What Is Forest Bathing?

Forest bathing or “Shinrin-yoku” in Japanese, is defined as “taking in the forest atmosphere or forest bathing”. It is venerated in Japan for its capacity to provide relaxation and reduce stress.

Researchers have been studying the effects of total environment of forests or to only certain elements of this environment. These include the odor of wood, the sound of running stream water, and the scenery of the forest. They have obtained physiological measurements of the human nervous system and biomarkers reflecting stress level in forest area and city area subjects.

The results showed (of course) that people in the forest area had a lower stress level. [1]

Another study suggested that forest environments promote lower concentrations of cortisol, lower pulse rate, lower blood pressure. Moreover, it showed greater parasympathetic nerve activity, and lower sympathetic nerve activity than do city environments. [2]

How Does Forest Bathing Work?forest bathing

These effects of “taking in the forest atmosphere or forest bathing” are believed to be achieved by inhaling the forest atmosphere, which includes various phytochemicals mainly produced by trees (particularly conifers).

The major components of the forest atmosphere are terpenes, which are the largest class of naturally occurring organic compounds. [3]

What Are The Health Benefits Of Forest Bathing?

Studies have demonstrated that terpenes exert anti-inflammatory effects by inhibiting various proinflammatory pathways in ear edema, bronchitis, chronic obstructive pulmonary disease, skin inflammation, and osteoarthritis.

1 – Anti-inflammatory Properties

  • α-Pinene, a monoterpene, found in oils of coniferous trees and rosemary, showed anti-inflammatory activity, suggesting its role as an anti-osteoarthritic agent.
  • d-limonene, another monoterpene, was reported to reduce allergic lung inflammation in mice probably via its antioxidant properties. It also showed an anti-osteoarthritic effect.
  • p-cymene treatment reduced elastase-induced lung emphysema and inflammation in mice.
  • linalool, a natural compound found in essential oils of aromatic plants, inhibited cigarette smoke-induced acute lung inflammation by inhibiting infiltration of inflammatory cells.
  • In another lung injury model, linalool attenuated lung tissue changes in mice.
  • Borneol, a monoterpene present in some plants has been used in traditional medicine. Borneol alleviated acute lung inflammation. [3]

2 – Anti-tumor Properties

  • The anti-tumorigenic activity of d-limonene is well-established. [4]
  • β-pinene also revealed its cytotoxic activity against cancer. It has also been suggested that p-cymene is an effective candidate for the prevention of tumor invasion and metastasis. [3]

3 – Neuroprotection Properties

  •  Borneol is a bicyclic monoterpene present in several medicinal plants, which has been associated with neuronal health. Borneol has showed a neuroprotective effect against β-amyloid (a sticky compound that accumulates in the brain, disrupting communication between brain cells and eventually killing them, which can lead to Alzheimer’s Disease).
  • β-caryophyllene has antioxidant effects , and functions as a regulator of several neuronal receptors and shows various pharmacological activities including neuroprotection. [5]

Two-hour ‘dose’ of nature significantly boosts health – study

Researchers say simply sitting and enjoying the peace of nature has mental and physical benefits.

The finding is based on interviews with 20,000 people in England about their activity in the previous week.

Among those who spent little or no time in nature, a quarter reported poor health and almost half said they were not satisfied with their life.

In contrast, only one-seventh of those who spent at least two hours in nature said they were in poor health, while a third were not satisfied with their life.

The study showed a definite link between spending time in nature and better health and well-being. [6]

[1] Trends in research related to “Shinrin-yoku” in Japan: https://www.ncbi.nlm.nih.gov/pubmed/19585091/

[2] The physiological effects of Shinrin-yoku: https://www.ncbi.nlm.nih.gov/pubmed/19568835

[3] Anti-inflammatory and chondroprotective activity of (+)-α-pinene: https://www.ncbi.nlm.nih.gov/pubmed/24455984/

[4] Effects of monoterpenes and mevinolin on murine colon tumor: https://www.ncbi.nlm.nih.gov/pubmed/25401162

[5] Polypharmacological Properties and Therapeutic Potential of β-Caryophyllene: https://www.ncbi.nlm.nih.gov/pubmed/26965491

[6] Two Hour Dose In Nature Boosts Health – https://www.theguardian.com/environment/2019/jun/13/two-hour-dose-nature-weekly-boosts-health-study-finds