How much time do you spend staring at a screen in an urban setting? And if you have children, how much time do they spend in front of one rather than playing outside in a park or garden?
Most people are less immersed in nature than they’d like, despite knowing the indirect health benefits of having more energy and a better frame of mind. However, science is now demonstrating a direct health impact too: one that’s far deeper and more wide-ranging than most of us realise.
What’s become clear is that the mechanisms, which plants and trees use to defend themselves against pathogens and viruses, have the same effect on our immune systems. Our contact with them helps to train the immune system to recognise what’s a threat to us and what isn’t.
This means that when our immune system comes across a new pathogen, such as Covid-19 for example, it should be better able to respond to it without overreacting and causing damage to different organs of the body.
Natural places are also teeming with life. If we interact with their microbes, they align with ours to support long-term health and wellbeing in multiple ways.
Back in the early 19th century, doctors were aware that being in nature provided a tonic to industrialisation without really understanding why. Spa towns sprung up all over Europe. In Germany, Kniepp therapy became popular through its five healing principles of water, plants, nutrition, exercise and balance.
Then in the 20th century, East Asian countries like Japan and South Korea began actively promoting nature therapy once more. They led scientific advancements into how it supports good health.
In the late 1970s, the Japanese government had become increasingly concerned about karoshi (death from overwork) and a big spike in autoimmune conditions, attributed to over-sterile homes and working environments. Shinrin yoku (forest bathing) was introduced as a government policy in 1982.
Other governments followed suit, especially from the late 1990’s when doctors across Australasia and the US started offering “park prescriptions” to their patients. This trend is accelerating once more in the hoped-for aftermath of Covid-19.
Floating through the air
Qing Li, from Japan’s Nippon Medical School (NMC), is one of the world’s leading authorities on the way that plants benefit human immune systems. One research focus is the role that phytoncides play.
The name derives from the ancient Greek words phyto (plant) and cide (to kill). Phytoncides are the biogenic volatile organic compounds (VOCs), or essential oils, that plants and tree emit to ward off irritants and predators. One particular sub-type called terpenes, are responsible for the way that plants smell.
Forests are the world’s greatest BVOC emitters. If we inhale these compounds as we walk through, we increase our immune system’s levels of natural killer (NK cells). These are a type of white blood cell whose role is to destroy abnormal or infected cells.
Research by Konkuk University in South Korea has also demonstrated how exposure to terpenes protects people from cancer. Ones such as d-limonene, which smells lemony, can induce apoptosis (destruction of cancer cells).
Food for the soul
We also now have a much better scientific understanding of why nature is such a mental tonic. Three decades ago, two American psychologists, Rachel and Stephen Kaplan, coined the concept of attention restoration theory.
Excessive concentration leads to mental fatigue. However, if we immerse ourselves in nature, the brain engages with what’s around us in a less taxing way, helping to clear the mind and restore concentration levels as well as inner wellbeing.
The soothing impact on our sympathetic nervous system, which governs our flight or fight response, also reduces levels of the stress hormone cortisol, lowers blood pressure and slows down our pulse rates. In addition to feeling calmer, it helps us to sleep better and reduce chronic pain.
Boosting the microbiome
Plant microbes also boost physical wellbeing because of the way they expand the different colonies of bacteria living on our skin and in our large intestine. Modern life reduces microbial diversity – the sterile environments, the processed foods and the antibiotics.
This prompts a range of health issues from chronic conditions such as diabetes and asthma, to neurological disorders such as Attention Deficit Hyperactivity Disorder (ADHD) and autoimmune diseases.
Taking probiotics can redress this. But in capsule form, they can never compete with the sheer abundance and variety in the natural world. Its bio-diversity aids our own.
So how can you improve your engagement with nature? Here are some tips:
1. Take up forest bathing
Not all forests are equal, although it’s always better to spend time in one that not. Trees associated with high phytoncide emissions include evergreens such as cedars, conifers, pine and spruce, plus other types of tree such as oak.
NMC’s Qing Li says the best way to experience forest bathing is to leave your phone behind and walk slowly, allowing all your senses to room free. Savour the sounds, smells, sights, tastes and textures around you.
Feel the bark of a tree and pick up the beneficial microbes living on it. Inhale the scent of fresh pine.
Allow your mind to unwind and your body to slow down. Don’t rush through the wood worrying about your latest deadline.
2. Stand close to a waterfall, or a fast gushing stream
These vistas energise in more ways than one. Rushing water produces oxygen atoms called negative ions. The more charged ions in the air, the bigger the benefit.
In one study, the Paracelsus Medical University in Salzburg Austria demonstrated improved lung function in children suffering from allergic asthma.
Researchers also detected changes in the immune system’s release of certain proteins known as cytokines. Pro-inflammatory ones, like interleukin-5 (IL-5), went down, while anti-inflammatory ones, like IL-10, went up.
3. Take off your shoes and socks
When we think of nutrition, it’s normally about what we put in our mouth. However, research shows that our feet can nourish us too through grounding, or earthing.
Direct contact with the planet’s surface connects us to its electrons (electrical charge). This helps to neutralise our bodies’ free radicals (molecules with unpaired electrons, which snatch other cells’ electrons, contributing to numerous diseases).
A 2017 study by Pennsylvania State University Children’s Hospital Neonatal Intensive Care Unit in the US revealed the benefit to premature babies. After an earthing patch was attached to their skin, the babies recorded significant improvements in their autonomic nervous system, which regulates certain functions such as blood pressure and breathing.
The same applies to adults given the impact that free radicals have on inflammation and ageing. But if you aren’t able to walk barefoot outdoors, another option is to put a grounding mat under your feet while sitting at a computer.
4. Let children play in the dirt
Natural environments convey a host of health benefits as young children develop. Many educational systems have responded to a lack of outdoor play at home by setting up forest camps and days at school instead.
Running around outside helps children to develop motor skills such as balance and coordination. Rolling around in the dirt also means they pick up all sorts of beneficial microbes.
The Natural Resources Institute in Finland conducted an experiment with two sets of 75 children who were sent outside to play for 50 minutes each day. One group had a gravel playground to play in and the other had one, which was turfed and planted with different shrubs and mosses.
Both groups were given the same meals during the study period. Within one month, the group playing amid the vegetation had one-third higher levels of beneficial microbes on their skin.
They also had more diverse microbes in their guts and elevated levels of anti-inflammatory markers such as IL-10.
5. Introduce a green wall into your office
Many offices have pot plants to increase oxygen levels. One new trend, pioneered in Finland, is a green wall.
This circulates air through plant roots, allowing their microbes to break down air pollutants. Staff members also gain exposure to their beneficial microbes.
A study, conducted by the University of Helsinki, discovered that after 28 days, participants in the office with a green wall had increased levels of good bacteria such as lactobacillus and gammaproteobacteria, which are both associated with good skin health.
So the science is clear. We will support out long-term health, if we re-engage with nature and our old microbial friends living there.