With a new study that assessed how GP-classified illnesses related to green spaces in their patients’ living environment, researchers in the Netherlands have found more evidence that links green spaces to better health, and better mental health in particular.

The study was the work of first author Dr Jolanda Maas from the EMGO Institute at VU University Medical Centre in Amsterdam and colleagues, and was published as an Online First paper on 15 October in the journal Journal of Epidemiology and Community Health.

The researchers wrote in their background information that there is mounting evidence that living near green spaces is linked to better health as assessed from self-reported measures of physical and mental health, and they wanted to see whether this pattern was the same if they used health indicators from general practitioner (GP) assessments instead.

For the study Maas and colleagues examined data on illnesses recorded by 195 GPs in practices throughout the Netherlands. The practices served a total population of over 345,000 people, but the researchers only included people registered with a GP for 12 months or more, since someone recently moved to the area could still be influenced by exposure to a different environment.

The illnesses recorded by the GPs were classified using the International Classification of Primary Care (ICPC), allowing the researchers to examine 24 different diseases in 7 different categories. The researchers also used a database where by inserting postal codes they could find out the percentage of green space within a one and three kilometer radius of a household.

They then used a statistical tool called multilevel logistic regression to find which clusters of diseases most strongly linked to how much green space was nearby.

When they did the analyses they first controlled for demographic and socio-economic characteristics to minimize any potential effect they may have had on the results, and then looked at what effect they did have.

The results showed that:

  • There was a positive link between lower disease prevalence and more green space.
  • The annual prevalence rate of 15 of the 24 disease clusters was lower in environments that had more green space in a 1 km radius.
  • The strongest link was for anxiety disorder and depression.
  • The link was stronger for children and for people with a lower socio-economic status.
  • The link was strongest in slightly urban areas and not apparent in very strongly urban areas.

The researchers concluded that their findings showed that the link established in other studies between self-reported indicators of health and green spaces can also be found in GP-assessed indicators for specific illness clusters.

“The study stresses the importance of green space close to home for children and lower socio-economic groups,” they added.

Last year, researchers in Scotland published a study in The Lancet that described how they examined data on hundreds of thousands of deaths in local areas to nearness of green spaces and concluded that living near green spaces can reduce the health gap between rich and poor and that local authorities should do more to create green spaces in local areas.

They said perhaps the presence of green spaces encouraged people to be more active, and this helped reduce strokes and heart attacks.

Other studies have also suggested that living near green spaces reduces blood pressure and stress.

“Morbidity is related to a green living environment.”
Jolanda Maas, Robert A Verheij, Sjerp de Vries, Peter Spreeuwenberg, Francois G Schellevis, Peter P Groenewegen.
J Epidemiol Community Health. Published Online First: 15 October 2009.

Written by: Catharine Paddock, PhD