Sleeping too little and sleeping too much both line up with faster biological aging across the body, according to a new analysis of organ-level aging led by researchers at Columbia University. The pattern showed up not only in the brain but also in the heart, lungs, immune system and other organs, and the same sleep patterns were linked to a wide range of diseases.
The work builds on earlier research tying sleep to brain aging and disease burden in the brain. "Our study goes further and shows that too little and too much sleep are associated with faster aging in nearly every organ," said study leader Junhao Wen, assistant professor of radiology at Columbia University Vagelos College of Physicians and Surgeons, who framed the results as evidence that sleep helps maintain organ health across a coordinated brain-body network, including metabolic balance and immune function.
The analysis rests on so-called aging clocks, tools that use machine learning and biological data - proteins measured in a blood sample, for instance - to estimate whether someone is aging faster or slower than their years would suggest. Most such clocks produce a single number for the whole body, but organs do not age in lockstep. The decline in ovarian function behind the fertility clock is one everyday example of an organ running on its own timetable, and this study takes that organ-by-organ view.
For anyone thinking about dementia risk, the appeal of this approach is that it treats sleep as a whole-body signal rather than a purely neurological one, which may help explain why sleep disturbance so often travels with cardiovascular, metabolic and immune problems that themselves affect the brain. The findings describe associations rather than proven cause and effect, so the open question is whether changes in sleep drive faster organ aging, reflect it, or both.