AFFECTIONS OF A GREEN HEART: THE HEALING POWER OF NATURE

We in the GCA are well aware of the benefits of nature. It is what connects all 18,000 of us, and for most of us, the knowledge is baked into our DNA. We know the benefits of walking in the woods and digging in the dirt. At the 2020 NAL conference in Washington, Dr. Aruni Bhatnagar was a featured speaker. His presentation was riveting and connected the dots of science most of us already knew—that nature has real and tangible benefits to holistic health. We are pleased and privileged that Dr. Bhatnagar accepted our invitation to write an article for The Real Dirt on a subject about which we are all passionate: the power of nature to heal.

espite impressive medical advances, heart disease continues to be the leading cause of death—not just in the United States, but in most other high- and medium-income countries as well. Although the rates of heart disease in Europe and United States have declined steadily from their all-time high in the 1960s, this trend has stalled and is beginning to reverse. The American Heart Association estimates that by 2030, nearly four out of every 10 people in the United States will be living with some form of heart disease. Clearly, current prevention approaches are not working, and new ideas are needed urgently to stem this rising tide of heart disease, fueled in part by rising rates of obesity and diabetes.

Traditionally, heart disease has been thought of as a self-inflicted condition, resulting from poor lifestyle choices such as unhealthy diets, lack of physical activity, and smoking. But recent research suggests that much of the burden of this disease is derived from wider social and environmental factors. For instance, those living in poor, polluted, and disadvantaged neighborhoods have a much higher risk of heart attacks and stroke than those who live in cleaner, and more affluent areas. So, improving the quality of residential areas, decreasing the levels of surrounding air pollution, or adding more green and walkable spaces in neighborhoods may be one way of

Dr. Aruni Bhatnagar. Photo courtesy of the Christina Lee Brown Envirome Institute, University of Louisville

“… many studies have

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Courtesy of Dr. Aruni Bhatnagar decreasing the risk of heart disease. Indeed, many studies have shown that people who live in greener neighborhoods have a lower risk of death. They also report lower levels of anxiety, depression, and stress, suggesting that we share a primordial bond with nature, and we feel happy and more relaxed in its presence.

These bonds run deep. For reasons we do not yet fully comprehend, our health and wellness are inextricably linked with our natural surroundings. In the early 2000s, when the emerald ash borer beetle decimated ash trees in the northern United States, there was an accompanying increase in the rates of heart disease in areas where the trees were lost. As years passed, the progressive loss of tree canopy was accompanied by a corresponding increase in the rates of death from heart disease (see chart), clearly showing that in communities where trees die, people die as well.

Although we are still trying to uncover the many ways in which health and nature interact, we have learned that even just looking at nature can restore our attention and ease our minds. For instance, after a major surgery, such as a gall bladder operation, people who recuperate in a room with a view of natural greenery heal faster and require less pain medication than those consigned to rooms facing a brick wall. After a stroke, those who live among green spaces recover faster and have a lower risk of death than those who live where signs of nature are less prevalent. A recent study even found that people with cancer who live in areas of high surrounding greenness survive longer than those living with a paucity of green around them.

Even brief jaunts in nature can be restorative. Walking in forests or meadows lowers blood pressure and heart rate and may even increase immune resilience. “I took a walk in the woods…” Thoreau once wrote, “… and came out taller than the trees.” Natural spaces and woodlands have a calming effect on the heart, they boost our mood, and nourish our growth. Children who grow up on farms or live around livestock or play in dirt have lower rates of allergies and asthma than those who grow up in sterile towns of chemicallycleansed apartments. Faced with such facts, some scientists have suggested that maybe early exposure to the natural environment is important for educating the immune system of children and preparing them to withstand more virulent pathogens they might face later in life.

“Even brief jaunts

Although scientists are only beginning to understand the value of green spaces, their calming and soothing influences have been long valued by poets and artists. As Shakespeare once pointed out, when “exempt from public haunt” we find “tongues in trees, books in the running brooks, sermons in stone, and good in everything.” As children of nature, we have an innate affinity for life. We cherish and seek large open green spaces, spreading trees, quiet ponds, and babbling brooks. We fill our homes with houseplants and surround our houses with gardens. But many of us live our lives in concrete jungles, marooned in a sea of asphalt, surrounded by snake-like freeways that spew poison in our veins. Small wonder that we feel alienated, anxious, and diseased.

What is lost is difficult to recover, but we can start by bringing nature back into our daily lives. We can rebuild our neighborhoods and green our surroundings. We can ensure that even those who live in crowded cities have nature around them, and that parks and open green spaces are available to everyone, not just the wealthy and the affluent. But in doing so, we have to remember that nature has a dark

To re-examine our relationship with nature, we in Louisville, Kentucky, are conducting an elaborate and unusual experiment. Our intent is to understand how planting 10,000 mature trees and shrubs would affect the levels of air pollution in the area and how this would impact the risk of heart disease. In collaboration with hundreds of area residents, we are assessing their health risks and gauging their levels of physical activity, anxiety, depression, and social cohesion. We are planting vegetative buffers along the freeway that runs through the neighborhood, and we are going door-to-door asking people whether they would like us to plant trees and shrubs in their yards. We are trying to identify major sources and areas of air pollution in the neighborhood, so that after planting, we can assess to what extent trees and shrubs can decrease the levels of air pollution and improve the health of the community. We call this study the Green Heart Project.

We expect that the findings of the project will teach us how and where to plant trees to maximize their ability to decrease air pollution levels, and promote health. Maybe we will even learn how more trees and green spaces in the neighborhood improve mental health and promote physical activity and social interactions. How they reduce stormwater run-off and energy consumption, and enhance biodiversity in urban landscapes. On the basis of the results of the Green Heart Project, we hope to develop a “green print” for creating healthier and greener cities. Importantly, we may find a new way to prevent heart disease and other chronic conditions, such as diabetes and obesity, that continue to limit the health and wellness of so many communities around the world.

“What is lost is

The Nature Conservancy’s planting partners installed more than 500 trees along a busy highway to serve as biofilters for the Green Heart Louisville study area, protecting neighborhoods from air pollution. Photo by Mike Wilkinson, courtesy of The Nature Conservancy

The benefits of urban trees include increasing property values, improved physical and emotional health, cooler city streets, and fewer particulate pollutants. Infograph courtesy of The Nature Conservancy

side. Untended nature, with its possibilities of bugs, pests, parasites, and disease, could be more of a threat than a refuge. Unkempt grassy neighborhoods incite unease and anxiety, and wild, pollen-laden shrubs and grasses trigger allergies and asthma. Therefore, we have to learn to how to live well with nature. We have to understand how trees and shrubs affect our health, how they ameliorate air pollution and noise, and how selective and thoughtful planting could make outdoor spaces more calming and inviting. We have to look thoughtfully and critically at nature and import only its salutary gifts.

Widely regarded for spearheading the new field of environmental cardiology, Dr. Aruni Bhatnagar is a professor of medicine at the University of Louisville and has spent more than 25 years studying the impact of toxic substances, tobacco smoke constituents, and environmental pollutants on heart disease. A leader in cardiovascular health, he is also the director of the Christina Lee Brown Envirome Institute at the University of Louisville, which has united a multidisciplinary team to turn scientific discovery into actionable knowledge that can help us build healthier cities. The Envirome Institute was founded in 2018 by GCA club member Christy Brown of the Glenview Garden Club, who was the 2021 recipient of the Zone VII Civic Improvement Award. Both Christy Brown and Dr. Bhatnagar were guest speakers at the GCA’s 2020 NAL conference. For more information, visit greenheartlouisville.com and enviromeinstitute.com