Nature and the Immune System: The Immune Boosting Effects of Trees
Discover the Connection Between Nature, Better Health and the Immune System
The scientific evidence is conclusive — spending time in nature is good for you. Just being in green spaces, like gardens, parks and forests, has been shown to lower stress, heartrate and blood pressure, while boosting the immune system and buoying your mood.
According to data collected from over 140 studies involving 290 million people worldwide, exposure to nature is associated with a long list of health benefits that support longevity. The report revealed that living near or having access to open green spaces reduces the risk of depression, obesity, heart disease, type 2 diabetes, high blood pressure, preterm birth and premature death.1
In fact, studies show that neighborhood greenness is consistently tied to life-expectancy. According to a paper published in Frontiers in Psychology, “the less green in a person’s surroundings, the higher the risk of morbidity and mortality, even when controlling for socioeconomic status and other possible confounding variables.”2
Nature Boosts Your Immune System for Better Protection
The range of positive health outcomes linked to nature is astonishing. Nature protects against all different kinds of diseases, including cardiovascular, respiratory, mental health and musculoskeletal. And researchers believe that nature’s ability to boost immunity plays a central role.
After reviewing every piece of research on the subject, University of Illinois environment and behavior researcher Ming Kuo was able to trace as many as 21 possible pathways between nature and good health. She was surprised to discover that all but two shared a single common denominator — enhanced immune system function.3
“The realization that there are so many pathways helps explain not only how nature promotes health, but also why nature has such huge, broad effects on health," Kuo told ScienceDaily. "Nature doesn't just have one or two active ingredients. It's more like a multivitamin that provides us with all sorts of the nutrients we need. That's how nature can protect us from all these different kinds of diseases – cardiovascular, respiratory, mental health, musculoskeletal, etc. – simultaneously.”
Nature Reduces Stress Levels, Which is Good for Your Immune System
One possible explanation for the relationship between nature, human health and the immune system is that we are innately more at ease surrounded by nature. Science shows that spending time in nature stimulates the parasympathetic nervous system, switching your body out of “fight or flight” and into “rest and digest” mode.4
Not only does that mean that spending time in nature lowers stress and cortisol levels, but also the promotion of involuntary functions, like digestions and glandular secretion, that benefit your long-term health. As Kuo points out, when the body is in “fight or flight” mode all immediately nonessential functions, like the immune system, are suppressed.
“When we feel completely safe, our body devotes resources to long-term investments that lead to good health outcomes – growing, reproducing and building the immune system,” she said. “When we are in nature in that relaxed state, and our body knows that it’s safe, it invests resources toward the immune system.”
However that doesn’t fully explain the immune boosting effects of nature. According to a recent review published in the International Journal of Environment Research and Public Health, scientific evidence indicates that exposure to nature has positive effects on immunological parameters, such as anti-inflammatory effects and increased Natural Killer (NK) cell activity. And for that we look to the trees and the Japanese art of “forest bathing.”5
The Immune Boosting Effects of Trees
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In Japan, where “forest bathing” is already a popular preventative medicine, scientists discovered that breathing in phytoncides strengthens the immune system, among other therapeutic benefits. Phytoncides are airborne chemicals released by trees and plants to protect themselves from disease. They have antibacterial and antifungal properties that, when inhaled by humans, boost our immune system.
Much of the research from Japan suggest that breathing in phytoncides released by trees increases the number and activity of NK cells, which are specialized immune cells involved in the body’s innate immune response. 5 The world's foremost expert in forest medicine, Dr. Qing Li’s research at Nippon Medical School found that inhaling phytoncides increases the number of NK cells in the blood stream. And in another, more recent study, researchers discovered that the increased NK cell activity from a 3-day, 2-night forest bathing trip lasted for more than 30 days. 7
Additionally, research has shown that terpenes, which are a specific type of phytoncide, have accredited anti-inflammatory effects, and are able to reduce both acute and chronic inflammatory responses. What’s more, terpenes have also been shown to enhance the innate immune response by increasing immune cell activity.5,8
Conclusion: Get Outside!
Now that you know the immune boosting effects of nature, it’s time to head outdoors. If you don’t happen to live near nature, or on a tree-lined street, then head to your closest neighborhood park for a stroll. Walk at your own pace, but leave your devices at home – the key is to immerse yourself in your surroundings.
And if you are unable to immerse yourself in nature as often as you’d like, don’t stress, there are many ways to support your immune system for better health. In addition to getting enough sleep, eating a nutritious diet and exercising, a daily postbiotic scientifically tested for immune support can help. IMMUSE™ (LC-Plasma) has been clinically shown to provide more comprehensive immune support for year-round health when taken regularly.* Learn more by clicking the button below.
1University of East Anglia. "It's official -- spending time outside is good for you." ScienceDaily, 6 July 2018.
2Kuo M. How might contact with nature promote human health? Promising mechanisms and a possible central pathway. Front Psychol. 25 August 2015; 6: 1093.
3University of Illinois College of Agricultural, Consumer and Environmental Sciences. "Immune system may be pathway between nature and good health." ScienceDaily, 16 September 2015.
4Hunter M. R., et. al. Urban Nature Experiences Reduce Stress in the Context of Daily Life Based on Salivary Biomarkers. Front. Psychol. 4 April 2019; 10.
5Andersen L., et. al. Nature Exposure and Its Effects on Immune System Functioning: A Systematic Review. Int J Environ Res Public Health. 2021 Feb; 18(4): 1416.
6Li Q., et. al. Effect of phytoncide from trees on human natural killer cell function. Int J Immunopathol Pharmacol. 2009 Oct-Dec; 22(4): 951-9.
7Lvu B., et. al. Benefits of A Three-Day Bamboo Forest Therapy Session on the Psychophysiology and Immune System Responses of Male College Students. Int. J. Environ. Res. Public Health. 2019; 16: 4991.
8Kim T., et. al. Therapeutic Potential of Volatile Terpenes and Terpenoids from Forests for Inflammatory Diseases. Int J Mol Sci. 2020 Mar; 21(6): 2187.