Hinoki Oil, Phytoncides and Forest Bathing
Saturday 28th September 2024
Since I started practicing nature mindfulness and Forest Bathing regularly, I have seen a noticeable improvement in both my mental and physical health and wellbeing. I feel much better, and it is also now several years since I have had a respiratory infection. Much of this I attribute to my Forest Bathing practice, so this week I am going to share with you the science behind my beliefs.
Immune Functioning and Natural Killer Cells
You may have noticed that some people seem to be more immune to viruses and ‘catching bugs’ than other people, and that is often because they are! One of the ways that the functioning of the immune system is measured is by looking at the activity of ‘Natural Killer (NK) Cells’. Some people have better immunity because they naturally have more ‘Natural Killer Cells’, but don’t worry, there are a few easy ways to increase your ‘Natural Killer Cell’ count.
Natural killer cells are a type of white blood cell designed to attack and kill unwanted cells, for example, those infected with a virus, or tumour cells. They do this with the help of special proteins that create holes in cell membranes and this causes the death of the target cells.
Research has shown that Forest Bathing enhances NK activity in humans by increasing the number of NK cells and intracellular levels of anticancer proteins. The increased NK activity was shown to last for more than 30 days after a Forest Bathing trip, and this has very important implications for preventive medicine. Taking an urban trip has not been shown to increase human NK activity or numbers of NK cells, indicating that increased NK activity during Forest Bathing is not due to the trip itself but due to the forest environment.
So what is it about the Forest environment that makes the difference?
Oxygen levels are usually higher in forested areas (as trees absorb carbon dioxide and emit oxygen) but there are also higher levels of other substance in the forest air and two of these that have been identified as contributing to the beneficial effects that can be gained from Forest Bathing are ‘Phytoncides’ and ‘Terpenes’. Research by Dr. Quing Li, a world-renown expert in Forest Medicine, shows that NK cells have been found to increase in number and activity when people inhale phytoncides, and that exposure to phytoncides has also been shown to have an anti-inflamatory effect.
What are Phytoncides and Terpenes?
In 1928 a Russian Biochemist called Dr. Tonkin found that many trees and plants produce natural oils containing volatile antimicrobial and insecticidal compounds that are emitted by the plants and trees, and to protect them from bacteria, fungi and being eaten by insects and animals. He named these ‘Phytoncides’ [phyto = plant and cide = to kill] although this can be a little confusing as they also have some very beneficial effects, for both the trees themselves, and for us. Later evidence suggests that phytoncides also form part of the system through which trees communicate with each other. When a tree gets attacked by herbivores, insects or other dangers it can start to emit an increased amount of phytoncides, warning other trees to secrete more phytoncides into their bark (where the highest concentrations of phytoncides are usually found) to protect their outer layer against dangers. In this way the tree can make itself less appetising! Many people who practice Forest Bathing believe that exposure to the phytoncides and terpenes (see below) are one the main benefits of Forest Bathing.
Trees known to produce especially high levels of phytoncides include the evergreen trees such as Cedars, Spruces, Conifers and Pine, but also Oak trees. These bioactive molecules are not only beneficial for the trees, they have also been shown to have benefits for humans, as breathing in phytoncides has been shown to:
Improve the immune response by increasing the numbers of NK cells in the body’s circulatory system
Have an anti-inflammatory effect
Help people to relax and lower autonomic nervous system activity
Reduce stress as exposure to forest air reduces cortisol levels
Sleep: Phytoncides like α-pinene enhance sleep
Lower blood glucose levels
However, as noted in this article from Environmental Health and Preventative Medicine, there is a common misconception that the beneficial effects of Forest Bathing are solely or primarily due to phytoncides. The concentration of phytoncides in the forest air is affected by temperature (30 degrees Celsius is said to be the optimum temperature) and can vary greatly from forest to forest and by time of year, much more than the benefits of Forest Bathing in different locations and at different times of year do. The same article proposed that phytoncides exert their effects through the physiological effects of breathing them in and sensing their smell (olfactory processing) rather than absorption into the blood stream, due to the comparatively low levels of phytoncides measured in forests.
What are Terpenes?
Terpenes are specific kind of phytoncide (such as the monoterpene limonene found in citrus peel) produced by trees and plants. Some terpenes attract pollinators, whilst others help to protect the trees and plants against diseases and being eaten. These compounds are what give trees such as Pines and Spruces and plants such as lavender their distinctive smell and they are commonly the main constituents of essential oils. When a plant containing terpenes is dried, the terpenes can oxidise and become terpenoids.
There are thousands of different terpenes, but some of the important ones to Forest Bathers include:
D-Limonene which smells ‘lemony’ (not surprisingly); Alpha-pinene which is the fresh ‘piney’ scent that you smell if you crush pine needles; Beta-pinene that has a more ‘herby’ smell; Camphene that smells like turpentine (terpinetine!) and is more concentrated in pine needles nearest the tree trunk.
As we move towards Autumn and Winter here in the Northern Hemisphere, the incidence of Winter Cold and Flu viruses increases and our ability to expose ourselves to beneficial phytoncides and terpenes decreases as the temperature decreases. This is where using essential oils indoors comes in, and one of my favourites is definitely Hinoki Oil!
Where Does Hinoki Wood Oil Come From?
The Hinoki Cypress (Chamaecyparis obtuse) is a species of cypress native to central Japan (the Japanese character is 檜). Hinoki is a slow growing tree with dark red-brown peeling bark and deep green needles, and it grows up to 35m tall, producing a beautiful golden coloured wood with a slightly smoky citrusy smell. It is slow growing due to the cold climate in which it thrives, but this results in it producing very strong wood. Since the 8th Century it has been used to make statues of the Buddha and to build shrines. The Ise Jingu Shrine, Japan’s most important Shinto shrine is built (and rebuilt every twenty years as a symbol of religious renewal) with Hinoki wood. Its excellent wood properties, beautiful texture and characteristic fragrance also make it a popular choice for domestic house construction, furniture, traditional Japanese bathtubs (rotenburo) and other everyday items. The smell of Hinoki wood therefore has a special meaning for many Japanese people due to its use in constructing significant buildings and artifacts.
Historically, during the Edo period (between 1603 and 1867), the Hinoki was one of Five Sacred Trees of Kiso, or the Kiso Goboku, that were only allowed to be cut down to build houses and temples for the most powerful families. The punishment for transgressors was ‘one head for one tree’ (decapitation).
The Effects of Hinoki Oil on Stress and Anxiety
A 2015 study examined the effects of inhaling Hinoki oil on reducing anxiety and inducing relaxation. The study confirmed that inhalation of Hinoki oil produced the same physiological response associated with the practice of Forest Bathing. After inhaling Hinoki oil, blood pressure and heart rate decreased, as such there was a beneficial decrease in parasympathetic nervous system activity. It was also suggested that inhaling Hinoki oil may enhance mood. In fact, one study, at the Department of Psychiatry at Mie University in Japan, has shown that the citrus fragrance of the phytoncide D-limonene is more effective in some people than antidepressants for lifting mood and ensuring emotional well-being. However, research conducted by Yoshifumi Miyazaki and described in ‘Shinrin-yoku: The Japanese Way of Forest Bathing for Health and Relaxation’ has shown that inhaling the essential oils from the Hinoki Cypres may only be effective if people enjoy the smell as the physiological effects were not as profound in people who did not like it.
Using Hinoki Oil
There are a wide range of ways to use Hinoki oil including
Putting three or four drops into bathwater
Putting a couple of drops onto a terracotta disk
Use it in a diffuser (either electronic or a container with diffuser reeds in) diluted as recommended
Hinoki oil, as with all the evergreen essential oils, can be good when energy is flagging, helping fight fatigue, relieve tension and anxiety and improve concentration. It is especially good in the winter months when we need extra support for our immune systems. My office currently smells of Hinoki and Scots pine.
10 ml of Therapeutic Grade Hinoki Cypress Essential Oil in a dropper bottle.
Bring the calming scent of the Japanese forest into your home with Hinoki Oil. Distilled from the sacred Hinoki Cypress, this beautifully woody and citrus-fresh essential oil is inspired by the restorative practice of forest bathing and helps create moments of calm, mindfulness, and nature connection.
Hinoki Oil – Bringing the Essence of the Japanese Forest into Your Home
Imagine stepping into a quiet forest of ancient Japanese cypress trees. The air is cool and still. Sunlight filters through the canopy, and the scent of warm wood, fresh needles, and distant citrus fills your senses. This is the experience that Hinoki Oil can evoke.
Distilled from the revered Hinoki Cypress (Chamaecyparis obtusa), a tree that has been treasured in Japan for centuries, Hinoki Oil carries a distinctive aroma that is soft, woody, slightly smoky, and subtly citrusy. Its fragrance is often associated with traditional Japanese temples, forest shrines, and the restorative practice of forest bathing, or Shinrin-yoku.
Many people find Hinoki's scent deeply calming and grounding. Rich in natural plant compounds known as phytoncides, it offers a simple way to bring a little of the forest indoors when spending time among trees is not possible.
Use a few drops in a diffuser during meditation, yoga, journalling, or quiet reflection. Add it to a warm bath to create a spa-like atmosphere, or simply inhale its aroma whenever you need a moment of stillness and reconnection.
At Forest Healing, we love Hinoki because it captures something of the quiet wisdom of old forests. Its scent invites us to slow down, breathe deeply, and remember that we are part of the natural world, not separate from it.
Ways to enjoy Hinoki Oil:
• Diffuse to create a peaceful, woodland-inspired atmosphere
• Add to a nature connection or mindfulness practice
• Blend with cedarwood, bergamot, frankincense, or lavender
• Use as part of an evening wind-down ritual
• Bring the scent of the forest into your home, workspace, or therapy room
A small bottle of Hinoki Oil offers more than a fragrance. It offers an invitation to pause, reconnect, and experience a little of the restorative spirit of the forest wherever you are.
Postage and Packing is £2 for up to six 10ml bottles in the UK.
Due to insurance and liability reasons, we no longer ship our essential oils to the USA or Canada - Sorry!
30ml (a bigger bottle) of Therapeutic Grade Hinoki Cypress and and Yuzu Essential Oils.
Shinrin Yoku Blend #1 – The Essence of Forest Bathing
Bring the atmosphere of a Japanese forest into your home with our signature Shinrin Yoku Blend #1.
Inspired by the Japanese practice of Shinrin-yoku – often translated as ‘Forest Bathing’ – this carefully crafted blend combines therapeutic-grade Hinoki Cypress and Yuzu essential oils to create an aroma that is both deeply grounding and gently uplifting. The practice of Shinrin-yoku was developed in Japan as a way of reconnecting with the natural world through mindful immersion in the sights, sounds, scents, and atmosphere of the forest. Research has shown that time spent in woodland environments can help reduce stress, support wellbeing, and foster a greater sense of calm and connection.
The rich, woody fragrance of sacred Hinoki Cypress evokes ancient temple forests and mountain woodlands. Revered in Japan for centuries, Hinoki is associated with peace, harmony, and quiet reflection. Its warm forest aroma is beautifully balanced by the bright, fresh notes of Yuzu, a traditional Japanese citrus fruit valued for its refreshing and revitalising scent. Together they create a fragrance that captures the feeling of walking slowly through a sunlit woodland after rain.
Many people use this blend during meditation, journalling, yoga, relaxation, or simply as part of a daily ritual to bring a sense of nature indoors. A few drops in a diffuser can transform a room, helping to create a peaceful atmosphere that encourages you to slow down, breathe deeply, and reconnect with yourself and the natural world.
Our Shinrin Yoku Blend #1 is supplied in a generous 30ml dropper bottle and contains therapeutic-grade Hinoki Cypress and Yuzu essential oils. The Hinoki oil is distilled from sustainably sourced by-products of the timber industry, making use of wood remnants and shavings that would otherwise go to waste.
Ways to enjoy Shinrin Yoku Blend #1
• Diffuse during meditation, mindfulness, or yoga practice
• Add a few drops to a terracotta leaf diffuser
• Create a calming atmosphere in your home or workspace
• Use as part of an evening wind-down ritual
• Enhance your indoor nature connection practice when visiting a woodland is not possible
More than an essential oil blend, Shinrin Yoku Blend #1 is an invitation to experience something of the restorative spirit of the forest wherever you are. Each drop carries the scent of woodland air, helping you cultivate moments of stillness, presence, and connection throughout your day.
Postage and Packing is £2 for up to three 30ml bottles in the UK.
Due to insurance and liability reasons, we no longer ship our essential oils to the USA or Canada - Sorry!
