Columbia University study in Nature links 6.4–7.8 hours of sleep to the best biological aging markers
Data on about half a million people show the most favourable biological aging markers at 6.4–7.8 hours of sleep a day; the authors note the link is not proof of causation.
Researchers at Columbia University in the United States published a study in Nature in May 2026, as reported by zdrowie.interia.pl. They used data from the UK Biobank covering about half a million participants zdrowie.interia.pl
zdrowie.interia.plzdrowie.interia.plOpen source ↗. The team examined 23 biological aging clocks, which assess the condition of individual organs and tissues, across 17 body systems and structures, including the brain, heart, lungs and parts of the immune system.
Sleep duration and aging markers
The most favourable results were seen in people who reported 6.4 to 7.8 hours of sleep per day. The exact value differed by organ and by the sex of participants, so the data do not point to a single ideal number of hours for everyone. People who slept less than six hours and those who slept more than eight hours more often showed signs of accelerated biological aging.
The researchers described a U-shaped relationship: the least favourable results appeared at both ends of the scale and the best in the middle. The authors stress that this does not prove that sleep length directly accelerates or slows aging. The pattern may instead be a signal of the general condition of the body.
According to the report, chronic lack of sleep can disturb hormonal balance, intensify stress responses and hinder recovery. It also affects how the body regulates blood sugar and blood pressure. Longer sleep is a more complex matter: it is not necessarily harmful in itself, but it may accompany chronic diseases, mental disorders or poor quality of night rest.
Associations with disease
Sleep duration was linked not only to aging indicators but also to the occurrence of many diseases zdrowie.interia.pl
zdrowie.interia.plzdrowie.interia.plOpen source ↗. People who slept less than six hours more often had depression, anxiety disorders and obesity. Associations were also observed with type 2 diabetes, hypertension, ischaemic heart disease and heart rhythm disorders.
Both short and long sleep were tied to a higher risk of respiratory and digestive diseases, among them asthma, chronic obstructive pulmonary disease, gastritis and gastro-oesophageal reflux disease. The results suggest that sleep may be an indicator of the health of the whole body, though not the only factor determining disease development.
Biological age does not always match the age on a birth certificate: two people born on the same day can differ in condition because of genes, diet, physical activity and daily habits. The publication also notes that, besides length, the quality and regularity of night rest matter.
