[PLACEHOLDER TOPIC — swap for a real pick] Both too little and too much sleep are linked to higher mortality risk
Published May 1, 2010
Methods
Researchers pooled data from 16 prospective studies that had tracked self-reported sleep duration and mortality in more than 1.3 million adults, with follow-up periods ranging from 4 to 25 years across the individual studies.
Findings
Both short sleep and long sleep were associated with a higher risk of death from any cause compared with sleeping around 7 hours a night — producing a U-shaped curve. The association was somewhat stronger for long sleep than for short sleep.
Caveats & Context
This is observational, pooled data — it shows an association, not proof that short or long sleep directly causes earlier death. People who are already ill often sleep more, which can inflate the long-sleep association (reverse causation). Sleep duration was self-reported, not measured, and different studies used different cutoffs for what counted as short or long sleep.
Sleep Duration and All-Cause Mortality: A Systematic Review and Meta-Analysis of Prospective Studies
Sleep · doi.org/10.1093/sleep/33.5.585