Children living in green neighbourhoods are less likely to develop asthma

May 8, 2018 by Jeroen Douwes And Geoffrey H. Donovan, The Conversation
Several studies have shown that spending time in nature is good for health. Now new research has looked specifically at asthma and found that living in green neighbourhoods protects children from developing the condition. Credit: www.shutterstock.com, CC BY-SA

Since the pioneering work of architecture professor Roger Ulrich, who found that patients with a view of a natural scene recovered more quickly from surgery, research has shown that exposure to the natural environment is associated with a wide range of health benefits.

We have focused our work on asthma, and our research, published today, shows that who live in greener neighbourhoods are less likely to develop it.

Not all greenness was equally effective, however. If a child was exposed to a broader range of plants, they were even less likely to get asthma. Exposure to landscapes with low plant diversity, such as gorse and exotic conifers, on the other hand, were a risk factor for asthma. Thus, greenness is good, but more biodiverse greenness is even better.

How nature protects against asthma

One intriguing explanation is provided by the hygiene hypothesis, which proposes that for children's immune systems to develop properly, they need to be exposed to a broad range of microbes in early life. Without this exposure, children may be more susceptible to immunological diseases, like allergies and asthma.

The explains why children living on farms, where they are exposed to a wide range of animals, are less likely to develop asthma. However, it's not only farm children who benefit from exposure to animals. Having a pet in the house can also help protect against asthma. Similarly, children with more siblings are less likely to be asthmatic.

Living around a more diverse range of plants may also increase a child's exposure to microbes. In fact, past studies have shown that people who live in more biodiverse areas have more diverse skin bacteria. Exposure to the natural environment may, therefore, improve our health by increasing the diversity of microbes living on our skin and in our gut.

This, in turn, may promote a healthy immune response and reduce the risk of allergies and asthma. Reduced stress and increased physical activity, associated with living close to green space, may be another reason for the observed protective effects.

Tracking children's environment

This study used the Integrated Data Infrastructure (IDI), which is a large database of individual-level data maintained by Stats New Zealand. Currently, it contains 166 billion pieces of information on education, benefits, tax, families and households, health, justice and migration.

Using these data, we were able to track where children lived from birth until age 18, calculate the greenness of their neighbourhoods using satellite imagery and land-use data, and link to health records throughout each child's life. This was all done anonymously, in a secure data lab, to safeguard the children's privacy.

This study is an unusual collaboration between economists at the US Forest Service and epidemiologists in New Zealand. It contributes to our understanding of why asthma is on the rise.

Our results may lead to some innovative strategies to combat asthma, although there is a need to elucidate the underlying immunological mechanisms.

Improved prevention and treatment options for asthma are urgently needed as the burden of asthma is considerable, with 334 million people affected worldwide. Asthma prevalence in English-speaking countries such as New Zealand, Australia, the US and the UK is particularly high, with approximately one in six people suffering from it.

Good for people, good for the planet

Showing a link between biodiversity and human health may also change how we manage natural resources, especially in cities. Unfortunately, biodiversity is declining around the world due to population growth, climate change and intensive agricultural practices. Our work suggests that this is not just an ecological problem, but may also present a significant threat to public .

Other studies have suggested that the exposure to the natural environment also protects against low birth weight, heart disease, and breast cancer, although results have not always been consistent. Therefore, as the diversity of our natural environment and resultant microbial declines, we may see further increases in diseases, such as childhood allergies and .

Explore further: Low neighborhood walkability increases risk of asthma in kids

Related Stories

Low neighborhood walkability increases risk of asthma in kids

May 5, 2018
(HealthDay)—Children living in neighborhoods with low walkability are at increased risk of asthma, according to a study published online April 17 in the Annals of the American Thoracic Society.

Gas stoves and damp houses increase Aussie asthma rates

April 16, 2018
University of Queensland researchers have found that childhood asthma in Australia is associated with gas stoves and damp houses.

Sleeping on animal fur in infancy found to reduce risk of asthma

September 8, 2014
Sleeping on animal fur in the first three months of life might reduce the risk of asthma in later childhood a new study has found.

Breastfeeding does not protect children against asthma and allergies: study

November 13, 2017
The effect of breastfeeding on the risk of developing asthma and allergy has been debated for a long time. In a recent study, Uppsala University researchers show that breastfeeding might in fact increase the risk of developing ...

Breastfeeding may help prevent children's asthma exacerbations later in life

September 1, 2017
In a Pediatric Allergy and Immunology analysis of children with asthma, those who had been breastfed had a 45 percent lower risk of asthma exacerbations later in life compared with children who had not been breastfed.

Exposure to pet and pest allergens during infancy linked to reduced asthma risk

September 19, 2017
Children exposed to high indoor levels of pet or pest allergens during infancy have a lower risk of developing asthma by 7 years of age, new research supported by the National Institutes of Health reveals. The findings, published ...

Recommended for you

Researchers uncover immune cell dysfunction linked to photosensitivity

August 16, 2018
Researchers at Hospital for Special Surgery (HSS) have discovered that a type of immune cell known as Langerhans appears to play an important role in photosensitivity, an immune system reaction to sunlight that can trigger ...

Chemicals found in vegetables prevent colon cancer in mice

August 14, 2018
Chemicals produced by vegetables such as kale, cabbage and broccoli could help to maintain a healthy gut and prevent colon cancer, a new study from the Francis Crick Institute shows.

Researchers artificially generate immune cells integral to creating cancer vaccines

August 14, 2018
For the first time, Mount Sinai researchers have identified a way to make large numbers of immune cells that can help prevent cancer reoccurrence, according to a study published in August in Cell Reports.

Doctors may be able to enlist a mysterious enzyme to stop internal bleeding

August 14, 2018
Blood platelets are like the sand bags of the body. Got a cut? Platelets pile in to clog the hole and stop the bleeding.

Team finds missing immune cells that could fight lethal brain tumors

August 13, 2018
Glioblastoma brain tumors can have an unusual effect on the body's immune system, often causing a dramatic drop in the number of circulating T-cells that help drive the body's defenses.

Cannabis link to relieving intestinal inflammation explained

August 13, 2018
Reports from cannabis users that the drug reduces the symptoms of inflammatory bowel disease (IBD) may finally be explained by new research from the University of Massachusetts Medical School and the University of Bath showing ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.