Study: Heart attacks are less common in greener neighborhoods

Aug. 30 (UPI) -- Living in a neighborhood with trees and plenty of green space has a positive effect on heart health, according to a new study.

The research, which showed heart disease and stroke were less common in neighborhoods with higher levels of vegetation, was presented this month at the 2021 meeting of the European Society of Cardiology.

"Higher levels of greenness were associated with lower rates of heart conditions and stroke over time, both when an area maintained high greenness and when greenness increased," lead study author Dr. William Aitken said in a press release.

"It was remarkable that these relationships appeared in just five years, a relatively short amount of time for a positive environmental impact," said Aitken, a cardiology fellow at the University of Miami's Miller School of Medicine.

For the study, scientists analyzed the health records of some 243,000 Medicare beneficiaries, aged 65 and older, living in Miami, Florida. Researchers only studied residents who remained in the same neighborhood between 2011 and 2016.

Satellite images allowed researchers to quantify the levels of vegetation in different neighborhoods across the city. Because chlorophyll from plants absorbs visible light and reflects near-infrared light, researchers were able to use spectral data to gauge the greenness of different city blocks.

Scientists classified blocks has having low, medium or high levels of greenness, and analyzed the rates of new cardiovascular disease on different blocks. Residents of the greenest blocks were 16% less likely to develop heart disease than those living on the least green blocks.

Dozens of studies have shown the human health benefits of greenery.

People living amongst more trees and closer to green spaces enjoy a variety of health benefits, including lower rates of anxiety and depression.

Unfortunately, those benefits aren't equally shared, with wealthier, whiter neighborhoods more likely to feature high levels of vegetation, previous research has shown.

Thankfully, cities can work to increase access to green space and vegetation. The latest study is one of the first to document the benefits of greening programs.

Because Miami-Dade County Parks carried out tree planting projects between 2011 and 2016, some residents began the study living on a block with low levels of vegetation, but were residing on a block with high levels of vegetation by the end of the study.

Researchers found these residents were 15% less likely to develop cardiovascular problems than resident who remained on the least green blocks for the entirety of the study.

"We suspect that multiple factors may account for these observations," Aitken said.

Among these factors is that people living in greener areas are more likely to participate in outdoor exercise, in addition to feeling overall less stressed because they are regularly surrounded by more nature.

On top of this, Aitken said vegetation may provide some level of protection from both air and noise pollution, though further research is needed on these effects.

"Tree planting and greening of neighborhoods is associated with multiple benefits and offers a relatively low-cost investment to enhance health and well-being in many circumstances," Aitken said.

"For the cost of one emergency room visit for a heart attack, trees could be planted in a neighborhood with 100 residents and potentially prevent ten heart diseases in this group," he said