Vitzthum, Dr. Virginia Judith, State U. of New York, Binghamton, NY - To aid research on 'Testing Hypotheses of the Dietary Determinants of Ovarian Hormones: A Comparative Study of Three Populations'
DR. VIRGINIA J. VITZTHUM, Institute of Primary and Preventative Health Care, Binghamton University, Binghamton, New York, was awarded a grant in May 2006 to aid research on 'Testing Hypotheses of the Dietary Determinants of Ovarian Hormones: A Comparative Study of Three Populations.' This research is part of a larger project to elucidate the ecological, behavioral, and ontogenetic determinants of variation in women's reproductive functioning. This phase of the project evaluated the relative importance of total caloric intake versus dietary fat consumption in determining ovarian steroid variation by comparing hormone levels in nomadic-herding Mongolian women (high fat/low calorie diets) with those in previously collected samples of agropastoral Bolivian women (low fat/low calorie diets) and Chicago women (high fat/high calorie diets). Daily biological samples spanning a menstrual cycle and data on covariates were collected from 40 nomadic Mongolian women during July through September 2006. Assays were conducted in collaboration with Dr. Tobias Deschner at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Initial analyses suggest that ovarian steroid levels are at least as high as those of U.S. women, suggesting that dietary fat may be the more important factor. In addition to increasing current understanding of the sources of variation in ovarian functioning, this finding suggests that the modulation of reproductive functioning during a woman's lifespan may be sensitive to variation in dietary fat intake. Ongoing research includes the collection of a comparative sample of German women and planned research includes genetic analyses to ascertain the potential contribution of genotypic variation to hormonal variation.
Melby, Dr. Melissa Kathleen, National Institute of Health and Nutrition, Tokyo, Japan - To aid research on 'Developmental Origins of Metabolic Syndrome: Study Utilizing the Japanese Maternal and Child Health Handbook'
DR. MELISSA K. MELBY, National Institute of Health and Nutrition, Tokyo, Japan was awarded a grant in October 2008 to aid research on 'Developmental Origins of Metabolic Syndrome: Study Utilizing the Japanese Maternal and Child Health Handbook.' The 'Developmental Origins of Health and Disease' hypothesis posits that in utero stress such as nutritional restriction resulting in low birth weight (LBW) increases later life risk of metabolic-syndrome related disease. Understanding risk factors for LBW thus has implications for later life health. Among singleton full-term births (N~437) in Japan, females were three times more likely to be born at LBW than males. For males, gestational length was the biggest predictor of LBW, but gestational length was not a significant predictor of female LBW. Instead maternal weight at first prenatal exam, and total gestational weight gain after that exam, were most predictive. For girls only, primiparity and maternal history of LBW babies also increased risk, while maternal height decreased risk. If given adequate time in the womb, male babies appear largely immune to early pre-natal or pre-conception maternal condition and low maternal gestational weight gain. Female babies appear to be very sensitive to maternal condition, particularly early/initial weight and weight gain, as well as reproductive history. BMI at age 6-7 appears independent of birth weight and maternal gestational weight gain for boys, while girls' age 6-7 BMI appears more dependent on reproductive history, gestational weight gain, and resulting birth weight.
Thayer, Zaneta Marie, Northwestern U., Evanston, IL - To aid research on 'Intergenerational Programming of Stress Reactivity: Role of Epigenetic Mechanisms,' supervised by Dr. Christopher Kuzawa
ZANETA THAYER, then a student at Northwestern University, Evanston, Illinois, received funding in April 2011 to aid research on 'Intergenerational Programming of Stress Reactivity: The Role of Epigenetic Mechanisms,' supervised by Dr. Christopher Kuzawa. Anthropologists have a long history of studying biological responses to environmental stress from diverse perspectives. Within our field the effects of maternal psychosocial stress on biology and health in the next generation is becoming a topic of increased interest. This research project evaluated the intergenerational effects of maternal stress experience among an ethnically and socioeconomically diverse sample of pregnant women from Auckland, New Zealand. Women who had lower socioeconomic status and who experienced ethnic discrimination had higher evening cortisol in late pregnancy and gave birth to infants with elevated cortisol reactivity and altered gene regulation (methylation) profiles. These findings are consistent with the hypothesis that maternal social environment impacts maternal and offspring biology. Notably, the types of stress exposures that impacted cortisol in the present study are relatively novel from an evolutionary perspective. Thus the evolved capacity for an intergenerational transfer of information could be maladaptive in the contemporary ecology when activated in response to structural inequalities within society. Future research evaluating diverse sources of stress and a range of biological responses in offspring are necessary to clarify whether modifications in offspring biology reflect adaptation or biological impairment.
Hoke, Morgan Kathleen, Northwestern U., Evanston, IL - To aid research on 'Changing Economic Activity, Infant Feeding, and Early Growth among the Quechua of Nuñoa, Peru,' supervised by Dr. William Leonard
Preliminary abstract: This biocultural research project examines the changing practices of infant feeding and the emergence of early growth inequalities in Nuñoa, Peru in light of ongoing political and economic changes, specifically the emergence of a new dairy industry and an increasing reliance on wage labor. Infancy is a critical period in which environmental and social inputs can have a significant effect on both health and socioeconomic outcomes later in life. Early nutrition has been shown to be particularly important. Drawing on anthropological and health literature on infant feeding, scholarship on the developmental origins of health and disease, and biocultural anthropology to inform research questions, this study represents a work of 'ethnographic human biology' (Wiley 2004). Previous anthropological research in Nuñoa dating to the 1960's allows findings to be contextualized within the political-economic and biological history of the region. Research methods include both ethnographic and biological approaches such as participant observation, interviews, infant nutritional assessment, anthropometric measurements, and infant focal follows. Original data will be analyzed to compare infant nutrition and growth between contemporary communities participating in different economic activities. Additional comparisons will be made with data collected in previous waves of research to identify dietary changes and highlight key changes in the growth process in the face of fifty years of economic changes.
DeCaro, Jason A., Emory U., Atlanta, GA - To aid research on 'The Social Ecology of Childhood Stress: Reactivity and Family Function in North Central Georgia, U.S.A.' supervised by Dr. Carol M. Worthman
JASON A. DECARO, while a student at Emory University in Atlanta, Georgia, was awarded a grant in November 2001 to aid research on the social ecology of childhood stress in north-central Georgia, U.S.A., under the supervision of Dr. Carol M. Worthman. DeCaro's research was designed to evaluate whether children's reactivity (physiological response to stress or arousal) during the transition from preschool to kindergarten was related to their parents' economic security; whether the 'routinization' of family life and stability in the social ecology of the home predicted children's reactivity during this transition; and whether the stability of children's social environment and their reactivity predicted functional outcomes. Ethnographic interviews with parents in forty-five metropolitan Atlanta families focused on work, finances, economic security, time management, and school and neighborhood choices and satisfaction. Prior to and following the transition into kindergarten, DeCaro collected saliva samples from children and parents three times a day for seven days, in order to test for levels of cortisol, a hormone of physiologic arousal. He also monitored children's heart rates during a puppet-based psychobehavioral interview. Parents were asked to track on hand computers their and their children moods, contexts, and experiences for seven days. Questionnaires covered children's behavioral and somatic symptomatology and preschool educational outcomes. Preliminary analysis suggested that cardiovascular response during a mild social challenge predicted the density of parents' schedules but that mothers' and fathers' types of 'busyness' had different effects on household ecology and on children's responses to experience. The study was expected to provide insights into the cultural construction of the 'work' of the family, which profoundly affects both the actual form and the perception of family life by family members and thus what precisely is 'stressful' about it.
DeCaro, Jason A. and Carol M. Worthman. 2006 Cultural Models, Parent Behavior, and Young Child Experience in Working American Families. Parenting: Science and Practice 7(2): 177-203.
Madimenos, Felicia Chrisafo, U. of Oregon, Eugene, OR - To aid research on 'Lifestyle and Reproductive Effects on Bone Mineral Density in an Ecuadorian Forager-Horticulturalist Population,' supervised by Dr. James Josh Snodgrass
FELICIA C. MADIMENOS, then a student at University of Oregon, Eugene, Oregon, received funding in April 2009 to aid research on 'Lifestyle and Reproductive Effects on Bone Mineral Density in an Ecuadorian Forager-Horticulturalist Population,' supervised by Dr. James Josh Snodgrass. Bone mineral density (BMD) is the primary diagnostic parameter of bone health and a predictor of future fracture risk. The mechanisms and life history trade-offs affecting bone integrity evolved under conditions quite different from those experienced by industrialized populations, yet minimal data on bone health are available from non-Western, subsistence populations. Such data are particularly important because people in subsistence-based populations have dietary, reproductive, and activity patterns more like those of our evolutionary past. Using calcaneal ultrasound, this study presents the first available data on bone health among the Shuar, an indigenous Ecuadorian Amazonian population, and non-Shuar colonists (colonos) from the same area. Results show that among colonos, BMD is positively correlated with the consumption of fish and greens but not other food categories. Among Shuar, no such relationship is found but BMD is negatively associated with greater ownership of market goods. Further analyses considering the effects of reproductive history show that in both populations multiparity provides a protective effect on BMD but this protection is lost with increased duration of lactation per child (> 24 months). The most protective effect on bone health is realized when mothers breastfeed multiple children for shorter durations.
Noback, Marlijn Lisanne, Eberhard Karls U., Tubingen, Germany - To aid research on 'Climate- and Diet-related Variation in Human Functional Cranial Components,' supervised by Dr. Katerina Harvati
MARLIJN NOBACK, then a student at Eberhard Karls University, Tubingen, Germany, was awarded a grant in April 2011 to aid research on 'Climate- and Diet-Related Variation in Human Functional Cranial Components,' supervised by Dr. Katerina Harvati. This study seeks to elucidate the physiological basis of craniofacial variation and the selective forces driving modern human cranial geographic diversity. Funding enabled the CT scanning of 45 individual crania from three different collections based in Paris, London, and Tübingen. These scans form part of a larger database of over 330 CT scans, representing populations from different climatic and dietary regimes. With the use of the software package AVIZO and a high performance laptop, 3D models of functional facial components are developed from the CT scans. Analyses are currently undertaken and include studies of variation and co-variation of the cranial components and their relation to diet and climate. This project will enhance understanding of the biological processes underlying the evolution of modern human anatomy, adaptation and geographic diversity.
Shirley, Meghan, U. College London, London, UK - To aid research on 'Body Composition and the Brain: Investigating Life History Trade-offs in Living Humans,' supervised by Dr. Jonathan Wells
Preliminary abstract: Energy resources in any given environment are finite. Life history theory examines trade-offs between competing functions such as maintenance and reproduction across an organism's life course. For early humans, the evolution of a metabolically expensive brain was likely associated with reorganized energy investment and/or alterations in life history strategy and behavior. Insight into how the human brain was afforded may be most readily achieved with attention directed to investment 'decisions' at the level of organs and tissues. For example, Aiello and Wheeler's (1995) 'expensive tissue' hypothesis proposed that a reduction in the size of the human gut enabled encephalization. Research has demonstrated tissue trade-offs in a range of animals, yet empirical studies of human investment strategies remain rare. With the collection of MRI and body composition data from healthy adults, this project will investigate trade-offs between the human brain and other 'expensive' tissues of the body, trade-offs between the brain and adipose tissue, and also positive brain-body phenotype associations. Further, the study will examine the effect of early life experience on phenotype. This data will add to knowledge of the variability with which modern humans 'strategically' manage energy investment and lead to more robust inferences concerning hominin life history evolution.