"In forty years of medical practice, I have found only two types of non-pharmaceutical 'therapy' to be vitally important for patients with chronic neurological diseases: music and gardens."
-- Oliver Sacks
"Wherever medicine has no magic ... gardens reappear," says Dr. Sam Bass Warner, an urban historian at Brandeis University.
The Case for the Healing Power of Nature
There's a reliable relationship between nature and our physical and mental health. There seems to be a connection between greenery and health markers for obesity, hypertension, and diabetes. There also appears to be a relationship between greenery and the strength of our immune systems. After people spend several days in nature, researchers have found measurable increases in what are known as natural killer cells. This and many others studies are cited in this Hidden Brain podcast.
A 10-year study of patients recovering from surgery, conducted by Dr. Roger Ulrich, an environmental psychologist at Texas A&M's College of Architecture, compared 23 patients whose windows looked out on trees and sky with 23 patients whose windows faced brick walls. Those with views of nature had shorter stays, took fewer painkillers, and complained less to nurses.
University of Miami researchers crunched the numbers to determine that nearly 250,000 Medicare recipients living in the greenest parts of the county were 25 percent less likely to have a heart attack than those in the least green neighborhoods. The researchers found a significant correlation between living near green space and a lowered risk for three of the four heart diseases studied. Along with the 25% lower risk of heart attack, people living in the greenest parts of Miami saw their risk drop by 20% for ischemic heart disease and 16% for heart failure. “Some studies suggest even viewing nature and greenness can be beneficial,” as this Heart Insight article notes.
In summary, research has shown many cognitive, social, emotional, physical, and physiological benefits.
me in my garden
But why?
Although much evidence is already available, much remains unknown.
Some of the effects appear to be psychological in origin. Natural scenes and activities can stimulate our sense of awe, making our concerns seem less significant, while stimulating the feeling that we’re part of something larger and grander. This can measurably reduce stress, anxiety, and depression as this article notes.
But perhaps the beneficial effects of nature go deeper than that.
The great Oliver Sacks once wrote, "Biophilia, the love of nature and living things, is an essential part of the human condition. The effects of nature’s qualities on health are not only spiritual and emotional but physical and neurological. I have no doubt that they reflect deep changes in the brain’s physiology, and perhaps even its structure."