Research conducted at the University of California, San Diego suggests that getting the right amount of sleep may be key to a long life.
Investigators followed 444 women between the ages of 50 and 81 years. After 14 years, researchers followed up with the subjects. At that point 86 of the study participants had died.
The study’s lead author, Daniel F. Kripke, MD, points out that previous studies, based upon questionnaires of people’s sleep habits, found that sleeping 6.5 to 7.5 hours per night was associated with best survival. However, the study conducted by Dr. Kripke and his colleagues used wrist-worn sleep monitors to measure sleep time.
“The surprise was that when sleep was measured objectively, the best survival was observed among women who slept 5 to 6.5 hours,” says Dr. Kripke. “Women who slept less than five hours a night or more than 6.5 hours were less likely to be alive at the 14-year follow-up.”
“This means that women who sleep as little as five to six-and-a-half hours have nothing to worry about since that amount of sleep is evidently consistent with excellent survival.”
Sleep Medicine – September 25, 2010;Epub.