New research confirms the importance for health of living near green spaces. Dr. Jolanda Maas of the VU University Medical Centre in Amsterdam, The Netherlands, and colleagues explain that due to increasing urbanization, people face the prospect of living in environments with few green spaces.
Several studies have shown that a more natural living environment positively influences people’s self-perceived health and leads to lower health risks. “There is increasing evidence for a positive relation between green space in people’s living environment and self-reported indicators of physical and mental health,” the researchers report in the Journal of Epidemiology and Community Health.
Their new study looks at health as assessed by doctors. They analyzed medical records from 345,143 people, looking at different socioeconomic groups separately. These were based on education, work status and health care insurance type.
Living within a one-kilometre radius of a green space was significantly linked with reduced risk of 15 out of 24 disease clusters, that is, cardiovascular disease, musculoskeletal disorders, mental illness, respiratory disease, neurological disease, digestive disease, and miscellaneous complaints.
“The relation was strongest for anxiety disorder and depression,” say the researchers. It was also stronger for children and people in lower socioeconomic groups, although the researchers did not have information on individual income.
“The relation was strongest in slightly urban areas and not apparent in very strongly urban areas,” they add. “This study stresses the importance of green space close to home for children and lower socioeconomic groups.”
However, the causes are still unclear. Some links are more plausible than others, they state, so “further research will have to shed more light on the mechanisms behind the relation between green space and health, and to what extent green space indeed plays a causal role in the observed relationships.”
Overall, the team writes, “The strong relation we found, particularly for anxiety disorder and depression, suggests that mental health in particular might be affected by the amount of local green space.”
Previously, the team investigated whether exercise can explain the link between green space and health. They looked at rates of walking, cycling, sports and gardening, among 4,899 people with varying exposure to green space in the living environment.
But no relationship was found between the amount of green space and whether or not people met recommendations for physical activity. In fact, those with greater proximity to green spaces walked and cycled less often during their leisure time, probably because in greener living environments, facilities such as shops are farther away and people more often use a car to reach them.
However, it is possible that people living in such places do their exercise in a green environment as opposed to an urban environment, which could have health benefits in the form of reduced stress.
The team also investigated whether differences in social relationships are the underlying cause behind the link between green space and health. They gathered figures from 10,089 residents of the Netherlands, and calculated the amount of green nearby. “Less green space in people’s living environment coincided with feelings of loneliness and with perceived shortage of social support,” they found, supporting the theory.
There is also evidence that the presence of green spaces can act as a buffer between stressful life events and health. Looking at survey results from 4,529 Dutch people, the researchers found that the amount of green space in a three-kilometre radius influenced the relationship between stressful life events and perceived general health. Those with a higher amount of green space in a three-kilometre radius were less affected by experiencing a stressful life event than those with a low amount of green space.
The same pattern was seen for perceived mental health, supporting the notion that green space provides a buffer against the negative health impact of stressful life events.
But there is no reason to discard any of the other possible causes, they believe. For example, physical activity is known to have mental health benefits, and the risk of respiratory illnesses is lower in areas with more green space, possibly due to better air quality.
These studies stress the importance of green space close to people’s homes, with a particularly strong relationship for children and lower socioeconomic groups, the team concludes.
Maas, J. et al. Morbidity is related to a green living environment. The Journal of Epidemiology and Community Health, published online October 15, 2009.
Maas, J. et al. Physical activity as a possible mechanism behind the relationship between green space and health: A multilevel analysis. BMC Public Health, Vol. 8, June 10, 2008, p. 206.
Maas, J. et al. Social contacts as a possible mechanism behind the relation between green space and health. Health & Place, Vol. 15, June 2009, pp. 586-95.
van den Berg, A. E. Green space as a buffer between stressful life events and health. Social Science & Medicine, Vol. 70, April 2010, pp. 1203-10.