Sleep quality and duration improve cognition in aging populations

http://www.eurekalert.org/pub_releases/2014-06/uoo-sqa061614.php

PUBLIC RELEASE DATE: 16-Jun-2014
Contact: Jim Barlow
University of Oregon
Sleep quality and duration improve cognition in aging populations

University of Oregon-led research finds women sleeping longer and struggling with quality

EUGENE, Ore. -- (June 16, 2014) -- Maybe turning to sleep gadgets -- wristbands, sound therapy and sleep-monitoring smartphone apps -- is a good idea. A new University of Oregon-led study of middle-aged or older people who get six to nine hours of sleep a night think better than those sleeping fewer or more hours.

The study, published in the June issue of the Journal of Clinical Sleep Medicine, reaffirms numerous small-scale studies in the United States, Western Europe and Japan, but it does so using data compiled across six middle-income nations and involving more than 30,000 subjects for a long-term project that began in 2007.

"We wanted to look at aging, particularly dementia and cognitive decline as people get older, and the importance of sleep. Our results provide compelling evidence that sleep matters a lot," said lead author Theresa E. Gildner, a doctoral student in the UO's anthropology department. "In all six countries, which are very different culturally, economically and environmentally -- despite all these differences -- you see similar patterns emerging."

Video Overview of Project and Study: http://youtu.be/5wx-aZLY5W4

The study, based on the first wave of data from a continuing long-term project, focuses on people 50 years old and older in China, Ghana, India, Mexico, the Russian Federation and South Africa. Among the key findings were:

Men reported higher sleep quality than women in all six nations, with men and women in Mexico reporting the highest.
Women reported longer sleep durations than men in all countries except Russia and Mexico. Men and women in South Africa slept longer than in any other country. The least sleep hours for both sexes occurred in India.
Individuals sleeping less than six hours and more than nine hours had significantly lower cognitive scores compared to those in the intermediate group.

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"From doing this research and being familiar with the literature," he added, "an emphasis on sleep issues by the media in recent years is warranted. Every single piece of evidence that people look at now as they are investigating sleep and different health associations is all showing that sleep really, really, really matters. We're just now scratching the surface on what patterns of sleep normally are, and also what are these associations between sleep and health issues."