The team used data from the CDC's Behavioral Risk Factor Surveillance System, which surveyed 255,171 representative U.S. adults, to learn whether there was an association between self-reported days of insufficient sleep and access to green space.

The team also used a USDA index that scores the country's geographical areas for their natural amenities, using hours of sunlight, which is important in regulating a person's circadian rhythm, and temperature.

In response to the survey question about sleep quality in the last month, the researchers found that the most common answer was that respondents had slept poorly for less than one week.

For men, the relationship between sleep and exposure to green space was much stronger than for women. And males and females 65 and over found nature to be a potent sleep aid.

Men appeared to benefit much more from their natural surroundings. The researcher speculated that women may take less advantage of nearby natural settings out of concern for their safety, but more research is needed.

The finding should be a boon for people who are having trouble sleeping as they age. "If there is a way for persons over 65 to spend time in nature, it would improve the quality of their sleep--and their quality of life--if they did so," Grigsby-Toussaint said.

The study points to the importance of conserving nature in general, she added.

"And, specifically, our results provide an incentive for nursing homes and communities with many retired residents to design buildings with more lighting, create nature trails and dedicated garden spaces, and provide safe outdoor areas that encourage outdoor activity for men and women," said Diana Grigsby-Toussaint.

Source:

sciencedaily.com; spring.org.uk;news.yahoo