By: Elie Gottlieb, Ph.D.

Income inequality and social inequality have long been acknowledged as critical issues in the United States. Emerging research now highlights a pervasive problem: sleep inequality. Despite the well-documented physiological benefits of sleep, recent findings reveal that not everyone has equal access to adequate sleep. Historically, public health research on sleep has considered populations through a broad lens, aggregating data across diverse races, ethnic groups, and socioeconomic statuses. This approach has masked the uneven distribution of sleep deficiencies within society. A closer examination, such as the recent study by the CDC, exposes a stark reality: affluent white Americans enjoy significantly better sleep than poorer Americans of any race.

Disparities in Sleep Across Racial and Ethnic Groups

The CDC’s 2014 Behavioral Risk Factor Surveillance System survey, which involved nearly 450,000 adults, offers a comprehensive view of sleep inequality. The initial findings are alarming: over a third of white Americans do not achieve the recommended minimum of 7 hours of sleep per night. This figure escalates dramatically among other racial groups, with Black Americans, Native Hawaiian/Pacific Islanders, and multiracial Americans being the most affected, as nearly 50% of individuals in these groups report sleeping less than 7 hours per night.

These results, based on self-reported data, align with objective sleep measures. For instance, one study found that Black, Hispanic/Latino, and Chinese participants slept up to one hour less than their white counterparts. Moreover, the quality of sleep among Black adults was notably poor, with these individuals being 57% more likely to experience poor sleep quality and up to 90% more likely to suffer from excessive daytime sleepiness.

Some research indicates that a subset of Black Americans might experience excessive sleep, potentially indicative of underlying health issues. This may also reflect compensatory mechanisms for altered sleep architecture, such as reduced slow-wave sleep. Indeed, there may be racial differences in sleep architecture, with Black Americans shown to experience approximately 5% less slow wave sleep and significantly more light sleep than white Americans. The lack of deep sleep can lead to extended sleep durations as a potentially compensatory mechanism, though excessively long sleep is also associated with various health concerns, necessitating further research.

Health Implications of Poor Sleep

The combination of excessively long sleep durations and insufficient slow-wave sleep can exacerbate conditions like type-2 diabetes. The absence of adequate slow-wave sleep impairs the body’s glucose metabolism and increases insulin resistance, predisposing individuals to obesity and diabetes—conditions already disproportionately affecting Black and Hispanic/Latino Americans. Furthermore, Black Americans are twice as likely to suffer from severe obstructive sleep apnea (OSA), with Black children being 4-6 times more likely to develop OSA compared to white children.

Early Onset of Sleep Disparities in Childhood

Sleep disparities manifest early in life. A recent meta-analysis of over 20 studies found that white American youth generally enjoy more sufficient sleep than their minority peers. Nearly all the studies reviewed reported racial disparities in sleep duration, sleep quality, and bedtime/wake time among school-aged children. These disparities have cascading effects on physiological development and academic performance. For example, optimal sleep efficiency is strongly associated with higher math and language grades, whereas even one hour less sleep can increase the risk of obesity in adolescents. These findings underscore the inclusion of sleep improvement for minority children as a core objective in Healthy People 2030.

Socioeconomic Determinants of Sleep Inequality

Sleep inequality is a multifaceted issue rooted in a complex interplay of societal disadvantages. Socioeconomic factors play a significant role in exacerbating sleep disparities.

Poverty-Related Sleep Disparities

Sleep inequality is a multifaceted issue rooted in a complex interplay of societal disadvantages. Socioeconomic factors play a significant role in exacerbating sleep disparities. Several studies link poverty indicators with sleep issues. For example, a 2013 survey of over 4,000 participants found that an excessively long sleep onset latency (> 30 minutes) was associated with lower education levels, lack of private health insurance, and food insecurity. Additionally, sleep maintenance problems and early morning awakenings were common among those experiencing food insecurity. Snoring was also more prevalent among Hispanic/Latino individuals, the less educated, and those with food insecurity.

The likelihood of poor sleep increases with poverty. One study using objectively measured sleep data found that lower-income individuals took longer to fall asleep and had worse sleep efficiency. The CDC reports that nearly 35% of individuals in households below the poverty threshold reported sleep less than 6 hours per night, compared to just 25% of those living at four times above the poverty level. Unemployment and inability to work further exacerbate sleep problems, and discrimination reduces the chances of securing better jobs and housing for non-white Americans.

Environmental Influences on Sleep Quality

Poor sleep environments, characterized by light pollution, air pollution, and excessive noise, severely impact sleep quality. A 2018 study revealed that adolescents in suboptimal socioemotional conditions experienced significantly worse sleep duration and regularity. Improvements in housing quality can profoundly enhance sleep. For instance, residents of Argentinian slums who moved to basic prefabricated homes experienced significant improvements in sleep quality, physical and mental health, and overall quality of life.

Mental Health and Sleep Inequality

Socioeconomic instability detrimentally affects mental health, increasing stress, anxiety, and depression. These mental health issues, in turn, worsen sleep problems. Stress and anxiety can cause an overactivation sympathetic nervous system, elevate blood pressure, and raise cortisol levels, making sleep more difficult. Several studies have found correlations between discrimination and sleep problems, with Black Americans experiencing high discrimination rates experiencing less deep sleep and elevations in blood pressure. Similarly, Hispanic/Latino Americans facing acculturation stress were more likely to suffer from insomnia symptoms. Chronic stress about financial stability, safety, and daily survival significantly raises mental health issues among low-income households, which often lack resources and education for managing psychological health.

Addressing the Sleep Inequality Epidemic: The Path Forward

Sleep inequality in America represents a critical public health issue that necessitates urgent attention. Improving sleep among racial and ethnic minorities could provide a pathway to better health outcomes, addressing intractable health disparities. As we continue to explore and address these disparities, it is imperative to consider the broader societal and economic factors contributing to this pervasive issue. Solving sleep inequality is complex and requires a multidisciplinary approach involving health professionals, researchers, and government agencies. Addressing sleep inequality as a public health crisis could help mitigate health conditions disproportionately affecting racial and ethnic minorities.