The genetics of difference: what genetic discovery and the modern biology of "race" mean for communities of color fighting health inequities.

In recent years, policymakers have begun rumblings about reducing health and health care inequalities in the United States. At the same time, the advent of the Human Genome Project (HGP) and the development of genetic technologies have given scientists a revolutionary new means to study these inequities and discover ways to improve public health across the board.

The HGP study found that human beings share a virtually identical genome: 99.9 percent of their DNA is identical. And while genuine genetic variation across the human population must be better understood to address health questions, the greater challenge of eliminating health disparities among racially and ethnically identified populations maybe that it requires consciousness of the political causes of racism without reinforcing the biological falsehood of race. In any case, the timing is ideal for social justice advocates to help reframe the terms of this crucial debate, which will have an immediate impact on public health and far-reaching consequences for communities of color.

Evolution of Racist Terminology

As a general rule, history cautions against scientific research on the relationship of "race" to disease. Sickle cell anemia-the first racialized disease--provides the best-studied example. The association of sickle cell anemia with the black "race" came through mandated screening programs reflecting social bias and prejudice. It took decades to recognize that the illness was not a marker of race. More recently, scientists have found that the genetic variation associated with breast cancer appears to be more prevalent among Ashkenazi Jewish women. Given the consequences of Nazi racial science, people of Ashkenazi descent have reason to fear the notion that they're somehow biologically distinct.

Societies have, historically, identified "race" by way of physiological characteristics such as skull size, skin color, facial features, and other qualities readily available for scrutiny. The concept of immutable, biologically based human races developed in concert with Western exploration and colonialism, providing a scientific justification for exploitation and practices such as slavery. Prior to that period, the idea of biologically distinct human subspecies did not exist. Hierarchies of difference such as that reflected in the Greek term "barbarian" were based on social proximity to civilization and language instead of biology.

At the height of colonization in the 18th century, botanist Carolus Linnaeus identified four racial groups: americanus, "reddish, obstinate, and regulated by custom"; asiaticus, "sallow, severe, and ruled by opinion"; africanus, "black, crafty, and governed by caprice"; and europaeus, "white, gentle, and governed by law." The terminology and the dividing lines between "races" shift in every age and political era. Attaching scientific weight to the distinctions-of-the-day is inherently problematic. Yet, arguing against the legitimacy of race as a category in biomedical research does not mean that the social category of race is false.

Race is real because societies have acted as if certain people are inferior based on innate characteristics. Human populations categorized by race have, ostensibly, been racialized. While health status varies among U.S. racialized populations, it's essential that genetic and biological differences be studied directly, not through the distorting lens of a previous era's racial thinking.

Equal Health for All

During the political leadership of Surgeon General David Sarcher, the National Institutes of Health (NIH) published Healthy People 2010, a national agenda that includes the elimination of glaring health disparities among racial and ethnic minorities. The report states that current information about the biological and genetic characteristics of African Americans, Hispanics, American Indians, Alaska Natives, Asians, Native Hawaiians, and Pacific Islanders does not explain the health disparities experienced by these groups compared with non-Hispanic whites.

Statistics cited in the report are alarming. Death rates due to heart disease and all cancers are more than 40 percent and 30 percent higher, respectively, for African Americans than for whites; for prostate cancer, they're more than double that of whites. African American women have a higher death rate from breast cancer despite having a mammography screening rate that is nearly the same as white women. Latinos are almost twice as likely to die from diabetes than non-Hispanic whites. They also have higher rates of hypertension and obesity than non-Hispanic whites. African Americans, American Indians, and Alaska Natives have an infant mortality rate that is almost double that of whites.

Asians and Pacific Islanders, on average, are reported to be among the healthiest population groups in the U.S. However, when this broad Census category is divided into its sub-populations, disparities for specific groups are quite marked. Women of Vietnamese origin, for example, suffer from cervical cancer at nearly five times the rate of white women. What remains consistent throughout is a comparison to an implicit category of "whiteness" that is left undefined.

Interestingly, the report entirely neglects to mention any possible relationship between racialized identity and disease.

The "Kenniwick Man" Controversy

The eagerness to use genetic technology and research to determine race and ethnicity has resulted in a renewed faith that genetics will help us identify who and what we are. Vermont legislators have proposed a bill stipulating that results of voluntary genetic testing should be accepted as definitive "proof" of Native American ancestry.

The bill leaves many questions unanswered: the potential for prejudicial applications of this data, the genetic criteria for making this determination, the political purpose of the test. If humans have socially meaningful ways of determining group membership, is why genetic testing necessary? If an individual has lived in a Native American community, has adopted the cultural practices and beliefs of her tribe, and is socially recognized as a member, what does a "negative" genetic test mean for her and perhaps, more importantly, to the group as whole?

The "Kenniwick Man" controversy--in which 9,000-year-old remains were declared the property of a consortium of Native American tribes-illustrates the power of racial politics. Attempts to reconstruct the skull of Kenniwick Man led several scholars to conclude it seemed more similar to that of modern Europeans than that of Native Americans. This resulted in speculation that the original settlers of North America were not from Asia, as originally thought, but were of European origin. Headlines declaring Kenniwick Man "white" reflected not only the careless shorthand used by the media to interpret scientific data, but the need to assign race in the study of human evolution.

Eventually, archaeological evidence confirmed that Kenniwick Man lived among ancestors of contemporary Native Americans. Recently, some anthropologists have argued that Kenniwick Man has more in common with the Ainu of Japan than with Northern Siberians or Native Americans. The tug-of-war over Kenniwick Man was resolved by the Native American Graves Protection and Repatriation Act, which stipulates that property taken from tribal lands be returned to Native Americans. This law dissipated a potentially explosive issue, allowing a resolution despite the scientific ambiguity Upon his return, Kenniwick Man will be reburied at an unidentified location on Native American land.

African Ancestry and Jefferson's Forgotten Son

Reconstructing genealogy has been of great interest to African Americans seeking to locate their ancestral homelands, lost through the social disruptions of slavery. Recently, a geneticist from Howard University advertised the service of DNA analysis for African Americans who wanted to determine their point of origin in Africa.

Through a website entitled African Ancestry, Rick KittIes urged African Americans to send in blood samples to determine their genetic makeup. Although Kitties abandoned his original plan to sell his services for $300 per test due to mounting scientific criticism, his project is an example of the idea that generics can validate one's identity This is surprising given the warnings of scholars like Patricia King, who writes, "In a racist society that incorporates beliefs about the inherent inferiority of African Americans in contrast with the superior status of whites, any attention to the question of differences that may exist is likely to be pursued in a manner that burdens rather than benefits African Americans."

Scientists with the African Burial Project are conducting genetic analyses of skeletal remains of long-deceased slaves. Having received over $5 million from the government, the project attempts to match DNA extracted from skeletal remains found at a U.S. construction site in 1992 with genetic samples from populations all across Africa and the Caribbean.

Michael L. Blakey, the project director, says the outcome of the genetic analysis could "help restore the specifics of identity that were deliberately damaged by slaveholders in order to make enslaved Africans seem less human." Blakey has indicated that upon completion of the burial project, the DNA database will be made available to individuals in search of their African heritage. Oddly enough, both the Kittles and Blakey projects adhere to the "one-drop rule" of racial categorization, ignoring the potentially significant degree of mixing between populations.

A reverse example is the recent "discovery" that the youngest son of Sally Hemings, Eston Hemings-Jefferson, was fathered by Thomas Jefferson. Despite longstanding folk narrative confirming these family relations, the Hemings-Jefferson union became "fact" only when genetic evidence was marshaled. What's interesting is how the genetic information affected the current racialized identities of the living progeny of Hemings and Jefferson. The Monticello Association, a private organization of some 700 descendents of Jefferson and his wife, Martha, continue to dispute claims by Hemings' descendents that they be included in the group, or be allowed burial in the cemetery at Monticello.

The story of proving one's lineage based on discovery of a genetic forefather is a powerful theme in discussions of racial difference.

Denial of the inevitable interaction among human populations is necessary to the story of race. To acknowledge the constant mixing between groups and genetic variation within and across populations would render the concept of race meaningless.

Race, Genetics, and Invisibility

The hope of genomic science is that medicines can be developed to target diseases found more frequently in people with a particular ancestry. The danger is that this thinking could transform and "geneticize" our understanding of identity. An unintended byproduct of the genomics revolution is a naive, almost religious faith in the power of genetics that moves attention and funding away from sociopolitical factors that cause ill health.

According to Healthy People 2010, adolescent smoking rates increased in the 1 990s among white, African American, and Hispanic high school students after declining rates in the 1970s and 1980s. Although a larger proportion of blacks than whites smoke, blacks consume fewer cigarettes and start smoking later in life than whites. Blacks smoke cigarettes higher in tar and nicotine and are specifically targeted by the tobacco industry as potential consumers. Smoking among African Americans causes a higher incidence of lung cancer, cardiovascular disease, low birth weight, and infant mortality. But research on a genetic basis for differences between African Americans and whites has focused on their differences in metabolizing tobacco.

Prejudice can also impact the correlations scientists draw between genes and disease. Economic factors such as poverty, employment, and unequal access to resources that impact nutrition, housing, and access to health care get lost in the shuffle. Ironically, such racial thinking renders the effects of racism on the health status of groups invisible. Population-targeted research leaves significant non-genetic factors unaddressed and individuals not identified with "at-risk" populations who may be afflicted are simply overlooked.

Refining the Language of Race

Although racial dividing lines are, ultimately, political, researchers who submit proposals to the NIH must demonstrate, using Census categories, that their participants will represent the diversity of the U.S. population. The original intent of this rule is to improve the health care for minority populations, but this laudable policy goal has the unintended effect of discouraging researchers from using more subtle distinctions. It conveys the idea that racial distinctions are scientifically meaningful, in spite of significant evidence to the contrary

How we speak is a direct reflection of how we think; the language of race is a crucial policy issue. It's nor enough for researchers to substitute a more politically correct term- such as "ethnicity" or "culture"-and continue to make use of an archaic race concept. The evidence demonstrates that genetic variation does not neatly map onto socially meaningful groups. If we use the idea of "racialized" groups, we emphasize the concept that race is historically contingent. It is important that social justice advocates discourage research that conveys that biologically distinct human races exist, but we should publically encourage research into genetic variation and bear witness to the very worthwhile national effort to address health inequalities in racialized communities.

Sandra Soo-Jin Lee is a post-doctoral fellow at the Center for Biomedical Ethics and a lecturer at Stanford University. This article is adapted from an article Lee wrote along with Joanna Mountain and Barbara A. Koenig in the Yale Journal of Health Policy, Law, and Ethics.