- A nationwide county level analysis found insufficient sleep was linked to lower life expectancy across most US states and across multiple years
- The association was stronger than several other lifestyle factors studied, with smoking the standout factor that was stronger
- This is correlation, not proof, but it supports sleep as a serious health priority, not a nice to have
We all notice the short term effects of poor sleep, but new research suggests the long term impact could be bigger than many people assume.
Researchers from Oregon Health and Science University analysed US county level life expectancy data alongside survey data on sleep and other health behaviours collected between 2019 and 2025.
Their aim was to see which factors tracked most consistently with life expectancy across states and over time.
Sleep stood out.
Counties with a higher proportion of adults sleeping less than seven hours tended to have lower life expectancy, and the pattern held up year to year and in most states.
In the models reported, insufficient sleep showed a stronger association with life expectancy than several other behavioural and social factors they examined, while smoking showed the strongest relationship overall.
- Physical activity levels higher among people who go to sleep early
- Type 2 diabetes risk lowered by leisure-time physical activity
There are important caveats.
This is not an experiment and it is not person level data, so it cannot prove that sleeping less causes a shorter life.
It could partly reflect other differences between counties, such as deprivation, healthcare access, shift work patterns or underlying illness.
Still, the consistency across time and geography is the point the authors want people to notice.
If you want a simple target, many adult sleep recommendations cluster around seven to nine hours for most people, with individual variation.
If you regularly struggle to hit that, the most useful next step is often not willpower but problem solving, for example checking caffeine timing, alcohol, stress load, screen habits or possible sleep disorders such as sleep apnoea.
