Sufficient sleep helps longevity

A new study in the journal Sleep Medicine suggests that adequate sleep time may help women live longer. 

The new study found women who slept as much as 5 to 6.5 hours per night were less likely to die during a 14-year follow -up than those who slept less than 5 hours or more than 6.5 hours per night.  

Daniel F. Kripke, MD, professor emeritus of psychiatry at University of California San Diego School of Medicine examined data from 459 women aged 50 to 81 living in San Diego who participated in the Women's Health Initiative between 1995 and 1999. 

Fourteen years after entering the study, eight-six of 444 who were able to be located and evaluated died.  

Kripke used a device to record sleep durations and found women did not need a long sleep duration to live longer.  Early studies showed sleeping 6.5 to 7.5 hours per night was linked with best survival. 

"The surprise was that when sleep was measured objectively, the best survival was observed among women who slept 5 to 6.5 hours," Kripke said. "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." 

It should be noted that this association isn't necessarily causal, meaning that if you try to sleep 5 to 6.5 hours per night, you may not necessarily live longer. 

Chances are good, a health observer suggested, that those who slept each night for a shorter period might be healthier than those who slept for a longer time in the first place. 

Shorter sleep periods can create a range of health problems and affect a person's productivity. On the other hand, ill people often need longer sleep duration than healthy people. 

The time period during which a person sleeps is also important.  It has been found that women who work on the second shift are at higher risk of breast cancer. 

Want to live longer?  Have sufficient sleep and don't work on the second shift, the health observer suggests.

Jimmy Downs and editing by Stockton