Oct. 14, 2009 -- There is more evidence that living near parks, woods, or other green spaces may improve your mental and physical health.
Close proximity to green spaces was associated with less depression, anxiety, and other health problems in a newly published study. The relationship was strongest for children and people with low incomes.
The research is not the first to suggest that green spaces help keep people healthy, but it is the first to assess their impact on specific health conditions.
Investigators in the Netherlands examined patient health records from medical practices throughout the country. Using postal codes, they were also able to determine the percentage of green space existing within about 2 miles of each patient's home.
"The strongest associations we saw between green space and health occurred within a 1 kilometer [0.6 mile] radius of the home," study researcher Jolanda Maas, PhD, of Amsterdam's VU University tells WebMD.
Biggest Impact on Anxiety, Depression
The study included data on the prevalence of 24 different health conditions treated over the course of a year among about 350,000 patients seen at 96 practices.
For 15 of the 24 conditions, the annual prevalence was lower among patients living in the greenest areas, even after the researchers controlled for factors known to influence health.
Among the other major findings:
- The impact was greatest for mental health conditions. Compared to people living in areas with the least green spaces, those living in areas with the most were a third less likely to have anxiety disorders that required treatment and roughly one-fifth less likely to receive treatment for depression.
- Among the physical health conditions, the apparent protective benefits of living in greener areas appeared strongest for respiratory diseases such as asthma, COPD, and upper respiratory infections.
- A much weaker association was seen for other common health conditions, including cardiovascular disease, diabetes, and cancer.
Surprisingly, greater access to green spaces appeared to have no impact on health of people living in the most urban neighborhoods included in the study.
The researchers speculate that this might be because green spaces in poor, highly urban areas may not be used as much because they are perceived as unsafe.
Green Spaces Reduce Stress, Encourage Exercise
Earlier studies suggest green spaces in primarily urban areas improve health by lowering stress and encouraging exercise.
"There is a huge body of research showing that having access to green spaces is psychologically beneficial," says urban naturalist Mike Houck, who is executive director of the Urban Greenspace Institute in Portland, Ore.
When Houck began his career in 1980, urban planners often told him there was no place for nature within the city limits.
"They told me my job was to protect the natural areas outside the city and that everything within was essentially up for grabs," he tells WebMD. "It has taken 30 years, but attitudes have definitely changed."
So much so that two major health insurance providers in Portland, Ore. were active in persuading voters to pass a $227 million bond in 2006 dedicated to acquiring new green spaces.
"That was the first time they had ever endorsed a bond measure, but they understood its importance," he says. "It is inconceivable to me that a person out for a walk or a bicycle ride or a kayak trip does not benefit both physically and mentally."