What’s the most important behavior driving life expectancy? You may be tempted to say diet or exercise, but new research indicates it’s actually how much sleep you get.
For the study, published in SLEEP Advances, researchers at Oregon Health & Science University used a nationwide database to search for survey trends associated with average life expectancy county by county. They compared county-level data about average life expectancy with comprehensive survey data collected by the Centers for Disease Control and Prevention between 2019 and 2025.
According to the data, as a behavioral driver for life expectancy, sleep stood out more than any other aspect, except smoking. Researchers found clear correlations in each year and in most U.S. states between sleep and life expectancy.
The statistical analysis did not delve into reasons why inadequate sleep appears to shorten life expectancy, but the researchers noted that sleep influences cardiovascular health, the immune system and brain function.
Scientists have broadly understood the importance of sufficient sleep for a variety of positive health outcomes. However, the research team said they were surprised by the strength of the connection to life expectancy. The effect of insufficient sleep swamped the impact of diet and exercise as a predictor of life expectancy.
“It’s intuitive and makes a lot of sense, but it was still striking to see it materialize so strongly in all of these models,” said senior author Andrew McHill, associate professor in the OHSU School of Nursing, “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.”
Data from OHSU