Sleeping nine hours nightly linked to higher overall mortality risk

A Taiwanese cohort study tracking over 3,000 adults for 30 years reported that nightly sleep of nine hours or more correlates with a 17% increase in all-cause mortality compared with the optimal seven-to-eight-hour range. The lowest death rate, 10.57 per 1,000, was recorded for the seven-to-eight-hour sleepers, while those sleeping less than six hours faced a modest rise to 10.97 per 1,000, and long sleepers saw the highest rate at 11.27 per 1,000.

Researchers noted that extended sleep is linked to elevated blood pressure, greater inflammation, and possible disturbances in hormonal regulation, the internal clock, and immune response. The findings were published in the Journal of Sleep Research, where authors argued that measuring sleep duration during medical check-ups could help identify individuals at heightened health risk. Prior research has also connected excessive sleep with heart disease, type-2 diabetes, obesity, and cognitive decline. Health guidelines continue to recommend seven to nine hours of sleep for adults.