Adherence
Extreme sleep durations (≤4 hours or ≥10 hours per night) are associated with significantly faster rates of global cognitive decline in older adults compared to a reference duration of 7 hours per night.
If you are over 45, aim for approximately 7 hours of sleep per night. Both sleeping 4 hours or less and 10 hours or more are associated with faster cognitive decline. If you consistently sleep outside this range, consider monitoring your cognitive health and consulting a healthcare provider to rule out underlying issues like sleep apnea (for long sleepers) or insomnia (for short sleepers).
During 100 000 person-years of follow-up, global cognitive z scores in individuals with 4 hours or less (pooled β = −0.022; 95% CI, −0.035 to −0.009 SD per year; P = .001) and 10 hours or more (pooled β = −0.033; 95% CI, −0.054 to −0.011 SD per year; P = .003) of sleep per night declined faster than in the reference group (7 hours per night) after adjusting for a number of covariates.
Why this rating
Large pooled cohort study (N=20,065) with longitudinal data, but limited by self-reported sleep data and observational design preventing causal inference.
Source
Association Between Sleep Duration and Cognitive Decline
Yanjun Ma et al. · JAMA Network Open · 2020
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