• April 17, 2014

The Pressure of Race

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

To Battle a Plague, an Anthropologist Challenges Medical Wisdom 1

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."

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close To Battle a Plague, an Anthropologist Challenges Medical Wisdom 1

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."

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.


1. ellenhunt - September 13, 2010 at 01:07 pm

Good article! Since black Americans are as mixed as, if not more so, than "white" Americans, it has long been my thinking that skin color is likely to have little to do with such specifics except where a related gene system is concerned such as leptin-melanin. Additionally, the genetic distance between tribes (like Ashanti and Watusi) is greater than the distance between either one and Caucasians. This is is a genetic feature in all creatures - as you get closer to the origin, genetic diversity and distance increases.

Against that idea in the case of hypertension are studies from Africa such as this 2004 on the Ashanti people. (hyper.ahajournals.org/cgi/content/full/hypertensionaha;43/5/1017 ) Prevalence, Detection, Management, and Control of Hypertension in Ashanti, West Africa
This can be compared with studies of Native Americans who are another aboriginal group recently moving into urban settings. (www.ncbi.nlm.nih.gov/pmc/articles/PMC1381660/)Clinical hypertension in Native Americans: a comparison of 1987 and 1992 rates from ambulatory care data. This Native American study shows roughly 1/3 the rate of hypertension than inthe Ashanti people.

In Africa, there is a link between semi-urban settings and increased hypertension. My suspicion is that a significant factor in that population is lack of sufficient exercise. Black Americans commonly don't get sufficient exercise, particularly aerobic endurance type.

I am quite sure that there is also a link between poverty and low status and hypertension. The work of Sapolsky et al shows that in baboons. Being at the bottom of the social heirarchy causes stress and high blood pressure. So that sounds exactly right to me.

I think that for Gravlee to bolster his study, he should compare his local subjects and a set of subjects in African villages of similar ancestry.

2. ellenhunt - September 13, 2010 at 01:09 pm

And Gravlee, don't forget the other primate studies on social status and stress.

3. ellenhunt - September 13, 2010 at 01:33 pm

Now, I wonder what the self-perception is among Native Americans relative to status? Some reservations have serious problems with violence, others do not. There is large linguistic distance (I know nothing about genetic distance in Native Americans) between tribes, and some surprising linkages with the entire continent between tribes. Tribes have very variable culture and history. Some have remained autonomous, only ravaged by disease, and maintaining economic strength.

That would also be a good thing to look at to bolster this study.

Very good. Behind you all the way Gravlee.

4. 11144703 - September 13, 2010 at 02:52 pm

Very little on Asians or Asian Americans in this article: not a single specific stat about them. Asians are a growing community in the U.S. and cannot be ignored.

5. evastar - September 13, 2010 at 02:55 pm

lead poisoning from old lead painted homes.

6. chronicleme - September 13, 2010 at 05:41 pm

This is consistent with my long-standing observation in Ethics and Moral Development Theory, that the phenomenon I call "Ethical Stress," a read tension requiring shared moral labor, results from the very real harms and injustices of social "diseases" like racism, homophobia, and sexism. So certain forms of high blood pressure result from detecting serious ethical stress, but not having enough tools to deal with them. I noticed myself that when I was being discriminated against, treated in sexist ways or the only woman in a tenured-up Department of Philosophy, or even shunned by young post-modernists, ... most of all, being abused by my own spouse, my blood pressure was always very very high. When I thought about injustice, it got higher. When I did yoga and all was well, I could make it go lower by thinking different thoughts. So this result is not surprising, and I welcome it. Blood pressure is of course related to certain kinds of stress. But we all NEED some stress: it's what we do with it that counts. Perhaps that's why so many activists live so LONG and are so relatively healthy! They get out and demonstrate, work in the community, volunteer, stuff envelopes, make calls, and EXPRESS the ethical stress (even in Sierra Club, I've seen "little old ladies" raise a rucus about Water policy issues, out of justice as well as environmentalist righteous rage) in constructive ways. More power to this movement, but please let it go beyond diagnosis or rule outs to real shared moral labor against injustices.

7. boiler - September 14, 2010 at 07:06 am

As Max Qda would say, "Fugen sie bitte hier eine text ein."

8. 22228715 - September 14, 2010 at 08:45 am

Interesting. The premise that it's stressful to be a discrimination-targeted person seems kind of obvious, but some interesting ways to study and approach it. I'm still thinking, but some things that aren't yet sitting right... If race is a social construction, it seems odd to set up skin color as a perceived test of race and African genetic content as a test of true race. Wouldn't a test of "real" blackness need to be a social construction too? As I'm thinking this out... if one devised a way to test most white Americans' initial fears or prejudices against a person based on very short first impressions, comparing Africans and African Americans, would the results run along literal skin color lines, or African genetic ancestry, or would cultural/social cues be more powerful?

Also, I wonder about the historical progression. If prejudice and racial discrimination cause high blood pressure, then shouldn't the problem have been worse when racial discrimination was worse? If so, wouldn't blacks as a class of people been far less physically hardy 50 or 100 or 200 years ago, having many more heart attacks, strokes, etc at even young ages? Or, is the stressor something more complicated, whereby almost-equality is more stressful than outright disenfranchisement? Or are there other explanations, other intersections with other factors?

9. v8573254 - September 14, 2010 at 09:00 am

This is a terrific piece because of the information, but it is also terrific because of the writing and what it shows about research methods. I just love that you interviewed at the "Fusion" Cafe.

10. frankschmidt - September 14, 2010 at 09:43 am

And yet, genetics has a role:

Science 13 August 2010:
Vol. 329. no. 5993, pp. 841 - 845
DOI: 10.1126/science.1193032
Association of Trypanolytic ApoL1 Variants with Kidney Disease in African Americans

One should always be careful of studies that show stress to be the cause of some pathology. Think ulcers which are now known to be due to bacterial infection in the majority of cases, although conventional wisdom attributed them to stress. Because stress (like other conditions, including racism) is so pervasive, other more addressable causes can be overlooked.

In this case, a genetic variation that protects against infection in Africa apparently leads to hypertension-caused kidney pathology in the U.S. (It may do so in Africa too, but that would have relatively little effect on the ability to pass one's genes on.) Yup. Evolution again.

11. tridaddy - September 14, 2010 at 09:51 am

I agree with others, in the fact that this is one of most interesting articles I've read in CHE for some time. I appreciate the fact that the study does not leave everything up to genetics - predetermined status. This concept should be applied to other issues. Not to start a firestorm, but reading this article made me question the validity of a number of "genetically determined outcomes" for example, sexual orientation. This isn't to say that there is no genetic influence but that its more than just a gene, culture and life experiences seem to have an effect. I look forward to follow Gravlee's research.

12. angelfire1712 - September 14, 2010 at 01:30 pm

Growing up and seeing a young black girl in front of me in a grocery line have a fit of rage for some reason..I surmized way back then (in the 60's) that if I were black, I'd be angry or have a little rage or have feelings of depression and disconnection after reading about the civil rights movement...I was 14. To me this is a no-brainer. Certainly genetics plays into that somewhat in how your coping capabilites may kick in (your religeous affiliations, support network, etc.) but, like everything else, it seemed to me anyway, only a fraction of that was the real picture...I think social exclusion is on the same level as how a torture victim may percieve life. To be honest, I would have thought this kind of research on this subject would have been done years ago. We're a little behind aren't we?...my question is why?

13. davi2665 - September 14, 2010 at 01:32 pm

It is indeed refreshing to read a thoughtful article AND discussion on the complex genetic and social/cultural components of a phenotype such as hypertension, especially on with deadly consequences if left untreated. This is also an excellent arena in which biomarker studies (both genomic and proteomic) may provide early insights to permit preventive measures. Kudos to Prof. Gravlee.

14. angelfire1712 - September 14, 2010 at 01:40 pm

I would just like to comment on two of the posts: To 222228715...I'm thinking that 100 years ago, 50 years ago...like with all of us...our social structures were greater back then. People were surrounded more by family ... that might play into it.
and as for tridaddy....I think looking at sexual orientation vs. race are two very different subjects. However, perhaps another study should look to see if gays and lesbians have a higher incidence of chronic illnesses due to their sexual orientation and the discrimination they face. They can, if they want, hide that side of their life but skin color is another story.

15. dank48 - September 14, 2010 at 05:02 pm

Is it possible that the tendency toward high blood pressure might have both a genetic and a societal cause?

16. minnesotan - September 14, 2010 at 06:38 pm

tridaddy: the overwhelming majority of scientists have not believed in genetic determinism for many decades. You're really only attacking a straw man by exclaiming "Finally, culture is vindicated!" In the social sciences, cultural anthropology among them, it is far more likely that you'll find a bias against biology than for it. The Standard Social Science Model is weakening, but there are still plenty of hangers-on who believe the human mind is a blank slate.

17. apollo - September 14, 2010 at 09:39 pm

I haven't read the full article yet to see how good the writing is, but I know what a good man Lance is. Our kids are in the same class at school. Good job, Lance.

18. gadget - September 20, 2010 at 06:24 pm

The people who live in the US-Mexico border colonias have expressed the same concerns about all the researchers, academics, grad students, etc. who show up to do studies. The community opens itself up, often provides hospitaily and always provides lots of time, but doesn't get anything of value back. Kudos to new methods for research designed to give back directly.

One issue that always comes up is that community residents want intellectual capital to be part of the relationship. They have children in college who can be hired as research assistants, data collectors and tabulators, clerical staff, outreach workers and interviewers, and so forth. Their children will benefit from knowing faculty from different universities that can be a friendly face when they go to college or for email advice and support in navigating higher ed institutional obstacles. Their community centers could use the computers and other equipment that has been deployed in the field and often not needed on the home campus when the study is over (I have never had trouble following federal procedures to do this). Their children need scholarships to college, homework help, and guidance in school. Finally, colonia residents want long term relationships where they and their communities receive, not just give. These relationships might not be with individuals from the university or government agency who are using them for research, but with departments, agencies, and universities over the long haul.

19. ayhunt - September 26, 2010 at 01:44 pm

As a 3rd year medical student who is also wary of using racial modifiers (equally absurd is Caucasian - where are those genes from?), I am also aware that medications have different effects in different groups of people. Does that mean every person from a certain ethnicity will respond the same way? No, but it does represent a trend that if not taken into account could seriously harm a patient:

Lim RF,. Clinical manual of cultural psychiatry. Washington, DC: American Psychiatric Pub.; 2006.

It is tragic that humans have mistreated each other so much in the past. Visible differences are crude ways to alert physicians to possible differences in drug metabolism or disease burden, just as freckles alert us to a trend of increased skin cancer, but freckled individuals have not been so incredible mistreated historically.

I'm just asking to leave some room for clinicians who are truly trying to give a patient the best care they possible using crude markers that point toward increased burden of disease (without knowing why it is the way it is). Not noticing could equate with harming a patient.

I listened to story on KUOW here in Seattle of a woman whose ethnic background was *not* taken into account and it was detrimental to her. She was convinced she had breast cancer, but had no family history of it and was too young to meet criteria for screening. Well, she did have it and it turns out for unknown reasons, African American women tend to get breast cancer earlier in life. If it was your sister, Aunt, or cousin, would you be more worried about the racial modifier or the breast cancer?

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