Adults who sleep between roughly 6.4 and 7.8 hours a night show the slowest signs of biological aging, according to a new study from researchers at Columbia University Irving Medical Center, published in Nature. The findings, drawn from about 500,000 UK Biobank participants, applied 23 biological “aging clocks” covering 17 organ systems, built from imaging data, organ-specific proteins, and blood markers.
Sleeping less than 6 hours or more than 8 hours a night was linked to faster aging across nearly all organs measured, following a U-shaped pattern with the healthiest range in the middle. Short sleep tracked most closely with depression, anxiety, obesity, type 2 diabetes, hypertension, and heart disease, while both short and long sleep were linked to conditions such as COPD, asthma, and acid reflux.
“Sleep is important in maintaining organ health within a coordinated brain-body network, including metabolic balance and a healthy immune system,” said study leader Junhao Wen, according to ScienceDaily. The researchers noted that unusual sleep duration likely reflects broader physiological dysfunction rather than directly causing it.