The Green Heart Project is planting thousands of trees throughout Louisville, Kentucky to learn if trees can prevent heart disease in humans. The project began in 2018.
Aruna Bhatnager, director of the Christina Lee Brown Envirome Institute at the University of Louisville, is overseeing the effort with lots of help from interested people as well as $14.5 million in donations. Major donations have come from The National Institutes of Health and the Nature Conservancy.
Through the project, about 10,000 trees were planted in many neighborhoods in Louisville during the last three years. According to a 2015 report about the city's trees, approximately 150 trees a day die in Louisville, or 54,000 trees a year. They die from bigger storms, diseases, attacks from invasive beetles, and other factors.
The city has other challenges too, including homicide, suicide, cancer, drug addiction and angry reactions to the death of Louisville resident Breonna Taylor in 2020. Heart disease has become a serious problem in the city, which has some of the highest rates of cardiovascular disease in the United States, according to an article about the project in the May 2021 Discover Magazine.
Pollution levels are high enough that the American Lung Association has consistently given Louisville a poor grade for pollution levels. Research over the past 15 years has shown a correlation between air pollution and the development of heart disease.
The Envirome Institute wants to conduct environmental research that will help to create healthier cities. A pilot project of the institute recently found that planted trees reduced pollution by 60 percent around a local school, according to the Discover article.
Bhatnager specializes in environmental cardiology. He became fascinated by information he discovered in literature that both cigarette smoke and pollution impair nitric oxide production in the body. The molecule nitric oxide plays an important role because it helps to regulate insulin in the body, and it relaxes the inner muscles of blood vessels so that blood circulation increases.
He and his staff began doing toxicology studies to find out how many different pollutants affect our cardiovascular system. Their studies showed that pollution causes many problems. Among those problems is vascular damage in humans. In a study of mice, that vascular damage suppressed stem cells, which are needed to repair damaged blood vessels.
He also learned that dozens of studies show a relationship between living near green spaces and better health outcomes, among them lower stress levels and lower rates of asthma and depression. Bhatnager is convinced the Green Heart Project can make a positive difference in many people's lives.