June 16, 2014
Science Daily/University of Oregon
Maybe turning to sleep gadgets -- wristbands, sound therapy and sleep-monitoring smartphone apps -- is a good idea. A new 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. Researchers found consistent associations between intermediate sleep durations, high sleep quality and enhanced cognitive performance across diverse populations, which suggests that improving sleep patterns may help reduce the level of cognitive decline as seen in older adults.

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.

"This study is hugely powerful and so different from what's been done in the past, simply because of the consistency of how the data was collected -- multi-national, random samples of people," he said. "Sleep is something that is important but often undervalued in our society.

"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."
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2014/06/140616141545.htm