Research

Mixed

Long sleep duration (≥9 hours) is not a causal factor for mortality but is a consequence of underlying medical conditions and age-related changes, particularly in elderly adults.

If you are over 60 and notice you need more sleep (9+ hours), do not restrict it to 'fix' your health. This increased need is likely a marker of underlying health issues (like cardiovascular risk or inflammation) rather than the cause of death. Focus on medical check-ups for underlying conditions rather than forcing yourself to sleep less.

GoodRefutesHIGH confidence
Long sleep duration is unlikely to contribute toward mortality but, rather, is a consequence of medical conditions and age-related sleep changes.
James E. Gangwisch et al. · SLEEP · 2008

Why this rating

Large longitudinal sample (n=9789) with multivariate adjustments, though observational design limits causal inference.

Source

Sleep Duration Associated with Mortality in Elderly, but not Middle-Aged, Adults in a Large US Sample

James E. Gangwisch et al. · SLEEP · 2008

DOI 10.5665/sleep/31.8.1087

cohort · n=9789Cited 221×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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