in remote areas of the country. But the gradual abandonment of local cuisine and the adoption of a menu rich in processed foods brings the riverside dwellers to an impasse similar to that of the urban dweller in Amazonia: with more money in their pockets, they adopt a more sedentary lifestyle in which they eat more, but lower quality food. “On the one hand, it’s commendable that these people are benefiting from inclusive public policies. On the other hand, this type of food may be more harmful to their health and cause a sociocultural disruption in these communities. Besides money, these people also need education,” says Maria Elisa.

The Project
Diversity of eating habits in Brazil – An isotopic approach (nº 2007/51342-8); Modality Regular Aid to Research Project; Coordinator Luiz Antonio Martinelli – Cena-USP; Investment R$ 176,536.72 (FAPESP)

Scientific article
NARDOTO, GB et al. Frozen chicken for wild fish: Nutritional transition in the Brazilian Amazon region determined by carbon and nitrogen stable isotope ratios in fingernails. American Journal of Human Biology. Published online May 31, 2011.