Taking My NK Cells to the Forest.

Remy

Administrator
Int J Immunopathol Pharmacol. 2009 Oct-Dec;22(4):951-9.
Effect of phytoncide from trees on human natural killer cell function.

Li Q1, Kobayashi M, Wakayama Y, Inagaki H, Katsumata M, Hirata Y, Hirata K, Shimizu T, Kawada T, Park BJ, Ohira T, Kagawa T, Miyazaki Y.
Author information


Abstract

We previously reported that the forest environment enhanced human natural killer (NK) cell activity, the number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that the increased NK activity lasted for more than 7 days after trips to forests both in male and female subjects.

To explore the factors in the forest environment that activated human NK cells, in the present study we investigate the effect of essential oils from trees on human immune function in twelve healthy male subjects, age 37-60 years, who stayed at an urban hotel for 3 nights from 7.00 p.m. to 8.00 a.m.

Aromatic volatile substances (phytoncides) were produced by vaporizing Chamaecyparis obtusa (hinoki cypress) stem oil with a humidifier in the hotel room during the night stay. Blood samples were taken on the last day and urine samples were analysed every day during the stay.

NK activity, the percentages of NK and T cells, and granulysin, perforin, granzyme A/B-expressing lymphocytes in blood, and the concentrations of adrenaline and noradrenaline in urine were measured. Similar control measurements were made before the stay on a normal working day. The concentrations of phytoncides in the hotel room air were measured. Phytoncide exposure significantly increased NK activity and the percentages of NK, perforin, granulysin, and granzyme A/B-expressing cells, and significantly decreased the percentage of T cells, and the concentrations of adrenaline and noradrenaline in urine. Phytoncides, such as alpha-pinene and beta-pinene, were detected in the hotel room air.

These findings indicate that phytoncide exposure and decreased stress hormone levels may partially contribute to increased NK activity.
 

MAC

Member
It's an interesting and attractive idea. I'm a forester and i feel good when I'm in a forest (not much these days). And every year for Christmas we get a live pine tree because it smells so good. It's possible to imagine that the culture of bringing in pine trees and branches for Christmas in countries where Christmas is in winter evolved partly because it confers an advantage in immune function.

But unfortunately the study, as far as I can see from the abstract, is pretty flawed. Only 12 healthy subjects. All have measurements made the day before 'on a normal working day'. Then the subjects all stayed 3 nights in hotel rooms with phytoncides provided by aromatherapy. So it seems that there were no controls staying in the hotel rooms without phytoncides.

What were the men doing on the days when they were staying at the hotel? - still working? or was it the weekend? If they were working, did they have a shorter commute (commuting is often stressful in Japan). Did the men have a nice relaxing time away from the demands of family? Did they perhaps sleep better or longer?

This study would have been a great deal more convincing with a better experimental design.
 

Remy

Administrator
I agree, @MAC. I just thought it was an appealing idea.

There are actually quite a few studies in this vein though on PubMed. Search for "forest bathing". It's a thing now for people to go do yoga in the forest at fancy retreats.

A forest bathing trip increases human natural killer activity and expression of anti-cancer proteins in female subjects.
Li Q, et al. J Biol Regul Homeost Agents. 2008 Jan-Mar.
Show full citation
Abstract
We previously reported that forest bathing trips enhanced human NK activity, number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that the increased NK activity lasted for more than 7 days after the trip in male subjects. In the present study, we investigated the effect of forest bathing trip on human NK activity in female subjects. Thirteen healthy nurses, age 25-43 years, professional career 4-18 years, were selected with informed consent. The subjects experienced a three-day/two-night trip to forest fields. On day 1, the subjects walked for two hours in the afternoon in a forest field; on day 2, they walked for two hours each in the morning and afternoon in two different forest fields; and on day 3, the subjects finished the trip and returned to Tokyo after drawing blood and completing a questionnaire. Blood and urine were sampled on the second and third days during the trip, and on days 7 and 30 after the trip. NK activity, numbers of NK and T cells, and granulysin, perforin, and granzymes A/B-expressing lymphocytes in the blood samples, the concentrations of estradiol and progesterone in serum, and the concentrations of adrenaline and noradrenaline in urine were measured. Similar control measurements were made before the trip on a normal working day. The concentrations of phytoncides in the forests were measured. The forest bathing trip significantly increased NK activity and the numbers of NK, perforin, granulysin, and granzymes A/B-expressing cells and significantly decreased the percentage of T cells, and the concentrations of adrenaline and noradrenaline in urine. The increased NK activity lasted for more than 7 days after the trip. Phytoncides, such as alpha-pinene and beta-pinene were detected in forest air. These findings indicate that a forest bathing trip also increased NK activity, number of NK cells, and levels of intracellular anti-cancer proteins in female subjects, and that this effect lasted at least 7 days after the trip. Phytoncides released from trees and decreased stress hormone levels may partially contribute to the increased NK activity.

PMID
18394317 [PubMed - indexed for MEDLINE]
 

Hip

Well-Known Member
This is an interesting subject, and I am wondering if ME/CFS patients might benefit from creating "essence of forest air" in their rooms using an essential oil vaporizer, as per the method used in the first study quoted above.

The numerous studies examining the effect of forest air on immune function point to alpha-pinene, beta-pinene, D-limonene and 1,8-cineole as the essential oil constituents responsible for the boost in NK cell number and function, as well as the boost in perforin, granulysin and granzyme cells.

NK function is known to be low in ME/CFS, and additionally perforin has been shown to be low this study. The study concludes that perforin "deficiency may prove to be an important factor in the pathogenesis of CFS." Granzyme has also been shown to be low in ME/CFS.

So one can speculate that boosting perforin (as well as NK activity) may help ME/CFS patients fight off their viral infections.

Looking at the effect of perforin on viral clearance: although this study on acute coxsackievirus B infection of the heart found that perforin-deficient mice did not differ from normal mice in their ability to eradicate the virus, by contrast, this study on acute Theiler's virus infection in the central nervous system of mice found that perforin was critical for clearing the virus from the CNS, because although normal mice cleared the infection and survived, the perforin-deficient mice died from Theiler's virus encephalomyelitis after around 2 weeks.



In terms of creating forest air in your room, it is easy to find essential oils that contain alpha-pinene, beta-pinene, D-limonene and 1,8-cineole — which are the main essential oil constituents referred to in the forest air studies.

Two or three oils could be heated on an essential oil vaporizer in order to fill the room air with these "essence of forest" constituents:

Juniper berry essential oil contains 29% alpha-pinene 18% beta-pinene (ref: here).

Lemon essential oil contains 70% D-limonene, as well as 13% beta-pinene and 2% alpha-pinene (ref: here).

Eucalyptus essential oil contains 90% 1,8-cineole.



If you look at the full paper of this study: Phytoncides (Wood Essential Oils) Induce Human Natural Killer Cell Activity on Sci-Hub, you see in figure 6 that alpha-pinene increases perforin expression by around 80%, and 1,8-cineole by around 75% (at air concentrations of 0.1 ppm).

And in figure 4, you see that alpha-pinene, D-limonene and 1,8-cineole all increase granzyme (at air concentrations of 0.1 ppm).

In figure 1, you see that alpha-pinene and 1,8-cineole increase NK function by around 50% (at air concentrations of 0.1 ppm).
 
Last edited:

Cort

Founder of Health Rising and Phoenix Rising
Staff member
Int J Immunopathol Pharmacol. 2009 Oct-Dec;22(4):951-9.
Effect of phytoncide from trees on human natural killer cell function.

Li Q1, Kobayashi M, Wakayama Y, Inagaki H, Katsumata M, Hirata Y, Hirata K, Shimizu T, Kawada T, Park BJ, Ohira T, Kagawa T, Miyazaki Y.
Author information


Abstract

We previously reported that the forest environment enhanced human natural killer (NK) cell activity, the number of NK cells, and intracellular anti-cancer proteins in lymphocytes, and that the increased NK activity lasted for more than 7 days after trips to forests both in male and female subjects.

To explore the factors in the forest environment that activated human NK cells, in the present study we investigate the effect of essential oils from trees on human immune function in twelve healthy male subjects, age 37-60 years, who stayed at an urban hotel for 3 nights from 7.00 p.m. to 8.00 a.m.

Aromatic volatile substances (phytoncides) were produced by vaporizing Chamaecyparis obtusa (hinoki cypress) stem oil with a humidifier in the hotel room during the night stay. Blood samples were taken on the last day and urine samples were analysed every day during the stay.

NK activity, the percentages of NK and T cells, and granulysin, perforin, granzyme A/B-expressing lymphocytes in blood, and the concentrations of adrenaline and noradrenaline in urine were measured. Similar control measurements were made before the stay on a normal working day. The concentrations of phytoncides in the hotel room air were measured. Phytoncide exposure significantly increased NK activity and the percentages of NK, perforin, granulysin, and granzyme A/B-expressing cells, and significantly decreased the percentage of T cells, and the concentrations of adrenaline and noradrenaline in urine. Phytoncides, such as alpha-pinene and beta-pinene, were detected in the hotel room air.

These findings indicate that phytoncide exposure and decreased stress hormone levels may partially contribute to increased NK activity.
That's pretty amazing....It's amazing that study even got done...somebody was thinking outside of the box.

I know those chemicals are powerful from experience. When my chemical sensitivities were really bad I couldn't tolerate forests or sagebrush country because the volatile chemicals wafting off the leaves were so strong. I got headaches, couldn't sleep....it was really something.

Now they don't have that effect but it's clear to me that that plants such as pines send enormous levels of chemicals wafting out in the air.

It reminds me of Ronald Reagan's famous saying "Trees create more pollution than humans". He was referring wrongly to different substances produced by trees.

"During hot weather many tree species release volatile organic compounds into the atmosphere, notably terpenes[wp] and isoprenes (pine pitch is a terpene)."
 
Last edited:
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Cort

Founder of Health Rising and Phoenix Rising
Staff member
This is an interesting subject, and I am wondering if ME/CFS patients might benefit from creating "essence of forest air" in their rooms using an essential oil vaporizer, as per the method used in the first study quoted above.

The numerous studies examining the effect of forest air on immune function point to alpha-pinene, beta-pinene, D-limonene and 1,8-cineole as the essential oil constituents responsible for the boost in NK cell number and function, as well as the boost in perforin, granulysin and granzyme cells.

NK function is known to be low in ME/CFS, and additionally perforin has been shown to be low this study. The study concludes that perforin "deficiency may prove to be an important factor in the pathogenesis of CFS." Granzyme has also been shown to be low in ME/CFS.

So one can speculate that boosting perforin (as well as NK activity) may help ME/CFS patients fight off their viral infections.

Looking at the effect of perforin on viral clearance: although this study on acute coxsackievirus B infection of the heart found that perforin-deficient mice did not differ from normal mice in their ability to eradicate the virus, by contrast, this study on acute Theiler's virus infection in the central nervous system of mice found that perforin was critical for clearing the virus from the CNS, because although normal mice cleared the infection and survived, the perforin-deficient mice died from Theiler's virus encephalomyelitis after around 2 weeks.



In terms of creating forest air in your room, it is easy to find essential oils that contain alpha-pinene, beta-pinene, D-limonene and 1,8-cineole — which are the main essential oil constituents referred to in the forest air studies.

Two or three oils could be heated on an essential oil vaporizer in order to fill the room air with these "essence of forest" constituents:

Juniper berry essential oil contains 29% alpha-pinene 18% beta-pinene (ref: here).

Lemon essential oil contains 70% D-limonene, as well as 13% beta-pinene and 2% alpha-pinene (ref: here).

Eucalyptus essential oil contains 90% 1,8-cineole.



If you look at the full paper of this study: Phytoncides (Wood Essential Oils) Induce Human Natural Killer Cell Activity on Sci-Hub, you see in figure 6 that alpha-pinene increases perforin expression by around 80%, and 1,8-cineole by around 75% (at air concentrations of 0.1 ppm).

And in figure 4, you see that alpha-pinene, D-limonene and 1,8-cineole all increase granzyme (at air concentrations of 0.1 ppm).

In figure 1, you see that alpha-pinene and 1,8-cineole increase NK function by around 50% (at air concentrations of 0.1 ppm).
I hope some people try this and get back...I'm doing my own experiment. I'm camping out full time and I just moved from the desert/scrub environment into a Ponderosa pine forest...
 

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