Trees support mental health in older adults

ADULTS WHO live in neighbourhoods with 30 per cent or more covered in tree canopy have 31 per cent lower odds of developing psychological distress according to new research findings.

Funded by Hort Innovation under the Hort Frontiers strategic co-investment program, The Green Cities Fund investigates the benefits of increased urban greening in metropolitan cities with growing populations.

Led by researchers at the University of Wollongong, complementary research projects have already identified benefits to children’s overall health, post-partum weight control, improvements in the prevalence of children with asthma or respiratory issues and now the focus has turned to mental health.

According to the research findings, which are due to be published in The Journal of the American Medical Association Network Open this weekend, having at least 30 per cent of tree cover in neighbourhoods has also been linked to 33 per cent lower odds of developing fair to poor general health.

Hort Innovation Head of Research and Development Byron De Kock said this longitudinal research project involved tracking the health changes of around 46,000 adults aged 45 years or older and living in Sydney, Newcastle or Wollongong over a six-year period.

“The objective of this project was to identify whether total green space, or specific types of green space were more beneficial for mental health,” he said.

“Associated research found that tree canopy proved to be more biodiverse than low-lying vegetation. This is significant because increased biodiversity supports immune-regulatory benefits of microbial microorganisms that help shape our immune systems - but which have been largely eliminated from our urban environment.

“Focussing on the protection and restoration of urban tree canopy specifically, rather than any urban greening, may be a good option for supporting community mental health.”

Professor Thomas Astell-Burt said while other studies had indicated that green space in general was good for mental health, this new research suggested that the type of green space does matter.

“We found that the residents of neighbourhoods with a higher amount of tree canopy had better mental and general health,” he said.

“This suggests that increasing urban tree canopy could potentially deliver significant community health benefits.

“In summary, our findings suggest urban greening strategies with a remit for supporting community mental health might prioritise the protection and restoration of urban tree canopy, as well as support and promote greater equity in mental health.”