Before Jennifer Ahern studied social epidemiology under S. Leonard Syme, before she joined the UC Berkeley faculty as a social epidemiologist herself, she grew up in Baltimore.
“Baltimore had a lot of social problems, very high in violence and crime, antagonistic race relations, complicated history,” says Ahern. “None of which I really understood at the time.”
Associate Professor of Epidemiology Jennifer Ahern
Not unlike many cities across the country, Baltimore has long been emblematic of how social determinants affect health. This is the city where Anthony Iton—alumnus and now senior vice president for health communities at the California Endowment—came up with the trope that aptly describes the social determinants of health: When it comes to health, our zip code counts more than our genetic code. Neighborhood factors like a lack of adequate housing, transportation, education, and safe public green space—compounded by environmental injustices like air pollution and toxic water—result in health disparities between those at the center of society and their neighbors at the margin. The life expectancy of some Baltimore neighborhoods can be 20 years lower than in others. What’s more, these social determinants are often representative of structural and systematic racial and economic disenfranchisement.
At Brown University, Ahern took a class with social epidemiologist Sally Zierler, who introduced her to the concept of looking beyond the medical system to evaluate these social factors that affect health outcomes. “Taking that class with Sally was eye opening,” Ahern says, to the point that she sought further education—and eventually joined the faculty—at UC Berkeley, where the social determinants of health have been progressively woven into the research DNA of the School of Public Health over the last 50 years.
“Medical care is important when we need it,” says Stephen Shortell, Dean Emeritus and a professor of the graduate school in Health Policy and Management, “but it’s not really the major determinant of our health.”
The School abides by the value that health is a human right. But one step further, the faculty believe that a human’s right to health is also a right to a safe and healthy place to live, work, and play, as well as to a healthy and clean environment. “To really address health equity, we need to talk first and foremost about equity more broadly,” says Professor Emerita Meredith Minkler, “You can’t have health equity without racial and social equity.”
UC Berkeley’s pioneering legacy
“It goes back in many ways to Len Syme,” says Shortell. “He’s one of the fathers of social epidemiology.”
In 1955 a 23-year-old Syme attended a medical sociology program at Yale University. He and three other fellows were given a choice between two concentrations: sociology of medicine—which examined the institution of medicine and patient attitudes—or sociology in medicine. Syme understood the latter to mean the study of how social factors impact health. He was the only fellow to choose this option.
According to the Yale faculty at the time, sociology in medicine actually evaluated the link between social class and mental illness. But Syme had little interest in mental illness. “I wanted to know if social factors were related to diseases that were not so obviously connected to the social world,” he wrote in an article for Epidemiologic Perspectives & Innovation. “Diseases such as heart disease, cancer and arthritis.”
In retrospect, he called this a “naive view” and a “reckless decision,” because “there was virtually no literature on these topics at the time and no one was sure there ever would be.” Naivete or sociological intuition—either way, his decision to look at the social causes of diseases, not just the diseases themselves, was a turning point in efforts to bring sociological methods to epidemiology. He later became the first sociologist to hold a position in an epidemiology department, when he joined the School’s faculty in 1968.
“What’s going on here? Is this a study of these diseases, or should we be studying the job of the driver that’s leading to all of these diseases?”
Syme often points to a study he conducted on San Francisco bus drivers to explain his social epidemiological approach. The research focused on the high rates of hypertension among bus drivers compared to other employees in other industries and profession—but the research team soon noticed that these bus drivers also had higher rates of lower-back pain, respiratory problems, and alcohol-related diseases.
“What’s going on here?” Syme recounts asking himself. “Is this a study of these diseases, or should we be studying the job of the driver that’s leading to all of these diseases?”
That distinction, says Syme, is the difference between a social epidemiological, public health approach and a traditional, clinical medical approach. Going beyond the medically-minded mold of epidemiology, which looks primarily at diseases, Syme began to look at community forces—in the case of this study, the job as a bus driver—to determine the social causes for those diseases.
Syme’s career at Berkeley saw him apply this approach to various social contexts, alongside many students and postdoctoral scholars who would go on to become giants in the field of social health determinants by their own right. He conducted early research on how social factors and acculturation among Japanese immigrants to California influenced their cardiovascular mortality. One student on this project, Lisa Berkman, branched off this study to explain how supportive social ties—or the lack thereof, or loneliness—can influence chronic disease susceptibility.
Syme also advised a doctoral student named Nancy Krieger, who has since become a prominent Harvard epidemiologist examining at the impact of racism on health outcomes. In a recent editorial for the British medical weekly The BMJ, she asked, “Are hate crimes a public health issue?”
Another student of Syme’s, Sir Michael Marmot, went on to conduct the renowned Whitehall study of British Civil Servants, which showed that health risk directly correlates with social class. The higher you are on the hierarchy, the better your health. Over the course of his career, Marmot has brought the social determinants of health into the global spotlight. In 2000 he was knighted by Queen Elizabeth II for his work in this field. He chaired the Commission on Social Determinants of Health set up by the World Health Organization in 2005, and later conducted a review of health inequalities in both his native England and continental Europe. He currently teaches at University College London.
Syme’s five decades at the School saw the social determinants permeate the research of many other alumni as well. George Kaplan, a former postdoc, founded the Center for Social Epidemiology & Population Health at the University of Michigan. Maternal and Child Health alumnus Michael Lu worked to explain racial disparities in birth outcomes. And alumna Kate Pickett co-authored a well-circulated book on health inequality called The Spirit Level with her partner and fellow epidemiologist Richard Wilkinson.
However, as Syme and his colleagues provided more and more evidence for the social causes of certain health outcomes, they became increasingly concerned about how best to approach solving these endemic problems.
“It’s estimated that only about one percent of research results ever end up benefiting society,” says Linda Neuhauser, who co-leads (with Syme) a research center called Health Research for Action. “The accepted idea that researchers make discoveries and then community practitioners and policymakers are expected to apply them doesn’t usually work.”
Meredith Minkler, another longtime faculty member at the School and an alumna herself, has spent her 40 years at UC Berkeley developing a research approach known as community-based participatory research, or CBPR. Minkler defines CBPR as “research that is community-based, rather than merely community placed.” Community-based research, she says, “helps to turn the traditional ‘outside expert’ research paradigm on its head, so that we work with rather than on communities and really focus on issues that matter to the people.” This means that local residents participate in defining the research agenda and the data collection process in their own communities, and afterwards give input to help refine and translate the findings into action.
Minkler herself has employed CBPR in many areas of community health, particularly involving criminal justice reform, food security, and public policy. About a decade ago, she worked on a project known as the San Francisco Chinatown Restaurant Worker Health and Safety Study, in which she worked with members of the Chinatown community to refine research questions, improve data measurements, and interpret findings. It turned out that many restaurant workers were not getting the wages and benefits to which they were entitled. A few years later, Minkler’s research influenced legislation. In 2011, San Francisco became only the second city in the country to pass a wage theft law.
The social determinants of health inequality
Associate Professor of Epidemiology Mahasin S. Mujahid
“Health equity means attaining the highest level of health for all,” says Mahasin Mujahid, a social epidemiologist and associate professor at the School of Public Health. “For me that does not mean equitable input. It means equitable output.”
In other words, that means investing more time and public resources in vulnerable populations—groups that “start ten feet under,” as Mujahid says—where the need is greatest.
Through the legacy of Syme, Minkler, and others, the School of Public Health has long been fertile ground for advanced research into the impacts of systems theory, environmental causation of health problems, and upstream social factors and social justice. This legacy has paved the way for today’s continued pursuit of health equity, particularly for those marginalized communities facing an ongoing struggle brought on by a history of exclusion and racism.
The “health equity team” of faculty at the School uses a multi-pronged approach to addressing these complex problems. Rachel Morello-Frosch and Jason Corburn, both with joint appointments in other departments on campus, focus on the environmental injustices that plague low-income and minority communities. Mujahid and Amani Allen (formerly Nuru-Jeter) research how racial discrimination and neighborhood stressors such as racial residential segregation and gentrification increase the risk of chronic disease among African Americans and other racial minority groups. Denise Herd examines the interplay of culture and behavior on racial health disparities and serves as the associate director of the Haas Institute for a Fair and Inclusive Society. And Shortell, along with colleagues Hector Rodriguez and Amanda Brewster, looks at the functionality of the healthcare system and how providers are incentivizaed to integrate social determinants into clinical patient care.
“Berkeley is known for doing work that’s strong methodologically,” says Ahern—and this is true across the range of approaches used under the umbrella of social epidemiology. Ahern herself researches the social implications of violence. She also teaches the graduate seminar on social epidemiology methods, through which she directly imparts Syme’s methodological legacy to the next generation of students. The students then chart new territory, come up with new combinations of theoretical and statistical approaches, and ask new questions to move beyond the status quo.
Neighborhoods do matter for health
Mujahid became a social epidemiologist by asking why.
When she was a graduate biostatistics student at the University of Michigan, a professor explained to her that all biostatistical models need to account for certain variables, including race, gender, and age. Statisticians understood that health disparities often fall along racial and ethnic divides, but Mujahid wanted to investigate the causes for these variables. “Race was associated with every health outcome, but I wanted to know why,” she says. “Why were African Americans more likely to live sicker and die younger?”
The answer, she would discover, lies in social and physical contexts Mujahid’s research has connected higher rates of heart disease—the leading cause of death in the United States today—with neighborhood characteristics like food insecurity, crime, inadequate housing, and poorly funded education. These social determinants “get under the skin” of the residents in these neighborhoods, affecting the physiology of their bodies.
“Neighborhoods do matter for health,” she says.
Professor of Environmental Health Sciences Rachel Morello-Frosch
Morello-Frosch has employed other methods to come to a similar conclusion. In one 4-year CBPR project called the Household Exposure Study, she trained low-income residents in Richmond, California, to monitor air quality and collect dust samples along the fence line of the Chevron petroleum refinery that towers over their neighborhood. These residents had long been concerned that elevated cancer and asthma rates were due to living in close proximity to the refinery. Their samples were then compared to similar samples collected in Bolinas, where there is essentially no industry. Unsurprisingly, there was a significant difference in dangerous
exposure levels.
This study quantifies the health impact of living in proximity to environmental hazards, which is a common characteristic of many low-income communities across the country from Flint, Michigan to Houston’s Manchester neighborhood and parts of Brooklyn and the Bronx.
Even before he studied urban environmental planning as a graduate student at MIT, Corburn recognized these urban disparities as clear signs of environmental injustice. A native New Yorker, he grew up noticing that low-income communities across the five boroughs contained bus depots, refineries, and other sources of asthma-inducing air pollution.
“This doesn’t happen by accident,” says Corburn, who has since become a far-reaching researcher on environmental justice issues around the world. “It turns out there are reasons behind why there are toxins in certain neighborhoods, why there’s air pollution, waste, terrible infrastructure, or lack of infrastructure like water and sanitation and safe toilets in places like Nairobi—the root cause of all that is discrimination and racism.”
In other words, today’s systemic racial discrimination is tomorrow’s higher rates of cardiovascular disease, asthma, HIV, and other chronic illnesses in minority communities.
The intersection of race and place
Just as neighborhood contexts matter for health, according to Mujahid, these social and physical factors can also serve as “the root causes of racial and ethnic disparities in cardiovascular disease” and other health outcomes. These factors aren’t limited to the environmental injustices that minority communities often face (Richmond, along the fenceline with the Chevron refinery, is a historically black and hispanic neighborhood). As School faculty research reveals, there are health effects of racial disenfranchisement even more invisible than toxic particulate matter in the air.
For instance, there’s allostatic load, defined as the physiological wear and tear on our bodies due to repeated adaptation to stress.
“Allostatic load is an indicator of multi-system physiological dysregulation,” says Amani Allen, “It’s a composite measure of a variety of biological markers indicative of how well different systems in the body are functioning. It’s an early marker of disease risk.”
When Allen was a postdoc in the Robert Wood Johnson Health and Society Scholars program, and trying to make sense of some of her prior research on income inequality and racial segregation, she began talking to colleagues in health psychology about stress. “I wanted to know how neighborhood factors turned into preterm birth or cardiovascular disease.”
“We keep looking at things like behavior—people need to eat better, they need to exercise, go to the doctor more. Even if people do all of those things, I would argue that we would still see health disparities.”
One study was particularly influential—a 2006 study by University of Michigan’s Arline Geronimus, which found that middle-aged, black females measured significantly higher levels of allostatic load compared to white men and women and black men. Allen wanted to know why, so she designed the African American Women’s Heart & Health Study to examine whether social stressors like racial discrimination are connected to these physiological outcomes.
Allen surveyed 208 middle-aged African American women in the Bay Area about their experiences of racial discrimination in different contexts—at work or school, finding housing or employment, applying for a bank loan, and so on—over their life course. The research team then gave these women a physical exam and drew blood samples to determine their allostatic load. The results, recently published in the journal Psychoneuroendocrinology, show that less-educated African American women who reported higher levels of racial discrimination had higher levels of allostatic load and faced a higher risk of developing chronic diseases.
Professor of Community Health Sciences Denise Herd
Allen’s research explores one way in which racial discrimination can lead to poorer health outcomes. But there are other mechanisms. Take Herd’s long-term studies of racial disparities in alcohol-related diseases for example. A medical anthropologist and behavioral
sciences professor, Herd evaluates culture for the social determinants of health.
“In the United States and Europe, youth drinking has gone down,” says Herd. “However, those rates have not dropped as much for vulnerable populations like African American kids.”
Higher alcohol consumption in turn translates to higher rates of alcohol-related diseases, like liver cirrhosis. And the problem may be worse than what her research shows. She depends on school and household surveys, which omits even the most vulnerable—those who have dropped out of school or may be homeless. Herd’s research attempts to connect these higher rates of liver cirrhosis and other outcomes to the promotion of alcohol through hip-hop artists and other youth icons, as well as to the inferior alcohol prevention education low-income students receive in the public school system.
“A vulnerable population doesn’t get the services it needs,” says Herd. “There’s a great disparity in almost every single kind of condition, with almost every health outcome you can think of.”
“We keep looking at things like behavior—people need to eat better, they need to exercise, go to the doctor more. Even if people do all of those things, I would argue that we would still see health disparities,” says Allen. “We now know that the experience of social stress is associated with so many poor health outcomes. I think that this changes the conversation from ‘intervention focused on behavior’ to ‘intervention focused on society itself.’”
Research to action in the healthcare system
Social epidemiology, environmental injustice, and racial health disparities bring us outside the medical system to ask questions about what truly causes health outcomes. “But public health is not only about identifying risks,” says Allen. “Ultimately it’s about improving population health and reducing health disparities.”
The next step for many researchers is intervention. For Steve Shortell, that means linking the healthcare system to community organizations that address the underlying social determinants of health.
Dean Emeritus and Professor of the Graduate School Stephen Shortell with Health Policy PhD students Leeann Comfort and Jessica Poon
In his 45-year career as a professor and health services and policy researcher—including 11 years as dean of the School of Public Health—Shortell has seen the conversation surrounding the social determinants of health evolve, particularly as it pertains to how the healthcare system itself should respond to the growing body of health disparity scholarship. “It’s only now becoming top of mind to medical providers that these [social determinants] are important,” he says.
Much of Shortell’s research focuses on reforming the organizational healthcare delivery system to better include the social determinants of health. In 1993 he coined the phrase “holographic organization” to describe an integrated healthcare system. “In parts,” he says, “you embed the whole.”
Alongside colleague Hector Rodriguez, Shortell started the Center for Healthcare Organizational and Innovation Research, or CHOIR, in part to evaluate the interface between healthcare organizations and the social determinants that affect their communities. The CHOIR team has worked to integrate factors like transportation, housing, and access to healthy food into patient screening, engagement, and care.
“It’s a huge undertaking,” says Shortell, not least because disparate data exchange and uneven budget distribution across health and social service organizations present obstacles to his “holographic organization.” The CHOIR center works to integrate a system that up to this point has been structurally siloed.
Mujahid has also begun to pivot her social epidemiological research into intervention into health systems and clinical care. In 2014, the National Academy of Sciences, Medicine and Engineering released a report calling for the inclusion of more behavioral and social factors in electronic health records systems. In response, Mujahid and colleagues from UCSF recently completed a project geocoding 5.9 million electronic health records in the UCSF medical system. These health records will now include indicators of neighborhood environments, and therefore social determinants of health, to help care providers accurately screen patients and better understand “how social context really shapes patient outcomes.”
Citizen science can help
Beyond hospital management, place-based interventions—or “intervention focused on society itself”—present a new set of possibilities, though not without problems. “It’s costly and complex,” says Herd, explaining why “research on the cause of the problem is much more developed than the research on the solution to the problem.”
Professor of Public Health and City and Regional Planning Jason Corburn
According to Mujahid, interventions in certain communities might not be reaching the people who need it the most because of gentrification, in which the most vulnerable people in these communities are at risk of displacement. Mujahid studies the effects of gentrification on health outcomes and has found strong links between living in a gentrifying neighborhood and poor health status among African Americans. “If we want to address health disparities,” she says, “we have to be sure that we can create certain policies, like rent-control policies, that both protect the rights of residents as well as address structural racism.”
“Better health and a better society,” says Herd, “takes a lot of social and political motivation.” In many ways, this motivation for change comes from the bottom up.
“An anchor part of my research in health equity is definitely community engagement, community participation,” says Corburn. Like Rachel Morello-Frosch, Linda Neuhauser, Meredith Minkler, and others, Corburn has found CBPR to be a bedrock for research that instigates policy change. He primarily focuses on citizen science, saying that whether in Kenya’s slums, Brazil’s favelas, or the streets of Richmond or Brooklyn, “citizen science moves into action. It encourages an action-oriented approach to health equity.”
Community-based participatory research also puts data collection in the hands of people exposed to social and physical inequalities, he explains, which in turn extends the reach of data collection beyond where the academic can go. “And importantly,” he says, “it explicitly includes residents in translating that data into action.”
His first book, Street Science, documented the use of citizen science to measure environmental injustices in Brooklyn: residents learn to use air monitors and water samplers to quantify environmental injustices like subsistence fishing in a dirty East River, childhood lead poisoning, and asthma-inducing air quality.
“Citizen science isn’t just getting folks to use professional technology,” he says. “They’re part of the analysis and the meaning-making. Finding out what these data mean for us and our community, and what needs to be done.”
A new research standard
In 2002, Syme and a postdoc named Katherine Frohlich co-wrote an article for the journal Epidemiology observing that in the prior decade, 10 new books focused on the social determinants of diseases had been published. “We suggested that this explosion of work marked the coming of age of the field of social epidemiology,” Syme wrote in a subsequent article a few years later. By 2005, Syme had seen a dozen more social epidemiology books published, along with at least a dozen National Research Council reports and hundreds of journal articles on social and behavioral approaches to health inequalities.
Today, the social determinants of health have become ubiquitous in public health scholarship. “It’s almost unusual if there is no acknowledgement of social determinants in someone’s research,” says Ahern.
In the same way, CBPR raised the bar to a new base level of ethical research in community public health. Research with, rather than on, a community is a new standard for researchers who don’t want to be, as Minkler characterizes them, “mosquitoes that suck your blood, then leave.”
As Syme, Minkler, and others have pioneered approaches to bring epidemiology beyond the medical mold, the social determinants of health have shaped the educational mission of the School. In the last few decades, students have come to the School to take courses in topics such as cultural diversity in health, social epidemiology theory, stress biology, and research advances in health disparities, healthy cities, and structural competency.
Beyond documenting problems and organizing solutions, the next step for these faculty researchers is education—training their successors to continue addressing the social side of health outcomes, to help create a more equitable society for all.
