Daniel W. Sellen

RELATIONSHIP BETWEEN SUBSISTENCE AND AGE AT WEANING IN "PREINDUSTRIAL" SOCIETIES

Cross-cultural studies have revealed broad quantitative associations between subsistence practice and demographic parameters for preindustrial populations. One explanation is that variationin the availability of suitable weaning foods influenced the frequency and duration of breastfeeding and thus the length of interbirth intervals and the probability of child survival (the “weaning food availability” hypothesis). We examine the available data on weaning age variation in preindustrial populations and report results of a cross-cultural test of the predictions that weaning occurred earlier in agricultural and pastoral populations because dairy and cereal production increased the availability of easily digestible, nutrientrich foods appropriate for weaning. We found that, contrary to predictions, supplementation with liquid foods other than breast milk was delayed in agricultural populations relative to less agriculturally dependent ones and complementary feeding with solid foods was delayed in pastoral populations relative to those less dependent on herding. Although the duration of breastfeeding was longer in populations dependent on hunting, there was no qualitative evidence that such populations lacked foods appropriate for weaning. The patterns observed suggest that the relationships between demography and subsistence observed among preindustrial societies cannot be explained by the “weaning food availability” hypothesis. We discuss the implications for understanding the mechanisms underlying prehistoric human demography, subsistence shifts, allocation to parenting and mating effort, and the evolutionary implications of tradeoffs between diet and disease.

Weaning, Complementary Feeding, and Maternal Decision Making in a Rural East African Pastoral Population

A small-scale, prospective study of breastfeeding and weaning practices was conducted in a seminomadic pastoral population in northern Tanzania (Datoga of Mbulu District, Arusha Region). Focus group participants suggested that weaning patterns are strongly influenced by seasonal factors, and individual mothers often stated an intention to introduce adult staple foods and terminate breastfeeding at the end of the long rains. However, a combination of maternal self-perception, assessment of infant well-being, and indicators of household food supply influenced the actual progression of weaning for individual children. The results suggest that interventions to promote exclusive breastfeeding and improve complementary feeding practices in rural East African pastoral populations could build on maternal attention to infantcentered cues and address household-level constraints on caregivers making decisions about young child feeding.

Food Security and Child Hunger among Recently Resettled Liberian Refugees and Asylum Seekers: A Pilot Study

Little is known about the food insecurity situation among families resettled into the United States as part of the refugee resettlement program. This paper reports on a pilot study examining food insecurity among recently arrived refugee families (n=33). Objectives were to evaluate the usefulness and feasibility of methods to assess the prevalence of food insecurity and child hunger, and to examine associations between child hunger and measures of socio-economic status and measures of acculturation. Results indicated that 85% of households were food insecure, and 42% experienced child hunger. Hunger was more likely to be indicated in households using foods stamps, with lower income, and lower education. Hunger was also more likely to be indicated in households where the primary shopper experienced difficulty shopping and with language. Results are in broad agreement with those reported in other studies and highlight economic and information barriers to achieving food security. These data suggest that further study of food insecurity is warranted among recently resettled refugee communities resettled in the United States.

Polygyny and Child Growth in a Traditional Pastoral Society. The Case of the Datoga of Tanzania

In this paper I use measures of childhood growth to assess from both an evolutionary theoretical and an applied public health perspective the impact of polygyny on maternal-child welfare among the Datoga pastoralists of Tanzania. I report that the growth and body composition of children varies in such a way as to suggest that polygyny is not generally beneficial to women in terms of offspring quality. Cross-sectional analysis of covariance by maternal marriage status revealed that children of first and second wives in polygynous marriages grow relatively poorly, that this is correlated with maternal physical status, and that the pattern is not modified by household wealth. I discuss how the dynamics of sexual conflicts operating during the formation and maintenance of marriages may be important factors in the etiology of poor child growth in this population, leading to complex patterns of variation in anthropometric indicators of both women and children. The theoretical conclusion is that improved evolutionary models of polygyny should be designed to examine the potential for adaptive tradeoffs between the currencies of offspring quality and quantity for all types of parents in a polygynous population. The practical conclusion is that a better understanding of the relationships between marriage practices and health outcomes would assist in the development of culturally appropriate health and nutrition interventions.

Food insecurity is associated with attitudes towards exclusive breastfeeding among women in urban Kenya

This study aimed to document whether food insecurity was associated with beliefs and attitudes towards exclusive breastfeeding (EBF) among urban Kenyan women. We conducted structured interviews with 75 human immunodeficiency virus (HIV)-affected and 75 HIV-status unknown, low-income women who were either pregnant or with a child ≤24 months and residing in Nakuru, Kenya to generate categorical and open-ended responses on knowledge, attitudes and beliefs towards EBF and food insecurity. We facilitated six focus group discussions (FGD) with HIV-affected and HIV-status unknown mothers (n = 50 women) to assess barriers and facilitators to EBF. Of 148 women with complete interview data, 77% were moderately or severely food insecure (FIS). Women in FIS households had significantly greater odds of believing that breast milk would be insufficient for 6 months [odds ratio (OR), 2.6; 95% confidence interval (95% CI), 1.0, 6.8], that women who EBF for 6 months would experience health or social problems (OR, 2.7; 95% CI, 1.0, 7.3), that women need adequate food to support EBF for 6 months (OR, 2.6; 95% CI, 1.0, 6.7) and that they themselves would be unable to follow a counsellors advice to EBF for 6 months (OR, 3.2; 95% CI, 1.3, 8.3). Qualitative analysis of interview and FGD transcripts indicated that the maternal experience of hunger contributes to perceived milk insufficiency, anxiety about infant hunger and a perception that access to adequate food is necessary for successful breastfeeding. The lived experience of food insecurity among a sample of low-income, commonly FIS, urban Kenyan women reduces their capacity to implement at least one key recommended infant feeding practices, that of EBF for 6 months.

Addressing the HIV/AIDS–food insecurity syndemic in sub-Saharan Africa

Recently a few vocal health experts have suggested that some of the billions of dollars currently used to prevent and treat HIV and AIDS be reallocated to address more basic problems such as malnutrition, tuberculosis, malaria, and enteric and diarrheal disease caused by lack of access to clean water. While not universally agreed upon, this reassessment of policy priorities acknowledges that there are multiple other health problems that deserve renewed attention from the international community. It also highlights the fact that the impacts of the HIV pandemic are exacerbated by widespread poverty, food insecurity and malnutrition, and gender inequality. Nowhere is this more evident than in sub-Saharan Africa, where multiple epidemics conflate and seriously compromise the survival of individuals and communities. Given the widespread occurrence of famine in sub-Saharan Africa, issues of food and economic security become of paramount importance in efforts to address the regions HIV epidemics. This paper examines the historical, political-economic, and cultural dimensions of the HIV epidemic in the context of the growing problem of food and economic insecurity. Furthermore, using theoretical frameworks that emphasize the dynamic interrelation between HIV/AIDS and food insecurity, we present suggestions for combining traditional HIV-prevention strategies with food production and nutritioneducation programming. In light of the complex interactions between HIV/AIDS and food insecurity and the lack of accessible treatment modalities, such programming could potentially reduce the risk for transmission of HIV through behavioural changes and improved nutritional and immune status, and increase the life expectancy of people living with HIV or AIDS.

INFANT AND YOUNG CHILD FEEDING PRACTICES AMONG AFRICAN PASTORALISTS: THE DATOGA OF TANZANIA

Breast-feeding and weaning practices were observed for a cohort of 81 children under 3 years of age in the context of a longitudinal study of social, ecological and nutritional factors affecting growth in a semi-nomadic population of pastoralists in northern Tanzania (WaDatoga of Mbulu District). The adequacy of indigenous infant and young child feeding practices was assessed in relation to current international recommendations. Objectives were to provide baseline data for future investigations of any changes in young child feeding practices which accompany population shifts towards settlement and non-pastoral modes of subsistence, and to improve understanding of the strengths and limitations of indigenous feeding practices in this type of population. It was found that while breast-feeding was universally initiated, other aspects of young child feeding practices do not meet current international recommendations. Prelacteal feeds are commonly used, supplementary feeding with non-human milks usually occurs before 4 months of age, use of solid foods normally begins later than 6 months, and breast-feeding does not continue until 2 years of age for the majority of children. The data have implications for the design of breast-feeding promotion and improved weaning food interventions among African pastoralists.

Randomized trial of the effect of zinc supplementation on the mental health of school-age children in Guatemala

BACKGROUND Rates of mental illness in children are increasing throughout the world. Observational studies of depression, anxiety, and attention-deficit hyperactivity disorder suggest that zinc is an alternative treatment. OBJECTIVE We examined the effect of zinc supplementation on the mental health of school-age children in Guatemala. DESIGN From January to October 2006, we conducted a 6-mo randomized, double-blind, controlled trial comparing zinc supplementation (10 mg ZnO/d for 5 d/wk) with a placebo (10 mg glucose) in 674 Guatemalan children in grades 1-4. Outcome measures included internalizing (ie, depression and anxiety) and externalizing (ie, hyperactivity and conduct disorder) problem behaviors, positive behaviors (ie, socialization and leadership), and serum zinc concentrations. RESULTS Zinc and placebo groups did not differ significantly in any behavioral measures at baseline or at follow-up. At baseline, 21.4% of children had serum zinc concentrations <65 μg/dL. At follow-up, both groups improved significantly, and zinc concentrations were higher in the zinc group. Increases in serum zinc concentrations were inversely associated with decreases in depressive symptoms (estimate: -0.01 points per μg Zn/dL; P = 0.01), anxiety (estimate: -0.012 points per μg Zn/dL; P = 0.02), internalizing symptoms (estimate: -0.021 points per μg Zn/dL; P = 0.02), and social skills (estimate: -0.019 points per μg Zn/dL; P = 0.01) in adjusted models that were controlled for child age, sex, socioeconomic status, household, and treatment group. CONCLUSIONS Six months of zinc supplementation did not induce differences in mental health outcomes between zinc and placebo groups. However, increases in serum zinc concentrations were associated with decreases in internalizing symptoms (ie, depression and anxiety) in a community-based sample of children at risk of zinc deficiency. This trial was registered at clinicaltrials.gov as NCT00283660.

Food insecurity among refugee families in East London: results of a pilot assessment

OBJECTIVE To identify child hunger and examine its association with family factors, receipt of benefits, housing conditions and social support among recently arrived refugee families with young children. DESIGN Structured and semi-structured questionnaire administered to a service-based, purposive sample of caregivers. SETTING East London, United Kingdom. SUBJECTS Thirty households with children <5 years old, resident in the UK for <2 years. RESULTS All households sampled were food-insecure, and 60% of index children were experiencing hunger as defined on the Radimer/Cornell scale. Child hunger was significantly associated with recent arrival, marginally significantly associated with receipt of fewer benefits and younger parenthood, and not associated with maternal education or self-efficacy score, household size or composition, or measures of social support. CONCLUSIONS A community-based, participatory approach for rapid assessment of the prevalence, extent and causes of child hunger among newly arrived asylum seekers recently arrived in Britain is feasible, and preliminary results suggest a programmatic need for a broader, population-based assessment of food insecurity in this rapidly growing population group.

Nutritional Consequences of Wealth Differentials in East African Pastoralists: The Case of the Datoga of Northern Tanzania

Among African pastoralists evidence that wealth is associated with other measures of household success is scant and the significance of wealth differentials for family welfare remains poorly understood. Predictions that wealth in livestock is associated with increased adequacy of household food supply and with improved child nutrition are tested with longitudinal data on herd size, household composition, food supply, and anthropometric status collected in 1992 for a sample of traditional Datoga households (n = 20) living in the Eyasi basin in northern Tanzania. Although a majority subsisted below poverty cutoffs estimated for east African pastoral populations, there was large variation among households in measures of wealth and resource availability. Individuals in relatively wealthy households did not appear to benefit either in terms of adequacy of household food supply or in terms of average growth performance of young children. Theoretical and methodological challenges in the study of the relationship between wealth and health in nomadic pastoralists are discussed.