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Forest bathing has a variety of health benefits [Treegirl 2009].

 

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forest bathing photo from Treegirl

Treegirl visits the Penpergwm yew in Wales, 2009.

Forest Bathing

by Eric Van Buskirk for True Blue, 2022.08.13

In 1982, the Japanese Ministry of Agriculture, Forestry and Fisheries started the Shinrin-yoku health program, which translates as "spending time among trees", better known as “forest bathing” (Park et al. 2010). Generally the forests involved are dominated by native Japanese conifers such as sugi (Cryptomeria japonica) or hinoki (Chamaecyparis obtusa). The forest bathing program was introduced due to the growing number of individuals, living in metropolitan areas, not allowing themselves sufficient exposure to nature in day-to-day life.

Forest bathing is a form of nature-based therapy that can provide a natural antidote to tech burnout. Various studies have shown that “humans intuitively know the relaxing, soothing and ‘awe’ effects of being in or viewing forests, plants, flowers, urban green spaces, parks and natural wooden materials” (Hansen et al. 2017), which is why the practice of forest bathing has encouraged residents to reconnect with their local forests and inspired many to protect them. What is forest bathing, and how can it benefit both the body and the mind?

What Is Forest Bathing?

Forest bathing is a quiet activity, focused on breathing and on simply being in nature among the trees. Though many try to incorporate other activities such as jogging, working out, or stretching, the proper way to maximize the benefits of forest bathing is to do no more than allowing the forest to heal you naturally as you quietly stroll or repose.

A 2010 field experiment reported in Environmental Health and Preventative Medicine showed that “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” (Park et al. 2010). The non-stop hustle of urban life, as well as constantly being surrounded by synthetic materials and technology, have contributed to the rise in conditions like anxiety and depression. The experiment found that exposure to naturally occurring healing compounds released by conifers can help moderate the symptoms of these conditions and also provide other health positive effects.

Benefits of Forest Bathing

Coniferous forest bathing “may significantly improve people’s physical and psychological health” (Wen et al. 2019). In 2007, the International Journal of Immunopathology and Pharmacology published a study on forest bathing’s cancer-fighting efficacy (Li et al. 2007), which inspired further research into the effects of forest bathing on the human immune system. Specifically, Li et al. (2009) examined exposure to natural terpenes released by hinoki (Chamaecyparis obtusa). Terpenes are among the most ubiquitous essential oils found in conifers, and have been described for virtually every conifer species. Li et al. (2009) exposed human subjects to terpenes belonging to a class called phytoncides, which are terpenes having an antibacterial function. The measured effects included reduced levels of stress hormones in study subjects, accompanied by increased levels of intracellular anti-cancer proteins in lymphocytes. Prior work by Li et al. indicated that these benefits persist for a week or more following a period of forest bathing.

Terpenes

Terpenes are one of the most abundant and diverse naturally occurring compounds; they’re responsible for the aroma and flavor of most plants, as well as a significant amount of their therapeutic qualities. While thousands of terpenes have already been identified, a single plant can contain hundreds at a time. The myrcene terpene is particularly abundant in a number of plants utilized in daily life, including everything from mangoes to industrial hemp.

Phytoncides: Their Effects and the Compounds Responsible

Japanese doctors promote forest bathing as a means of taking a break and resetting the mind. This is in no small part due to the many benefits of dominant terpenes within the phytoncides coniferous trees release. Below we’ll briefly discuss some of the aspects coniferous forest bathing has a positive effect on, as well as the terpenes responsible for them. These are only some of the naturally occurring benefits that the terpene combinations in phytoncides can offer. Simply absorbing them through the lungs can reduce depression and anxiety, boost energy levels, and even lower heart and blood pressure. This refreshing experience requires very little effort but offers a wealth of potential upsides.

Sleep

The combination of α-pinene and 3-carene, two primary pine tree phytoncide components that enhance inhibitory synaptic responses, have been found to have sleep-promoting properties (Wu and Lee 2020). It established that these phytoncides “enhance the quantity of [non-rapid eye movement sleep] without affecting the sleep quality.”

Inflammation

α-pinene and β-pinene have each been shown to have numerous health benefits including being able to aid in improving your memory and alertness. Both are effective anti-inflammatory and analgesic compounds (Salehi et al. 2019). They can also improve circulation and reduce stress.

Breathing

α-pinene and cineole might be especially beneficial to those with asthma or suffer from labored breathing, as both are effective bronchodilators. Cineole is also an effective myucolic, which is why it’s a common ingredient in cough and cold medicines. Cineole makes up approximately 69% of eucalyptus essential oil and can also be found in many other plants associated with healing like rosemary and thyme. Camphene has a cooling effect and is used to treat chest pain, shortness of breath, and anxiety (Russo and Marcu 2017).

Cell Protection and Immune System Support

In a study on forest bathing’s effect on human immune function, Li (2010) concluded that “phytoncides released from trees and the decreased production of stress hormones may partially contribute to the increased NK [natural killer] activity.” Terpinene and limonene have shown powerful antioxidant properties and help reinforce the human immune system (Anandakumar et al. 2020). They are effective antibacterial compounds (Yang et al. 2014), which is why they’re often incorporated on household cleaning products.

Terpinene has been shown to positively affect heart health, memory, and cognitive function (Boiangiu et al. 2020); limonene can improve mood and reduce stress, along with helping to regulate blood-sugar levels, boosting metabolism, and improving digestion (Ruiza and Flotats 2016).

Worth the Time Investment

Various physiological and psychological experiments have even been conducted on “exposure to the total environment of forests or to only certain elements of this environment, such as the odor of wood, the sound of running stream water, and the scenery of the forest” (Tsunetsugu et al. 2009). Though further research into different population segments should still be conducted, there’s evidence supporting exposure significantly lowers cortisol concentrations, therefore lowering stress levels and improving mood.

Though forest bathing was first popularized in Japan and quickly spread throughout Asia, this natural form of therapy has been discussed in numerous travel blogs and even major Western publications like National Geographic. Forest bathing continues to grow in popularity among those wanting to give their eyes, lungs, and minds a break from urban lifestyles. Given spending a mere 2 hours a week out in nature has been shown to improve overall health and well-being (White et al. 2019), even the most assiduous office worker could reasonably consider incorporating coniferous forest bathing into their day-to-day lives.

See Also

Plevin, Julia. 2018. From haiku to shinrin-yoku: A brief history of forest bathing. Forest History Today 24(1,2):17-19. Accessed 2023.11.11.

Last Modified 2023-12-16