Minority groups in the United States are at an elevated risk for numerous health disorders. If you’re Black in the U.S., you’re more likely to have hypertension. If you’re Hispanic, you’re almost twice as likely to have diabetes. But how to explain these facts? Why would diseases be targeting minorities more than Caucasians?
In sifting through the complex web of explanations for these disparities, researchers have learned that many are associated with both low #socioeconomic status and insufficient #sleep. In fact, data suggest that chronic sleep deficits may in part explain why certain illnesses disproportionately affect ethnic and racial minorities.
“In my mind, sleep is partially a social justice issue,” says Dr. Michael Grandner, Director of the Sleep and Health Research Program at the University of Arizona. Due to social and environmental pressures, minorities are less likely to lead lives that promote health. Inequality is “setting cards up against them, it’s putting them at a disadvantage,” says Grandner.
The strong relationship between sleep and racial group membership is clear — minorities sleep fewer hours and don’t sleep as deeply as dominant majority populations.
But why? The specific mechanisms that cause this disparity are many and deeply intertwined, but researchers across the country are working to tease apart these mysterious relationships.
A growing body of evidence points to discrimination as one of these mechanisms. Independent of socioeconomic or physiological factors, discrimination consistently correlates with sleep quality and quantity.
Across multiple studies, scholars have found that “people who feel that their racial group is discriminated against sleep much worse,” says Dr. Lianne Tomfohr, a psychologist at University of Calgary. “If you are discriminated against during the day, a lot of what you have is sort of ruminative cognition going to bed. Let’s say you’re out and somebody is following you around the store and you think it’s because you’re Black. There’s little you can do about it without exposing yourself to confrontation, even violence. So, you have to stuff that down. What many African American men and women told me is they get home and they feel very angry because they’ve been discriminated against, but they suppress it. That anger suppression is very bad for them.”
In other words, not only do individuals who experience prejudice sleep less—but they sleep differently from those who don’t feel marginalized. Research associates discrimination with spending more time in Stage 2 sleep and less in the restorative slow wave sleep stages. These are the discrepancies that have been consistently connected to other health concerns.
In addition to the psychological impacts of angry rumination at bed-time, Tomfohr notes that people’s chronic stress levels tend to rise in the face of discrimination. This stress may lead to physiological responses that further prohibit sleep.
But the reason we don’t yet fully understand the racial disparities of bad sleep may ironically be for the same reason causing those disparities. “Minorities don’t get referred for sleep studies,” Grandner explains.
If scientists aren’t referring minorities to the very studies that would help explain their lack of sleep, how can we ever hope to help them?