A National Journal report explores the racial inequality in sleep and the studies that show blacks are not sleeping as well as whites.
The study was just one data point in a mounting pile of evidence that black Americans aren’t sleeping as well as whites. This past June, the journal Sleep published a study on the sleep quality of black, white, Chinese, and Hispanic adults in six cities across the United States. The participants were pooled from the Multi-Ethnic Study of Atherosclerosis (MESA), a cohort of more than 6,000 people who, for the last 15 years, have been intermittently pricked, prodded, and assessed to discover how geography and race influence health over time. (More than 950 papers have been published on this cohort. It’s from them that researchers have found evidence that the farther people live from a wealthier area, the more likely they are to develop insulin resistance—or that blacks appear to have higher levels of the substances that cause blood to clot.)
For a week, participants in the MESA study wore actigraphy bands, Fitbit-like bracelets that can estimate the amount of time a person is asleep. In a separate test, they underwent polysomnography. The results? “The insufficient amount of sleep, the short sleep duration of the African-Americans really stood out,” says Susan Redline, a Harvard professor of sleep medicine and one of the study’s co-authors. “It really emphasized that African-Americans, as a group, are getting the least amount of sleep compared, at least, to the three other groups.” Whites in the study slept an average of 6.85 hours; blacks slept an average of 6.05 hours.
Compared with white participants in the study, black participants—most epidemiologists prefer “black” to African-American; it encompasses more people—were five times more likely to get short sleep, defined as less than six hours a night. (Hispanic participants were 1.8 times more likely to get short sleep; Chinese participants were 2.3 times more likely.) Blacks were also more likely to report feeling sleepy in the daytime, and they woke up more often in the middle of the night. “Notably,” the study reads, “these associations remained evident after adjustment for sex, age, study site, and [body mass index].”