For years, we’ve been told that eating well and exercising regularly are the cornerstones of a long, healthy life. But new research from Oregon Health & Science University (OHSU) suggests that one of the most powerful predictors of life expectancy may be something far simpler: getting enough sleep.
Published last week in SLEEP Advances, the study analysed nationwide data collected by the Centres for Disease Control and Prevention (CDC) between 2019 and 2025. Researchers compared county-level life expectancy with survey responses about lifestyle habits. What stood out most was sleep. In fact, insufficient sleep was more strongly tied to shorter life expectancy than diet, exercise, or loneliness—second only to smoking.
“I didn’t expect it to be so strongly correlated to life expectancy,” said senior author Andrew McHill, PhD, associate professor at OHSU’s School of Nursing, School of Medicine, and Oregon Institute of Occupational Health Sciences. “We’ve always thought sleep is important, but this research really drives that point home: People really should strive to get seven to nine hours of sleep if at all possible.”
The findings surprised even seasoned sleep scientists. While the health benefits of adequate rest are well documented—better cardiovascular health, stronger immunity, sharper brain function—the sheer strength of the correlation with life expectancy was striking. According to McHill, the impact of insufficient sleep “swamped” the predictive power of diet and exercise.
A remarkable connection
“It’s intuitive and makes a lot of sense, but it was still striking to see it materialise so strongly in all of these models,” he explained. “The strength of the association between sleep sufficiency and life expectancy was remarkable to me.”
Although previous studies have linked poor sleep to higher mortality risk, this is the first to show year-to-year correlations across every U.S. state. Using the CDC’s definition of sufficient sleep—at least seven hours per night—the researchers found consistent patterns: in nearly every state and every year studied, sleep sufficiency aligned closely with life expectancy.
The work was conducted primarily by graduate students in OHSU’s Sleep, Chronobiology and Health Laboratory. Lead author Kathryn E. McAuliffe, along with colleagues Madeline R. Wary, Gemma V. Pleas, Kiziah E.S. Pugmire, Courtney Lysiak, Nathan F. Dieckmann, and Brooke M. Shafer, contributed to the analysis.
The study did not attempt to explain why inadequate sleep shortens life expectancy, but the mechanisms are well known. Sleep regulates cardiovascular health, bolsters the immune system, and supports cognitive function. Chronic sleep deprivation, by contrast, increases risks for heart disease, diabetes, depression, and dementia.
McHill emphasised that sleep should be prioritised alongside diet and exercise. “Sometimes, we think of sleep as something we can set aside and maybe put off until later or on the weekend,” he said. “Getting a good night’s sleep will improve how you feel but also how long you live.”
The bottom line here is that wellness isn’t just about eating more kale or morning jogs. It’s also about turning off the lights, silencing the phone, and giving your body the rest it needs. Sleep is not a luxury—it’s a necessity, and perhaps the most powerful longevity tool we have.
