This philosophical approach to health and wellbeing has been around for centuries across the world. For instance, Cyrus the Great of Persia built lush green gardens in the crowded Persian capital 2500 years ago to promote human psychological and physical health. A perspective best captured by Paracelsus, a 16th century German physician, who said: “The art of healing comes from nature, not from the physician”.

For instance, Shinrin-Yoku also known as Forest Bathing is a traditional Japanese practice of immersing oneself in nature by mindfully using all five senses. The practice has been shown to have therapeutic effects on the immune, the cardiovascular and the respiratory system; as well as contributing towards reduced depression and anxiety and improving mental relaxation for disorders such as attention deficit hyperactivity disorder.

Specifically, forest plants and trees emit substances called phytoncides which are antimicrobial allelochemical organic compounds with some plants giving off very active phytoncides that help to protect them from bacteria, fungi, and insects. Simply put, phytoncides are micro versions of the tree’s essential oils. The natural killer cells that exist within humans (a type of white blood cell that boosts our immunity against bacteria, viruses and tumours) that help fight disease such as cancer, have been shown to increase through exposure to phytoncides with some of the effects lasting for about 4 weeks after exposure. Thus, it has been suggested that regular Forest Bathing trips may have a preventative effect on the development of some diseases. In one study, for example, (https://pubmed.ncbi.nlm.nih.gov/19568835/) researchers found that people who spent just a few hours walking through a forest / wooded area had lower levels of cortisol (a steroid hormone that regulates metabolism – high levels can weaken the immune system).

However, it’s possible to benefit from forest bathing through essential oils, which are rich in phytoncides. It has demonstrated for example that exposure to Hinoki essential oil (diffused as an inhalation) resulted in a 20% increase in white blood cells. Trees such as Cedar, Pine, Tea Tree and Oak contain several of the 5000 known types of phytoncides and these each contain specific phytoncide oils and aromas that may benefit specific diseases. The oils derived from the Kumano Kodo cedar from instance has been shown to counteract the symptoms of Alzheimer’s. 

There are plenty of therapeutic phytoncides present in other aromatic wood essential oils, such as desert rosewood which has a long history of medicinal and ceremonial use among Aboriginal communities in Australia. These potent aromatic molecules are also found in resins like frankincense and flowers like lavender. These aromatic oils have been proven to calm the mind and reduce stress and anxiety as have other oils derived from white cypress, rosemary, cedar, pine and eucalyptus.

Written by Dr Joe Hinds (MSc, PG Dip, DPhil) on behalf of Menteath

Author of Ecotherapy: Theory, Research and Practice 

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In this thought-provoking book, Jordan and Hinds provide a comprehensive exploration of this emerging area of practice. Divided into three parts, the book offers a unique examination of a range of theoretical perspectives, unpacks the latest research and provides a wealth of illuminating practice examples, with a number of chapters dedicated to authors' own first-hand experiences of the positive psychological effects of having contact with nature.