Green spaces give you more than just a place to stretch your legs — they can also affect your risk of having a stroke, according to a new study that links proximity to green spaces with a 16% reduction in stroke risk.
For research purposes, nearby green spaces were counted as those within 300 meters or one-fifth of a mile from the house. Data from the public health system covering more than 3.5 million adults in the Catalonia region of Spain was collected in 2016 and 2017.
Although the data does not show that green spaces are the direct cause of reduced stroke risk, the researchers note that the association is strong enough to warrant further investigation — and to support the idea that having more nature around is beneficial for our health.
“The study demonstrates the importance of environmental determinants in stroke risk,” says neurologist Carla Avellaneda, from IMIM-Hospital del Mar in Barcelona, Spain.
“Given that the incidence, mortality and disability attributed to the disease are expected to increase in the coming years, it is important to understand all of the risk factors involved.”
Greenery and natural spaces can improve health in several ways: they can reduce stress, they can provide places for people to exercise, and they can protect mental health. There also appears to be an effect on the likelihood of cerebrovascular problems.
There are many more factors to consider than nearby greenery of course. The team also looked at three air pollutants in the same study: nitrogen dioxide (NO2), particles smaller than 2.5 microns (PM2.5) and soot particles.
As found in previous studies, greater exposure to these pollutants was linked to a greater risk of stroke. Previous studies have also shown that greater exposure to these pollutants is linked to a slightly higher risk of stroke. In this recent analysis, for example, for every 10 microgram increase in NO2 per cubic meter, the risk increases by 4%.
“You have to keep in mind that, unlike other air pollutants, which have various sources, NO2 is mainly caused by road traffic,” says environmental epidemiologist Cathryn Tonne, researcher at ISGlobal.
“Therefore, if we are serious about reducing the multiple risks this pollutant poses to people’s health, we need to put in place bold measures to reduce car use.”
These links – between green space and stroke risk, and air pollutants and stroke risk – have been reported before, but few previous studies have looked at such a large sample and entered into so many details by examining both nearby greenery and air quality.
Further research could examine exactly why more green space in an area appears to help reduce the risk of stroke for the people who live there. The researchers are also calling for a review of regulations on permitted levels of pollutants in cities.
Associations between stroke risk, green spaces and pollutants remained even when controlling for socioeconomic factors, age and smoking habits — suggesting that we pay a price in terms of health when we choose to live in urban areas.
“We must strive to create more sustainable cities where living does not mean an increased risk of disease,” says neurologist Jaume Roquer, also from IMIM-Hospital del Mar.