A new study from Columbia University suggests that sleeping either too little or too much may accelerate biological aging.
Researchers analyzed self-reported sleep data from roughly 500,000 people, comparing it with 23 biological aging clocks. They found that both short and long sleep were linked to signs of older biology, including higher risks of future disease and death.
In nine of the aging clocks, significant links between sleep and aging appeared in the brain, heart, immune system, and skin. The lowest biological age gap was found in women who slept 6.5 to 7.8 hours and men who slept 6.4 to 7.7 hours.
Longer sleep was more strongly associated with psychiatric outcomes, while shorter sleep had greater physical impacts on cardiovascular, metabolic, and other systems. Short sleep led to a 50% higher relative risk for all-cause mortality; long sleep, about 40%.
Dr. Saema Tahir, a New York sleep medicine physician, says sleep is when the body performs critical repair, including cellular restoration and clearing metabolic waste from the brain. Disrupted sleep accumulates damage at the cellular level, increasing inflammatory markers linked to accelerated aging.
Tahir cautions that the six- to eight-hour range is not a rigid prescription, as sleep needs vary by age, health, and lifestyle. She emphasizes that quality matters as much as quantity: patients who log seven hours of light sleep may age worse than those getting six hours of deep, consolidated rest.
The study concludes that consistent, good-quality sleep is one of the most accessible tools for healthy aging.