Longevity, Mortality, and Preconception-to-Adult Models of Health

Globalization and Health Outcomes
IPR/C2S faculty are interested in how globalization affects health outcomes, and faculty members have been part of two ongoing studies: the Tsimane’ Amazonian Panel Study in Bolivia and the Cebu Longitudinal Health and Nutrition Survey in the Philippines. Both are rich resources for studying the long-term health effects of early environments and might provide additional insight on domestic health outcomes.

The Cebu Survey has followed more than 3,000 mothers who were pregnant in 1983 and their children, who are now young adults and having children of their own. Working with U.S. and Filipino collaborators, anthropologist Christopher Kuzawa studies the influence of fetal/infant nutrition and growth on adult health and function in the Philippines. Three extensions of the study are underway. The first uses 22 years of longitudinal data to investigate predictors of metabolic disease risk factors in the mothers and their young adult offspring. The second combines these data with saliva and plasma samples to examine if early life nutrition affects adult male reproductive functioning, A third follows up with the original offspring, now adults with children of their own, and looks at the intergenerational influences on offspring nutrition and growth. The National Science Foundation supports the latter two projects.

Using plasma samples from 1,875 Filipino women participating in the Cebu study, McDade and Kuzawa, with IPR postdoctoral fellow Julienne Rutherford and Linda Adair of the University of North Carolina at Chapel Hill, examined how obesity and infectious agents affected the women’s levels of C-reactive protein (CRP). Elevated levels of CRP can indicate the presence of cardiovascular disease (CVD), hypertension, and diabetes. Their data indicate that being overweight or obese and exposed to infectious diseases are associated with elevated CRP levels, and these associations are not linked to socioeconomic status or other health behaviors. Their findings also indicate that other cultures transitioning to high-calorie, Western-style diets with lower levels of physical activity are also experiencing comparable levels of elevated inflammation, probably contributing to the worldwide epidemic of CVD and metabolic diseases. The findings were presented at the Population Association of America meetings in April 2008 and appeared in three new articles published in the Journal of Nutrition and American Journal of Clinical Nutrition.

Childhood Growth and Adult Outcomes
The Tsimane’ study links the effects of globalization to health and early developmental conditions to later outcomes. In a study led by McDade, the researchers identify significant costs associated with activation of immune defenses to growth among children in a remote area of Amazonian Bolivia. They find that young Tsimane’ children (aged 2 to 4) with low body fat stores might lose 10 to 15 percent of their expected annual height gain. Such stunted growth is associated with reduced work capacity and poorer reproductive outcomes in adulthood, as well as increased mortality risk.

In another study, Kuzawa, McDade, and their co-authors are the first to find evidence for changes in the relationship between leptin, a hormone that seems to signal energy intake and expenditure, and body fat during childhood growth and development. In males, there was a small relationship between body fat and the hormone, while in females the correlation between the two increased markedly as they approach puberty. The correlation suggests a more important role for leptin as a signal of energy status in females, perhaps indicating a larger effect on female development and reproduction.

Intergenerational Model of Health Disparities
Kuzawa is exploring the application of an intergenerational model of biology and health to the problem of U.S. health disparities. He and graduate student Elizabeth Sweet published a model of the environmental origins of health disparities in cardiovascular disease (CVD) between U.S. whites and blacks. They review evidence linking stressors within the African American community, such as discrimination, with maternal stress during pregnancy—leading to poorer birth outcomes, such as lower birth weights, and a higher risk of CVD among adult offspring. They argue that the embodiment of negative socio-environmental factors in the prenatal environment provides a better explanation than genetics for the biological persistence of disease disparities. While they recognize that legislation cannot directly address certain contributors, they point to social policies, such as better access to prenatal care and promoting breast feeding, that could mitigate patterns of U.S. health disparities in future generations.

Genetics and the Social Sciences
Sociologist Jeremy Freese continues to pursue the place of sociology in interdisciplinary research that spans social, psychological, and biological analyses within the context of social and technological change. In a special issue of the American Journal of Sociology exploring genetics and social structure, Freese provides a basic theoretical statement for sociologists about the centrality of psychological constructs in drawing explanatory relations between genetics and social outcomes, as well as in describing how the causal potency of genes carries across social contexts. Freese argues that social scientists will not be thrown out of work in the coming years by increased understanding of the biological mechanisms of genomic causation. Genomic causation is not in competition with social conditions, but a product of them, Freese explains. Thus, sociologists will be needed to provide explanations for why genetic differences are more—or less—relevant to individual outcomes.

Controlling the Expression of Prejudice
In psychologist Jennifer Richeson’s study of how people control the expression of prejudice, she explores how individuals’ concerns about either being or appearing racially biased influence subtle aspects of cognition, emotion, and behavior. She directs Northwestern’s Social Perception and Communication Laboratory, which seeks to better understand the effects of diverse environments on individuals’ feelings and behavior and to investigate the antecedents and consequences of prejudice and stereotyping.

Using a dot-probe detection paradigm and photos of black and white individuals with either a neutral or happy facial expression, Richeson and C2S postdoctoral fellow Sophie Trawalter tested the selective attention of white individuals who are highly motivated to avoid appearing prejudiced toward blacks. Their study reveals that the white participants are drawn to black faces with neutral expressions when exposed for 30 milliseconds and avert their gaze when shown the same neutrally expressive black faces for longer (450 ms). Smiling black faces eliminated the attentional bias altogether. Their results, published in Psychological Science, indicate that pressure to avoid appearing prejudiced leads to anxious reactions and threat responses to out-groups. Their study indicates a new direction for future research on racial bias and holds implications for building a harmonious, multiracial society.

Negative Group Stereotypes, Stigmatization
Many companies, schools, and other organizations strive to increase their diversity, yet how do stigmatized individuals fare within them? Richeson is examining the experiences of racial minorities and members of other low-status groups as they attempt to persist—and even succeed—in the face of low numbers and negative group stereotypes. Specifically, Richeson is investigating the extent to which racial minority and low-SES students at a predominantly white private university engage in “covering”—a compensatory form of self-regulation that surfaces in managing a stigmatized identity—when they feel their group identity threatened and/or they feel they are the targets of prejudice. She is also tabulating potential intrapersonal costs of covering, including physiological stress reactions, feelings of inauthenticity and shame, increased loneliness, and cognitive depletion.

Racial Bias and Mental Illness
Richeson and Nicole Shelton of Princeton University are exploring whether racial bias constitutes a risk factor for mental disorders (namely depression) among African Americans and Latinos. Specifically, their work considers the effects of subtle—as compared with blatant—expressions of racial discrimination during interpersonal interactions in the development of mental disorders. They also consider how suppressing emotional reactions to interpersonal discrimination can affect mental disorders and examine whether the stigma of mental illness operates in a similar manner to racial bias in one-on-one interactions. The National Institute of Mental Health and the Office of Behavioral and Social Sciences Research provide project funding.

Oncofertility
The Oncofertility Consortium, a national research, clinical, and education program led by oncofertility researcher Teresa Woodruff, brings physicians, medical ethicists, social scientists, and basic scientists together to develop new strategies for fertility preservation for female cancer survivors. They are developing an experimental technique that uses emergency in-vitro fertilization (IVF) to store ovarian tissue for future conception before girls and women undergo cancer treatment. After one ovary is removed and cryopreserved, or frozen, immature follicles are extracted and matured in the lab so that they can later be fertilized. McDade is currently working on a related project to develop a minimally invasive method for assessing ovarian reserve. Woodruff, Thomas J. Watkins Memorial Professor of Obstetrics and Gynecology, is also director of the Division of Fertility Preservation, which is establishing the first “follicle bank” for U.S. cancer survivors. She directs one of the National Institutes of Health’s specialized cooperative centers in reproduction research.

Evolution of Biological Knowledge
Psychologists Sandra Waxman and Douglas Medin of Northwestern are currently writing a book about their research on the evolution of biological knowledge and reasoning across cultures and across development. They led an interdisciplinary research team of psychologists, linguists, and anthropologists who interviewed young children and adults from a wide range of language and cultural communities. The participants included urban and rural U.S. English speakers from majority culture and Native American populations. Their research offers evidence of strong universal patterns in most fundamental notions of the natural world. It also highlights striking differences that illuminate intimate connections among culture, language, and the organization of knowledge. In a recent experiment with Florencia Anggoro of Georgia State University, they ask 4- and 9-year old English- and Indonesian-speaking children to identify various entities as “alive.” Older Indonesian speaking children selected both plants and animals, but their English-speaking counterparts tended to exclude plants. This suggests a misalignment in meaning for the English speakers with one of the ‘‘animal’’ senses.

Is Race Biological?
Intrigued by a resurgence of scientific interest in race-based genomic variation and the use of racial categorization in biomedicine, law professor Dorothy Roberts, Kirkland & Ellis Professor, investigates the expansion of race consciousness in biomedical research and technologies in its sociopolitical context to determine how it is related to race consciousness in social policies. Drawing on her larger study of race consciousness in biotechnology, law, and social policy, including interviews of 30 scientists, activists, and bioethicists, Roberts is exploring how experts are redefining the scientific meaning of race and its relationship to biology in both illuminating and inconsistent ways. Funding for the project comes from the National Science Foundation and Robert Wood Johnson Foundation.

Screening for Cardiovascular Disease
Given the availability of today’s technology to measure the functioning of the human heart, should there be routine screening to check for cardiovascular disease (CVD)? Commenting in the Journal of the American College of Cardiology, cardiologists Philip Greenland and Donald Lloyd-Jones advised against adopting a routine strategy for CVD screening. They point to limited evidence that current screening procedures, which carry varying amounts of risk and harm for patients, cannot accurately predict CVD in asymptomatic individuals. They call for more research to justify implementation of a policy to systematically conduct population-level screenings for CVD. Greenland is Harry W. Dingman Professor and executive associate dean for clinical and translational research at Northwestern.

Biomarker Training
A nationally recognized center of biomarker training and methodological development, C2S held its third summer biomarker institute from June 9 to 11, welcoming 28 participants. The three co-organizers—McDade, Adam, and Kuzawa—emphasized biological theory and methodology in this year’s session with a daylong introduction to biology’s role in the social sciences, in addition to hands-on training on salivary and blood spot biomarkers. Freese led a module on the integration and analysis of genetic data into survey research.

Colloquium Series
C2S has continued its efforts to foster a community of scholars interested in multidisciplinary research on how social, economic, and cultural factors “get under the skin” and influence the pathways and processes of human development, health, and well-being. To this end, C2S brings researchers and practitioners together through its colloquia. Six talks were held on topics, such as the epidemiological evidence for obesity and sleep by Diane Lauderdale of the University of Chicago.

Health and Attainment Over the Lifecourse
More than 100 researchers, policymakers, foundation leaders, and postdoctoral and doctoral students attended the May 16 conference “Health and Attainment Over the Lifecourse: Reciprocal Pathways from Before Birth to Old Age.” The conference brought together experts from diverse disciplines to address complex linkages between health and human capital over time. Both are seen as lifelong processes, but too often, research on attainment and health has developed in separate silos. Scholars from demography, anthropology, sociology, economics, developmental psychology, and molecular genetics participated, including several C2S faculty.
C2S was co-sponsor of the conference.

Seed Grant Program
C2S awarded six seed grants over the academic year to the center’s tenure-track and research faculty for projects integrating the social sciences with the life or biomedical sciences. In March 2008, the center also launched a Student Research Grant program for students conducting dissertations or doing postdoctoral research.

New Graduate Training Program
Northwestern Graduate School’s Interdisciplinary Cluster Initiative recently provided funding for a graduate training program in society, biology, and health in conjunction with C2S. The program will allow graduate students to pursue a formalized course of study on the topic starting in 2009–10 with 19 faculty affiliates. Led by McDade, the cluster is aligned with C2S initiatives and will provide a roadmap for graduate students in the quantitative social sciences who are interested in integrative, community-based research on human biology and health.

Postdoctoral Fellows and Graduate Students
C2S’ first postdoctoral fellows have graduated and obtained key positions in postdoctoral fellowship programs or as faculty members. Sophie Trawalter, who studies racial interaction and student stress and development, will join the University of North Carolina at Chapel Hill in July 2008 as an assistant professor of psychology. Julienne Rutherford, an anthropologist who studies the role of the placenta in maternal ecology, fetal development, and health outcomes, will take up a position as an assistant professor at the University of Illinois at Chicago in August 2009. Elizabeth Sweet, who obtained her PhD in anthropology, became a Robert Wood Johnson Health and Society Fellow at Harvard University in fall 2008. Laura Chyu, who holds a PhD in public health from the University of California, Los Angeles, joined C2S in fall 2008 as a postdoctoral fellow. She is examining how the dynamic interplay of biological and social factors affects health over the lifecourse. Graduate student Chelsea McKinney, who is completing her doctorate in human development and social policy, was awarded an NICHD Diversity Supplement.

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