Spending time in nature: The secret to good health?
What could be in the forest air that makes us feel better?
Wednesday, May 19, 2010 - 15:54
"Shinrin-yoku," which can be defined as "wood air bathing" is the practice of taking in the forest atmosphere or forest bathing, and has been receiving increasing attention in Japan in recent years for its ability to provide relaxation and reduce stress. The gifts of nature escape many of us, particularly urban dwellers. Trees, sunshine, oceans and even grass take a backseat in gray and gloomy concrete jungles. Spring offers us a relief, the chance to walk through newly green parks that have been hibernating during the winter months, covered in snow. Spring is a time of rebirth in nature, and it can also be a time for rebirth in our souls. It is not surprising to find that even spending small amounts of time in a natural setting can help ease mental fatigue, fight off obesity, lower levels of pain caused by sever diseases (like cancer), and lower average blood sugar in patients with type 2 diabetes.
Think of the times on hikes when you paused to look closely at a colorful autumn leaf or stooped down to examine a lush carpet of moss, only to discover a family of fungi hiding on a small log nearby. These moments of discovery and fascination make up a "spontaneous, effortless kind of attention" that is distinguishable from office-bound tasks like reading, writing a report, or preparing to give a presentation. As you follow your curiosity from leaf to stone to caterpillar, you relax into an exploration of your natural surroundings, which gives the attention-driven part of your brain a much-needed break.
While the fascination experienced spending time in nature refreshes our brain circuits, sounds in nature also enhance human health. You may have noticed your own preference for the sounds of water, whether it be waves, rain drops or a waterfall. While it's not clear why we respond to the sounds of water, the calming, mind-easing effects seem to balance the body's hormones in a health-enhancing way. Furthermore, the smells of nature can also affect human health, as we take for granted that pollution in the air we breathe can cause asthma and other health problems. So what could be in the forest air that makes us feel better?
In a study done in the Sierra Nevadas of California, researchers found 120 different chemical compounds in old growth forests, but could only identify 70 of them. We are literally breathing things we don't understand, which also means that by losing these forests, we don't know what we are losing.
There have been numerous test studies that have linked spending time in nature to improved overall health:
In a 1997 study, Dr. Lee Berk, a psychoneuroimmunology researcher with Loma Linda University, took 10 cancer patients with chronic pain and showed them a 30- to 40-minute nature video, of which 15 minutes focused on water sounds, such as waves, waterfalls and creeks. After the brief viewing, stress hormones such as epinephrine and cortisol dropped 20 to 30 percent.
In a 1998 study, Japanese researchers at the Hokkaido University School of Medicine showed that nine walks through an old growth forest over a six-year period led to a lower average blood sugar in patients with type 2 diabetes. The average blood glucose level after forest walking dropped from 179 to 108. The researchers concluded that the forest environment brings about changes in hormonal secretion and nervous system function that provide glucose-lowering benefits beyond those gained by just walking alone.
Researchers from the Medical Research Council in Wales set out to discover whether living in less-pleasant areas was linked to higher levels of obesity. They tested the theory that living in pleasant areas with lots of green spaces and less rubbish encourages people to exercise more. They found that people living in greener areas were three times more likely to be physically active than those living in less green places; their likelihood of being overweight or obese was about 40 percent less. But in contrast, those people living in areas with high amounts of litter and graffiti and less greenery were 50 percent less likely to be physically active; their likelihood of being overweight or obese was also 50 percent higher.
The majority of the aromatic compounds given off by trees are classified chemically as monoterpenes, which are found in the essential oils of many plants. Two of the best known are limonene, found in orange peel, and perillyl alcohol, found in the essential oils of peppermint, spearmint, sage, cherries and cranberries. There has been a great deal of research done on dietary monoterpenes, and has shown to both prevent and cure cancer. Aromatherapists also claim that the monoterpenes in pine are anti-viral and antiseptic, good for asthma and respiratory infections.
Henry David Thoreau, a naturalist, philosopher, and transcendentalist, preached the importance of people communing with nature. In 1845, Thoreau went to live for two years, two months and two days in the woods near Walden Pond. When asked why, he responded, "I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived ... I wanted to live deep and suck out all the marrow of life." Although Thoreau led a fairly solitary life for those three months, he did open himself up to the wonders of the world, and surely he lived.
h.koppdelaney/Flickr (Man in forest)
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