Researchers say sleep problems lead to health disparities for Black and brown Minnesotans

Researchers and policymakers have paid attention in recent years to how everything from housing to racism and pollution influences health, and how such social determinants contribute to health disparities.

But new research is finding that one thing has been missing from that list: sleep.

People who don't sleep well appear to be at a higher risk for a slew of negative health outcomes, including cancer, cardiovascular disease, diabetes, hypertension, obesity and even death. And Black and brown people have less access to sleep as a resource than white people, said Prof. Rachel Widome of the University of Minnesota School of Public Health.

"Sleep is absolutely a determinant of health," she said. "Sleep has an impact on a whole host of health outcomes from physical to mental."

Prof. Ivan Wu of the U's School of Public Health, who researches the connection between sleep, obesity and cancer, said that poor sleep perpetuates ongoing health disparities. "Not getting enough sleep is related to all these terrible things," he said.

Until recently, most research in sleep disparities focused on documenting the problem. But now, Wu and others are beginning the process of finding solutions.

The picture that has emerged from a decade of research is that Black and brown Americans are much more likely to sleep poorly than white Americans. The darker a person's skin color is, the worse their sleep tends to be, said Prof. Dayna A. Johnson, a sleep epidemiologist at Emory University in Atlanta.

"The theory is that racial minorities experience a stress that is unique and chronic and additive to the general stressors that all people experience," said Johnson, one of the first researchers to work on sleep disparities. "We all experience stress, but there are added stressors for certain groups. For certain populations, racism fits into that category."

People who experience racism and ruminate about it at night may have problems falling asleep, according to a study led by Johnson in the journal Sleep. If people anticipate racism, they may find interference with their sleep-wake cycle, she said, since their body may be in a heightened state of arousal, with higher blood pressure and variability of heart rate.

Structural racism is also a fundamental contributor to sleep disparities, Johnson said. For example, people of color are more likely to live in neighborhoods not conducive to sleep, areas that experts sometimes call "sleep deserts."

Air pollution can cause inflammation and contribute to sleep apnea. Places with higher pollution often have fewer trees and sidewalks, amenities that allow people to exercise safely. Noisier nights, whether the result of nearby traffic or thin apartment walls, can hinder sleep. The lack of a sense of safety can also cause sleepless nights.

The longer a foreign-born person lives in the United States, the worse their sleep becomes, Johnson said. She suspects that may stem from the stress of language barriers or worsening dietary habits.

The National Institutes of Health has funded more research on sleep disparities in the last several years, and it is now considered a priority area, Johnson said. But developing ways to solve the issue is in its infancy.

Wu, a clinical psychologist, began researching sleep inequities while working at the University of Texas MD Anderson Cancer Center in Houston. He recognized that the subject of sleep was often missing from research on obesity and cancer risk.

A pilot study that Wu began in Houston involves evaluating whether the risk of cancer and obesity can be lessened through sleep interventions. Through individual counseling sessions over the course of a month, Wu adapts cognitive behavior therapy for insomnia to a population of Black adults. He's found that the practice works as long as neighborhood-related stressors, such as loud traffic, don't interfere.

Participants in Houston were recruited through relationships with Black churches. Now Wu is looking to work with local churches to expand that research in Minneapolis.

Wu also is teaming up with Prof. Abdifatah Ali of the U's Carlson School of Management on a cancer prevention initiative with the Twin Cities' East African community funded by the Masonic Cancer Center. The pair hopes to train community health workers to spread information on cancer-prevention strategies, including healthy sleep.

Individual fixes, such as yoga before sleep or Wu's sleep therapy program, can work. But there are often external factors, such as pollution, beyond an individual's control. Both Johnson and Wu believe that sleep equity solutions need to be community-oriented to bring substantial and sustainable change.

"It's not the individual; it's the context in which they live," Johnson said.

For example, adjusting school start times could foster better sleep for kids. Physicians could talk about sleep health with patients. In the public health sphere, knowledge about sleep and local customs could be given through healthy sleep campaigns.

Many Somali residents in the Twin Cities believe smoke detectors that beep around the clock are working properly, Ali said, or that it's the landlord's responsibility to fix them. Such misinformation could be corrected with a community-wide effort.

Widome pointed out that sleep is often viewed as "garbage" or "throwaway" time.

"If you're getting the right amount of sleep, you're spending a third of your life sleeping," she said. "How much time do we spend thinking about our health in the other two-thirds of the day — what we do in our leisure time, how physically active we are, what we eat?"