LOUISVILLE, Kentucky – A new study conducted in Louisville shows that more trees in residential neighborhoods reduce inflammation in the human body.
The University of Louisville’s Green Heart Louisville project planted trees in the south of the city to study their impact on residents. The data is in, and according to the university, trees are not only good for the environment, but also for people.
“This study shows us that trees actually mean healthier people and healthier cities,” said Kim Schatzel, president of the University of Louisville. “Trees are actually medicine.”
The University of Louisville’s Green Heart Louisville Project collected blood, urine, hair and nails from 745 people before and after planting more than 8,000 trees in south Louisville.
“We found that before and after planting the trees, there was a reduction in this protein, called C-reactive protein,” said Aruni Bhatnagar, director of the Christina Lee Brown Envirome Institute and professor of medicine at UofL. “It’s a very valuable marker that reflects the level of inflammation in the blood and the body.”
The researchers said the reduction in this marker they observed corresponds to a 10 to 15 percent reduction in the risk of heart attack, cancer or death from any other disease.
“We have over 1,800 to 2,000 heart attacks in Louisville every year, and if you can reduce that number by 10%, that’s 200 (fewer) heart attacks,” Bhatnagar said. “If you assume that each heart attack costs more than $50,000, you can calculate what the economic impact that could be.”
Earlier this month, the project received $4.6 million from the National Institute of Environmental Health Services to continue the research. Researchers said they now plan to study the urban heat island effect, which occurs when cities experience higher temperatures than nearby rural areas.
“Louisville has the worst urban heat island effect in the country … we think planting a dense forest right in the middle of downtown could perhaps make a difference,” Bhatnagar said.
The University of Louisiana said the more we learn about the effects of tree cover, the more important expanding tree cover may become to improving public health.
According to Green Heart Louisville, only 37% of Louisville is covered in trees, and that number is decreasing by 54,000 trees each year.
