As the number of COVID-19 cases continues to rise in many parts of the United States, a stark pattern has emerged. Increasing data from cities and states nationwide show that coronavirus cases are both more frequent and more severe in populations of color. Native Americans are being hospitalized for extreme coronavirus symptoms more than five times as often as white people, with hospitalization rates among Latino and Black Americans similarly high, according to the Centers for Disease Control and Prevention. And Black Americans represent nearly a quarter of COVID-19 deaths in the U.S., despite making up only about 13% of the population.
Against this grim backdrop, the country has also erupted with protests against systemic racism, following the killings of George Floyd, Breonna Taylor, and others by police. The disease burden born by Black people and the struggle for racial justice may seem unrelated. And yet, many experts point to racism as a public health issue. So what does that mean?
#CovidQ: How can the stress of racism harm your health, and what does that have to do with COVID-19?
Many of the factors believed to contribute to high rates of infection in communities of color—and Black communities in particular—can be traced back to structural inequalities. A long history of discrimination in education, housing, and the workplace means Black Americans are more likely to live in more densely populated areas and work in the lower-paying jobs that are now deemed “essential.” This may mean both higher daily exposure to the virus and lower possibility for social distancing at home and at work.
But on top of the situational factors that increase health risks is the stress of experiencing racism itself.
Researchers have been investigating mechanisms that connect the emotional world of stress with the physiological world of disease for more than 25 years. “Health is social,” says Zinobia Bennefield, a medical sociologist at the University of North Carolina, Charlotte. “It’s about where you are, whether it’s your physical, social, cultural, or economic environment.”
This “biopsychosocial” realm can help explain why Black communities in the United States are being hit so hard by COVID-19. Two key concepts show how systemic and individual racism can make people physically vulnerable: “allostatic load” and “weathering.”
The power to adapt
You may be familiar with the concept of homeostasis. It’s an old idea that posits that every person’s body has set points that stay more or less constant. For example, our internal pH always stays within a certain range, and we maintain a temperature close to 98.6 F. Straying too far from either is a sign of trouble.
But our bodies also have a profound capacity to adapt to changing environments. Our blood pressure, for example, is constantly adjusting to our situation, says neuroscientist Robert-Paul Juster, a professor of psychiatry and addiction at the University of Montreal. That’s a skill humans evolved to allow us to survive in different environments. Our ancestors’ pulses, blood sugar levels, and organ functions varied while they hunted and then later while they ate; millennia later, our levels are very different when we’re having sex versus sleeping. “Allostasis” refers to the work our bodies do to adjust to these new challenges. “It’s a good thing,” Juster says. “It’s how we adapt to change.”
Allostasis includes the so-called fight-or-flight response—the way your body reacts to a perceived threat. A stressful situation involves more than just abstract emotion; your body also prepares for conflict. Your blood pressure increases, along with your heart rate. Blood is diverted to your extremities to allow for easier movement. And your system is flooded with hormones like adrenaline and norepinephrine, which give you access to lots of energy quickly—key for either fighting or fleeing.
The catch is that these systems have evolved to be used for a few minutes at a time, then returned to baseline once the threat has passed. The problems arrive when stress becomes chronic. “Your body then remains in this hypervigilant mode, where you’re constantly anxious, constantly worried,” explains Tyan Parker Dominguez, a clinical professor of social work at the University of Southern California. “If you have your foot on the gas pedal of your car, and you’re just constantly revving your engine with no let up, that’s going to wear down the engine of your car much faster.”
The term “allostatic load,” was coined by Bruce McEwen and Elliott Stellar in 1993. It refers to damage wrought by persistent stress, which overtaxes the body’s delicate, overlapping regulatory mechanisms—including the immune, endocrine, and circulatory systems, and those regulating blood sugar and mood. As a person’s allostatic load grows, that wear and tear can create runaway dysregulation, with those systems thrown catastrophically out of whack.
Your body under chronic stress
Over time, allostatic load can affect nearly every facet of a person’s health. As stress hormones like cortisol circulate in the body, they turn fat into sugar that the body can use to fight or flee. Unused sugars are often then re-stored as fat in the midsection; this makes them accessible for future stress responses but can damage the kidneys, heart, and other organs. Because cortisol is made from cholesterol, many people who are chronically stressed crave fatty foods as a way to replenish their levels, Juster says, which can then lead to other health problems. And the elevated blood pressure and heart rate that prepare a person for conflict can also lead to hypertension and an enlarged heart.
Both of these heart conditions—as well as the diabetes that’s linked to chronic stress—can put people at a higher risk of serious illness from COVID-19.
Chronic flooding of the circulatory system with stress hormones also creates an overtaxed, overexcited immune system, which is less effective at recognizing a real foe and is prone to attacking the body instead. In the short-term, stress hormones inhibit damaging inflammatory reactions. But over time the body becomes cortisol resistant, instead promoting the production of proteins from the immune system called “pro-inflammatory cytokines.” People with especially high allostatic load (for example, people from chronically underserved communities who experience severe trauma and racism), can be prone to producing too many of these pro-inflammatory cytokines, which can begin attacking other cells or tissues that aren’t a threat—the “cytokine storms” that have come to characterize some of the most severe COVID-19 cases.
Stress hormones also affect our production of glutamate, a neurotransmitter used for brain function. People who are chronically stressed can experience shrinking of the hippocampus, a part of the brain that works on memory and contextualization, as well as the stress response itself. This is true even for fetuses in utero whose mothers experience high stress during pregnancy. Studies indicate that this stress can affect brain development, decreasing the number of stress hormone receptors in the baby’s hippocampus and increasing the receptors in the amygdala, which mediates feelings of anxiety and fear—a dynamic that sets some people up for stress and emotional regulation problems from birth. And high allostatic load has also been linked to higher levels of depression and anxiety.
This widespread damage from chronic stress also leads to a broad premature aging of cells, which have had to divide more often in order to repair damaged tissue. Each one of our cells is built to divide a limited number of times, explains Arline Geronimus, a professor of public health at the University of Michigan. And each time it divides, the caps at the ends of its chromosomes (called telomeres) shorten a little. Once a cell reaches the end of its telomeres, it can no longer divide. This process happens in every body as we age—but not at the same rate. People with chronic stress “have, in effect, an older biological age than other people at their same chronological age,” she says.
Developmental psychologist Virginia Huynh brings this dynamic back to the pandemic, pointing out that “Black people were already at a higher risk for health problems because of racism” and that structural and workplace inequalities have intensified during this time. “It makes sense they’re disproportionately affected by COVID-19,” she says.
Racism at the cellular level
“Just being in this society, as a Black person or a brown person means the recognition that you are potentially at risk for some sort of negative encounter,” Parker Dominguez says, “whether it’s with the police or elsewhere. Your level of threat perception in the environment is higher.” That threat perception leads to hypervigilance, which leads to heightened allostatic load.
It’s that “pervasive, persistent” experience of stress that can be so damaging to the health of Black Americans and other marginalized communities, Bennefield says. “It’s integrated into our housing, our education, our criminal justice system.”
That idea—that certain populations experience structural inequities on a cellular level—is what “weathering” is all about. Geronimus originated the term in a 1992 paper. “It happens with individual bodies, but it’s about lived experience in specific socioeconomic contexts,” she says. The concept began as a way to explain why young Black American women tend to get their periods and begin puberty earlier in life but has evolved to become a paradigm for understanding how structural inequality and public health intersect.
“If you’re vigilant against someone being rude to you, and trying to figure out if it’s because of your race or gender, then your body is constantly feeling like it needs to prepare.”
Huynh contributes to that paradigm in her lab at California State University, Northridge. Her research indicates that young people don’t need to be on the receiving end of racist behavior to be affected physiologically, nor does the behavior need to be overt or extreme for it to do damage. In one study, Huynh and her colleagues collected saliva from 300 teenagers over the course of a day to measure cortisol levels. Teenagers who reported experiencing discrimination had higher levels of cortisol that did not decline normally over the course of the day—suggesting that they were not only experiencing more stress but that they weren’t recovering from it fully. In a second study, a cohort of college students experienced increased levels of cortisol after simply witnessing or overhearing a racist comment, indicating that even vicarious discrimination can create a physiological response.
Huynh emphasizes that these daily experiences of discrimination are often less overt and more insidious, the offhand comments or small interactions sometimes known as microaggressions. “Years of being followed around in a grocery store or liquor market—subtle everyday slight insults—convey to people of color and marginalized communities that they don’t belong, don’t fit in,” she says. When it comes to allostatic load, “it’s often cumulative, a lifetime of experiences that affect multiple regulatory systems.”
In this way, subjectivity and individual perception can deeply affect health, she says. The stress of microaggressions reverberates painfully, regardless of original intent. “There’s often a number of explanations [for a microaggression], but ultimately the impact is that you felt it was offensive, racist, or discriminatory,” she says. “If you’re vigilant against someone being rude to you, and trying to figure out if it’s because of your race or gender, then your body is constantly feeling like it needs to prepare.”
“It’s amazing to genuinely feel afraid all of the time”
Not long ago, Bennefield, who is Black, got locked out of her house after dark in what she calls a “really nice neighborhood” in North Carolina. She was terrified at the prospect of having to call the police for help. “Thank God one of my white neighbors was like, ‘I’ll sit with you the whole time,’” she says. Living among her community’s Confederate flags, there’s a “very real sensation that we are in danger; we are not safe here.”
Even as a successful professor at a respected academic institution, she marvels, “It’s amazing to genuinely feel afraid all of the time. How do you encounter horrors every day and not allow that to slowly erode your chemical, neural, immune, muscular systems?”
Parker Dominguez, who studies birth outcomes across race and class, points to data that support Bennefield’s personal experience. Even accounting for differences in class (which, to some extent, overlap with race) doesn’t explain the differences in maternal health between white and Black Americans. “Even highly educated, high-earning Black women are at higher risk for adverse pregnancy outcomes than a white woman with a high school education,” she says.
In addition, Black professional women are more likely to have achieved status through education, she points out, having worked through challenging circumstances. “They’ve done all the right things, so to speak, and reached this level of economic success, but at what cost?” They may, like Bennefield, end up the only Black person in their neighborhoods or their workplaces. “That sense of solo experience—being the only one—that can be a very stressful situation.”
Still, in discussing her experience from both a personal and professional perspective, Bennefield emphasizes that Black Americans are not the only people whose allostatic load is affected by racism. It’s too simplistic to only talk about Black people living in fear, she argues, without also talking about their white counterparts. “Clearly these are people who are in fear of something, and it’s in a visceral, palpable way that makes them act the way they do,” she says. “They are afraid of something, of losing something they’re clinging to.”
In a very basic way “everyone is under the same stress. There has to be a conversation about how racism is harming us all,” Bennefield says. But, she adds, it’s the rest of systemic racism—access to good education, quality healthcare, safe housing and neighborhoods—that creates the inequality that results in weathering.
The risks and rewards of ‘resilience’
Along with helping to explain disease disparities, weathering and allostatic load can also help shed light on solutions. Research on resilience shows that social support, a sense of meaning, and feelings of control are “extremely beneficial in lowering allostatic load,” Juster says.
To this end, Hunyh points to research showing that kids who feel a stronger sense of ethnic identity—whose parents have talked to them about what it means to be Black or Mexican or taught them Indigenous traditions—have lower allostatic load. Parker Dominguez points to California's Black Infant Health Program, a program that provides social support and connection to resources during pregnancy to women across 20 regions of California and has made significant strides in closing gaps in pregnancy outcomes.
Research on resilience shows that social support, a sense of meaning, and feelings of control are “extremely beneficial in lowering allostatic load,” Juster says.
Juster connects this resilience research to the recent Black Lives Matter protests. “A common denominator with stress is the feeling that we don’t have control,” he says. “Now, with these protests, there’s a sense that people are taking control of the situation and expressing their frustration.” That sense of purpose has been shown to be protective against allostatic load.
Still, Parker Dominguez and Bennefield caution against focusing on an individual’s capacity for resilience at the expense of discussing larger context. “The term ‘resilience’ is really good; it’s also really dangerous,” Bennefield says. “When you say a group is resilient, it sometimes also lets other groups off the hook.”
The key isn’t in individual habits or choices; it’s structural change, she argues. “I don’t think it’s too much to require our government to give equal funding to all schools, to ban redlining, to make sure Flint and other rural areas have access to water. Systemic racism is not just police-sanctioned violence.”
Geronimus splits the difference between individual coping skills and major structural change, advocating as well for local policy that is community-informed, involving members of affected groups in the conversation. The strength of weathering (and allostatic load) as tools for understanding how psychology, health, and policy interact is that “it’s both micro and macro,” she says. “It accounts for all these structural and historical and ongoing processes. The molecular part just tells us how that happens.”
Correction: A previous version of this article stated that the California Black Women’s Health Project has supported women in 17 regions across the state. Tyan Parker Dominguez was referring to California's Black Infant Health Program, which works with women in 20 regions across the state.