The Chronicle Review

The Pressure of Race

The plague of hypertension that afflicts African-Americans may be driven by bigotry, not biology

Mark Wallheiser for The Chronicle Review

Gravlee in Frenchtown: "I discovered that a lot of ideas that anthropologists had discarded as relics of the 19th century were circulating pretty freely in contemporary medicine."
September 12, 2010

The name of the Fusion Cafe refers to its menu, where cucumber kimchi can be eaten along with fried catfish. But at one table amid the Saturday lunch crowd, the talk is more about fission and social separation. M. Miaisha Mitchell, a soft-spoken community organizer, is giving the table a lesson about how university researchers have repeatedly come into her poor neighborhood, studied it, and then disappeared. "You come in, you write your papers, you get grant money, you go away, and nothing here changes," she says. "Sometimes it's even become worse."

Edward Holifield, a local physician, nods his head vigorously. "There's a lot of history here, and a lot of suspicion."

Clarence C. (Lance) Gravlee, sitting at one end of the table, doesn't want to be one of the usual suspects. But he does want to study health. Gravlee, an associate professor of anthropology at the University of Florida, is trying to figure out the cause of a plague afflicting African-Americans here and across the country: high blood pressure. It occurs more often among them than in whites or any other ethnic group, bringing with it higher rates of heart attacks and killing thousands of people. And medical research has not been able to figure out why. "There's a general notion that it's race, that there's something in the genes, but nobody has been able to isolate what that is," he says.

Gravlee, 35, doesn't think genes can explain hypertension, or at least not genes alone. His research indicates that the biomedical emphasis on genes obscures the powerful impact of culture. Combining gene studies with fieldwork in a community of African origins in Puerto Rico, he has shown that people viewed by others in the community as having darker skin, a strong African heritage, and a poor background had high blood-pressure levels. That held true even if they did not have the most actual African DNA in the study and were relatively well off. "This social classification seems to lead to stress, which leads to a blood-pressure spike," says Gravlee.

That is the work he is now trying to replicate here, in a poor African-American community called Frenchtown. "But as white university researchers, we're running into obstacles," he says. "People here feel we take and we don't give back. Things like the Tuskegee experiment are very much in people's minds." So he has invited people like Mitchell and Holifield to join a steering committee to help direct his project.

Bringing community participation together with genetics and the traditional fieldwork of anthropology "makes this groundbreaking work," says Alan Goodman, a past president of the American Anthropological Association and dean of the faculty at Hampshire College. "It really shows that race is more than biology, and that the health inequities that we see have a strong social and cultural component."

Gravlee's research is part of a growing body of social-science work pointing to the ways that the social environment can "trigger" biological processes, often leading to diseases that hit one group harder than another. It is a tangled web, however, this interplay among genes, culture, and society, and many research projects have become lost in it, a risk that Gravlee and his colleagues face as well.

What is clear is that high blood pressure afflicts about 40 percent of the African-American population. In whites, the figure is about 28 percent. While some social scientists have pointed to disparities in access to health care, or to causes like excess salt in the diet, none of that has accounted for the magnitude of the difference. What's left is the perception, dominant in medical circles, that it must have something to do with race.

That was brought home to Gravlee one night about a decade ago, in talking with his wife, Jocelyn, who is now a physician. At the time she was a third-year medical student, and she wanted him to listen as she practiced presenting medical cases. She started, he recalls, by saying, "Mr. Johnson is a 52-year-old black man who presents with a chronic cough."

"And as a good critical cultural anthropologist, I stopped her and said, 'Now wait a minute. What does his blackness have to with his cough?'" She told him it was simply how her professors had taught her to describe patients. That, Gravlee says, sparked his interest in how race was used in medicine. "And I discovered that a lot of ideas that anthropologists had discarded as relics of the 19th century were circulating pretty freely in contemporary medicine."

One of them was a version of genetic determinism. With hypertension, he says, it was pretty much taken for granted that African ancestry had something to do with it, which is why physicians were taught—and still are—to mention race in their case presentations. While no one would claim that biology is irrelevant, Gravlee says, still no research has identified a "hypertension gene" in African-American groups.

His own background pushed him in the opposite direction. When he was a graduate student at Florida, one of his influential professors was Marvin Harris, a noted anthropologist who argued against racial and genetic determinism. And one of Gravlee's early research projects was to confirm data gathered by Franz Boas, one of the founding figures of American anthropology, on the influence of society over biology. Boas had collected data from immigrants at Ellis Island in the early 20th century, showing that the head shape of babies of various ethnic groups changed once their parents became established in the United States. Boas said this showed that the social environment—changing nutrition or cultural practices—could affect ethnic characteristics. Gravlee has a leather-bound copy of Boas's original treatise on a shelf in his office.

In his own attempt to show the power of social environments, Gravlee went to Puerto Rico in the summer of 2000 and put genes and culture head to head in a test to determine which better predicted blood pressure. The location was Guayama, a city of about 44,000 people south of San Juan. It is filled with people whose ancestors came from Africa, bringing African genes. But it is also a place where people are classified, socially, by their friends and neighbors, as blacker or whiter. Their cultural concept of color (pronounced "co-lohr" in Spanish) divides people into blanco (white), trigueño (intermediate), and negro (black). The first is a privileged class; the last is stigmatized and is seen as having stronger African heritage.

Over the course of 12 months of fieldwork, Gravlee collected information on the color classifications of individuals, and their feelings about encounters with discrimination based on their perceived skin color.

But he also introduced a reality check on color: actual estimates of African genes, based on swabs of cells from people's mouths. Back at the University of Florida, in Gainesville, Connie J. Mulligan, associate director of the university's genetics institute and a professor of anthropology, analyzed the genetic component of the cells, looking for bits of DNA that are clues to geographic origins.

"These stretches of DNA are called ancestry-informative markers," she says, because they are present at their highest frequencies in supposed ancestral groups, such as populations in Africa. "If you have that marker, but not ones that are present in Europeans or Asians, that would increase your African ancestry. You look at enough of these markers and you can get an estimate: 33 percent African, 15 percent Asian, et cetera."

In their analysis, the researchers compared those gene estimates, along with age, body mass, gender, social and economic status, and whether a person was taking blood-pressure medication, to see which factors best predicted hypertension.

There did seem to be some link to the African genes, Mulligan says. But when they added the concept of color to social and economic status, "it simply blew genetic ancestry out of the model." Culture, it seemed, trumped biology as a predictor.

The blood-pressure spike was largest in people who were both classified as negro and had high incomes or education levels. "That seems a little unexpected, because being better off economically is often associated with better health," Gravlee says. "But these people often spoke about frustrating daily interactions, where others treated them badly or looked down on them as if they were poor." That led to stress, and one physical response to stress is a rise in blood pressure.

People who really are poor also feel the stress of discrimination; but the people Gravlee focused on seemed to feel the conflict—between who they were and how they were perceived—especially sharply. (A physical, stress-related response to racism has been demonstrated by other scientists, such as the late Rodney Clark of Wayne State University, in laboratory experiments. Arline T. Geronimus, a professor of health behavior at the University of Michigan at Ann Arbor, has developed a concept called "weathering" to describe the corrosive, stress-driven effect that lifelong discrimination and poverty have on the body.) The scientists, along with a graduate student, Amy L. Non, published their finding in 2009 in the journal PLoS ONE.

 "The fundamental thing is that Lance shows the cultural contribution to race," says William W. Dressler, a professor of anthropology at the University of Alabama at Tuscaloosa, who was the outside reader on Gravlee's doctoral dissertation. "Everyone talks about this, but no one has tried to pin it down."

The results in Guayama, though intriguing, involved 87 people. That's not really enough on which to stake a connection between race and high blood pressure. And, of course, Puerto Rico isn't the mainland, which is where the big disparities between white health and black health have been measured. Gravlee and Mulligan needed another, larger group. So Gravlee began regular two-hour drives from Gainesville to Tallahassee, and meetings with Miaisha Mitchell to form the Health Equity Alliance of Tallahassee, a community-academic partnership.

Frenchtown, the African-American neighborhood where Gravlee wants to continue his project, has seen ups and downs. In the 1950s, it was home to thriving black-owned businesses, and people remember entertainers like Ray Charles and James Brown coming to give concerts. Things started going downhill in the 1960s, with higher crime rates and businesses shutting down. Today, Mitchell says, poverty is still fairly common, though in the past decade the state has put money into revitalization efforts.

But institutions such as the University of Florida and Florida State University—which is in Tallahassee and where Gravlee worked from 2004 to 2006—don't have good reputations in places like Frenchtown or similar areas, says Holifield, the physician, sitting at the table in the Fusion Cafe. "There is always an uneasy relationship between Florida State University in particular and the black community," he says. "Keep in mind that blacks couldn't even go to FSU until 1962."

More recently, Holifield says, when the city wanted to place an incinerator in a black part of town, Florida State "experts" used state statistics to show that it would not increase local air pollution. But a professor from Florida A&M University, a historically black institution in Tallahassee, reanalyzed the data and pointed out that state measures were averaged over a much wider area and thus would not show a higher concentration of pollutants immediately around the site.

"You have two universities, literally on opposite sides of the tracks, from two different worlds, one mostly Caucasian and one African-American, and that push-and-pull causes a lot of issues in the community," says Melvina N. Wilson, another member of the steering committee, who works at Florida State as an HIV-clinic coordinator. "Racism is what it is. Some people on one side try and act like it doesn't exist, and people on the other side, well, they know it exists."

She says that is why it's essential to have members of the African-American community at the table at the very start of projects like Gravlee's. "We've seen university research before. We know about the Tuskegee experiment. But it's more than that," she says. "Researchers come into our community. They study us. They get what they want from us. And then they're gone. ... We're left with the same thing we had, whether it's obesity or environmental diseases or what have you."

The amount of suspicion researchers encounter can vary, Mitchell says. "If you were walking down the street in Frenchtown and asking questions about race," she says, looking at the white journalist interviewing her, "then yes, people would really be suspicious. Me, I have relationships there and it's easier. But even I run into those problems. People want to know: 'Why do you want this information? What are you going to use it for?'"

Now, says Gravlee, imagine going up to people in Frenchtown and asking them for some blood or a cheek swab so you can analyze DNA. "You can see what kind of a minefield you'll be stepping into."

The point of community-based, participatory research is to change that, Mitchell says. "It's getting people to realize they have a voice in the project, that they have some power. And also getting researchers, coming in from powerful universities, to realize that the people they want to study have good ideas about how those studies should be done. That's the balance that we're striving for."

One of the first things the steering committee decided was that Gravlee wasn't going to jump in and study genetics and race. "We really needed to develop a project that was going to have a clear benefit to the community," he says. "And one of the big issues in this community is why people eat what they do," because the area has high rates of diabetes and obesity. So he, Mitchell, and the others developed a plan to map food-buying patterns in Frenchtown. This summer, they tracked who went to what stores and what they bought. They also asked store owners why they stock particular items. The idea was to understand the choices made by both merchants and customers, says Mitchell. And one of the things they discovered was that such choices were frequently dictated by food distributors for the wider region, rather than by the immediate community, which raised issues about local control.

With that project wrapping up, Gravlee, Mulligan, and another colleague at Gainesville, Christopher McCarty, who directs a survey-research center, will begin to interview African-Americans in Frenchtown about the ways they view race, their own skin color, and their encounters with racism and discrimination.

"We are trying to refine our questions in various ways," Gravlee says. "A lot of the questions we have asked previously focus on the direct experience of racism—you know, when someone doesn't look at you when you are waiting for service in a store. But when people talk about racism, indirect or vicarious experiences of discrimination seem to be important. When people say they encounter racism, it can often be through someone else's experiences, told to them. Some people, talking about this, sound very shaken. Also, uncertainty and ambiguity—not being sure how people are reacting to them—seems to affect people. So I think these are good aspects to get at."

In the next phase of the research, the scientists will replicate some of the features of the Puerto Rico study. They will get information about social and economic status, various aspects of health, and the matter of blood pressure and genes indicating African ancestry. Their hope is to spot signs that the way people experience racism, shaped by the cultural views of others, has an influence on high blood pressure—possibly in the same way that skin pigmentation played out in social interactions in Guayama.

In addition, Mulligan hopes to be able to home in on some of the genes that may link the stress of racism to rising blood pressure. Genes that react to chemicals involved in tightening blood vessels—one such gene codes for a molecule called a beta adrenergic receptor; another works with a substance known as angiotensin-converting enzyme—are candidates.

In order to do all that, the researchers have met several times this year with the community representatives to develop an informed-consent form for the research, one that will explain the purpose of the study and will be candid about the benefits to the scientists and to Frenchtown. "We've worked on making it straightforward and getting rid of the legalese, so people can understand it," Gravlee says. "And it very directly restricts the range of research. It says that DNA collected will only be used for cardiovascular research and not for other purposes. The steering committee seems pretty happy with the form now."

So the work is set to go forward. The whole project will take several years. It's not going to be simple to tease out the results, cautions Michael J. Bamshad, a professor of pediatrics at the University of Washington who studies genetic variation and disease. "The genes of African ancestry can be very problematic," he says. The continent has been a kind of genetic mixing bowl, which can make it difficult to point to a particular stretch of DNA and say "African" with no outside influences. Further, biological factors may take different forms in different situations, again making the statistics that point to a relationship among environment, culture, and biology extremely tricky.

But that is precisely the relationship that anthropology, more than other academic disciplines, is suited to explore, says Gravlee. "And I hope that it does have some impact. With this group and hypertension, the stakes are so high."

Josh Fischman is a senior editor at The Chronicle.