Race in Biological and Biomedical Research

Posted in Articles, Health/Medicine/Genetics, Media Archive on 2013-11-28 15:41Z by Steven

Race in Biological and Biomedical Research

Cold Spring Harbor Perspectives in Medicine
Volume 3, Issue 11 (November 2013)
10 pages
DOI: 10.1101/cshperspect.a008573

Richard S. Cooper, Anthony B. Traub Professor of Community and Family Medicine
Loyola University Medical School

The concept of race has had a significant influence on research in human biology since the early 19th century. But race was given its meaning and social impact in the political sphere and subsequently intervened in science as a foreign concept, not grounded in the dominant empiricism of modern biology. The uses of race in science were therefore often disruptive and controversial; at times, science had to be retrofitted to accommodate race, and science in turn was often used to explain and justify race. This relationship was unstable in large part because race was about a phenomenon that could not be observed directly, being based on claims about the structure and function of genomic DNA. Over time, this relationship has been characterized by distinct phases, evolving from the inference of genetic effects based on the observed phenotype to the measurement of base-pair variation in DNA. Despite this fundamental advance in methodology, liabilities imposed by the dual political-empirical origins of race persist. On the one hand, an optimistic prediction can be made that just as geology made it possible to overturn the myth of the recent creation of the earth and evolution told us where the living world came from, molecular genetics will end the use of race in biology. At the same time, because race is fundamentally a political and not a scientific idea, it is possible that only a political intervention will relieve us of the burden of race.

A Klee painting named Angelus Novus shows an angel looking as though he is about to move away from something he is fixedly contemplating. His eyes are staring, his mouth is open, his wings are spread. His face is turned toward the past. Where we perceive a chain of events, he sees one single catastrophe, which keeps piling wreckage upon wreckage and hurls it in front of his feet. The angel would like to stay, awaken the dead, and make whole what has been smashed. But a storm is blowing from Paradise; it has got caught in his wings with such violence that he cannot close them. The storm irresistibly propels him into the future to which his back is turned, while the pile of debris in front of him grows skyward. This storm is what we call progress.

Walter Benjamin
Theses on the Philosophy of History

RACE AS THE UNWELCOME GUEST IN THE DISCIPLINES OF SCIENCE

We rarely appreciate the presence of history in our day-to-day experience. The quotidian is a mixture of the repetitive and the predictable, carried forward by habit and punctuated by random events that we regard as either good or bad fortune. But in a more reflective mood, we have to acknowledge the relentless force of history that holds us in its grasp and accept that it creates the possibilities we use to negotiate with the future. The imposition of racial categories on human populations has been one of the most enduring historical forces that sets limits on opportunity and thereby shapes our life trajectory. As a projection of the underlying power relationships onto individuals, racial categories are used to structure social inequality. These power relationships are manifested both in the belief system that rank orders intrinsic human qualities according to group membership and the social institutions that enforce this hierarchy by restricting access to wealth, education, and other social goods. This daily reality is central to the history of all modern societies.

The racial structuring of society also has pervasive influence on biological research and the patterns of health and disease. Enormous effort has been expended to describe human demographic history through reference to an ever-changing array of constructs and categories, all of which include a hierarchical arrangement—either explicit or implicit. In the United States, most prominently, public health has embraced racial/ethnic categories as fundamental structural elements. Clinical medicine has similarly evoked racial categories to explain causation and outcomes across the entire spectrum of diseases. At the same time, race has met some of the strongest challenges to its legitimacy in biology and biomedicine. All of biology is grounded in the theory of descent from a common ancestor. The belief in racial categories was one of the most powerful liabilities of pre-modern biology and lent credence to the established view of divine creation. Indeed, it has recently been argued that the challenge to race brought by the abolitionist movement was a key factor behind Darwin’s transformative insight that the biological world—on the evolutionary time scale—is a single indivisible whole (Desmond and Moore 2009). Biomedicine still grapples with the implications of that insight for our species, yet substantial progress—uneven, tentative, and ultimately disappointing—has been made. In the current era, genomic science has opened new vistas onto previously unobserved dimensions of biology, and that proportion of the concept of race that has been attributed to genetics can finally be subjected to empirical scrutiny. Integrating this new knowledge into practice and focusing the technology on socially productive work, as always, remains our most difficult challenge.

The narrative of race therefore wanders the border territory between what we call science and what we recognize as history and politics. In the pre-genomic era, there was no requirement—indeed, no opportunity—to validate the authority of race with molecular evidence; causal inferences were made on the basis of phenotype, in its broadest possible sense, from disease to accumulated material wealth to social graces. The primary purpose of the race concept was to serve as a shortcut, an organizing tool that allowed post-enlightenment Europe to explain—and thereby justify—how imperialism had reshaped the world. Consequently, for both the social and biological sciences, race felt like the rude cousin whose claim on our affection was based on obligation, not choice. In every historical period, an incremental struggle has been waged to overcome the disruption that this unwelcome intruder has caused within empirical scientific disciplines.

In its origins, race was a “label of convenience” that biologists used interchangeably with the construct of “varieties” as they tried to create taxonomic categories below the level of the species (Cooper 1984). Writers from across the intellectual spectrum of literature and politics also felt free to make use of the idea. Thus, Baudelaire spoke of the “race of Abel” and the “race of Cain” when describing the polarization of 19th-century French society, and Marx characterized the English working class as a “race of peculiar commodity owners” (Baudelaire 1857; Marx 1957) (“Hence the sum of the means of subsistence necessary for the production of labour-power must include the means necessary for the labourer’s substitutes, i.e., his children, in order that this race of peculiar commodity-owners may perpetuate its appearance in the market.” [p. 172]). Malleability continues to be an essential quality of race, although it is now primarily used as a label for the temporary and often random aggregation of population subgroups, usually tied in some rough way to the perceived continent of origin (Kaufman and Cooper 1996). In its contemporary sense, biological race has now come to signify the inherited qualities of a population group hidden inside the DNA molecule…

Read the entire article here.

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Who gets the last laugh, again?

Posted in Anthropology, Articles, Health/Medicine/Genetics, Media Archive, Social Science, United States on 2013-11-26 18:32Z by Steven

Who gets the last laugh, again?

Africa is a Country
2013-11-18

Jessica Blatt, Assistant Professor of Political Science
Marymount Manhattan College, New York, New York

I enjoy seeing a smug, bearded white supremacist get his comeuppance as much as the next guy. (Though the joy of the exuberant lady sitting next to this one is hard to match. And reason enough to watch this video more than once.) In any event, I get why this video of Craig Cobb, the would-be founder of an all-white town in North Dakota, finding out on a TV show that a DNA test indicates that he is “14% sub-Saharan African” has gone viral.

At the same time, the talk-showification of molecular biology is really never a good thing, especially when that molecular biology is supposed to tell us things about “race.” (And let’s face it, “race” is pretty much the only way molecular biologists get any pop-culture shine.) Problem is, the idea that Cobb is 14% African rests on the assumption that there is such a thing as 100% “African,” or 100% “European.”…

Read the entire article here.

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Race and Medicine

Posted in Anthropology, Course Offerings, Health/Medicine/Genetics, Media Archive, United States on 2013-11-24 23:19Z by Steven

Race and Medicine

Princeton University
AAS 403 / ANT 403 (EM)
Spring 2013-2014

Carolyn M. Rouse, Professor of Anthropology

In 1998, then-President Clinton set a national goal that by the year 2010 race, ethnic, and gender disparities in six disease categories would be eliminated. While the agenda, called Healthy People 2010, was a noble effort, many of the goals were not met. This course examines what went wrong. For a final project, students will be asked to propose their own solutions for eliminating health disparities.

Sample reading list:

  • Brian Smedley, ed., Unequal Treatment: Confronting Racial & Ethnic Disparities
  • Harriet A. Washington, Medical Apartheid:The Dark History of Medical Experimentation
  • Agustin Fuentes, Race, Monogamy and Other Lies They Told Me
  • Troy Duster, Backdoor to Eugenics
  • Jonathan Kahn, Race in a Bottle: Racialized Medicine in a Post-Genomic Age
  • Rebecca Skloot, The Immortal Life of Henrietta Lacks

For more information, click here.

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The spectre of race in American medicine

Posted in Articles, Health/Medicine/Genetics, Media Archive on 2013-11-23 02:02Z by Steven

The spectre of race in American medicine

Medical Humanities
Volume 32, Issue 2 (2013)
pages 137-141
DOI: 10.1136/medhum-2013-010374

Mariam O. Fofana
Department of Epidemiology; Medical Scientist Training Program
Johns Hopkins Bloomberg School of Public Health / Johns Hopkins School of Medicine

Controversies and debates surrounding race have long been a fixture in American medicine. In the past, the biological concept of race—the idea that race is biologically determined and meaningful—has served to justify the institution of slavery and the conduct of unethical research trials. Although these days may seem far behind, contemporary debates over the race-specific approval of drugs and the significance of genetic differences are evidence that race still yields tremendous influence on medical research and clinical practice. In many ways, the use of race in medicine today reflects the internalisation of racial hierarchies borne out of the history of slavery and state-mandated segregation, and there is still much uncertainty over its benefits and harms. Although using race in research can help elucidate disparities, the reflexive use of race as a variable runs the risk of reifying the biological concept of race and blinding researchers to important underlying factors such as socioeconomic status. Similarly, in clinical practice, the use of race in assessing a patient’s risk of certain conditions (eg, sickle cell) turns harmful when the heuristic becomes a rule. Through selected historical and contemporary examples, I aim to show how the biological concept of race that gave rise to past abuses remains alive and harmful, and propose changes in medical education as a potential solution. By learning from the past, today’s physicians will be better armed to discern—and correct—the ways in which contemporary medicine perpetuates historical injustices.

Read or purchase the article here.

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What’s Biology Got to Do with It? The Social Life of Genetics

Posted in Anthropology, Health/Medicine/Genetics, Media Archive, Social Science, United States on 2013-11-12 04:26Z by Steven

What’s Biology Got to Do with It? The Social Life of Genetics

Brooklyn Historical Society
Crossing Borders, Bridging Generations
Saturday, 2013-11-16, 15:00-18:00 EST (Local Time)

Part One of the reading series Quantifying Bloodlines

  • What do we learn about ourselves through genetics and genealogy?
  • How does DNA connect with what we know about our family’s ancestry and cultural heritage?

Join anthropologist, Jennifer Scott in conversation with sociologist Ann Morning, author of The Nature of Race: How Scientists Think and Teach about Human Difference (2011), for a discussion examining the social life of DNA.

Having read The Immortal Life of Henrietta Lacks by Rebecca Skloot, we will explore the tremendous social impact of one woman’s cellular legacy upon the world. We will discuss the impact on her direct descendants as Henrietta Lacks’ family discovers how their genes were used to make unprecedented medical advancements and enormous profits without their consent. Looking at the connections between biology and culture, this discussion session will explore the meanings of heredity, inheritance, and questions of bioethics.

Please plan to have read the book prior to our meeting.

This reading and discussion group is co-sponsored by MixedRaceStudies.org

For more information, click here.

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The Meanings of “Race” in the New Genomics: Implications for Health Disparities Research

Posted in Articles, Health/Medicine/Genetics, Media Archive, United States on 2013-11-11 22:37Z by Steven

The Meanings of “Race” in the New Genomics: Implications for Health Disparities Research

Yale Journal of Health Policy, Law, and Ethics
Volume 1, Issue 1 (2001)
pages 33-76

Sandra Soo-Jin Lee, Senior Research Scholar
Stanford Center for Biomedical Ethics
Stanford University

Joanna Mountain, Assistant Professor of Anthropological Genetics
Stanford University

Barbara A. Koenig, Professor of Biomedical Ethics and of Medicine at the College of Medicine, Mayo Clinic;
Affiliate Faculty of the Center for Bioethics, University of Minnesota, Minneapolis;
Stanford Center for Biomedical Ethics, Stanford University

Eliminating the well-documented health disparities found within the United States population is a laudable public policy goal. Social justice demands that we understand the sources of health inequality in order to eliminate them. A central dilemma is: To what extent are health disparities the result of unequal distribution of resources, and thus a consequence of varied socioeconomic status (or blatant racism), and to what extent are inequities in health status the result of inherent characteristics of individuals defined as ethnically or racially different? How we conceptualize and talk about race when we ask these questions has profound moral consequences. Prior to the Human Genome Project (HGP), scientific efforts to understand the nature of biological differences were unsophisticated. The new technologies for genomic analysis will likely transform our thinking about human disease and difference, offering the promise of in-depth studies of disease incidence and its variations across human populations. In her opening remarks at a meeting of the President’s Cancer Panel, which focused on health disparities in cancer treatment in the United States, Dr. Karen Antman noted that racial differences in cancer rates have been reported for decades, “but for the first time, science now has the opportunity to quantify such differences genetically.” Will the light refracted through the prism of genomic knowledge illuminate straightforward explanations of disease etiology, offering simple solutions to health inequalities? Or are there consequences, currently hidden in the shadows, that require our attention?

The challenge is then to analyze the causes of racism while avoiding the implication that race exists.
-Steven Miles, 1993

A foolish consistency is the hobgoblin of little minds, adored by little statesmen and philosophers and divines.
-Ralph Waldo Emerson, “Self-Reliance,” 1841

Eliminating the well-documented health disparities found within the United States population is a laudable public policy goal. Social justice demands that we understand the sources of health inequality in order to eliminate them. A central dilemma is: To what extent are health disparities the result of unequal distribution of resources, and thus a consequence of varied socioeconomic status (or blatant racism), and to what extent are inequities in health status the result of inherent characteristics of individuals defined as ethnically or racially different? How we conceptualize and talk about race when we ask these questions has profound moral consequences.

Prior to the Human Genome Project (HGP), scientific efforts to understand the nature of biological differences were unsophisticated. The new technologies for genomic analysis will likely transform our thinking about human disease and difference, offering the promise of in-depth studies of disease incidence and its variations across human populations. In her opening remarks at a meeting of the President’s Cancer Panel, which focused on health disparities in cancer treatment in the United States, Dr. Karen Antman noted that racial differences in cancer rates have been reported for decades, “but for the first time, science now has the opportunity to quantify such differences genetically.” Will the light refracted through the prism of genomic knowledge illuminate straightforward explanations of disease etiology, offering simple solutions to health inequalities? Or are there consequences, currently hidden in the shadows, that require our attention?…

…Increasing ability to detect genetic mutations linked to disease susceptibility has not been paralleled by therapeutic discoveries. This disjuncture has contributed to the conflict about population-based testing and disagreement about the calculus of the largely unknown risks and benefits to individuals and populations. Knowing one has a BRCA mutation does not mean that one will ultimately develop cancer. Individuals must interpret complex, uncertain information to make sense of their cancer risk, and are often confused as to how to make sense of genetic information. The additional burden of contemplating the ramifications of targeted testing of their community, including the possibility of categorical discrimination and prejudice, is a daunting challenge. The mutations found most commonly among those of Ashkenazi ancestry were identified by chance. Blood stored for other purposes, notably screening for Tay Sachs, a heritable disease, was available for research. Other mutations in the BRCA-1 and BRCA-2 genes are specific to certain groups, generally isolated populations such as those in Iceland or Finland. How will knowledge that common diseases are associated with socially identifiable populations affect the treatment of those individuals? But more importantly, how will an increasingly sophisticated knowledge of molecular genetics affect our understanding of the nature of “difference” among human groups?…

…In this paper we provide a strong critique of the continued use of race as a legitimate scientific variable. We offer an historical analysis of how the concept of race has changed in the United States and discuss the reification of race in health research. We discuss how genetic technology has been deployed in “proving” racial identity, and describe the consequences of locating human identity in the genes. The implications of the continued use of race in the new genomic medicine—in particular the creation of racialized diseases—is highlighted. We warn about the consequences of a shift toward population-based care, including targeted genetic screening for racially identified “at-risk” groups, including the potential for stigmatization and discrimination. A less commonly identified hazard is the epistemological turn towards genetic reductionism. We suggest that the application of a naive genetic determinism will not only reinforce the idea that discrete human races exist, but will divert attention from the complex environmental, behavioral, and social factors contributing to an excess burden of illness among certain segments of the diverse U.S. population. The intersection of the genomics revolution with the health disparities initiative should serve as a catalyst to a long overdue public policy debate about the appropriate use of the race concept in
biomedical research and clinical practice…

Read the entire article here.

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Reading Series: Quantifying Bloodlines

Posted in Anthropology, Health/Medicine/Genetics, History, Live Events, Media Archive, Social Science, United States on 2013-11-02 22:24Z by Steven

Reading Series: Quantifying Bloodlines

Brooklyn Historical Society
Crossing Borders, Bridging Generations
Othmer Library
Saturdays, 2013-11-16, 2013-12-07 and 2014-01-25; 15:00-18:00 EST (Local Time)

Quantifying Bloodlines is a monthly reading group organized by anthropologist and oral historian Jennifer Scott.  Join others interested in exploring the relationship between biology and race, as we discuss three widely acclaimed books. Each work offers different examples of tracing family history—through a surname, through biological cells, through a specific geographic locale, through four generations of women’s lives. Through stories, we will discuss how we segment heritage and explain descent, paying close attention to past and existing ideas of purity, racial and economic privilege, and scientific thinking.

All sessions meet in the Othmer Library at the Brooklyn Historical Society. Light refreshments will be provided.

Sign up for individual sessions for $20, or join us for all three at a discounted price of $45! All sessions are available for a sliding scale fee, and no-one will be turned away for lack of funds.

What’s Biology Got to Do with It? The Social Life of Genetics
November 16th, 2013, 3:00 PM
Reading: The Immortal Life of Henrietta Lacks by Rebecca Skloot
Guest Speaker: Sociologist Ann Morning, author of The Nature of Race: How Scientists Think and Teach about Human Difference

What’s Purity Got to Do with It? Searching Family History and Genealogy
December 7th, 2013, 3:00 PM
Reading: The Fiddler on Pantico Run: An African Warrior, His White Descendants, A Search for Family by Joe Mozingo

What’s History Got to Do with It? Evolving Classifications of Race
January 25th, 2014, 3:00 PM
Reading: Cane River by Lalita Tademy

Quantifying Bloodlines Reading and Discussion Series is co-sponsored by MixedRaceStudies.org

For more information, click here.

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Geneticists and the Biology of Race Crossing

Posted in Articles, Health/Medicine/Genetics, Media Archive, Social Science on 2013-10-20 00:35Z by Steven

Geneticists and the Biology of Race Crossing

Science Magazine
Volume 182, Number 4114 (1973-11-23)
pages 790-796
DOI: 10.1126/science.182.4114.790

William B. Provine, Andrew H. and James S. Tisch Distinguished University Professor
Cornell University

Geneticists changed their minds about the biological effects of race crossing

Geneticists in England and the United States clearly reversed their published remarks on the effects of race crossing between 1930 and 1950. The reversal occurred in two steps. First came the change in the 1930’s from a condemnation of wide race crosses to an agnostic view. The second change, from the agnostic view to the belief that wide race crosses were at worst biologically harmless, took place during and shortly after World War II.

The entire reversal occurred in the light of little new compelling data from studies of actual human race crosses. The lack of new data is unsurprising. Few geneticists wished to initiate experiments that took three human generations to complete. And controlled race crosses are hard to arrange, even with government grants. What might be more surprising was the willingness of geneticists to make such positive statements about race crossing when they had so little reliable genetic evidence.

I interviewed or wrote to ten prominent geneticists who worked on human genetics between 1930 and 1950. Not one believed that new evidence on race crossing was the primary reason why geneticists changed their minds about the effects of race crossing. One plausible explanation, that the rise of “population thinking” (44) caused geneticists to change their minds, does not fit the evidence. Castle was no more of a “population” thinker than East, yet they differed radically in their conclusions about race crossing. What, then, did cause geneticists to change their minds?

Most important was the revulsion of educated people in the United States and England to Nazi race doctrines and their use in justifying extermination of Jews. Few geneticists wanted to argue, as had the Nazis, that biology showed race crossing was harmful. Instead, having witnessed the horrible toll, geneticists naturally wanted to argue that biology showed race crossing was at worst harmless. No racist nation could misuse that conclusion. And geneticists did revise their biology to fit their feelings of revulsion.

Geneticists’ ideas about the related question of hereditary mental differences between races is perhaps undergoing a similar development to that seen earlier in their ideas about race crossing. In 1951, judging from the response to the Unesco second statement on race and comments in genetics literature, most geneticists agreed with Muller that races probably differed in significant average mental traits. By 1969, when Arthur Jensen advocated this view in his controversial article (45), most geneticists who spoke publicly on the issue had adopted an agnostic position. Knowledge of hereditary racial differences in IQ had scarcely changed since 1951, but society had changed considerably in racial attitudes. It will be interesting to see if during the next several decades geneticists will argue, on the basis of little additional evidence, that hereditary mental differences between races do not exist.

I am not condemning geneticists because social and political factors have influenced their scientific conclusions about race crossing and race differences. It is necessary and natural that changing social attitudes will influence areas of biology where little is known and the conclusions are possibly socially explosive. The real danger is not that biology changes with society, but that the public expects biology to provide the objective truth apart from social influences. Geneticists and the public should realize that the science of genetics is often closely intertwined with social attitudes and political considerations…

Read or purchase the article here.

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New faculty: Amy Non links health disparities to genetics and environment

Posted in Articles, Health/Medicine/Genetics, Media Archive, United States on 2013-10-15 02:04Z by Steven

New faculty: Amy Non links health disparities to genetics and environment

Research News @ Vanderbilt
Vanderbilt University, Nashville, Tennessee
2012-11-30

Liz Entman, (615) 322-NEWS

For decades, researchers have struggled to identify the root causes behind racial disparities in health. Amy Non, assistant professor of anthropology, takes a multidisciplinary approach.

A molecular anthropologist specializing in epigenetics, the study of how environment and behavior affect the expression of genes, her work integrates genetics, anthropology and public health.

For example, why are African Americans at greater risk for many chronic diseases? “We don’t really know what’s causing it—whether it’s their genetic ancestry or whether it’s something about their social or cultural environment,” Non said. She has found no evidence that African genetic ancestry plays a role and is now trying to identify psychosocial mechanisms—such as stress—that may contribute to these disparities.

Stress triggers a release of hormones that can lead to inflammation or dysregulation of other biological processes, she said. Prolonged exposure to stress can permanently interfere with the genes that regulate these hormones, which can have long-term consequences on a person’s health.

Read the entire article here.

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Education, Genetic Ancestry, and Blood Pressure in African Americans and Whites

Posted in Articles, Health/Medicine/Genetics, Media Archive, United States on 2013-10-15 01:50Z by Steven

Education, Genetic Ancestry, and Blood Pressure in African Americans and Whites

American Journal of Public Health
August 2012, Volume 102, Number 8
pages 1559-1565
DOI: 10.2105/AJPH.2011.300448

Amy L. Non, Assistant Professor of Anthropology,
Vanderbilt University, Nashville, Tennessee

Clarence C. Gravlee, Associate Professor of Anthropology;  affiliate appointments in the Department of Behavioral Science and Community Health
University of Florida, Gainesville

Connie J. Mulligan, Professor of Anthropology; Associate Director, University of Florida Genetics Institute
University of Florida, Gainesville

  • Objectives. We assessed the relative roles of education and genetic ancestry in predicting blood pressure (BP) within African Americans and explored the association between education and BP across racial groups.
  • Methods. We used t tests and linear regressions to examine the associations of genetic ancestry, estimated from a genomewide set of autosomal markers, and education with BP variation among African Americans in the Family Blood Pressure Program. We also performed linear regressions in self-identified African Americans and Whites to explore the association of education with BP across racial groups.
  • Results. Education, but not genetic ancestry, significantly predicted BP variation in the African American subsample (b = –0.51 mm Hg per year additional education; P = .001). Although education was inversely associated with BP in the total population, within-group analyses showed that education remained a significant predictor of BP only among the African Americans. We found a significant interaction (b = 3.20; P = .006) between education and self-identified race in predicting BP.
  • Conclusions. Racial disparities in BP may be better explained by differences in education than by genetic ancestry. Future studies of ancestry and disease should include measures of the social environment. (Am J Public Health. 2012; 102:1559–1565. doi:10.2105/AJPH.2011.300448)

In recent decades, researchers have struggled to determine the causes of racial disparities in health. Many biomedical researchers have speculated that underlying genetic differences between races may contribute to these disparities. With the increasing availability of high-throughput genotyping platforms, a wealth of genomic data is now available to help address this issue. One consequence is that more researchers are estimating genetic ancestry to capture a presumed genetic basis of racial disparities in health. However, any associations found between genetic ancestry and disease could alternatively be explained by unmeasured environmental factors that are also associated with African genetic ancestry and contribute to health disparities, such as socioeconomic status (SES), neighborhood environment, and psychosocial factors including perceived stress or discrimination. Therefore, to avoid unwarranted inferences about the magnitude of genetic influences on health disparities, it is critical for any analysis of ancestry and disease to include appropriate social–environmental variables.

Social–environmental factors may be especially important when one is studying a complex disease such as hypertension. Complex diseases, by definition, involve multiple environmental and genetic causes, as well as interactions within and between them. Many studies have identified important social–environmental influences on racial inequalities in hypertension, such as SES, psychosocial stressors, and neighborhood environment, whereas other studies have begun to identify relevant genetic variants, such as those in the rennin–angiotensin–aldosterone axis and the adrenergic system. Few studies, however, have examined genetic and environmental factors simultaneously. The limited scope of this research to date has slowed progress toward explaining racial inequalities in hypertension and other complex diseases.

To address the relevance of both genetic and environmental factors in racial inequalities in hypertension, we tested associations between genetic ancestry, education, and blood pressure (BP) among Whites and African Americans in the Family Blood Pressure Program (FBPP) study. A previous analysis of this data set by Tang et al. found no evidence of a statistically significant association between African genetic ancestry and blood pressure. They concluded nonetheless that the results were “suggestive of genetic differences between Africans and non-Africans that influence blood pressure, but such effects are likely to be modest compared to environmental ones.” No environmental variables were included in their study, however. Here we reexamine the FBPP data set to test how the addition of education affects the association between ancestry and BP in African Americans. We also explored the association between education and blood pressure across racial groups. We hypothesized that education would show a greater association with BP than would African ancestry among African Americans, and that the association between education and BP may vary by racial and gender groups…

Read the entire article here.

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