Getting either too little or too much sleep may be linked to faster biological aging across nearly every major organ system, according to new research. The study found that sleep patterns outside a mid-range window were also tied to a wide spectrum of physical and mental health problems.
The work, led by Junhao Wen of Columbia University Vagelos College of Physicians and Surgeons, appears in the journal Nature Communications. Wen and colleagues argue that sleep duration seems to be intertwined with the body’s overall physiology, from the brain and heart to the lungs and immune system.
How organ aging was measured
Scientists increasingly use so-called aging clocks to estimate whether a person’s body is aging faster or slower than expected for their chronological age. These tools rely on machine learning to analyze biological data, such as proteins and metabolites in the blood, and structural changes seen in medical imaging.
Many existing clocks generate a single biological age for the whole body, but individual organs can age at different speeds. Wen’s team has been developing clocks tailored to specific organs to provide more precise insight into health risks and potential early signs of disease.
For the new study, the researchers analyzed data from around 500,000 adults enrolled in the UK Biobank project. They built 23 distinct aging clocks covering 17 organ systems using multiple data layers, including imaging, organ-related proteins and various blood-based metabolic markers.
The sleep sweet spot for slower aging
Participants reported how long they typically slept each night, and the team compared these self-reports with organ-specific biological ages. A clear U-shaped pattern emerged: both short sleepers and long sleepers showed evidence of faster aging in many organs.
People sleeping fewer than 6 hours or more than 8 hours a night tended to have older biological ages than their peers. The lowest levels of organ aging were observed among those who reported sleeping between about 6.4 and 7.8 hours per day, suggesting a moderate “sweet spot” for sleep duration.
The researchers stress that the findings do not prove that sleep duration directly causes organs to age faster or slower. Instead, unusual sleep patterns may signal underlying health problems or lifestyle factors that accelerate aging in multiple systems.
Links to disease throughout the body
The analysis connected short sleep in particular with a broad range of mental and physical conditions. People sleeping less than 6 hours a night were more likely to report depressive episodes and anxiety disorders, in line with previous evidence that chronic sleep loss harms mental health.
Short sleep was also associated with obesity, type 2 diabetes, high blood pressure, ischemic heart disease and heart rhythm disorders. These links support longstanding research showing that insufficient sleep disrupts metabolic regulation and cardiovascular function.
Both short and long sleep durations were related to chronic obstructive pulmonary disease and asthma, suggesting a respiratory component. The study also found associations with digestive issues such as gastritis and gastroesophageal reflux disease, underlining how sleep problems can ripple through multiple organ systems.
What the study reveals about depression
To probe how sleep and organ aging might connect to specific illnesses, the researchers looked closely at late-life depression. They could not determine whether abnormal sleep duration triggers depression or whether depression changes sleep patterns, since the data were observational.
Instead, they used mediation analysis to test whether biological aging might partly explain the link between sleep and depression in older adults. The results suggested that short sleep may have a more direct relationship with the burden of late-life depression.
Long sleep, by contrast, appeared to influence depression risk through biological pathways reflected in aging clocks for the brain and adipose (fat) tissue. Wen says these differences imply that long and short sleepers may need tailored approaches for managing sleep and treating depression.
Implications for health and lifestyle
The findings add weight to public health advice that adults should aim for roughly 7 hours of sleep per night. While individual needs vary, the organ-based aging clocks indicate that straying too far below or above this range may be a warning sign rather than a harmless habit.
Researchers say the next step is to study whether improving sleep duration can meaningfully slow biological aging in specific organs or reduce disease risk. Long-term intervention trials and more diverse study populations will be crucial for turning these early insights into practical clinical guidance.
For now, experts recommend focusing on consistent bedtimes, limiting late-night screen use and seeking medical advice for persistent insomnia or excessive sleepiness. According to Wen, connecting modifiable lifestyle factors such as sleep to organ aging could eventually help doctors personalize prevention strategies long before serious illness develops.
