Darna L. Dufour

Cyanide content of cassava (Manihot esculenta, Euphorbiaceae) cultivars used by Tukanoan Indians in Northwest Amazonia

Cassava (Manihot esculenta) is a cyanide-containing food crop used by many indigenous peoples in Amazonia. Tukanoan Indians in Northwest Amazonia utilize both “bitter” and “sweet” cassava cultivars. Those classified as “bitter” are the dietary staple. Analysis of 13 commonly used “bitter” cultivars indicates that they are high in cyanide in comparison to values reportedin the literature. The Tukanoan practice of including the inner peel in the edible portion contributes to the high cyanide values found.RésuméContenido de Cianuro en Variedades de Yuca Utilizada por los Tukanos en el Noroeste Amazónico. Las raíces de la yuca (Manihot esculenta,) constituyen un importante alimento energetico para grupos indígenas del Amazonas. Los Tukanos del noroeste Amazonico cultivan variedades “dulces” y “amargas” de yuca; las “amargas” proporcionan la mayoría de la energía en la dieta. El análisis de 13 de las más comunes variedades “amargas” por ellos utilizadas presenta valores altos de cianuro en comparación con aquellos previamente registrados en la literatura especializada. La inclusión de la corteza en la parte comestible se relaciona con los altos valores de cianuro encontrados.

Why “Bitter” Cassava? Productivity of “Bitter” and “Sweet” Cassava in a Tukanoan Indian Settlement in the Northwest Amazon1

Cassava (Manihot esculenta Crantz) is a cyanide-containing root crop used by many indigenous groups in Amazonia. Despite the availability of low-cyanogenic potential (CNP) cassava, the Tukanoans of the Colombian Amazon region and many other indigenous groups in lowland Amazonia cultivate primarily high-CNP cassava as their staple crop. Based on the assumption that the Tukanoan preference for high-CNP cultivars is due, in part, to the ability of these cultivars to consistently produce higher yields, we tested the null hypothesis that low-CNP cassava has yields that are greater than or equal to the yields of high-CNP cultivars in Tukanoan gardens. To do so we compared the yields of low- and high-CNP cassava in 10 Tukanoan gardens and in one control garden. We reject the null hypothesis: high-CNP cultivars yielded more than low-CNP cultivars in both traditional Tukanoan Indian gardens and a control garden. Although there are several possible explanations for the differences in yields, the most plausible inference is that the high-CNP plants are more likely to be disease and/or insect resistant.ResumenLa yuca o mandioca (Manihot esculenta Crantz) es una raíz comestible que contiene cianuro, utilizada por numerosos grupos indígenas en la Amazonia. A pesar de que existe una variedad de yuca de bajo contenido en cianuro (CNP), los Tukanos de la región amazónica colombiana y muchos otros grupos indígenas en las tierras bajas del Amazonas cultivan principalmente la variedad de yuca con alto contenido en cianuro como alimento básico. Basándonos en la presunción de que la preferencia de los Tukanos por los cultivos de yuca de alto contenido en cianuro, se debe, en parte, a que esta variedad produce mayores rendimientos, intentamos comprobar la hipótesis de que la yuca de bajo contenido en cianuro logra rendimientos iguales o mayores que los de los cultivos de alto contenido en cianuro que realizan los Tukanos. Para ello, comparamos los rendimientos de la yuca de alto y de bajo contenido en cianuro en diez huertos de los Tukanos y en un huerto de control. Debemos descartar la hipótesis: los cultivos de alto contenido en cianuro rindieron más que los de bajo contenido, tanto en los huertos tradicionales de los indígenas como un el huerto de control. Aunque existen varias explicaciones posibles para esta diferencia en rendimiento, la más plausible es que las plantas con alto contenido de cianuro poseen mayor resistencia a los insectos y a las enfermedades.

FISH AND FARINHA: PROTEIN AND ENERGY CONSUMPTION IN AMAZONIAN RURAL COMMUNITIES ON ITUQUI ISLAND, BRAZIL

In order to better understand food consumption among indigenous peasant (the so-called “Caboclos”) communities in Amazonia, this article describes and analyzes household and individual food consumption in the communities of Aracampina and São Benedito, located on ltuqui Island on the lower courses of the Amazon river, in the municipio (county) of Santarém, State of Pará, Brazil. ltuqui Islands landscape is dominated by savannas, meadows, secondary floodplain forests, pastures, and cultivation plots. Food consumption data were collected using 24-hour food recalls for a sample of 12 households and 42 individuals. The main patterns of consumption observed on ltuqui Island were higher consumption of protein than energy, dependency on regional staple foods, and a high reliance on imported secondary food items purchased at local urban centers. Also, interhousehold and community variation point toward a sociohistorical particularism of kindreds, as well as microenvironmental differences, both critical elements in understanding food consumption. Other important findings provide some insights about modifications and adjustment of food repertoires in coping with high seasonality. The simplification of staple-food repertoire and increased consumption of energy-rich items such as sugar and oil are probably the most important strategies observed. We conclude that to understand food consumption among Caboclo communities in Amazonia research should focus more closely on the composition of the local food repertoire and local ecological and sociocultural variations.

Nutritional ecology in the tropical rain forests of Amazonia.

Available data on diet and nutritional status of Amerindians living in the tropical rain forests of Amazonia are reviewed and evaluated. The diets of most Amerindians are based on cassava and plantains/bananas, with high‐quality protein coming from fish, game, and invertebrates. Although tropical rain forests are rich in plant species, wild plants do not appear to be very important in the diet. Their use, however, has not received much attention and may be underestimated. The composition of Amerindian diets is known for only a few groups, in whom the dietary intake of households and adults appears to be adequate in energy and protein. However, the high‐bulk, low‐caloric density of the diets means that they are probably not sufficiently concentrated for children. Anthropometric data are available for a number of groups. Adults are small in size, but nutritional status assessed in terms of the BMI is good. Children are small for age, and in some groups more than 10% would be classified as undernourished on the basis of weight‐for‐height and/or clinical signs.

Edible Invertebrates Among Amazonian Indians: A Critical Review of Disappearing Knowledge

For the indigenous populations of Amazonia, invertebrates constitute an important component of the diet. We have information on entomophagy for 39 ethnic groups, about 21,4 per cent of the 182 groups known in the Amazon Basin, but the use of this non conventional food resource is probably much more widespread. We present here a data-base of all the information available for each ethnic group regarding the species included in the diet, the scientific and the ethno name if known, the stage of life-cycle consumed, the manner of preparation and, when known, the host plant. This data-base lists 115 species scientifically identified and 131 ethno names. In addition, we have information about other 384 ethno names, with unsecure link to the Linnean taxonomy suggesting that local knowledge is very extensive. The data-base represents not only an easy to consult resource, but also a support for further research. The knowledge of the relations between indigenous populations and ecosystem is indeed the base for the natural and cultural biodiversity preservation.

Energy expenditure among farmers in developing countries: What do we know?

The trend toward overweight and obesity in developing countries is often assumed to be due, in part, to reductions in energy expenditure associated with the transition from agrarian to urban lifestyles. In this article we first review the published studies on energy expenditure in farming populations living in developing countries, populations generally assumed to have high levels of energy expenditure. To facilitate comparison we express energy expenditure as physical activity level (PAL), i.e. the ratio of total daily energy expenditure to basal metabolic rate. Then, with the goal of better understanding variability in energy expenditure between different human groups, we focus on case studies of women farmers in Colombia and Brazil for whom we have good ethnographic data. The published studies reviewed indicate that most farmers have PAL values in the moderate physical activity range, but toward the high end of that range. PAL values of male farmers tend to be higher than female, and show greater seasonal variation. The case studies illustrate that women farmers, living in broadly similar environments, and dependent on the cultivation of the same crop can have quite different patterns of physical activity and hence PAL values. These differences are a function of differences in behavior related to social and cultural variables like the organization of work at the household level and perceptions of how food crops should be processed, as well as micro‐level ecological factors. Am. J. Hum. Biol., 2008.

Living on the edge: dietary strategies of economically impoverished women in Cali, Colombia.

Economically impoverished women in Cali, Colombia, have restricted access to food in a city where food is abundant. Ethnographic observations, interviews and 2 day food records were used to better understand the coping strategies used by a group of these women (n = 85) to maintain adequate levels of energy intake. Anthropometric indicators of nutritional status were normal for the group. Interview data revealed that the ability to purchase food was a concern for 58% of the women. When faced with a restricted ability to purchase food, the women indicated they made compromises in meal composition, reduced portion sizes, and/or reduced the number of meals. They also relied on relatives, friends, neighbors, store credit, or local government programs for access to food. Changes in meal composition were identified in 17.1% of all diet records (n = 509). Low energy intake (defined as energy intake < or = 1.27 x BMR) was identified in 17.1% of all diet records. Carbohydrate consumption was significantly greater on low-energy intake days. The adequate nutritional status of this group of women suggests that their coping strategies are usually adequate to maintain energy intake, but the presence of uncertainty, the frequency of compromises in diet composition, and the frequency of low-energy intake days suggest that these women are at risk for undernutrition.

Exploring the multidimensionality of stature variation in the past through comparisons of archaeological and living populations

Adult stature variation is commonly attributed to differential stress-levels during development. However, due to selective mortality and heterogeneous frailty, a populations tall stature may be more indicative of high selective pressures than of positive life conditions. This article examines stature in a biocultural context and draws parallels between bioarchaeological and living populations to explore the multidimensionality of stature variation in the past. This study investigates: 1) stature differences between archaeological populations exposed to low or high stress (inferred from skeletal indicators); 2) similarities in growth retardation patterns between archaeological and living groups; and 3) the apportionment of variance in growth outcomes at the regional level in archaeological and living populations. Anatomical stature estimates were examined in relation to skeletal stress indicators (cribra orbitalia, porotic hyperostosis, linear enamel hypoplasia) in two medieval bioarchaeological populations. Stature and biocultural information were gathered for comparative living samples from South America. Results indicate 1) significant (P < 0.01) differences in stature between groups exposed to different levels of skeletal stress; 2) greater prevalence of stunting among living groups, with similar patterns in socially stratified archaeological and modern groups; and 3) a degree of regional variance in growth outcomes consistent with that observed for highly selected traits. The relationship between early stress and growth is confounded by several factors-including catch-up growth, cultural buffering, and social inequality. The interpretations of early life conditions based on the relationship between stress and stature should be advanced with caution.

Gastrointestinal parasitic infection, anthropometrics, nutritional status, and physical work capacity in Colombian boys.

This article tests the hypothesis that the presence of gastrointestinal parasites in Colombian boys is negatively associated with anthropometric characteristics, physical work capacity, blood hemoglobin (Hb) levels, and nutritional status. Anthropometric, Hb, V̇O2 max, and parasite load data were collected on 1,016 boys in Cali, Colombia. The boys were classified as lower socioeconomic class (SEC) from either urban or rural environments, and upper SEC from an urban environment. Sixty‐three percent of the boys were infected with gastrointestinal parasites and, of the infected boys, 80–95% had light parasite loads. Parasites found included Necator americanus, Ascaris lumbricoides, Entamoeba histolytica, Trichuris trichiura, Giardia spp., and Enterobius vermicularis. Infected boys had significantly lower weight, stature, weight‐for‐height (among 6–9‐year‐old boys), Hb levels, and V̇O2 max (ANCOVA, controlling for age and SEC). In terms of nutritional status, infected boys were 1.47 times more likely to be classified as iron deficient than noninfected boys (chi‐square, P < 0.001), and 1.61 times more likely to be classified as stunted (P < 0.001). Infection was not associated with wasting in any SEC group. In conclusion, light to moderate gastrointestinal parasite loads were associated with significantly lower weight, stature, weight‐for‐height (in 6–9‐year‐old boys), Hb levels, and V̇O2 max, and a significantly higher frequency of IDA and stunting. These data suggest that comprehensive analyses of the nutritional status of populations in regions endemic for parasitic infection should include testing for the presence of infection. Am. J. Hum. Biol. 11:763–771, 1999.

Diet and nutritional status of Ameridians: a review of the literature

This paper reviews and evaluates the available data on diet and nutritional status of Amerindians living in the tropical forests of Amazonia. The diets of most Amerindians are based on cassava and plantains/bananas, with high quality protein coming from fish, game and invertebrates. The composition of Amerindian diets is known for only a few groups. In these groups the dietary intake of households and adults appears to be adequate in energy and protein. However, the high bulk, low caloric density of the diets suggests that they are not concentrated enough for children. Anthropometric data is available for a number of groups. Adults are small in size, but nutritional status assessed in terms of weight-for-height is generally good. Children are small for their age, and in some groups more than 10% would be classified as undernourished on the basis of weight-for-height, and/or clinical signs.