Income inequality and adult nutritional status: Anthropometric evidence from a pre-industrial society in the Bolivian Amazon

Wealth, health and inequality in Agta foragers

Background and objectives

There is significant evidence from large-scale, industrial and post-industrial societies that greater income and wealth inequality is negatively associated with both population health and increasing health inequalities. However, whether such relationships are inevitable and should be expected to impact the health of small-scale societies as they become more market-integrated is less clear.

Methodology

Here, using mixed-effect models, we explore the relationship between health, wealth, wealth inequality and health inequalities in a small-scale foraging population from the Philippines, the Agta.

Results

Across 11 camps, we find small to moderate degrees of wealth inequality (maximal Gini Coefficient 0.44) which is highest in the most permanent camps, where individuals engage more heavily in the formal market. However, in both adults (n = 161) and children (n = 215), we find little evidence that either wealth or wealth inequality associates with ill health, except for one measure of nutritional condition-red blood cell count.

Conclusions and implications

We interpret these results in the light of high levels of cooperation among the Agta which may buffer against the detrimental effects of wealth inequality documented in industrial and post-industrial societies. We observe little intergenerational wealth transmission, highlighting the fluid nature of wealth, and thus wealth inequality, particularly in mobile communities. The deterioration of nutritional status, as indicated by red blood cell counts, requires further investigation before concluding the Agta's extensive cooperation networks may be beginning to breakdown in the face of increasing inequality.

The influence of gender and wealth inequality on Alzheimer's disease among the elderly: A global study

This study was designed to explore the relationship between Alzheimer's disease (AD) rates and socioeconomic conditions in 120 countries. We used mixed effect models to investigate the relationship between the rates of AD and socioeconomic data. This study is among the first studies to put forward statistical evidence of a significant association between AD and other dementias among the elderly and socioeconomic inequality. These findings could help to inform the policies to be designed to improve the quality of interventions for AD.

Assessing comparative asset-based measures of material wealth as predictors of physical growth and mortality

Social scientists and policymakers have increasingly relied on asset-based indices of household wealth to assess social disparities and to identify economically vulnerable populations in low- and middle-income countries. In the last decade, researchers have proposed a number of asset-based measures that permit global comparisons of household wealth across populations in different countries and over time. Each of these measures relies on different assumptions and indicators, and little is known about the relative performance of these measures in assessing disparities. In this study, we assess four comparative, asset-based measures of wealth-the Absolute Wealth Estimate (AWE), the International Wealth Index (IWI), the Comparative Wealth Index (CWI), and the "Standard of Living" portion of the Multi-Dimensional Poverty Index (MPI), along with a variable measuring television ownership-and compare how well each predicts health related variables such as women's BMI, children's height-for-age Z scores, and infant mortality at the household and survey level. Analyzing data from over 300 Demographic and Health surveys in 84 countries (n = 2,304,928 households), we found that AWE, IWI, CWI, MPI are all highly correlated (r = 0.7 to 0.9). However, IWI which is based on a common set of universally weighted indicators, typically best accounts for variation in all three health measures. We discuss the implications of these findings for choosing and interpreting these measures of wealth for different purposes.

Nuya kankantawa (we are feeling healthy): Understandings of health and wellbeing among Shawi of the Peruvian Amazon

Promoting and supporting Indigenous health includes ensuring health services reflect local concepts of health. There is, therefore, a need to better understand context-specific Indigenous understandings of health in order to design culturally appropriate health services. To this end, this study characterized two Shawi communities' understandings of what it means to be healthy. Using a community-based participatory research approach, 40 semi-structured interviews and a series of informal interviews were conducted and analysed thematically, using a constant comparative method. The Shawi definition of health extended beyond individual physical welfare and focused on emotional, collective, and environmental wellbeing. The primary factors underlying Shawi perceptions of health and wellbeing included providing for the family, ensuring the welfare of others, maintaining positive social relationships, preserving traditional values and practices, and living harmoniously with the natural environment. Conversely, Shawi classified illnesses according to their cause or treatment. These included illnesses caused by sorcery, those caused by spirits of the forest, and 'new diseases,' that first appeared in the communities when they were contacted by the Western civilization, for which no traditional remedies existed. Consequently, according to Shawi, sociocultural, environmental, and climatic changes are posing imminent health threats. This study highlights the differences between biomedical and Indigenous Shawi health understandings, and therefore emphasizes the importance of acknowledging and embracing Shawi culture and beliefs within the formal healthcare system.

Do wealth and inequality associate with health in a small-scale subsistence society?

In high-income countries, one’s relative socio-economic position and economic inequality may affect health and well-being, arguably via psychosocial stress. We tested this in a small-scale subsistence society, the Tsimane, by associating relative household wealth (n = 871) and community-level wealth inequality (n = 40, Gini = 0.15–0.53) with a range of psychological variables, stressors, and health outcomes (depressive symptoms [n = 670], social conflicts [n = 401], non-social problems [n = 398], social support [n = 399], cortisol [n = 811], body mass index [n = 9,926], blood pressure [n = 3,195], self-rated health [n = 2523], morbidities [n = 1542]) controlling for community-average wealth, age, sex, household size, community size, and distance to markets. Wealthier people largely had better outcomes while inequality associated with more respiratory disease, a leading cause of mortality. Greater inequality and lower wealth were associated with higher blood pressure. Psychosocial factors did not mediate wealth-health associations. Thus, relative socio-economic position and inequality may affect health across diverse societies, though this is likely exacerbated in high-income countries.

Poverty is bad for health. People living in poverty are more likely to struggle to afford nutritious food, lack access to health care, or be overworked or stressed. This may make them susceptible to chronic diseases, contribute to faster aging, and shorten their lifespans. In high-income countries, there is growing evidence to suggest that a person’s ‘rank’ in society also impacts their health. For example, individuals who have a lower position in the social hierarchy report worse health outcomes, regardless of their incomes. But it is unclear why living in an unequal society or having a lower social status contributes to poorer health.

One possibility is that inequalities in society are creating a stressful environment that leads to worse physical and mental outcomes. It is thought that this stress largely comes from how humans evolved to prioritize reaching a higher social status over having a long and healthy life. If this is the case, this would mean that the link between social status and health would also be present in non-industrialized communities where social hierarchies tend to be less pronounced.

To test this, Jaeggi, Blackwell et al. studied the Indigenous Tsimane population in Bolivia who live in small communities and forage and farm their own food. The income and relative wealth of 870 households from 40 Tsimane communities were compared against various outcomes, including symptoms associated with depression, stress hormone levels, blood pressure, self-rated health and several diseases.

Jaeggi, Blackwell et al. found poverty and inequality did not negatively impact all of the health outcomes measured as has been previously reported for industrialized societies. However, blood pressure was higher among people with lower incomes or those who lived in more unequal communities. But because the Tsimane people generally have low blood pressure, the differences were too small to have much effect on their health. People who lived in more unequal communities were also three times more likely to have respiratory infections, but the reason for this was unclear.

This shows that social determinants such as a person’s wealth or inequality can affect health, even in communities with less rigid social hierarchies. In industrial societies the effect may be worse in part because they are compounded by lifestyle factors, such as diets rich in fat and sugar, and physical inactivity which can also increase blood pressure. This information may help policy makers reduce health disparities by addressing some of the social determinants of health and the lifestyle factors that cause them.

The relationship between relative deprivation and adult nutritional status in rural Zambia

OBJECTIVES

To explore statistically the relationship between adult short-run nutritional status [body mass index (BMI)] and a measure of relative deprivation [subjective socioeconomic status (SES)] using panel data collected in a developing country where there is a high degree of poverty and a very uneven distribution of income.

METHODS

Study participants included men and women from a random sample of households located in a rural setting in Zambia. The data were collected during two waves of survey interviews in 2009. A multilevel model was used to estimate the relationship between subjective SES and adult BMI and controlled for individual absolute income as well as other correlates of adult health. The sample size included 254 observations.

RESULTS

A positive relationship was established between individual absolute income and adult BMI at the 1% level. A negative and statistically significant association was found at the 1% level between lower subjective SES and adult BMI. Lower perception of place within the socioeconomic hierarchy was on average associated with a 0.44 decrease in adult BMI.

CONCLUSIONS

This study found that, independent of individual absolute income, lower subjective SES was negatively related with adult BMI in rural Zambia. The result provides evidence that lower perception of place within the local socioeconomic hierarchy matters to health. Future studies should continue exploring the relationship between subjective and objective measures of relative deprivation and health in developing countries, where the bulk of the research focuses on material not relative deprivation as a key determinant of individual health.

Diurnal cortisol rhythms in Tsimane' Amazonian foragers: new insights into ecological HPA axis research

Although a growing body of research has documented important pathways by which the HPA axis mediates the interface between the psychosocial world and individual health, there is a paucity of data from nonwestern populations, particularly from those populations with distinct nutritional and infectious disease ecologies. The specific objectives of this study are: (1) to document variation in diurnal cortisol rhythms among the Tsimane', a remote population in the Bolivian Amazon, (2) to explore this variation by age and by gender, and (3) to compare diurnal rhythms from this study to other population based studies of cortisol conducted in industrialized nations. Salivary cortisol samples were collected twice daily, immediately upon waking and before bed, for three consecutive days from 303 participants (age 1.6-82 years, 1564 samples) in conjunction with the Tsimane' Amazonian Panel Study (TAPS). Cortisol rhythms showed strong age effects across the developmental span, with basal levels and slopes increasing into adulthood, although individuals older than 60 years demonstrated a precipitous flattening of the diurnal slope. Cortisol profiles were elevated in adult females compared to their age-matched male counterparts, and diurnal slopes, as well as mean cortisol concentrations among the Tsimane' were the lowest reported in any population based study of HPA axis function. Although the within-population variation in cortisol profiles was consistent with the established correlates of time of day, age, and sex, the between-population comparisons revealed dramatically lower levels of HPA activity among the Tsimane'. This study provides a benchmark against which to reference cortisol levels from industrialized populations, and expands the range of documented variation in HPA axis function in a nonwestern context.

CE, Leite MS. Prevalência e fatores associados à anemia em mulheres indígenas Suruí com idade entre 15 e 49 anos, Amazônia, Brasil

OBJETIVOS: investigar a prevalência e os fatores associados à ocorrência de anemia em mulheres indígenas Suruí com idade entre 15 e 49 anos. MÉTODOS: estudo transversal realizado a partir de levantamento censitário em 2005 na terra indígena Sete de Setembro, localizada em Rondônia, Brasil. A dosagem de hemoglobina (Hb) foi realizada pelo aparelho β-hemoglobinômetro portátil. Pontos de corte de anemia: Hb <12,0 g/dL nas não gestantes; Hb <11,0 g/dL nas gestantes. Dados demográficos e de status socioeconômico (SSE) foram obtidos por meio da aplicação de questionário padronizado. A primeira etapa da análise estatística incluiu os testes: qui-quadrado; qui-quadrado de tendência linear; t de Student; linearidade e análise de variância. Na segunda etapa, o modelo logístico final foi ajustado. RESULTADOS: a prevalência global de anemia nas não gestantes foi de 67,3% e nas gestantes de 81,8%. A análise multivariada demonstrou que as mulheres com um ou dois filhos anêmicos com idade entre 6 e 35 meses tiveram três vezes mais chances de serem anêmicas; mulheres do estrato SSE baixo apresentaram 3,5 vezes mais chance de serem anêmicas. A chance de uma mulher Suruí do SSE baixo ter anemia aumentou em 26% em relação às do estrato SSE alto. CONCLUSÕES: a anemia é um grave problema de saúde nas mulheres Suruí e é influenciada por características familiares/domiciliares, incluindo descendentes com anemia e condições socioeconômicas. Argumenta-se que medidas de tratamento e prevenção voltadas ao controle da anemia nos Suruí devem considerar tais fatores.

Nutrition in transition: dietary patterns of rural Amazonian women during a period of economic change

OBJECTIVES

The goal of this study was to understand the relationship between economic change (wage labor, retirement, and the Bolsa Família program) and dietary patterns in the rural Amazon and to determine the extent to which these changes followed the pattern of the nutrition transition.

METHODS

The study was longitudinal. The weighed-inventory method and economic interviews were used to collect data on dietary intake and household economics in a sample of 30 and 52 women in 2002 and 2009, respectively. Twenty of the women participated in both years and make-up the longitudinal sub-sample. Comparative statistics were used to identify changes in dietary patterns over time and multiple linear regressions were used to explore the relationship between economics, subsistence strategies, and diet.

RESULTS

There was a significant decline in kcal (P < 0.01) and carbohydrate (P < 0.01) but no change in protein intake over time in both the larger and smaller, longitudinal subsample. The percent of energy, carbohydrate, protein, and fat purchased increased in the larger and longitudinal samples (P ≤ 0.02) and there was an increase in refined carbohydrate and processed, fatty-meat consumption over time. The abandonment of manioc gardens was associated with increased dependence on purchased food (P = 0.03) while receipt of the Bolsa Família was associated with increased protein intake and adequacy (P = 0.02).

CONCLUSIONS

The dietary changes observed are only in partial agreement with predictions of the nutrition transition literature. The relationship between the economic and diet changes was shaped by the local context which should be considered when implementing CCT programs, like the Bolsa Família.

Individual wealth rank, community wealth inequality, and self-reported adult poor health: a test of hypotheses with panel data (2002-2006) from native Amazonians, Bolivia

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.

Tobacco smoking in urban neighborhoods: exploring social capital as a protective factor in Santiago, Chile

INTRODUCTION

Research examining the relationship between social capital and health in Latin America has been limited. The aim of this study is to evaluate the association between social capital and tobacco use in four low-income neighborhoods in Santiago, Chile.

METHODS

A multistage probability sample was used to select households in 4 of the 10 poorest neighborhoods in the district of Puente Alto, in Santiago, Chile. A cross-sectional survey of 781 participants (81.2% response rate for households) included sociodemographic variables, questions pertaining to neighborhood social capital, and questions pertaining to tobacco. Main analyses were carried out at the individual level by performing a multiple logistic regression of individual tobacco use on individual perceptions of community social capital.

RESULTS

The prevalence of smoking was 43.9% of the surveyed population. A five-factor structure for social capital was identified, including "perceived trust in neighbors," "perceived trust in organizations," "reciprocity within the neighborhood," "neighborhood integration," and "social participation." An inverse relationship between trust in neighbors and tobacco smoking was statistically significantly with an adjusted odds ratio of 0.95 (95% CI: 0.91-0.99). Trust in neighbors was also significantly inversely associated with the number of cigarettes smoked.

DISCUSSION

Tobacco control remains a significant challenge in global health, requiring innovative strategies that address changing social contexts as well as the changing epidemiological profile of developing regions.

Nutritional status and socioeconomic change among Toba and Wichí populations of the Argentinean Chaco

The prevalence of overweight and obesity is growing at an accelerated pace in disadvantaged populations. Indigenous populations all over the world, whose lifestyle is changing rapidly and drastically, seem to be particularly prone to show an increased prevalence of overweight and its co-morbidities among adults. The aim of this study was to evaluate the association between socioeconomic and nutritional statuses in adults of two indigenous populations of the Argentine Gran Chaco: the Toba and Wichí of the province of Formosa. Originally hunter-gatherers, they are now more settled and engage in temporary wage labor and local political positions. A total of 541 adults (>20 years old) participated in the study. Almost 50% of the adult Toba and 34% of the adult Wichí were overweight and 10% of adults in both populations were obese. Socioeconomic status was positively associated with body mass index in both populations. Furthermore, political connectedness with the non-indigenous sector, as in the case of community leaders, was highly correlated with obesity. Differences within and between groups can be explained by biocultural factors that include gender, diet (foraged vs store-bought), lifestyle (sedentary vs more active), and history of political power. Our study highlights the interactions among social, cultural, and political economic variables, such as political hierarchies within the group or degree of social connectedness with community leaders. By making these variables an integral part of our analysis and interpretation, we hope to improve our understanding of the situation of indigenous populations in transition.

The effect of rainfall during gestation and early childhood on adult height in a foraging and horticultural society of the Bolivian Amazon

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.

Network analysis in public health: history, methods, and applications

Network analysis is an approach to research that is uniquely suited to describing, exploring, and understanding structural and relational aspects of health. It is both a methodological tool and a theoretical paradigm that allows us to pose and answer important ecological questions in public health. In this review we trace the history of network analysis, provide a methodological overview of network techniques, and discuss where and how network analysis has been used in public health. We show how network analysis has its roots in mathematics, statistics, sociology, anthropology, psychology, biology, physics, and computer science. In public health, network analysis has been used to study primarily disease transmission, especially for HIV/AIDS and other sexually transmitted diseases; information transmission, particularly for diffusion of innovations; the role of social support and social capital; the influence of personal and social networks on health behavior; and the interorganizational structure of health systems. We conclude with future directions for network analysis in public health.

BMI, income, and social capital in a native Amazonian society: interaction between relative and community variables

Researchers have shown interest in the relation between (a) social capital and individual income and (b) the individual health of people of industrial nations. The socioeconomic complexity of industrial nations makes it difficult to arrive at firm conclusions. We circumvent the obstacle by using data from a small-scale rural society of foragers-farmers in the Bolivian Amazon (Tsimane'). We examine the interactions between the outcome (BMI) and relative income, relative social capital, village income, and village social capital. We test three hypotheses: people in villages with more social capital should have higher BMI, the positive association between social capital and BMI will be more marked among the less well-off, and better-off people who display generosity will have higher BMI than better-off people who do not. On the methodological side we show the importance of: focusing on relative measures of income and social capital, estimating interaction between community and relative measures of income and social capital, and showing results through contour plots that summarize the relation between BMI and pairs of explanatory variables. On the substantive side we find evidence that village social capital and village income complement each other and are associated with higher BMI, the rich who are stingy have lower BMI than the rich who display generosity, and increase in village income might reduce individual incentives to invest in social capital. We explore interactions between explanatory variables and their influence on BMI, and end by recommending the use of an experimental research design to obtain unbiased estimates of causal effects.

Nutritional status and spousal empowerment among native Amazonians

Researchers and development organizations have shown interest in individual empowerment because it presumably improves well-being. Estimates of empowerment's effects on well-being contain biases from the potential endogeneity of empowerment. Using data from a sexually egalitarian and highly autarkic society of foragers and horticulturalists in the Bolivian Amazon, the Tsimane', we overcome the problems that this poses by: (1) matching spouses' responses to the same questions about who makes decisions or who breaks ties in 10 domains to improve accuracy in measures of empowerment; and (2) using parental attributes of spouses as instrumental variables for spousal empowerment. Outcomes include two anthropometric indices of short-run nutritional status: body-mass index and age and sex-standardized z scores of mid-arm muscle area. The amount of empowerment of household heads did not affect their nutritional status or other indicators of their well-being, such as income, wealth, expenditures, happiness, social capital, or self-perceived health. It also did not affect the nutritional status of their offspring. Nor did it affect the difference in income, wealth, or monetary expenditures between spouses. The insubstantial effects persisted with other definitions of empowerment or types of regressions. We end with a discussion of why empowerment, despite its popularity in development discourse, has such tenuous links with objective indicators of well-being, and the implication of this finding for future studies of empowerment's effects.

Does village inequality in modern income harm the psyche? Anger, fear, sadness, and alcohol consumption in a pre-industrial society

Researchers have found a positive association between income inequality and poor individual health. To explain the link, researchers have hypothesized that income inequality erodes community social capital, which unleashes negative emotions, stress, and stress behaviors that hurt health. Few studies have tested the hypothesized path. Here we estimate the association between (a) village income inequality and social capital, and (b) three distinct negative emotions (anger, fear, sadness) and one stress behavior (alcohol consumption). We use four quarters of panel data (2002-2003) from 655 adults in 13 villages of a foraging-farming society in the Bolivian Amazon (Tsimane'). We found that: (1) village income inequality was associated with more negative emotions but with less alcohol consumption, (2) social capital always bore a negative association with outcomes, and (3) results held up after introducing many changes to the main model. We conclude that village income inequality probably affects negative emotions and stress behaviors through other paths besides social capital because we conditioned for social capital. One such path is an innate dislike of inequality, which might have pre-human origins. Our prior research with the Tsimane' suggests that village income inequality bore an insignificant association with individual health. Therefore, village income inequality probably affects negative emotions and stress behaviors before undermining health.

THE EFFECT OF MARKET ECONOMIES ON THE WELL-BEING OF INDIGENOUS PEOPLES AND ON THEIR USE OF RENEWABLE NATURAL RESOURCES

Assessing the effects of markets on the well-being of indigenous peoples and their conservation of natural resources matters to identify public policies to improve well-being and enhance conservation and to test hypotheses about sociocultural change. We review studies about how market economies affect the subsistence, health, nutritional status, social capital, and traditional ecological knowledge of indigenous peoples and their use of renewable natural resources. Market exposure produces mixed effects on well-being and conservation. Unclear effects arise from the small sample size of observations; reliance on cross-sectional data or short panels; lack of agreement on the measure of key variables, such as integration to the market or folk knowledge, or whether to rely on perceived or objective indicators of health; and endogeneity biases. Rigorous empirical studies linking market economies with the well-being of indigenous peoples or their use of renewable natural resources have yet to take off.