RESUMO
In the United States, children often generalize the meaning of new words by assuming that objects with the same shape have the same name. We propose that this shape bias is influenced by children's exposure to objects of different categories (artifacts and natural kinds) and language to talk about them. We present a cross-cultural study between English speakers in the United States and Tsimane' speakers in the Bolivian Amazon. We found that U.S. children and adults were more likely to generalize novel labels by shape rather than by material or color, relative to Tsimane' participants. Critically, Tsimane' children and adults systematically avoided generalizing labels to objects that shared no common features with the novel referent. Our results provide initial evidence that the relative exposure to objects of different kinds and language to talk about them can lead to cross-cultural differences on object name learning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
Assuntos
Comparação Transcultural , Idioma , Adulto , Bolívia , Criança , Humanos , Aprendizagem , Estados UnidosRESUMO
OBJECTIVES: This study compared the prevalence of concentrated urine (urine specific gravity ≥1.021), an indicator of hypohydration, across Tsimane' hunter-forager-horticulturalists living in hot-humid lowland Bolivia and Daasanach agropastoralists living in hot-arid Northern Kenya. It tested the hypotheses that household water and food insecurity would be associated with higher odds of hypohydration. METHODS: This study collected spot urine samples and corresponding weather data along with data on household water and food insecurity, demographics, and health characteristics among 266 Tsimane' households (N = 224 men, 235 women, 219 children) and 136 Daasanach households (N = 107 men, 120 women, 102 children). RESULTS: The prevalence of hypohydration among Tsimane' men (50.0%) and women (54.0%) was substantially higher (P < .001) than for Daasanach men (15.9%) and women (17.5%); the prevalence of hypohydration among Tsimane' (37.0%) and Daasanach (31.4%) children was not significantly different (P = .33). Multiple logistic regression models suggested positive but not statistically significant trends between household water insecurity and odds of hypohydration within populations, yet some significant joint effects of water and food insecurity were observed. Heat index (2°C) was associated with a 23% (95% confidence interval [CI]: 1.09-1.40, P = .001), 34% (95% CI: 1.18-1.53, P < .0005), and 23% (95% CI: 1.04-1.44, P = .01) higher odds of hypohydration among Tsimane' men, women, and children, respectively, and a 48% (95% CI: 1.02-2.15, P = .04) increase in the odds among Daasanach women. Lactation status was also associated with hypohydration among Tsimane' women (odds ratio = 3.35, 95% CI: 1.62-6.95, P = .001). CONCLUSION: These results suggest that heat stress and reproductive status may have a greater impact on hydration status than water insecurity across diverse ecological contexts.
Assuntos
Desidratação/epidemiologia , Temperatura Alta , Lactação , Urina/química , Insegurança Hídrica , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bolívia/epidemiologia , Criança , Desidratação/etiologia , Feminino , Humanos , Quênia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Urinálise , Adulto JovemRESUMO
Biological significance of food components suggests that preferences for basic tastes should be similar across cultures. On the other hand, cultural factors play an important role in diet and can consequently influence individual preference for food. To date, very few studies have compared basic tastes preferences among populations of very diverse environmental and cultural conditions, and research rather did not involve traditional populations for whom the biological significance of different food components might be the most pronounced. Hence, our study focused on basic taste preferences in three populations, covering a broad difference in diet due to environmental and cultural conditions, market availability, dietary habits and food acquirement: 1) a modern society (Poles, n = 200), 2) forager-horticulturalists from Amazon/Bolivia (Tsimane', n = 138), and 3) hunter-gatherers from Tanzania (Hadza, n = 85). The preferences for basic tastes were measured with sprays containing supra-threshold levels of sweet, sour, bitter, salty, and umami taste solutions. We observed several interesting differences between participating societies. We found that Tsimane' and Polish participants liked the sweet taste more than other tastes, while Hadza participants liked salty and sour tastes more than the remaining tastes. Further, Polish people found bitter taste particularly aversive, which was not observed in the traditional societies. Interestingly, no cross-cultural differences were observed for relative liking of umami taste - it was rated closely to neutral by members of all participating societies. Additionally, Hadza showed a pattern to like basic tastes that are more common to their current diet than societies with access to different food sources. These findings demonstrate the impact of diet and market availability on preference for basic tastes.
Assuntos
Comparação Transcultural , Dieta , Preferências Alimentares , Abastecimento de Alimentos , Paladar , Adolescente , Adulto , Idoso , Bolívia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polônia , Tanzânia , Adulto JovemRESUMO
Body height influences human mate preferences and choice. A typical finding in Western societies is that women prefer men who are taller than themselves and, equivalently, men prefer women who are shorter than themselves. However, recent reports in non-Western societies (e.g., the Himba in Namibia) challenge the view on the universality of such preferences. Here we report on male and female height preferences in two non-Western populations--the Hadza (Tanzania) and the Tsimane' (Bolivia)--and the relationships between body height preferences and the height of actual partners. In the Hadza, most individuals preferred a sexual dimorphism in stature (SDS) with the man being much taller than the woman. Preferences for SDS and actual partner SDS were positively and significantly correlated in both men and women, suggesting that people who preferred larger height differences also had larger height differences with their partners. In the Tsimane', the majority of men preferred an SDS with the man being taller than the woman, but women did not show such a preference. Unlike in the Hadza, SDS preference was not significantly correlated to actual partner SDS. We conclude that patterns of height preferences and choices in the Hadza and Tsimane' are different than those observed in Western societies, and discuss possible causes for the observed differences between non-Western and Western societies.
Assuntos
Estatura , Imagem Corporal/psicologia , Comportamento de Escolha , Parceiros Sexuais/psicologia , Adulto , Bolívia , Etnopsicologia , Feminino , Humanos , Masculino , Comportamento Sexual/psicologia , Tanzânia , OcidenteRESUMO
The issue of cultural universality of waist-to-hip ratio (WHR) attractiveness in women is currently under debate. We tested men's preferences for female WHR in traditional society of Tsimane'(Native Amazonians) of the Bolivian rainforest (Nâ=â66). Previous studies showed preferences for high WHR in traditional populations, but they did not control for the women's body mass.We used a method of stimulus creation that enabled us to overcome this problem. We found that WHR lower than the average WHR in the population is preferred independent of cultural conditions. Our participants preferred the silhouettes of low WHR, but high body mass index (BMI), which might suggest that previous results could be an artifact related to employed stimuli. We found also that preferences for female BMI are changeable and depend on environmental conditions and probably acculturation (distance from the city). Interestingly, the Tsimane' men did not associate female WHR with age, health, physical strength or fertility. This suggests that men do not have to be aware of the benefits associated with certain body proportions - an issue that requires further investigation.
Assuntos
Beleza , Índice de Massa Corporal , Cultura , Relação Cintura-Quadril , Adolescente , Adulto , Pesos e Medidas Corporais , Bolívia , Feminino , Fertilidade , Humanos , Julgamento , Masculino , Floresta Úmida , Adulto JovemRESUMO
Olfactory sensitivity varies between individuals. However, data regarding cross-cultural and inter-group differences are scarce. We compared the thresholds of odor detection of the traditional society of Tsimane' (native Amazonians of the Bolivian rainforest; n = 151) and people living in Dresden (Germany; n = 286) using "Sniffin' Sticks" threshold subtest. Tsimane' detected n-butanol at significantly lower concentrations than the German subjects. The distribution of thresholds of the Tsimane' was very specific, with 25% of Tsimane' obtaining better results in the olfactory test than any member of the German group. These data suggest that differences in olfactory sensitivity seem to be especially salient between industrialized and non-industrialized populations inhabiting different environmental conditions. We hypothesize that the possible sources of such differences are: (i) the impact of pollution which impairs the olfactory abilities of people from industrialized countries; (ii) better training of olfaction because of the higher importance of smell in traditional populations; (iii) environmental pressures shaping olfactory abilities in these populations.
Assuntos
Meio Ambiente , Etnicidade , Indústrias , Limiar Sensorial/fisiologia , Olfato/fisiologia , Árvores , Adolescente , Adulto , Bolívia , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Odorantes , Adulto JovemRESUMO
This paper examines three morphological indicators measuring obesity among a native Amazonian population of foragers-farmers in Bolivia (Tsimane') and estimates the associations between them and standard covariates of obesity (e.g., socioeconomic status [SES]). We collected annual data from 350 non-pregnant women and 385 men ≥20 years of age from all 311 households in 13 villages during five consecutive years (2002-2006). We used three indicators to measure obesity: body-mass index (BMI), waist circumference (WC), and body fat using bioelectrical impedance analysis (BF-BIA). We ran separate individual random-effect panel multiple regressions for women and men with wealth, acculturation, health, and household food availability as key covariates, and controlled for village and year fixed effects and village×year interaction effects. Although BMI increases by a statistically significant annual growth rate of 0.64% among women and 0.37% among men over the five years, the increase does not yield significant biological meanings. Neither do we find consistent and biologically meaningful covariates associated with adult obesity.
Assuntos
Indígenas Sul-Americanos , Obesidade/etnologia , Tecido Adiposo , Índice de Massa Corporal , Bolívia/etnologia , Desenvolvimento Econômico/tendências , Feminino , Inquéritos Epidemiológicos , Humanos , Modelos Lineares , Estudos Longitudinais , Masculino , Fatores Socioeconômicos , Adulto JovemRESUMO
OBJECTIVE: Although psychosocial stress has also been implicated as a contributor to growth failure by imposing energetic constraints during development, the direct physiological pathways by which these life history trade-offs are imposed are not well understood. This study explores associations between diurnal cortisol rhythms and differential patterns of linear child growth among the Tsimane, a horticulturalist and foraging society in the Bolivian Amazon. METHODS: Waking and bedtime salivary cortisol samples (n = 243) were collected from 53 Tsimane' children ages 1.6-6 over 3 days as part of a larger study of developmental trajectories in hypothalamic-pituitary-adrenal axis dynamics. Anthropometric measurements and survey data were collected in conjunction with the Tsimane' Amazonian panel study (TAPS). RESULTS: Among children under the age of 6, diurnal rhythms in stunted versus nonstunted children vary dramatically: stunted children display elevated cortisol at both the AM (P = 0.03) and PM (P = 0.02) collection points. Multilevel regression analysis demonstrates an inverse relationship between cortisol and height-for-age z-score status (P = 0.00), which is mediated, in part, by infection (P = 0.00), and is strongest among male children (n.s.). Moreover, the poorest statural growth is exhibited among children with high cortisol living in more acculturated Tsimane' communities, a proxy for a more adverse developmental milieu. CONCLUSIONS: This study reports a small, but significant, life history cost of elevated diurnal cortisol rhythms on linear growth among Tsimane' children, and provides critical insight into the developmental origins of health differentials among an indigenous Amazonian population experiencing rapid lifestyle changes.
Assuntos
Estatura , Ritmo Circadiano , Hidrocortisona/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Aculturação , Bolívia , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Indígenas Sul-Americanos/psicologia , Lactente , Estilo de Vida , Estudos Longitudinais , Masculino , Saliva/química , Fatores Sexuais , Estresse Fisiológico , Estresse PsicológicoRESUMO
Research on the benefits of local ecological knowledge for conservation lacks empirical data on the pathways through which local knowledge might affect natural resources management. We test whether ethnobotanical skills, a proxy for local ecological knowledge, are associated to the clearance of forest through their interaction with agricultural labor. We collected information from men in a society of gatherers-horticulturalist, the Tsimane' (Bolivia). Data included a baseline survey, a survey of ethnobotanical skills (n = 190 men), and two surveys on agricultural labor inputs (n = 466 plots). We find a direct effect of ethnobotanical skills in lowering the extent of forest cleared in fallow but not in old-growth forest. We also find that the interaction between ethnobotanical skills and labor invested in shifting cultivation has opposite effects depending on whether the clearing is done in old-growth or fallow forest. We explain the finding in the context of Tsimane' increasing integration to the market economy.
Assuntos
Agricultura , Etnobotânica , Árvores , Bolívia , Modelos Teóricos , Análise MultivariadaRESUMO
Social science has long recognized the importance of understanding how interactions between culture and behavior shape disease patterns, especially in resource-poor areas where individuals draw on multiple medical treatments to maintain health. While global health programs aimed at controlling high infection rates of soil-transmitted helminthes among indigenous groups often acknowledge the value of local culture, little research has been able to examine this value. This study investigates the association between parental ethnomedical knowledge, parental biomedical knowledge, and household sanitation behavior and childhood soil-transmitted helminth infections among a group of foragers-farmers in the Bolivian Amazon (Tsimane'). During 2007, a parasitological survey was completed for 329 children (≤ 16 years of age) from 109 households in combination with a comprehensive survey of both of the child's parents to assess biomedical and ethnomedical knowledge and household sanitary environment. Soil-transmitted helminthes were found to be common with 67% of sample positive for hookworm species. Indices that capture a household's relative state of risky and preventive hygienic behavior were significantly associated with risk of hookworm infection. Mother's but not father's ethnomedical knowledge was also negatively associated with a child's probability of being positive for hookworm infection. The effect was stronger for young children and boys. Like many rural populations, Tsimane' actively draw upon multiple medical systems to respond to health challenges. Integration into markets and national societies is likely to affect local medical systems by increasing the use of biomedicine as formal education prioritizes biomedical over ethnomedical systems. This study underscores the value of considering both ethnomedical knowledge systems and household hygiene in public health campaigns to treat and control soil-transmitted helminths. There is no question that providing medication is critical, but this study demonstrates that poverty is not synonymous with either poor hygiene or the lack of valuable ethnomedicinal knowledge.
Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Infecções por Uncinaria/epidemiologia , Higiene , Medicina Tradicional , Áreas de Pobreza , Adolescente , Fatores Etários , Bolívia/epidemiologia , Criança , Fezes/parasitologia , Feminino , Infecções por Uncinaria/diagnóstico , Humanos , Masculino , Relações Pais-Filho , Pesquisa Qualitativa , Fatores de Risco , População Rural , Fatores Sexuais , Meio Social , Solo/parasitologiaRESUMO
Researchers have hypothesized that the degree to which an individual's actual behavior approximates the culturally valued lifestyle encoded in the dominant cultural model has consequences for physical and mental health. We contribute to this line of research by analyzing data from a longitudinal study composed of five annual surveys (2002-2006 inclusive) from 791 adults in one society of foragers-farmers in the Bolivian Amazon, the Tsimane'. We estimate the association between a standard measure of individual achievement of the cultural model, cultural consonance, and three indicators of body morphology. Drawing on research suggesting that in societies in the early stages of economic development an increase in socioeconomic status is associated with an increase in mean body mass, we expect to find a positive association between cultural consonance and three anthropometric measures. We found the expected positive association between cultural consonance and anthropometric measures-especially for men-only when using ordinary least square (OLS) regression models, but not when using fixed-effects regression models. The real magnitude of the association was low. The comparison of estimates from OLS and fixed-effect regression models suggests that previous findings on the effects of cultural consonance on body morphology using cross-sectional data should be read with caution because the association might be largely explained by fixed characteristics of individuals not accounted in OLS models.
Assuntos
Antropologia Cultural/métodos , Índice de Massa Corporal , Estilo de Vida , Ocupações , Fatores Socioeconômicos , Adulto , Antropologia Física , Bolívia/epidemiologia , Coleta de Dados , Feminino , Humanos , Análise dos Mínimos Quadrados , Estudos Longitudinais , Masculino , Análise Multivariada , Análise de RegressãoRESUMO
BACKGROUND: Evolutionary theory suggests that natural selection favors the evolution of cognitive abilities which allow humans to use facial cues to assess traits of others. The use of facial and somatic cues by humans has been studied mainly in western industrialized countries, leaving unanswered whether results are valid across cultures. METHODOLOGY/PRINCIPAL FINDINGS: Our objectives were to test (i) if previous finding about raters' ability to get accurate information about an individual by looking at his facial photograph held in low-income non western rural societies and (ii) whether women and men differ in this ability. To answer the questions we did a study during July-August 2007 among the Tsimane', a native Amazonian society of foragers-farmers in Bolivia. We asked 40 females and 40 males 16-25 years of age to rate four traits in 93 facial photographs of other Tsimane' males. The four traits were based on sexual selection theory, and included health, dominance, knowledge, and sociability. The rating scale for each trait ranged from one (least) to four (most). The average rating for each trait was calculated for each individual in the photograph and regressed against objective measures of the trait from the person in the photograph. We found that (i) female Tsimane' raters were able to assess facial cues related to health, dominance, and knowledge and (ii) male Tsimane' raters were able to assess facial cues related to dominance, knowledge, and sociability. CONCLUSIONS/SIGNIFICANCE: Our results support the existence of a human ability to identify objective traits from facial cues, as suggested by evolutionary theory.
Assuntos
Cognição , Face , Seleção Genética , Sexualidade , Bolívia , Feminino , Humanos , Masculino , Modelos Estatísticos , FotografaçãoRESUMO
Among adults of industrial nations, growth stunting (<-2 SD height Z score) is associated with worse indicators of adult well-being (e.g., income). Does adult stunting also inflict private costs in traditional societies? Adult stunting penalties or height premiums might only emerge when traditional societies modernize. Here we estimate the association between adult stunting and indicators of adult well-being using data from a panel study in progress among the Tsimane', a foraging-farming society of native Amazonians in Bolivia. Subjects included 248 women and 255 men >or=age 22 measured annually during 5 consecutive years (2002-2006). Nine outcomes (wealth, monetary income, illness, access to credit, mirth, schooling, math skills, plant knowledge, forest clearance) were regressed separately against a stunting dummy variable and a wide range of control variables. We found no significant association between any of the indicators of own well-being and adult stunting. Additional analysis showed that stunting bore an association only with poorer mid-arm muscle area. Height premiums and stunting penalties, though evident and marked in modern societies, might not be common in all traditional societies.
Assuntos
Estatura/fisiologia , Desenvolvimento Infantil/fisiologia , Satisfação Pessoal , Classe Social , Adolescente , Bolívia , Criança , Pré-Escolar , Feminino , Humanos , Indígenas Sul-Americanos , Modelos Lineares , Masculino , Adulto JovemRESUMO
The ubiquity and consequences of childhood growth stunting (<-2 SD in height-for-age Z score, HAZ) in rural areas of low-income nations has galvanized research into the reversibility of stunting, but the shortage of panel data has hindered progress. Using panel data from a native Amazonian society of foragers-farmers in Bolivia (Tsimane'), we estimate rates of catch-up growth for stunted children. One hundred forty-six girls and 158 boys 2 < or = age < or = 7 were measured annually during 2002-2006. Annual Delta height in cm and in HAZ were regressed separately against baseline stunting and control variables related to attributes of the child, mother, household, and village. Children stunted at baseline had catch-up growth rates 0.11 SD/year higher than their nonstunted age and sex peers, with a higher rate among children farther from towns. The rate of catch up did not differ by the child's sex. A 10% rise in household income and an additional younger sibling lowered by 0.16 SD/year and 0.53 SD/year the rate of growth. Results were weaker when measuring Delta height in cm rather than in HAZ. Possible reasons for catch-up growth include (a) omitted variable bias, (b) parental reallocation of resources to redress growth faltering, particularly if parents perceive the benefits of redressing growth faltering for child school achievement, and (c) developmental plasticity during this period when growth rates are most rapid and linear growth trajectories have not yet canalized.
Assuntos
Desenvolvimento Infantil/fisiologia , Transtornos da Nutrição Infantil/etnologia , Transtornos da Nutrição Infantil/fisiopatologia , Indígenas Sul-Americanos , Fatores Etários , Estatura , Peso Corporal , Bolívia/epidemiologia , Criança , Pré-Escolar , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Fatores Sexuais , Fatores SocioeconômicosRESUMO
Researchers have hypothesized that the degree to which an individual's actual behavior approximates the culturally valued lifestyle encoded in the dominant cultural model has consequences for physical and mental health. We contribute to this line of research by analyzing data from a longitudinal study composed of five annual surveys (2002-2006 inclusive) of 791 adults in one society of foragers-farmers in the Bolivian Amazon, the Tsimane'. We estimate the association between a standard measure of individual achievement of the cultural model and (a) four indicators of psychological well-being (sadness, anger, fear and happiness) and (b) consumption of four potentially addictive substances (alcohol, cigarette, coca leaves and home-brewed beer) as indicators of stress behavior. After controlling for individual fixed effects, we found a negative association between individual achievement of the cultural model and psychological distress and a positive association between individual achievement of the cultural model and psychological well-being. Only the consumption of commercial alcohol bears the expected negative association with cultural consonance in material lifestyle, probably because the other substances analyzed have cultural values attached. Our work contributes to research on psychological health disparities by showing that a locally defined and culturally specific measure of lifestyle success is associated with psychological health.
Assuntos
Cultura , Satisfação Pessoal , Grupos Populacionais , Adulto , Bolívia , Emoções , Feminino , Humanos , Entrevistas como Assunto , Estilo de Vida , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Adulto JovemRESUMO
Growing evidence suggests that economic inequality in a community harms the health of a person. Using panel data from a small-scale, preindustrial rural society, we test whether individual wealth rank and village wealth inequality affects self-reported poor health in a foraging-farming native Amazonian society. A person's wealth rank was negatively but weakly associated with self-reported morbidity. Each step up/year in the village wealth hierarchy reduced total self-reported days ill by 0.4 percent. The Gini coefficient of village wealth inequality bore a positive association with self-reported poor health that was large in size, but not statistically significant. We found small village wealth inequality, and evidence that individual economic rank did not change. The modest effects may have to do with having used subjective rather than objective measures of health, having small village wealth inequality, and with the possibly true modest effect of a person's wealth rank on health in a small-scale, kin-based society. Finally, we also found that an increase in mean individual wealth by village was related to worse self-reported health. As the Tsimane' integrate into the market economy, their possibilities of wealth accumulation rise, which may affect their well-being. Our work contributes to recent efforts in biocultural anthropology to link the study of social inequalities, human biology, and human-environment interactions.
Assuntos
Nível de Saúde , Hierarquia Social , Renda , Fatores Socioeconômicos , Bolívia , Coleta de Dados , Humanos , Características de Residência , AutorrelatoRESUMO
Research on the social determinants of health has highlighted (a) the adverse effects of social inequality on individual health and (b) the association between individual social rank and health. In this paper, we contribute to the growing literature on the health consequences of social inequalities by assessing the association between village level inequality in social rank, a form of non-material inequality, and indicators of nutritional status. We use quantitative survey information from 289 men (18+ years of age) from a society of forager-farmers in the Bolivian Amazon (Tsimane'). We construct village level measures of non-material inequality by using individual measures of men's positions in the village hierarchy according to prestige (or freely conferred deference) and dominance (or social rank obtained through power). We find that village inequality in dominance, but not village inequality in prestige, is associated with short-term indices of individual nutritional status. Doubling the coefficient of variation of dominance in a village would be associated to a 6.7% lower BMI, a 7.9% smaller mid-arm circumference, and a 27.1% smaller sum of four skin folds of men in the village. We also find that once we decouple individual social rank based on dominance from individual social rank based on prestige, only prestige-based social rank is associated with nutritional status. Potential explanations for our findings relate to the differential forms of resource access derived from the two forms of social hierarchies and to the social and psychological benefits associated with prestige versus the social costs and psychological stress generated by dominance.
Assuntos
Estado Nutricional , Classe Social , Predomínio Social , Adulto , Índice de Massa Corporal , Bolívia , Coleta de Dados , Indicadores Básicos de Saúde , Humanos , Masculino , Análise Multivariada , Análise de Regressão , Fatores SocioeconômicosRESUMO
Research with humans and non-human primate species has found an association between social rank and individual health. Among humans, a robust literature in industrial societies has shown that each step down the rank hierarchy is associated with increased morbidity and mortality. Here, we present supportive evidence for the social gradient in health drawing on data from 289 men (18+ years of age) from a society of foragers-farmers in the Bolivian Amazon (Tsimane'). We use a measure of social rank that captures the locally perceived position of a man in the hierarchy of important people in a village. In multivariate regression analysis we found a positive and statistically significant association between social rank and three standard indicators of nutritional status: body mass index (BMI), mid-arm circumference, and the sum of four skinfolds. Results persisted after controlling for material and psychosocial pathways that have been shown to mediate the association between individual socioeconomic status and health in industrial societies. Future research should explore locally-relevant psychosocial factors that may mediate the association between social status and health in non-industrial societies.
Assuntos
Agricultura , Estado Nutricional , Classe Social , Adulto , Antropometria , Bolívia , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Autonomia Pessoal , Apoio Social , Adulto JovemRESUMO
Leptin is thought to signal energy stores, thus helping the body balance energy intake and expenditure. However, the strong relationship between leptin and adiposity in populations with adequate nutrition or common obesity is not universal across ecologic contexts, and leptin often correlates only weakly, or not at all, with adiposity in populations of lean or marginally-nourished males. To clarify whether the relationship between adiposity and leptin changes during development, this study examines leptin and body fat among children and adolescents of lowland Bolivia. Anthropometric measures of body composition and dried blood spot samples were collected from 487 Tsimane' ranging from 2 to 15 years of age. Leptin was assayed using an enzyme immunoassay protocol validated for use with blood spot samples. In this population, leptin concentrations were among the lowest reported in a human population (mean +/- SD: 1.26 +/- 0.5 and 0.57 +/- 0.3 in females and males). In addition, the relationship between leptin and adiposity follows distinct developmental trajectories in males and females. In males, leptin is weakly correlated with most measures of body composition at all ages investigated. However, in females, the level of body fat and the strength of the correlation between body fat and leptin (a measure of its strength as a signal of energy stores) both increase markedly with age. These findings suggest a more important role of leptin as a signal of energy stores among females as they approach reproductive maturity, while raising questions about the function of this hormone in lean males.
Assuntos
Adiposidade , Leptina/metabolismo , Obesidade/epidemiologia , Obesidade/metabolismo , Adolescente , Fatores Etários , Antropometria , Índice de Massa Corporal , Bolívia/epidemiologia , Criança , Pré-Escolar , Metabolismo Energético , Feminino , Humanos , Masculino , Estado Nutricional , Obesidade/fisiopatologia , Projetos PilotoRESUMO
Recent research documents the effects of adverse conditions during gestation and early childhood on growth responses and health throughout life. Most research linking adverse conditions in early life with adult health comes from industrial nations. We know little about the plasticity of growth responses to environmental perturbations early in life among foragers and horticulturalists. Using 2005 data from 211 women and 215 men 20+ years of age from a foraging-horticultural society of native Amazonians in Bolivia (Tsimane'), we estimate the association between (a) adult height and (b) rainfall amount and variability during three stages in the life cycle: gestation (year 0), birth year (year 1), and years 2-5. We control for confounders such as height of the same-sex parent. Rainfall amount and variability during gestation and birth year bore weak associations with adult height, probably from the protective role of placental physiology and breastfeeding. However, rainfall variability during years 2-5 of life bore a negative association with adult female height. Among women, a 10% increase in the coefficient of variation of rainfall during years 2-5 was associated with 0.7-1.2% lower adult height (1.08-1.93 cm). Environmental perturbations that take place after the cessation of weaning seem to leave the strongest effect on adult height. We advance possible explanations for the absence of effects among males.