Eat dirt. You’ll feel better.


So suggest some researchers into eco-therapy, a trendy new concept that has doctors writing prescriptions for spending time in a park. While they don’t specifically recommend eating dirt (a pathological condition known generally as “pica”), they do say the soil contains mood-enhancing micro-organisms that enhance happy-making brain chemicals, such as serotonin.

The star of current research is the benign Mycobacterium vaccae, a micro-organism found in soil and discovered to enhance serotonin levels in mice.  Serotonin is the neurotransmitter du jour in psychotropic medications like Prozac and is known for its ability to alleviate depression and anxiety. (Mayer, et al.  “Gut Microbes and the Brain:  Paradigm Shift in Neuroscience”. The Journal of Neuroscience. 12 November 2014, 34(46))

I practiced eco-therapy long before science discovered it. I’ve been a river rat since childhood.  After leaving home, I wound up in New York, but two years of noise, bad smells, pollution, too much concrete and pavement drove me to the opposite extreme—the mountains of Colorado– in 1977.  After some bouncing around, I moved to another big city, Atlanta, in 1992 for career training and lived there three years.  I spent all my free time in the back yard, planting flowers.  Because of the garden, the house sold for much more than the realtor believed I could get.  So my eco-therapy was financially rewarding, too.


I spent too many years after that working in offices, often with no windows or with windows fronting on parking lots, and missing the best part of the day outside. Now retired and living on the old family homestead, I spend as much time as possible outside, scratching in the dirt with my chickens, and surrounded by the greens and blues of nature.  I’ve always liked the smell of earth, and now science is telling me why.

The scientific community is discovering what humans have instinctively known forever. In “The Nature Cure:  Why some doctors are writing prescriptions for time outdoors,” by James Hamblin, MD (Atlantic magazine, October, 2015) tells of the emerging “eco-therapy” concept. Dr. Hamblin writes of the M. vaccae. He also references a UK study showing physical activities in natural versus “artificial” environments, induced less anger, fatigue, and sadness.  Another study found that patients recovering from gall bladder surgery fared better if they were in rooms facing trees instead of a wall.

“The Nature Cure” also cites research that says people are attracted to and feel restored by looking at images of nature, especially savannas, slow-moving water, foliage, and “birds or other unthreatening wildlife.”


Since then, I’ve stumbled on similar articles about the healthful and mood-enhancing effects of nature in Yes! magazine and Mother Earth News.  The winter, 2016 issue of Yes! is devoted to creating a “culture of good health.”  In “The Curious Case of the Antidepressant, Anti-anxiety Backyard Garden,” family practitioner Dr. Daphne Miller says “It’s well-established that the microbes in soil enhance the nutritional value of food and, as found in studies of farm children in Bavaria and among the Indiana Amish, improve immune function.  (Researchers were finding that exposure to a diversity of microbes early in life led to fewer allergies.)”

Dr. Miller states we need a diversity of organisms found in animals, plants, soil, water, and air for optimal functioning of our immune and nervous systems. She laments the modern practice of crop monoculture and use of pesticides and herbicides, which all deplete soil of micro-organism diversity.

Finally, “Nature Really Does Make Us Happy,” by Eva M. Selhub and Alan C. Logan, in the December, 2015/January, 2016 issue of Mother Earth News, takes a slightly different tack.  Here, behavioral scientist Roger S. Ulrich is given credit for the original research on gall-bladder patients.  He is also given credit for a landmark 1979 study on stressed students.  He showed them images of nature scenes and cities.  “The nature scenes increased positive feelings of affection, playfulness, friendliness and elation.  Urban views, on the other hand, significantly cultivated one emotion . . . sadness.  Viewing nature tended to reduce feelings of anger and aggression, and urban scenes tended to increase these feelings.  Also, seeing natural landscapes was associated with increased production of serotonin,” say the article’s authors.


Other studies cited in the Mother Earth News article indicated elderly inhabitants of a residential care center in Texas had lower levels of cortisol (a stress hormone) when in a garden rather than a classroom.  The presence of plants, particularly flowering ones, in a room can reduce stress caused by an emotional video.  In Taiwan, rural farm scenes produced higher alpha-wave activity, particularly in the right brain.   Alpha-waves are associated with peaceful states of mind.  Forest scenes and natural water scenes also decrease heart-rate.  In Japan, forest walks reduced cortisol levels.  Forest walks are also credited with reducing depression and hostility, while increasing vigor and improving sleep.

Norwegian research shows that having a plant near or within view of a work station significantly reduces the amount of sick leave workers take. Japanese research adds that greening high-school classrooms with potted plants significantly reduces students’ visits to the infirmary.  Nature scenes fired up opioid receptors in subjects’ brains, imaged by fMRI in California.  Endogenous (produced by the body) opioids reduce perception of stress, enhance emotional bonding, and decrease brooding over negative memories.  Urban scenes were found in Korea to activate the amygdala, a part of the brain associated with anger and fear.  Chronic stress and cortisol may promote activity in the amygdala, which selectively prioritizes memorization of negative experiences and events.

So there you have it. My take-home message is to escape as often as possible the boxes where we live, drive, and work, and to enjoy the health-sustaining multi-dimensionality of the great outdoors.


Photos, top to bottom:  Camellia;  White-tailed deer;  Trees and marsh;  Pecan tree with Spanish moss; Moon River at high tide.

22 thoughts on “Eat dirt. You’ll feel better.

  1. ksbeth

    this all makes so much sense. i teach kindergarten and we are out every day, as long as it’s not 10 degrees f or less. as a child i used to eat dirt, wood and ants. hmmmm…..

    1. katharineotto Post author

      Do you think ant eating is a skill that could be taught? I’m plagued with three different species of ants, eating wood (carpenter ants, the big ones), fire ants that sting like the dickens and leave huge pimples that scar forever (the medium-sized ones), and sugar ants, that find the cat food as soon as I put it down, all summer. I don’t use pesticides because of . . . you know. Trying to teach the chickens to eat ants, but so far, no luck.

      By the way, I thought of you when a friend gave me a copy of Diet for a Small Planet. (Author Frances Moore Lappe has an article in this issue of Yes! too.) I read in the new introduction about a class of sixth graders in Amesville, Ohio, who “didn’t trust the EPA” after a local chemical spill. They formed the Sixth Grade Water Chemists and raised money to do their own lab testing. The teacher is retired now (Lasky?–my book is buried under my piles of priorities). But he’s a big mucky-muck in the Ohio school system.

      What a great way to teach science!

      Libby Belle

      1. ksbeth

        i teach kindergarten and always tell my class about this. this year, we grew our own little garden at school for the first time, have been visiting the farmer’s market to buy things and talk to the farmers, cook what we buy, bake things, and had a garden to table chef come in to talk to us about food. ti’s been a wonderful education for al of us.

    1. katharineotto Post author

      The more people appreciate them, the easier to preserve. Reasons include the fact that trees and green spaces have a global cooling effect, so saving more trees makes more sense than carbon credits to corporations not to cut them down. Once people see the common sense of this cash saving option, the faster they will see the (outdoor) light.

  2. katharineotto Post author


    Yippee! Tell everybody. I think an earlier issue of Yes! praised Detroit for its empty-lot-neighborhood-and community-gardening projects. can’t remember which issue. Savannah also has a school or two practicing the gardening arts.

    (I just recalled our elementary school gardening project. We grew radishes. There is nothing so appetizing as eating something you’ve grown yourself, and there was never a better radish. Maybe first grade? Or second. A highlight of my early school career. How many kids like radishes now?)

    Demote a few bureaucrats, salary-wise, say I, and apportion the savings to teacher salaries. Then the teachers won’t need unions or tenure. Then they can become more accessible to parents via re-vitalized PTAs. The assault on PTAs by the unions appears (from an outsider’s point of view–except by fondly recalling a friendly PTA atmosphere in the 1950s and 1960s) a most destructive interference that only replaces one overlord for another.

    I’m proposing eco-therapy for the geezers in my Senior Group: A kayak club that toodles along the rivers, collecting trash and taking it to the next town council and county commission meetings. A bicycle club that does the same thing, and advocates for bikes in parks and bike racks to seal the deal. A mentoring program for learning and teaching practical skills. These are things any community can do, to embarrass governments into behaving. The advantage of all these bankruptcies is it’s forcing communities to take care of their own, because they can no longer depend on the government to take care of them.

    Should I suggest my Geezers group start its own blog? These folks are begging to be euthanized under Obamacare. The “Been There, Done That” crowd needs a voice in a big way. I want them to take some of their millions off Wall Street and invest in local soil and water testing. Won’t that be fun? And into hiring help for our sweet custodian, who is in his sixties and expected to keep that huge building clean all by himself. His back hurts all the time, but his attitude is like mine, to wit: “If everyone leaves smiling, it’s a blessed day”.

    Now James is smarter than these urban Yankee escapees, who don’t know how racist they are. In the gentle South, blacks and whites have cared for each others families, since the survivors of Lincoln’s war had to pull together or pull apart. For a white woman to trust a black woman with her children says a lot about the mutual bonds of child-rearing among women of both races. The lack of that bond is what shows outsiders up, when they start to talk about Southern racism.

    James creeps through our meetings, as invisible as he can be, and these Yankees who don’t even acknowledge his existence, bemoan the fact that there’s no black representation in our group. “Good morning, James. How are you?” might be a start.

    Maybe these geezers could hire a team of landscapers to make a garden in a neglected corner of this beautiful, historic lot. Bye, bye Montsanto and Pfizer stock.

    Forgive my rambling. I figure if sixth graders can do it, these old farts sure can.

    Dr. Kathorkian,
    an alter ego of
    *independent country of one*
    $ world’s only free market capitalist $

      1. katharineotto Post author

        I’ll tell them you said so. I’m going to recommend some of my favorite bloggers so they won’t waste time before they know how to navigate.

        Thanks for your ongoing support. One of our guys is a retired pediatrician and obsessed with early childhood education.


  3. urbansimulator

    Just want to add that nature is a value in itself while we are only advanced primates as a more lately development of this giant creator existing much longer than our today’s industrialized civilization. So I am happy that my hometown Berlin is a real green big city with huge forests and lakes! And when you eat bananas this will also increase the serotonine level in your body.

    1. katharineotto Post author

      Exactly. Europeans did not have the luxury of waste, so cities grew naturally, from the centers of commerce outward. They didn’t need zoning or debt-backed overkill infrastructure. Public transportation is so well developed and user friendly that you rarely need a car, as you well know. Germans are sturdy stock because you have to be in that climate.

      So tell me this. Why has Germany developed solar technology better than the southeast United States? And why is German-based company Mage here in Dublin, GA, apparently with a DOD contract?

      I hear they are in high gear working for Fort Stewart, in case you’re interested. Also, the most mined country in the world is the United States, primarily on military bases and ex-military bases. We have a de-miner in our senior group. When will these wars end?

      My last name is German, don’t know how far back. My grandfather immigrated here from Norway.

      1. urbansimulator

        Well our climate has also changed a lot, at Christmas we had 15° Celsius with spring flowers coming out of Earth and Roses starting to blossom again, quite crazy to be honest. Winter started only around 3 weeks ago and is now showing full power with some snow, etc. pp. and I like this very much so far it is dry, sunny & cold. The last summer was incredibly hot in contrast with temperatures going to around 38° Celsius like in South-Europe. So it would really need quite quick more renewable energy everywhere in the world, but still nuclear energy plants are constructed even after Fukushima what I really can not understand while I have already protested against this stupidity nearly 40 years ago like many others. From this more basically orientated protests a now quite powerful green party (8 – 10%) has been founded long time ago what has also changed our society and the minds of many people very much. So renewable energies have a great support today also by politics. But we get more renewable energy from the wind and/or biomass than from the sun. Even private house-owners put solar-receivers on their roofs. However, politics do not want to stop coal-power plants here in Germany actually, but the traditional energy enterprises face big problems with their business system (no more great profits and partly huge losses with their traditional power plants) because they failed to switch to renewable energy plants early enough. So in this respect there is real progress and hope for Germany. Besides we have also a strong weapons industry exporting military material whereever what is not deescalating conflict areas in the world like the Middle East. This is worrying me a lot, because I can not understand why American/British/French are throwing bombs in colonialistical manner on Syria which used to be a nice Arab country where it was no problem for Christians to live and practise their religion (even alcohol available because the Assad-regime is more secular orientated) besides other not so nice political matters which are also existing in other countries of this world. I have been their several times (also visited the archeological site Palmyra, etc.), and it is shocking to see how this country is destroyed by several war-parties (not only IS). When will this end?

      2. katharineotto Post author

        I read Germany is making good use of burning plastic for energy. Maybe landfill methane, too. It was in NYT or WSJ. Now, those are sustainable ideas, because as long as we animals are farting, we will have methane that can be tapped.

        Savannah has a non-operational waste-to-energy plant that was generating steam for a paints industry. When the company closed, so was the plant. Now, is that a stupid waste of taxpayer dollars, or what? Let’s collude to share ideas publicly, so that everyone can participate in the solution. No patents allowed.

        One thing that stands out like a sore thumb is America’s stubborn adherence to the fractional system of weights and measures. My Bosch products are outfitted completely differently for American buyers than for anyone else in the world. If the global economy is ever going to roll forward again, we must standardize gauges, screw sizes, wrenches, measuring instruments. Decimals make so much more sense.

        By the constitution, Congress is given control of weights and measures. This was a political issue between Britain and France, around 1795. The compromise was that Britain would get time (Greenwich), and Paris would get the metric system. This was also one of Thomas Jefferson and Haha Hamilton’s fiercest battles. TJ finally won the fight for a decimal-based monetary system. His reasoning was that the British system (fractions) “works for bankers, but not for farmers.” More in an upcoming blog.

        My roosters laugh at Daylight Savings Time, as though the sun can be moved by an act of Congress.

        CLUCK! Cluck Cluck cluck cluck . . .

        Kaka Big Chicken

  4. Outlier Babe

    Dear Big Chicken,

    I will probably turn this into a post and link back to your lovely post that so perfectly gathered lots of the research already (there was just another t’other day that showed standardized test scores rise when students can see out a window–I believe at a view of a green field w/trees). ‘Cause I wanted to write about something…culturally difficult: The despising of greenery by a subset of the Mexican culture. How deciduous trees are often despised because the leaves are dropped. How some of my students thought views of greenery were hideous, but they thought views of parched and cracked desert ground were beautiful. How the only trees that are viewed worthy of being kept are those that bear fruit. How front and back yards are immediately paved over when houses are purchased, sometimes with holes left for 3, 4, or 5 sparsely-trimmed rosebushes. How after cups of coffee and bottles of soda are consumed, they are disposed of, not by tossing them on the ground, but by tucking the empties into the nearest bush or hedge–because, apparently, this is placing trash with trash. How, when a house is purchased with a tree in the yard, the leaf-bearing branches of the tree are cut off with a chainsaw, leaving the branchless trunk and arms standing there like a bare spike (if evergreen), or monstrous deformed Quasimodo. The ugly sight bothers the new homeowners not one whit, as they consider it far more attractive than the “messy” (beautiful) shade or evergreen tree that previously graced their yard.

    When I began encountering this attitude, it felt like there was some emotional damage involved. It was hard to accept that this could be solely cultural preference. I still find it hard to accept.

    1. katharineotto Post author

      Me, too. How very strange, because I tilt so far in the opposite direction. I believe that if there is climate change, it more attributable to the destruction of forests and the paving over of green land for highways and housing developments.

      In “Collapse,” Jared Diamond claims deforestation–with resultant erosion and destruction of bird and other wildlife habitats–to the collapse of unsuccessful civilizations, such as the Easter Islanders.

      We all know that plants generate O2 from CO2, but few have connected the dots to realize junk mail and the mass thermal effect of pavement and concrete contribute enormously to climate change. Pavement and concrete generate thermals in cities and don’t allow cooling water to percolate through the soil.

      I look forward to your blog(s) on this topic. Regular people need to tune into their common sense and to remember that the “scientists” on the payroll are heavily invested in government solutions to government-and-corporate created problems.

      1. Outlier Babe

        Re: Gov’t solutions:

        While other cities across the U.S. strive on behalf of more beautiful surroundings, healthful air, cooler summers, and happier citizens
        – to be named Tree Cities;
        – to add mini parks wherever possible;
        – to encourage, or even require, rooftop greenery on new high-rises
        even while taking water-conservation measures into account–

        Los Angeles went another route. Its citizens were offered hefty bucks to dig up lawns–supposedly to convert to more desert-friendly plantings. How much oversight/auditing, do you think? How many beautifully-landscaped yards on the moneyed much-smaller side of the tracks, versus an overnight LEAP in 100% paved, heat-radiating surfaces on the other? No push by our wise leaders to plant trees–to increase shade, decrease A/C use, lower air temps. No forethought (but now, some afterthought rumblings) into simple recapture systems.

      2. katharineotto Post author

        That’s what tends to happen when you’re spending other people’s money and needn’t take any personal responsibility for the outcome. Even when local governments are claiming to do the ecologically “correct” things, they manage to make it cost-ineffective by farming out the work to expensive and incompetent contractors.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s