Sleeping less than seven hours dialy quietly shortens life, reveals study

By Sade Oguntola

Researchers say sleep isn’t just about feeling rested; it may be one of the strongest predictors of how long you live.

Analysis of large nationwide data found that regularly getting too little sleep was more closely tied to shorter life expectancy than diet, exercise, or loneliness. The connection was consistent year after year across US states.

Published in the journal Sleep Advances, the new research from Oregon Health and Science University indicated that regularly getting seven to nine hours of sleep a night could help to support long-term health, and getting less than seven hours could cut years off your life.

To reach their conclusions, researchers analysed a large national database, examining survey patterns related to life expectancy across counties throughout the United States. They compared county-level life expectancy figures with detailed survey data collected by the Centres for Disease Control and Prevention between 2019 and 2025.

For their models, researchers used the CDC definition of sufficient sleep as at least seven hours per night, which aligns with recommendations from the American Academy of Sleep Medicine and the Sleep Research Society.

When researchers evaluated lifestyle factors tied to how long people live, sleep stood out clearly. Its association with life expectancy was stronger than that of diet, physical activity, or social isolation. Smoking was the only factor that showed a greater influence.

Across nearly all states and in each year analysed, the data showed a clear relationship between sleep duration and life expectancy.

The researchers said they were surprised by how closely sleep duration tracked with life expectancy, outweighing diet and exercise, although sleep has long been recognised to support overall health.

In a reaction, senior author Andrew McHill, Ph.D., Associate Professor in the OHSU School of Nursing, the OHSU School of Medicine and OHSU’s Oregon Institute of Occupational Health Sciences, said, “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.”

While scientists have long recognised that adequate sleep supports overall health, the authors said they were still struck by how closely sleep duration tracked with life expectancy. In the analysis, insufficient sleep outweighed diet and exercise as a predictor of lifespan.

“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.

“This research shows that we need to prioritise sleep at least as much as we do what we eat or how we exercise. 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 not only how you feel but also how long you live,” McHill said.

The study did not look into the biological reasons behind the connection, but McHill noted that sleep plays a critical role in heart health, immune function and brain performance.