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espite the American obsession with race, growing numbers of
experts believe that it is a meaningless concept, at least as far as
medicine goes. Dr. J. Craig Venter, the president of Celera Genomics
But some still see a place for race in medicine, including a number of African- American scientists and medical experts.
Dr. David Satcher, the surgeon general, who is black, has said that "compelling evidence that race and ethnicity correlate with persistent, and often increasing, health disparities among U.S. populations demands national attention."
Under his leadership, the government has directed millions of dollars toward eliminating racial health disparities by 2010. More recently, the Association of Black Cardiologists agreed to sponsor a clinical trial enrolling blacks only, to test a heart medicine designed for African-Americans.
In his new book "The Emperor's New Clothes: Biological Theories of Race at the Millennium" (Rutgers University Press), Dr. Joseph L. Graves Jr., a professor of evolutionary biology and African-American studies at Arizona State University, argues that races do not exist and that race is simply a social and political construct that the world would be better without.
Racism, he says, is fueled by the idea that human beings can be separated by genetics into races.
Dr. Graves, who is 46 and lives in Glendale, Ariz., discussed genes, race and health recently while in New York City to be on a panel sponsored by the Gene Media Forum, a nonprofit organization promoting dialogue about genome research.
Q. What prompted your interest in race and genetics?
A. The catalyst was the success of the book "The Bell Curve," which claimed that there was a genetic basis for differences in I.Q. scores between blacks and whites. Most disagreeable was the way it characterized individuals into discrete racial categories they identified as "black" and "white."
This simplistic categorization was not defensible by what we know about
human genetic diversity and the amount of shared genes between people of
European and African descent in the United States.
Q. You're questioning the existence of racial categories like black and white?
A. Biologically, yes. Only an incredibly small percentage of genes in human beings are involved in skin color. Possibly only six genes determine the color of a person's skin out of between 30,000 and 40,000.
Q. There may be only six genes involved in skin color, but don't they still separate people by race?
A. You have to understand that what biologists mean when they say race is different from what the common person or even society means. There are two parts to the biological definition: first, a race is a population that has significant genetic differences from other populations such that it can be considered a subspecies. A subspecies is a group that is on the way to becoming a new species. Second, a race is a population whose lineage can be considered sufficiently distinct from other lineages.
Q. Aren't the different groups of humans that most people think of as races different subspecies, and therefore different races?
A. Even though we are anatomically different from each other, there is no subspecies in our group. In fact, there are far more genetic differences within a population of humans than between them. For example, there is only about 3 to 7 percent genetic divergence between groups, compared to 20 percent in subspecies of drosophila fruit flies. It doesn't compare.
As far as distinct lineages, throughout history, we have had too much
gene flow between so-called races. If sub-Saharan Africans only mated with
sub-Saharan Africans and Europeans only mated with Europeans, then there
might be unique lineages. But that hasn't occurred, particularly in
America. Here, because of our history of chattel slavery, individuals are
still classified as black by means of the "rule of hypodescent," whereby
one drop of black blood makes one black. However, there is no biological
rationale for this rule.
Q. Doesn't race, in the social and cultural definition, have an impact on health? For instance, isn't sickle cell disease much more common in blacks than whites?
A. Contrary to popular belief, sickle cell anemia is not a black disease nor did it originate in West Africa. The gene responsible for sickle cell provides protection against malaria, so it is present wherever we find malaria. That includes Greece, Yemen, India, East and West Africa and the Middle East, where it originated. The only reason we think of it as a black disease in America is because the slaves came from West Africa. If the slaves who worked the cotton fields of America had come from Yemen or Greece, then we would have seen it as a Yemeni or a Greek disease.
Q. You're opposed to raced-based research, like the recent study published in The New England Journal of Medicine, which showed that some heart medications do not work as well for blacks as whites. Why?
A. Present day thinking about pharmacogenetics is that there is genetic variability that relates to how a drug acts in different people. But the genes for drug activity and response don't seem to be localized in the socially defined races. What is more important is to use an experimental design to find out what the genes are. We need to know which genes are responsible for a drug given to someone, and that is not going to be limited by a person's socially constructed race.
Q. Enalapril, a blood-pressure medication, worked less well for African-Americans than whites. How do you explain that?
A. I think there were other variables at play in this study. It is entirely possible that there was some underlying physical cause to explain the different action of the drugs, coded by the social construction of race, but not genetic.
It could have been stress. Blacks and whites were matched by supposed
levels of stress, but that was defined only as financial distress.
African-Americans in this country face different forms of stress because
of racism than whites. It could have also been diet, which was
uncontrolled in the study. Since African-Americans and European- Americans
don't eat the same diets, before you can explain why the drugs acted
differently, you'd need to control for diet.
Q. Is there no genetic explanation for high rates of hypertension in blacks?
A. Yes, there is a gene linked to hypertension, but we do not as yet have a clear understanding of how genetic variation and environmental differences interact to cause hypertension. For example, the gene for increased risk for hypertension is very high in Nigerians and very low in African-Americans. Yet, African-Americans in Chicago, for instance, are 2.5 times more likely to suffer from hypertension than Nigerians, though you'd expect the opposite to be true.
Q. What is the harm, particularly for physicians, in knowing racial differences in risk for disease?
A. When doctors think in terms of race, they say, "Oh, you're black" and start ticking off what you might have. But what's important to know is a person's family history. You are treating individuals, not races.
Q. What kinds of problems occur when doctors think in terms of race?
A. A student of mine came to talk to me because her husband was having trouble with his doctor. She suggested that her husband might have scleroderma, but the doctor said, "No, African-Americans don't get that disease; it's a Caucasian disease."
I explained to her that that wasn't true because we have significant
amounts of European genes, so there are no so-called "black diseases." She
went back and talked to the doctor, and he did have it.
Q. It is still true that blacks suffer from significant health disparities. How do we combat that?
A. No one in America, regardless of socially constructed race, should be getting sick. Studies show that 53 percent of toxic waste sites in America are located in communities that have greater than 75 percent minority composition. Toxic materials are known to have disease causing effects, and mutations can be passed on from generation to generation. So the bottom line is that if we clean up the environment, African-Americans and other minorities will benefit. But so will everyone else. If we also give people access to education and improve the economy, we will begin to see the end of racial disparities in health. These are things we should be doing anyway. It's a win-win situation.