A comprehensive meta-analysis of 85 longitudinal studies involving more than 2 million participants has established sleep quality as the single strongest modifiable predictor of healthy aging and longevity, surpassing even exercise and diet.
Published in The Lancet Healthy Longevity, the analysis found that individuals who consistently achieved high-quality sleep — defined as 7 to 8 hours of uninterrupted rest with adequate deep sleep phases — had a 42% lower risk of all-cause mortality and aged biologically 4 to 7 years slower than poor sleepers.
"The magnitude of sleep's impact on aging caught even us by surprise," said Professor Sarah Chen of Stanford University's Sleep Medicine Center. "Poor sleep accelerates virtually every hallmark of aging, from telomere shortening to chronic inflammation."
The study identified several key mechanisms linking sleep to aging: during deep sleep, the brain's glymphatic system clears toxic proteins including beta-amyloid, growth hormone peaks drive tissue repair, and the immune system undergoes critical maintenance processes.
Practical recommendations from the research include maintaining consistent sleep and wake times, limiting screen exposure before bed, keeping bedrooms cool and dark, and seeking treatment for sleep disorders such as apnea, which affects an estimated 30% of adults over 65.