Is NZ’s vanishing nature worsening kids’ asthma rates?


Scientists are investigating whether the loss of green spaces is linked to asthma among Kiwi kids, in a new study that could have global implications.

A team of researchers from Massey and Otago universities are taking a deeper look at the connection, following earlier work that followed tens of thousands of children.

New Zealand has amongst the highest rates of asthma and allergy in the world, with Māori and Pasifika disproportionately affected.

Because scientists don’t yet have a clear understanding of what triggers asthma development, there’s still no cure in sight for sufferers.

Studying a group of 50,000 children, the research team previously discovered that children exposed to more green space were less likely to develop asthma – and that effect was even stronger in places with plenty of native trees and plants about.

“We followed these children for 18 years and looked at where they are living at different stages of their lives, and then we used satellite data to look at how green the neighbourhoods were that they grew up in – and how diverse those green spaces were,” Massey’s Professor Jeroen Douwes said.

“We found an inverse relationship with green spaces and asthma – children who grew up in areas that were greener had a lesser likelihood of developing it.

“When we started digging a little bit deeper, we found having a more diverse green space was more protective.

“So, just having an area near your house that’s green – it could be grass or trees – may give you some protection. But the biggest factor we found was being exposed to multiple sources of green space.”

Douwes said the overall reduction in asthma risk that came with this likely buffer was 15 per cent.

“To put that into perspective, globally, there’s about 300 million people who suffer from asthma. If you reduce that by 15 per cent, we’re talking quite a substantial proportion.”

The explanation could potentially be found in kids’ gut microbiota, given the growing evidence that the mix of microorganisms living within us play critical roles in maintaining our health.

Their next project will investigate whether changes in gut microorganisms over time are associated with loss of biodiversity, or less access to green spaces.

They’ll also compare samples from asthmatic and non-asthmatic kids here, and also in Ecuador, Brazil and Uganda, to see whether there are differences in human microbiota.

“The exciting bit for me is, if we can replicate those earlier findings, and we do find out what actually confers protection, then we can start applying it to the general population,” he said.

“There are various options here – and one is working with city councils to start making more high-quality green spaces that are more available to people, which would have a number of other benefits as well.”

The three-year, $3m study is among 134 new research projects awarded more than $84m under this year’s Marsden Fund, administered by Royal Society Te Apārangi.

“New Zealanders are world leaders in many research areas and the Marsden Fund plays a critical role in ensuring that we continue to have expertise available in these fields,” Marsden Fund Council chair Professor David Bilkey said.

“Furthermore, Marsden Fund support enhances connectivity between researchers, both nationally and internationally whilst also facilitating the engagement between researchers and their communities.”, 10 November 2020