It’s not just about exercise—

simply being in and near forests and trees makes us

healthier in ways scientists are just beginning to understand.

 

 compiled by Eco-A, EcoAddendum.org

(references listed below)

  1. Qing Li, a professor at Nippon Medical School in Tokyo, measured the activity of human natural killer (NK) cells in the immune system before and after exposure to the woods. These cells provide rapid responses to viral-infected cells and respond to tumor formation, and are associated with immune system health and cancer prevention. In a 2009 study Li’s subjects showed significant increases in NK cell activity in the week after a forest visit, and positive effects lasted a month following each weekend in the woods . . . This is due to various essential oils, generally called phytoncide, found in wood, plants, and some fruit and vegetables, which trees emit to protect themselves from germs and insects. Forest air doesn’t just feel fresher and betterinhaling phytoncide seems to actually improve immune system function.

  1. Researchers at Japan’s Chiba University . . . measured subjects’ salivary cortisol (which increases with stress), blood pressure, pulse rate, and heart rate variability during a day in the city and compared those to the same biometrics taken during a day with a 30-minute forest visit. “Forest environments promote lower concentrations of cortisol, lower pulse rate, lower blood pressure, greater parasympathetic nerve activity, and lower sympathetic nerve activity than do city environments,” the study concluded.

  1. Residents living “on blocks with more trees showed a boost in heart and metabolic health equivalent to what one would experience from a $20,000 gain in income.”

  1. Another study “found less death and disease in people who lived near parks or other green space—even if they didn’t use them.”

  1. Researchers from the University of Exeter Medical School recently analyzed mental health data from 10,000 city dwellers and used high-resolution mapping to track where the subjects had lived over 18 years. They found that people living near more green space reported less mental distress, even after adjusting for income, education, and employment (all of which are also correlated with health). In 2009 a team of Dutch researchers found a lower incidence of 15 diseases—including depression, anxiety, heart disease, diabetes, asthma, and migraines—in people who lived within about a half mile of green space.

  1. “ . . . studies show these restorative effects whether you’ve gone for walks or not.” Moreover, the lowest income people seemed to gain the most: In the city . . . being close to nature is a social leveler.

  1. Korean researchers used functional MRI to watch brain activity in people viewing different images. When the volunteers were looking at urban scenes, their brains showed more blood flow in the amygdala, which processes fear and anxiety. In contrast, the natural scenes lit up the anterior cingulate and the insula—areas associated with empathy and altruism.

  1. Korea Forest Service scientists used to study timber yields; now they also distill essential oils from trees such as the hinoki cypress and study them for their ability to reduce stress hormones and asthma symptoms.

  1. Stephen Kaplan and his colleagues found that a 50-minute walk in an arboretum improved executive attention skills, such as short-term memory, while walking along a city street did not. “Imagine a therapy that had no known side effects, was readily available, and could improve your cognitive functioning at zero cost,” the researchers wrote in their paper. It exists, they continued, and it’s called “interacting with nature.”

  1. Compared with people who have lousy window views, those who can see trees and grass have been shown to recover faster in hospitals, perform better in school, and even display less violent behavior in neighborhoods where it’s common. Measurements of stress hormones, respiration, heart rate, and sweating suggest that short doses of nature—or even pictures of the natural world—can calm people down and sharpen their performance.

  1. In Sweden physician Matilda van den Bosch found that after a stressful math task, subjects’ heart rate variability—which decreases with stress—returned to normal more quickly when they sat through 15 minutes of nature scenes and birdsong in a 3-D virtual reality room than when they sat in a plain room.

  1. In a 2015 study, researcher Paul Piff of the University of California, Irvine, found that people who spent 60 seconds looking up at towering trees were more likely to report feeling awe, after which they were more likely to help a stranger than people who looked at an equally tall–but far less awe-inspiring–building.

  1. People in cities with lots of green space were more likely to report having more energy, good health and a sense of purpose too.

  1. An April 2016 study published in the journal Environmental Health Perspectives reported that women living in areas with a lot of vegetation had a 12% lower risk of death from all causes compared with people in the least green places.

  1. All other things being equal, patients with bedside windows looking out on leafy trees healed, on average, a day faster, needed significantly less pain medication and had fewer postsurgical complications than patients who instead saw a brick wall.

  1. More than 50% of people now live in urban areas. By 2050 this proportion will be 70%. Urbanization is associated with increased levels of mental illness, but it’s not yet clear why. Through a controlled experiment, we investigated whether nature experience would influence rumination (repetitive thought focused on negative aspects of the self), a known risk factor for mental illness. Participants who went on a 90-min walk through a natural environment reported lower levels of rumination and showed reduced neural activity in an area of the brain linked to risk for mental illness compared with those who walked through an urban environment. These results suggest that accessible natural areas may be vital for mental health in our rapidly urbanizing world.

Sources

1,2 World Economic Forum, “The Japanese practice of ‘forest bathing’ is scientifically proven to be good for you’” https://www.weforum.org/agenda/2017/03/the-japanese-practice-of-forest-bathing-is-scientificially-proven-to-be-good-for you?utm_content=buffer1c549&utm_medium=social&utm_source=facebook. com&utm_campaign=buffer

3-11 National Geographic, This is Your Brain on Nature, by Florence Williams http://www.nationalgeographic.com/magazine/2016/01/call-to-wild/

12-14 Time Magazine, The Healing Power of Nature, Alexandra Sifferlin Jul 14, 2016 http://time.com/4405827/the-healing-power-of-nature/

15 Scientific American, Deborah Franklin, March 1, 2012, https://www.scientificamerican.com/article/nature-that-nurtures/

16 Proceedings of the National Academy of Sciences of the United States of America Contributed by Gretchen C. Daily, May 28, 2015 http://www.pnas.org/content/112/28/8567