Vanquish Pain and Stress With a Waterless 'Bath'
Could a bath lift your spirits, melt away stress, and relieve pain... without a drop of water?
It can, if it's shinrin-yoku.
That's the Japanese term for "forest bathing."
All you need is to plant yourself in the woods and as you walk, focus on the present moment as you take everything in with all five of your senses.
The Japanese government promoted it as a public-health measure back in the 1980s. And forest bathing reflects something we've long known... that time spent in greenery – forests in the countryside and urban parks alike – benefits our mental health, relieving stress and boosting mood.
But more research has been emerging on how hanging out with Mother Nature can powerfully benefit our immune systems, too.
As it turns out, it has to do with a certain defense mechanism of the plants themselves.
You see, trees release invisible chemicals called phytoncides. These molecules protect the plants against pesky pests like fungi and bacteria.
And this plant-based pesticide of sorts also does wonders for our built-in defense, or immune, systems...
For instance, a 2009-published multiyear study on the practice identified a decline in adrenaline in folks who spent three days and two nights camping in the forest... signaling a reduction in stress.
But get this: The campers also experienced stronger immune systems. Namely, researchers measured an increase in these folks' natural killer ("NK") white blood cells, which are cells that help fight infections and even cancer. And that immunity boost remained for more than 30 days after their trips.
When the researchers compared these campers with a time when they visited a city and found no boost in NK cells in the urban group... The forest made all the difference.
Also, a 2024 systematic review and meta-analysis examined six studies involving 79 participants and phytoncide exposure.
Just like the 2009 study, the review concluded that phytoncide exposure significantly ramped up the number of NK cells, along with other cancer- and infection-fighting T-cells and molecules... signaling a reduction in stress.
Along with their immunological perks, phytoncides deliver some brain benefits...
A small 2024 double-blind, randomized controlled trial split up 24 folks with mild cognitive impairment ("MCI") – which is considered to be a dementia precursor – into two groups, where one breathed in phytoncides for 30 minutes and the other a placebo.
Compared with the control group, the phytoncide group showed a significant drop in brain waves associated with being stressed and anxious, as well as decreased brain activity in the frontal lobe, which indicates being calm.
Plus, a similar study from February split up 21 MCI patients into two groups where, for 30 minutes, the control group inhaled saline mist and the other group inhaled phytoncides.
Researchers found that unlike the control group, the plant-perfume breathers did significantly better on a brain test and their brains showed less evidence of overwork or strain.
How to Breathe in That Tree Tonic
Even if you live in a busy city, you can still reap some of the benefits by carving out some free time and spending it at a local park, green space, lake, or reservoir. You can also bring nature to you by taking up gardening. Check out a nearby community garden, bring in some houseplants, or grow your own herbs indoors. (Here's a brief introduction to indoor gardening.)
Also, finding a green space in the city can be mightily rewarding for your mood, according to a small 2022 study of 40 middle-aged adults. It showed that walking for just 20 to 30 minutes in an urban green space with shade and plants can significantly lower stress and boost your mood compared with walking in a less-green urban area.
Personally, I try to walk outside every day. If I happen to take my daily walking break in a city, I try to focus on the hints of nature around me – like observing any small trees, bushes, or potted flowers that pepper the block, feeling the wind and sun on my face, and taking note of any squirrels or birds that cross my path. (Did you know our avian city dwellers, or pigeons, naturally love hard surfaces?)
And the more time you spend in nature, the better... A 2019 study on nearly 20,000 folks suggests that spending at least two hours in nature a week leads to better reported health and well-being. And a study published earlier this year on people in three of Finland's biggest cities found a link between frequent weekly pilgrimages to a nearby green space and less pill-popping. Researchers saw making three to four trips per week to a park, forest, or meadow was associated with lower odds of having to take prescription medications for common health issues... 26% lower odds for asthma drugs, 36% lower odds for blood-pressure drugs, and 33% lower odds for anxiety, depression, and sleep-disorder drugs.
If you live in an area without a lick of green or blue nearby, plan a weekend trip to visit a national park. You can use this website to find some nearby. If you're lucky enough to live near the coast, head over to the beach. For the landlocked folks, seek out streams or lakes which typically have hiking trails.
And one more thing... a major threat lurks amid all that greenery, one that can wreak havoc on your body if you aren't careful. Before you head off to get your weekly dose of nature, don't forget to check out this issue of Retirement Millionaire. (If you're not an existing subscriber, feel free to give it a trial run.)
What We're Reading...
- Something different: This Lord of the Rings actor climbed a mountain to get to work.
Here's to our health, wealth, and a great retirement,
Dr. David Eifrig and the Health & Wealth Bulletin Research Team
August 12, 2025