Poor sleep is robustly correlated with accelerated aging but the evidence for causation is mixed.

Sleep gets worse with age and is correlated with risk for disease and mortality. The possibility that poor sleep causes aging to accelerate has prompted interest in improving sleep to slow aging and prevent disease. However, the existing evidence on the link between poor sleep and accelerated aging is unclear. Here, we tested for correlation and causation between poor sleep and accelerated aging using five independent datasets of adults (total N > 64,000). We found strong evidence for a correlation between poor sleep and fast aging that is consistent across young, middle, and late adulthood and across aging biomarkers derived from different tissues and modalities. We found that this correlation is robust to the influence of chronic disease burden, but not to the influence of shared genetic and early environmental factors among twins. Finally, we found mixed evidence for a causal influence of poor sleep on accelerated aging using Mendelian randomization. Our findings indicate that the correlation between poor sleep and accelerated aging is highly robust; however, the claim that poor sleep causes aging to accelerate is not consistently supported.