Is 100 year olds' secret to longevity sleep?

Is the trick to living out a healthy and productive twilight getting a good night’s sleep? Those who’ve already celebrated their 100th birthday sleep longer and better than the rest of the elderly.

The study, published in the May 1st issue of SLEEP used survey data to look at the sleeping habits of the oldest populations in China.

They discovered Chinese ages 100 or above slept an average of 7.5 hours a day, including naps. Controlling for factors like wealth and health conditions, the extremely elderly were 70 percent more likely to report sleeping well than 65-year-olds to 79-year-olds.

Men were significantly more likely to report sleeping well than women. Those with health problems were nearly half as likely to report quality sleep.

The study found access to health care and economic status were strongly related to good sleep.

The authors of the study picked China because it has the world’s largest elderly population, with nearly 40.5 million people over age 75. The Chinese Longitudinal Healthy Longevity Survey, completed in 2005, is used by global researchers to study the lifestyle habits of the elderly. The survey was conducted using in-home interviews.

While the study sheds light on the sleeping habits of oldest people in the world, it does not explain why they lived to be so old. The authors say they suspect it may be due in part to sleeping well, but because the research was based on a survey, it’s impossible to prove at the moment.