Both too little and too much sleep can increase the risk of death, says a UK study presented Monday to the British Sleep Society.
University of Warwick researchers studied 10 308 people between 1985 and 1988, and between 1992 and 1993, and found that seven hours of sleep a night was optimal for the average adult, CBC News reported.
People who slept five hours a night had a 1.7-fold increased risk of death from all causes and a two-fold increased risk of cardiovascular-related death. But the study also found that those who slept eight hours a night were more than twice as likely to die as people who slept for seven hours.
Researcher Francesco Cappuccio noted that a lack of sleep has been shown to be a risk factor for weight gain, hypertension and type 2 diabetes, CBC News reported.
"But in contrast to the short sleep-mortality association, it appears that no potential mechanisms by which long sleep could be associated with increased mortality have yet been investigated. Some candidate causes for this include depression, low socio-economic status and cancer-related fatigue," Cappuccio said. – (HealthDayNews)