Are very short and very long sleep linked to faster biological aging?

News summary

ScienceDaily reported that both short and long sleep are associated with greater biological aging across the body. The Nature paper used data from UK Biobank, a large UK research resource, together with 23 aging clocks derived from imaging, proteomics, and metabolomics—large-scale measurements of proteins and small metabolic molecules. It found a U-shaped pattern: the lowest biological-age gaps generally appeared around 6.4 to 7.8 hours of sleep, although the optimum varied by organ and sex.

Sleep shorter than 6 hours and longer than 8 hours, compared with 6–8 hours, was associated with higher risks of several systemic diseases and all-cause mortality. The relationship between sleep and biological aging also varied across body systems.

The study supports the importance of adequate sleep, but 6.4–7.8 hours should not be treated as an exact prescription for everyone. Sleep needs vary by age, health, and individual factors, and the analysis focuses on associations.

Sleep duration was largely self-reported, and the observational design cannot by itself prove that short or long sleep directly accelerates aging. Genetic analyses also could not eliminate every causal pathway or reverse-causality possibility. An author correction was published in July 2026; this summary uses the updated paper.