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.     

Androgen Receptor Gene Polymorphism,Aggression, and Reproduction in Tanzanian Foragers and Pastoralists

The androgen receptor (AR) gene polymorphism in humans is linked to aggression and may also be linked to reproduction. Here we report associations between AR gene polymorphism and aggression and reproduction in two small-scale societies in northern Tanzania (Africa)—the Hadza (monogamous foragers) and the Datoga (polygynous pastoralists). We secured self-reports of aggression and assessed genetic polymorphism of the number of CAG repeats for the AR gene for 210 Hadza men and 229 Datoga men (aged 17–70 years). We conducted structural equation modeling to identify links between AR gene polymorphism, aggression, and number of children born, and included age and ethnicity as covariates. Fewer AR CAG repeats predicted greater aggression, and Datoga men reported more aggression than did Hadza men. In addition, aggression mediated the identified negative relationship between CAG repeats and number of children born.     

Lack of prominent compensatory polycythemia in traditional native Andeans living at 4,200 meters

Red blood cell count (RBC), hemoglobin concentration ([Hb]) and hematocrit (Hct) were measured in 303 male Quechua children and adults, aged 6 to 57 years, living a lifestyle as traditional pastoralists and horticulturalists at a mean altitude of 4,200 m in the Southern Peruvian Andes. Values for RBC, [Hb], and Hct increased with age from middle childhood to young adulthood. However, among adults there was no significant association between age and any of these three parameters. Overall, there was approximately a 10-12% increase in the RBC, [Hb], and Hct above sea-level norms for all age groups. Mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) showed a slight but significant increase with age in children and adolescents, but the mean corpuscular hemoglobin concentration (MCHC) did not. We conclude that the study of highland Quechua Indians, living a traditional lifestyle as pastoralists and horticulturalists, does not support the long-held belief that altitude hypoxia provokes a dramatic compensatory polycythemia in healthy Andeans.     

Physical growth and nutritional status of Car Nicobarese and Moplah children of Andaman–Nicobar Islands in India

The objective of this cross-sectional study was to assess growth and nutritional status of Car Nicobarese children and compare it with Moplah children, who live in a similar environment. A total of 436 Car Nicobarese children and 438 Moplah children, aged 6–10 years, were selected for the study. The anthropometric measurements included stature, body weight, sitting height, bi-acromial breadth, bi-iliac breadth, mid-upper arm circumference, skinfold thickness of biceps, triceps and subscapular region. 50th percentile (median) growth curves were calculated among the studied children and compared with Centers for Disease Control and Prevention (CDC) 2000 reference. Z scores of weight for age (WAZ), height for age (HAZ) and BMI for age (BMIZ) were computed using growth references of the CDC 2000.It was observed that the Car Nicobarese children were shorter but heavier than Moplah children of both sexes all through the age range, which was also reflected in median value of anthropometric variables. Car Nicobarese children were nutritionally better compared to Moplah children based on the nutritional indices. The major differences between Car Nicobarese and Moplah children were found in their arm muscularity rather than arm adiposity. Overall, Car Nicobarese children were nutritionally in normal and better condition than Moplah children. However, present dietary change (intake of high calories and fat diet) of Car Nicobarese population may be reflected in the form of childhood obesity in the recent future, which has already been observed in their adult population.     

Accentuated lines in the enamel of primary incisors from skeletal remains: A contribution to the explanation of early childhood mortality in a medieval population from Poland

Physiological disruptions resulting from an impoverished environment during the first years of life are of key importance for the health and biological status of individuals and populations. Studies of growth processes in archaeological populations point to the fact that the main causes of childhood mortality in the past are to be sought among extrinsic factors. Based on this assumption, one would expect random mortality of children, with the deceased individuals representing the entire subadult population. The purpose of this study is to explore whether differences in early childhood survival are reflected in differences in deciduous tooth enamel, which can provide an insight into the development of an individual during prenatal and perinatal ontogeny. Deciduous incisors were taken from 83 individuals aged 2.0–6.5 years from a medieval inhumation cemetery dated AD 1300–1600. Prenatal and postnatal enamel formation time, neonatal line width, and the number of accentuated lines were measured using an optical microscope. The significantly wider neonatal line and the higher frequency of accentuated lines in the enamel of the incisors of children who died at the age of 2–3 years suggest the occurrence of stronger or more frequent stress events in this group. These results indicate that in skeletal populations mortality was not exclusively determined by random external factors. Individuals predisposed by an unfavorable course of prenatal and perinatal growth were more likely to die in early childhood. Am J Phys Anthropol 157:402–410, 2015. © 2015 Wiley Periodicals, Inc.     

Testosterone and paternal care in East African foragers and pastoralists

The 'challenge hypothesis' posits that testosterone facilitates reproductive effort (investment in male-male competition and mate-seeking) at the expense of parenting effort (investment in offspring and mates). Multiple studies, primarily in North America, have shown that men in committed relationships, fathers, or both maintain lower levels of testosterone than unpaired men. Data from non-western populations, however, show inconsistent results. We hypothesized that much of this cross-cultural variation can be attributed to differential investment in mating versus parenting effort, even among married fathers. Here, we directly test this idea by comparing two neighbouring Tanzanian groups that exhibit divergent styles of paternal involvement: Hadza foragers and Datoga pastoralists. We predicted that high levels of paternal care by Hadza fathers would be associated with decreased testosterone in comparison with non-fathers, and that no such difference between fathers and non-fathers would be evident in Datoga men, who provide minimal direct paternal care. Twenty-seven Hadza men and 80 Datoga men between the ages of 17 and 60 provided morning and afternoon saliva samples from which testosterone was assayed. Measurements in both populations confirmed these predictions, adding further support to the hypothesis that paternal care is associated with decreased testosterone production in men.     

Racial and ethnic differences in secular trends for childhood BMI, weight, and height

Objectives: The prevalence of childhood overweight in the United States has markedly increased over the last 30 years. We examined differences in the secular trends for BMI, weight, and height among white, black, and Mexican‐American children. Research Methods and Procedures: Analyses were based on nationally representative data collected from 2 to 17 year olds in four examinations (1971–1974 through 1999–2002). Results: Overall, black children experienced much larger secular increases in BMI, weight, and height than did white children. For example, over the 30‐year period, the prevalence of overweight increased ～3‐fold (4% to 13%) among 6‐ to 11‐year‐old white children but 5‐fold (4% to 20%) among black children. In most sex‐age groups, Mexican‐American children experienced increases in BMI and overweight that were between those experienced by blacks and whites. Race/ethnicity differences were less marked among 2 to 5 year olds, and in this age group, white children experienced the largest increase in overweight (from 4% to 9%). In 1999–2002, the prevalence of extreme BMI levels (≥99th percentile) reached 6% to 7% among black girls and Mexican‐American boys. Discussion: Because of the strong tracking of childhood BMI levels into adulthood, it is likely that the secular increases in childhood overweight will greatly increase the burden of adult disease. The further development of obesity interventions in different racial/ethnic groups should be emphasized.     

Differential mortality in Turkana agriculturalists and pastoralists

Nomadic pastoral populations appear to have much lower rates of growth than the otherwise very high growth rates now characteristic of populations in developing nations. Because dramatic declines in infant mortality have been a primary contributor to increased population growth rates in these countries, it has been assumed that nomadic pastoral populations are still characterized by high levels of mortality in the first few years of life. Few studies, however, have been undertaken to estimate demographic parameters for nomadic pastoral populations, and even fewer of a comparative nature have been undertaken to document the impact of subsistence strategy on demographic processes. This study compares indirect childhood mortality estimates for Turkana nomadic pastoralists with childhood mortality in a settled agricultural group within the same population and finds that pastoralists have substantially higher levels of mortality. Based on the childhood mortality estimates, model life tables are selected for pastoral and agricultural groups from which values for mean life expectancy and infant mortality are estimated and compared. Recent improvements in primary health care for the settled agricultural group are ruled out as being an important cause of their lower mortality levels, and some aspects of life-style associated with subsistence strategy are discussed as likely determinants of the mortality differences.     

Fluoride in drinking water and osteosarcoma incidence rates in the continental United States among children and adolescents

IntroductionIt has been suggested that fluoride in drinking water may increase the risk of osteosarcoma in children and adolescents, although the evidence is inconclusive. We investigated the association between community water fluoridation (CWF) and osteosarcoma in childhood and adolescence in the continental U.S.MethodsWe used the cumulative osteosarcoma incidence rate data from the CDC Wonder database for 1999–2006, categorized by age group, sex and states. States were categorized as low (≤30%) or high (≥85%) according to the percentage of the population receiving CWF between 1992 and 2006. Confidence intervals for the incidence rates were calculated using the Gamma distribution and the incidence rates were compared between groups using Poisson regression models.ResultsWe found no sex-specific statistical differences in the national incidence rates in the younger groups (5–9, 10–14), although 15–19 males were at higher risk to osteosarcoma than females in the same age group (p < 0.001). Sex and age group specific incidence rates were similar in both CWF state categories. The higher incidence rates among 15–19 year old males vs females was not associated with the state fluoridation status. We also compared sex and age specific osteosarcoma incidence rates cumulated from 1973 to 2007 from the SEER 9 Cancer Registries for single age groups from 5 to 19. There were no statistical differences between sexes for 5–14 year old children although incidence rates for single age groups for 15–19 year old males were significantly higher than for females.ConclusionOur ecological analysis suggests that the water fluoridation status in the continental U.S. has no influence on osteosarcoma incidence rates during childhood and adolescence.     

Wartime evacuation and mortality from childhood leukaemia in England and Wales in 1945-9.

OBJECTIVE--To discover whether the wartime government evacuation of children from London and other population centres to rural districts was associated with any increase in childhood leukaemia. DESIGN--Observational study of mortality from leukaemia among the childhood population of England and Wales in relation to the unique population movements during the second world war. The 476 rural districts of England and Wales were ranked according to the ratio of government evacuees (two thirds of them children) to local children in September 1941. The districts were divided into three categories, each with similar numbers of children in 1947 but with different ratios of evacuees to local children ("low," "intermediate," "high"). Mortality from childhood leukaemia was examined in these three rural categories in 1945-9. Urban areas were also examined according to their exposure to evacuees. SETTING--Local authority areas of England and Wales. SUBJECTS--Children aged under 15. RESULTS--47% excess of leukaemia at ages 0-14 years occurred in 1945-9 in the rural "high" category for evacuees relative to the "low" category, with a significant trend across the three categories. There were increases in both the 0-4 and 5-14 year age groups, but these were larger in the older age group. Rates 25% lower than average occurred in rural areas with few evacuees. CONCLUSION--These findings suggest that wartime evacuation increased the incidence of childhood leukaemia in rural areas and that other forms of population mixing may have contributed to the increases in past decades. Overall, they add to the appreciable evidence for an infective basis in childhood leukaemia.     

Childhood Overweight Prevalence in the United States: The Impact of Parent‐reported Height and Weight

Parent‐reported height and weight are often used to estimate BMI and overweight status among children. The quality of parent‐reported data has not been compared to measured data on a national scale for all race/ethnic groups in the United States. Parent‐reported height and weight for 2–17‐year‐old children in two national health interview surveys—the 1999–2004 National Health Interview Survey (NHIS) and the 2003–2004 National Survey of Children's Health (NSCH)—were compared to measured values from a national examination survey—the 1999–2004 National Health and Nutrition Examination Survey (NHANES). Compared to measured data, parent‐reported data overestimated childhood overweight in both interview surveys. For example, overweight prevalence among 2–17‐year‐olds was 25% (s.e. 0.2) using parent‐reported NHIS data vs. 16% (s.e. 0.6) using measured NHANES data. Parent‐reported data overestimated overweight among younger children, but underestimated overweight among older children. The discrepancy between reported and measured estimates arose mainly from reported height among very young children. For children aged 2–11 years, the mean reported height from NHIS was 3–6 cm less than mean measured height from NHANES (P < 0.001) vs. no difference among children aged 16–17 years. Measured data remains the gold standard for surveillance of childhood overweight. Although this analysis compared mean values from survey populations rather than parent‐reported and measured data for individuals, the results from nationally representative data reinforce previous recommendations based on small samples that parent‐reported data should not be used to estimate overweight prevalence among preschool and elementary school–aged children.     

The salutary effect of milk on amoebiasis and its reversal by iron.

Observations among milk-drinking African nomads showed an unusual freedom from infection with Entamoeba histolytica compared with similar nomads taking a mixed diet. A controlled study among Maasai pastoralists showed that the administration of iron to correct their dietary iron deficiency sharply increased their susceptibility to amoebiasis. Examination of the milk of their Zebu cattle showed that it not only had a concentration of iron below the minimum necessary for the growth of E histolytica but also contained partly saturated lactoferrin and transferrin, which may actively compete with the parasite in the colon for ambient iron. These observations suggest the possibility of a long-standing ecological compromise between nomads, their milk diet, and E histolytica.     

Growth patterns and final height in congenital adrenal hyperplasia due to classical 21-hydroxylase deficiency. Results of a multicenter study

BACKGROUND: Longitudinal growth and bone age (BA) development are the most important clinical parameters for monitoring adequate glucocorticoid replacement in children with congenital adrenal hyperplasia (CAH). AIM OF THE STUDY: To analyze the growth pattern of patients treated for CAH of the salt wasting (SW) and simple virilizing (SV) clinical forms; to evaluate final height as compared to reference data and individual target height; to evaluate the course of BA development. PATIENTS AND METHODS: A large database of 598 patients with CAH was created in 5 Central European countries and growth data of 341 treated patients with 21-hydroxylase deficiency were analyzed retrospectively. The patients were of Caucasian origin. Centiles were constructed in a cross-sectional manner and an additional longitudinal analysis was performed in order to evaluate the pubertal growth spurt by applying particular statistical methods (Preece-Baines model). RESULTS: The growth of SW CAH patients was impaired in infancy and early childhood (0-3 years of age), but followed normal patterns in childhood until puberty. In contrast, children with SV CAH had normal patterns of growth in infancy and early childhood and were considerably taller than healthy references during childhood. In the longitudinal study, peak height velocity in both boys and girls was normal, but it occurred at an earlier age than in the standard population. The final height of patients with CAH was reduced in comparison to both the reference and the individual target height. No correlations were found between final height and age at the start of the therapy in SV patients or between final height and year of birth. BA was advanced in both types of CAH, but more accelerated in SV patients. CONCLUSION: Characteristic growth patterns for treated SV and SW CAH children were identified, with a normal pubertal growth spurt and reduced final height being observed.     

Genetic structure of pastoral and farmer populations in the African Sahel

Traditional pastoralists survive in few places in the world. They can still be encountered in the African Sahel, where annual alternations of dry and wet seasons force them to continual mobility. Little is known about the genetic structure of these populations. We present here the population distribution of 312 hypervariable segment I mitochondrial DNA (mtDNA) and 364 Y-short tandem repeat haplotypes in both farmer and pastoralist groups from the Lake Chad Basin and the West African Sahel. We show that the majority of pastoral populations (represented in the African Sahel by the Fulani nomads) fail to show significant departure from neutrality for mtDNA as evidenced by Fu's Fs statistics and exhibit lower levels of intrapopulation diversity measures for mtDNA when contrasted with farmers. These differences were not observed for the Y chromosome. Furthermore, analyses of molecular variance and population distributions of the mtDNA haplotypes show more heterogeneity in the sedentary groups than in the pastoralists. On the other hand, pastoralists retain a signature of a wide phylogenetic distance contributing to their male gene pool, whereas in at least some of the farmer populations, a founder effect and/or drift might have led to the presence of a single major lineage. Interestingly, these observations are in contrast with those recorded in Central Asia, where similar comparisons of farmer and pastoral groups have recently been carried out. We can conclude that in Africa, there have been no substantial mating exchanges between the Fulani pastoralists coming to the Lake Chad Basin from the West African Sahel and their farmer neighbors. At the same time, we suggest that the emergence of pastoralism might be an earlier and/or a demographically more important event than the introduction of sedentary agriculture, at least in this part of Africa.     

Chronic undernutrition and traditional weaning foods are associated with fat stores in ariaal infants of Northern Kenya

The high proportion of human infant fat is hypothesized to protect infant brains by mobilizing against growth disturbances caused by acute nutritional and pathogen stress during weaning. However, individuals who experience chronic nutritional stress have been shown to store fat rather than mobilize fat stores, although this has not been demonstrated during infancy. This study investigated the relationship between fat development, diet, and nutritional status among 239 breastfeeding Ariaal infants, a group of settled pastoralists who experience both acute and chronic nutritional stress residing in Marsabit District, Kenya. This study had three goals: 1) To investigate the pattern of fat accumulation among Ariaal infants compared with a reference population; 2) to explore the relationship between chronic nutritional stress and fat deposits; and 3) to determine the relationship between traditional weaning foods, particularly cow's milk, and infant's fat. Infants, particularly infants experiencing chronic nutritional stress, were found to accumulate fat deposits in a manner that suggests reduced oxidation of fat stores. Infant upper arm fat area significantly increases with age over the weaning period compared with reference populations, who show a decline in body fat. Chronically undernourished infants were particularly likely to have increased levels of upper arm fat compared with normal infants or acutely undernourished infants. In addition, infants who consume cow's milk are significantly fatter than those that do not. These results suggest that Ariaal infants have both physiological and cultural mechanisms for fat storage in the face of their nutritionally stressed environment. Am J Phys Anthropol 153:286–296, 2014. © 2013 Wiley Periodicals, Inc.     

The LMS method and weight and height centiles in Jujuy (Argentina) children

Human growth and its resulting patterns display a great inter- and intra-population heterogeneity that reflects the quality of life, health and nutritional condition of populations. The aim of this work was to expand the knowledge about the growth of Jujenean children by statistical procedures that graphically express the relation of anthropometric variables to age and allow their comparison with specific references. Anthropometric data came from 9092 children (0-5 years) from various localities of Jujuy province (northwest Argentina) located at 1200 m above sea level (ma.s.l.). The centiles of weight for age (W/A) and height for age (H/A) were obtained by the LMS method using maximum penalized likelihood. A statistical and graphic comparison was made with the corresponding Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) centile references. In general, estimated centiles were lower than those in both references. Discrepancies for H/A in comparison with the CDC reference ranged between 1.09+/-0.59% and 1.66+/-0.34%, and for W/A between 1.82+/-1.56% and 3.36+/-1.4%. In comparison with the WHO reference, discrepancies ranged from 1.38+/-0.65% to 1.87+/-0.41% for H/A, and from 1.12+/-1.28% to 2.74+/-1.49% for W/A. Centile discrepancies were attributed to the characteristics of early childhood feeding and the interaction of a set of biological and mesological factors that the Jujenean population is exposed to. Growth and nutritional conditions of this population should be evaluated with the WHO reference, for it reflects the recent growth pattern of biologically and culturally healthy children raised in favourable conditions, a pattern that also reflects that of Jujenean children.     

Polymorphism of the dopamine D4 receptor (DRD4) and serotonin transporter (5-HTTL) gene promoter regions in african tribes of Hadza and Datoga

Molecular genetic analysis of the allelic variants of the DRD4 and 5-HTTL gene promoter regions was performed in African tribes of Hadza and Datoga, characterized by different levels of socially acceptable aggression. It was demonstrated that Hadza and Datoga people differed in the structural organization of one of the 5-HTTL alleles (extra long allele xL). Analysis of the allele length polymorphism of both genes showed that in the Hadza and Datoga samples examined, variation parameters, as well as the genotype and allele frequency distribution pattern were almost the same. At the same time, analysis of the SNP polymorphism at the A/G substitutions of the 5-HTTL locus revealed a substantial decrease of the active allele L _A frequency in the population of Hadza compared to the population of Datoga (χ² = 3.77; d.f. = 1; p = 0.052).     

Infant mortality and intra‐household competition in the Northern Islands of Orkney,Scotland, 1855–2001

This study applies principles from the theory of household life cycles to the study of early childhood mortality in the population of the Northern Orkney Islands, Scotland. The primary hypothesis is that unfavorable household economic conditions resulting from changes in household demographic composition increase the risk of death for children under the age of 5 years because of limited resources and intra‐household competition. We apply Cox proportional hazards models to nearly 5,000 linked birth and death records from the Northern Orkney Islands, Scotland, from the period 1855 to 2001. The dependent variable is the child's risk of death before age 5. Findings suggest that children in households with unfavorable age compositions face higher risk of death. This elevated risk of death continues once heterogeneity among children, islands, and households is controlled. Results also show differential risk of death for male children, children of higher birth orders, and twin births. The analyses present evidence for intra‐household competition in this historic setting. The most convincing evidence of competition is found in the effects of household consumer/producer ratios and twinning on child mortality risks. Am J Phys Anthropol 151:191–201, 2013. © 2013 Wiley Periodicals, Inc.