For years, sleep has been treated like an optional luxury something people sacrifice to work longer, scroll more, or catch up later. A new nationwide study suggests that mindset may be quietly shortening lives.

Researchers at Oregon Health & Science University (OHSU) have found that people who regularly fail to get enough sleep tend to live shorter lives and the effect is stronger than that of poor diet, lack of exercise, or social isolation. The findings were published in SLEEP Advances.

Instead of focusing on individuals, the study looked at the bigger picture. Scientists examined sleep patterns and life expectancy across more than 3,000 U.S. counties, using CDC survey data collected between 2019 and 2025. When these figures were compared year by year, a striking pattern emerged: areas where more people slept less than seven hours a night consistently showed lower life expectancy.

Sleep Stands Out Among Lifestyle Risks

The research team evaluated a wide range of factors known to influence longevity including obesity, diabetes, physical inactivity, education levels, unemployment, food insecurity, health insurance access, and social ties. Sleep emerged as one of the most powerful predictors.

Smoking was the only factor that showed a stronger link to shorter life expectancy.

“I didn’t expect it to be so strongly correlated to life expectancy,” said senior author Andrew McHill, Ph.D., associate professor at the OHSU School of Nursing, OHSU School of Medicine, and OHSU’s 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.”

Consistent Pattern Across the Country

The relationship between sleep and lifespan held true regardless of geography or income. Metropolitan cities, rural counties, wealthy regions, and economically challenged areas all showed the same trend.

In Oregon, for example, counties with higher rates of sleep deprivation had visibly lower life expectancy than neighbouring regions where residents slept longer. Similar patterns appeared nationwide.

The study used the CDC’s definition of adequate sleep seven or more hours per night which aligns with recommendations from major sleep medicine organisations.

Researchers Themselves Were Surprised

Much of the work was carried out by graduate students in OHSU’s Sleep, Chronobiology and Health Laboratory. While scientists have long known sleep supports overall health, the authors said the consistency and strength of the findings across all states and years stood out.

“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,” McHill said.

“I’m a sleep physiologist who understands the health benefits of sleep, but the strength of the association between sleep sufficiency and life expectancy was remarkable to me.”

Why Sleep Matters So Much

Although the study did not examine biological mechanisms directly, researchers pointed out that sleep plays a critical role in heart health, immune defence, metabolism, and brain function. Chronic sleep deprivation is already linked to conditions such as high blood pressure, diabetes, obesity, heart disease, stroke, depression, and anxiety.

“This research shows that we need to prioritise sleep at least as much as we do to what we eat or how we exercise,” McHill said.

“Sometimes, we think of sleep as something we can set aside and maybe put off until later or on the weekend. Getting a good night’s sleep will improve how you feel but also how long you live.”