The Good Health Issue: In Depth
- The Curious Case of the Antidepressant, Anti-Anxiety Backyard Garden
The Curious Case of the Antidepressant, Anti-Anxiety Backyard Garden
Whether it's microbes in the dirt or fresh air—or both—researchers do know this: Gardening is strong medicine.
Gardening is my Prozac. The time I dedicate to training tomato vines or hacking at berry bushes seems to help me stave off feelings of sadness or dread and calm the chatter in my mind. My vegetable beds have even buoyed me through more acute stressors, such as my medical internship, my daughter’s departure for college, and a loved one’s cancer treatment. I’m not alone in appreciating the antidepressant and anti-anxiety effects of gardening—countless blogs are dedicated to this very subject, and a rash of new studies has documented that spending time around greenery can lead to improved mental health.
The idea that microbes in our environment might impact our health was not new to me. 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.) But garden microbes acting as mood enhancers—well, this was news to me.“How does this work?” I asked Jill Litt several years ago when I first became interested in what I call gardening’s “bio-euphoric” effect and was wondering whether to prescribe this activity to my depressed patients. Litt, a professor at the University of Colorado School of Public Health, was studying gardening’s impact on a variety of health outcomes—including mood disorders. She rattled off a list of possible explanations, including that gardens create community, encourage physical activity, offer a bounty of nutrient-rich food, and expose one to Vitamin D-producing sunshine, which helps regulate serotonin, the “happiness” neurotransmitter. But then Litt surprised me by adding, “Also there are the microbes themselves. We have no idea what they are doing.”
I soon discovered that there is, in fact, evidence to back up this idea. It’s a smattering of data, and most of it has been collected on our distant cousins, the mice, but it is still compelling.
This investigation into the soil-mood connection began, like much of science, quite serendipitously. British researchers were testing whether immune stimulation with Mycobacterium vaccae, a harmless microbe found in soil and water and potentially on unwashed vegetables, might help treat lung cancer in humans. While they discovered unchanged life expectancy in the subjects treated with the M. vaccae, they were surprised that these patients scored much higher on a standard quality-of-life questionnaire than the controls. Somehow the bug had enhanced their mood.
This finding inspired another researcher, Chris Lowry, a behavioral endocrinologist at the University of Colorado Boulder, to inject heat-killed M. vaccae into the bronchi of mice. The rodents, like the cancer patients, seemed to derive a psychological benefit from the treatment, exhibiting less depression and anxiety on a stressful “forced swim test.” In their article in Neuroscience, Lowry and his colleagues hypothesize that the immune reaction to M. vaccae activates the release of brain serotonin leading to reduced stress-related behavior.
Building on Lowry’s work, Susan Jenks and Dorothy Matthews, two researchers at Sage Colleges in Troy, New York, decided to administer M. vaccae to their mice and perform a new set of behavioral tests. Instead of using the heat-killed M. vaccae used in previous experiments, they cultured the live organism and fed it to the mice via a concoction of Wonderbread and peanut butter. It occurred to me that this exposure method most closely mirrored how I might come in contact with M. vaccae: by eating the casually washed greens that I regularly harvest from my backyard.
“It was just amazing,” Jenks said, discussing a maze test designed to expose rodents to stressful new situations. “We would place them in the maze and could clearly see that there were some mice doing better than others. We would think: ‘Is that the M. vaccae [mouse]?’ And sure enough it was.”
Forever in search of safe, low-tech solutions that I can offer my patients, I asked Jenks whether her experiment was essentially suggesting that M. vaccae exposure by eating backyard veggies or digging with glove-free hands could be a potential new antidepressant therapy.
“What our research suggests is that eating, touching, and breathing a soil organism may be tied to the development of our immune system and our nervous system. But you have to understand that we fed our mice much more of that organism than you are likely to find in a peck of dirt—it was more like a drug dose.”
In fact, an entire raised bed in my garden is unlikely to contain as much M. vaccae as what Jenks was serving her mice.
Our well-being likely depends on more early and frequent exposure to a diverse group of bacteria, fungi, protozoa, and worms.
Still wanting a treatment I could offer my patients, I called Jack Gilbert, a marine microbial ecologist by training, who teaches at the University of Chicago. Gilbert co-founded the Earth Microbiome Project and American Gut, two ambitious collaborative projects seeking to understand how humans and other animals interact with their microbial environments. Gilbert had previously shared with me that his son’s autism diagnosis had prompted his interest in the potential neuroregulatory effects of microbes.
When I asked him what I might advise my patients based on these findings, he sighed.
“Every talk I give, there are parents that want something. I totally get it. We want that thing that will help our kids feel better.
“All this research is really fascinating, but we don’t have enough information to make any claims. If I were to say to everyone, ‘Move to a farm, buy a dog, and eat more raw veggies,’ those statements would be vacuous from an experimental or clinical perspective.”
Speaking with Jenks and Gilbert reminded me that M. vaccae is not an isolated therapy. In fact, it is just one of an enormous palette of microbes that have been interacting and coevolving with us since our earliest days. Our immunological and psychological well-being likely depends on more early and frequent exposure to a diverse group of bacteria, fungi, protozoa, and worms than it does on any one organism.
These creatures, which interact with us through our skin, lungs, and gut, are what Graham Rook, physician, microbiologist, and professor emeritus at University College London, refers to as “Old Friends.” I met Rook last year at an evolutionary medicine meeting at the University of Arizona where he presented a series of compelling studies in support of his “Old Friend” theory of immune dysregulation: that a mismatch between our DNA and our modern microbe-depleted environment is responsible for a recent increase in chronic health problems, including autoimmune diseases and depression.
So what to advise my patients? I agree with Jenks and Gilbert. Microbiome research is still in its infancy, and there is much to discover before we can make definitive prescriptions. But there is compelling evidence that we need a diversity of organisms found in animals, plants, soil, water, and air for optimal functioning of our immune and nervous systems. I now equate preserving ecological diversity in our surroundings with protecting our own health.
On a large scale, we can begin to do this by increasing the diversity of what we grow on our farms because agriculture, covering more than a third of the earth’s land surface, is an obvious reservoir for biodiversity. Our prevailing system of crop monoculture has severely limited the variety of organisms hiding beneath the soil, lying on the plants, and roaming the fields. The herbicides and pesticides used in monocultures narrow this spectrum further. We can start to shift to a more diversified system of farming by patronizing farms that grow a range of crops and by educating friends, neighbors, medical providers, and lawmakers about the health importance of this type of agriculture.
Even closer to home, perhaps the best place for us each to begin is with our own backyard plot or window box. Planting a rainbow of seeds, avoiding the use of garden chemicals, nourishing the soil with plant matter, digging with our hands, and eating the bounty—while not guaranteed to replace a pharmaceutical grade antidepressant—is a wonderful chance to hang out with “Old Friends.”
The Good Health Issue: In Depth - The Curious Case of the Antidepressant, Anti-Anxiety Backyard Garden The Curious Case of the Antidepressant, Anti-Anxiety Backyard Garden Iwe ni vijidudu katika uchafu au hewa safi - au zote mbili - watafiti wanajua hii: Ujenzi ni dawa yenye nguvu. Ujenzi wa bustani ni Prozac yangu. Wakati ninaotumia kupasua mizabibu ya nyanya au kukata vichaka vya berry huonekana kunisaidia kuondoa hisia za huzuni au hofu na kutuliza mazungumzo katika akili yangu. Vitanda vyangu vya mboga vimenisaidia hata kupitia mambo yenye mkazo zaidi, kama vile mazoezi yangu ya kitiba, kuondoka kwa binti yangu kwenda chuo kikuu, na matibabu ya kansa ya mtu ninayempenda. Mimi si peke yake katika kufahamu athari za antidepressant na anti-kicho cha bustani - blogi zisizohesabiwa zimejitolea kwa mada hii, na mlipuko wa masomo mapya umeandika kwamba kutumia wakati karibu na kijani inaweza kusababisha afya ya akili iliyoimarika. Wazo la kwamba vijidudu katika mazingira yetu vinaweza kuathiri afya yetu halikuwa jipya kwangu. Ni imara kwamba vijidudu katika udongo kuongeza thamani ya lishe ya chakula na, kama kupatikana katika masomo ya watoto wa shamba katika Bavaria na miongoni mwa Indiana Amish, kuboresha kazi ya kinga. Watafiti wamegundua kuwa kuambukizwa kwa vimelea mbalimbali mapema katika maisha kunasababisha mzio mdogo. "Makrobio ya bustani hufanya kazi kama vichocheo vya hali ya moyo, na hii ilikuwa habari kwangu. ""Inafanyaje kazi?"" Niliuliza Jill Litt miaka kadhaa iliyopita wakati nilipopata kupendezwa na kile ninachokiita athari ya bustani ya ""bio-euphoric"" na nilikuwa najiuliza ikiwa ni lazima nipe dawa hii kwa wagonjwa wangu wa kushuka moyo." Litt, profesa katika Chuo Kikuu cha Colorado Shule ya Afya ya Umma, alikuwa kusoma athari za bustani juu ya matokeo mbalimbali ya afya - ikiwa ni pamoja na matatizo ya hisia. "Mwanamke huyo alieleza kuwa ""mashamba huunda jamii, huchochea shughuli za kimwili, hutoa chakula chenye virutubisho vingi, na humweka mtu kwenye jua linalotokeza vitamini D, ambalo husaidia kudhibiti serotonini, neurotransmitter ya furaha.""" Lakini kisha Litt aliniashiria kwa kuongeza, <unk> Pia kuna vimelea wenyewe. Hatujui wanachofanya. <unk> Punde si punde niligundua kwamba kwa kweli kuna uthibitisho unaounga mkono wazo hilo. Ni data chache sana, na nyingi zimekusanywa juu ya binamu zetu wa mbali, panya, lakini bado ni ya kuvutia. Uchunguzi huu juu ya uhusiano wa udongo na hali ya hewa ulianza, kama sayansi mingi, kwa bahati mbaya sana. Watafiti wa Uingereza walikuwa wakijaribu ikiwa kuchochea kinga na Mycobacterium vaccae, vimelea visivyo na madhara vinavyopatikana katika udongo na maji na uwezekano wa kuwa kwenye mboga zisizofuliwa, inaweza kusaidia kutibu kansa ya mapafu kwa wanadamu. Wakati waligundua muda wa kuishi haukubadilika katika masomo yaliyotibiwa na M. vaccae, walishangaa kwamba wagonjwa hawa walipata alama ya juu zaidi kwenye maswali ya kawaida ya ubora wa maisha kuliko udhibiti. Kwa njia fulani mdudu huyo alikuwa ameongeza hali yao ya moyo. Utafiti huo ulimchochea mtafiti mwingine, Chris Lowry, mtaalamu wa endocrinology ya tabia katika Chuo Kikuu cha Colorado Boulder, kuingiza M. vaccae iliyouawa na joto katika bronchi za panya. "Wanajimu hao, kama wagonjwa wa kansa, walionekana kupata faida ya kisaikolojia kutokana na matibabu, wakionyesha unyogovu na wasiwasi mdogo kwenye ""mtihani wa kuogelea kwa kulazimishwa"" wenye mkazo. ""Katika makala yao katika Neuroscience, Lowry na wenzake wanadhani kwamba athari ya kinga kwa M. vaccae huamsha kutolewa kwa serotonini ya ubongo inayoongoza kwa tabia inayohusiana na mkazo." Kwa kuzingatia kazi ya Lowry, Susan Jenks na Dorothy Matthews, watafiti wawili katika Chuo cha Sage huko Troy, New York, waliamua kutoa M. vaccae kwa panya wao na kufanya seti mpya ya vipimo vya tabia. Badala ya kutumia M. vaccae iliyokufa kwa joto, walikuza kiumbe hai na kumlisha panya kupitia mchanganyiko wa Wonderbread na siagi ya karanga. "Nilidhani kwamba njia hii ya kuambukizwa ilifanana sana na jinsi nilivyoweza kuambukizwa na ""M. vaccae"" kwa kula mboga zilizosafishwa kwa kawaida ambazo nilivuna mara kwa mara kutoka bustani yangu." "Ilikuwa ya kushangaza sana", Jenks alisema, akizungumzia jaribio la labyrinth lililokusudiwa kuwafunua panya hali mpya zenye mkazo. <unk>Tulikuwaweka katika labyrinth na tunaweza kuona wazi kwamba kulikuwa na baadhi ya panya kufanya vizuri zaidi kuliko wengine. "Mwanzoni, tulidhani, ""Je, hiyo ni M. vaccae?"" na kwa hakika ilikuwa hivyo. ""Kila wakati nikitafuta suluhisho salama, la teknolojia ya chini ambayo ninaweza kuwapa wagonjwa wangu, nilimwuliza Jenks ikiwa jaribio lake lilikuwa linadokeza kwamba mfiduo wa M. vaccae kwa kula mboga za nyuma au kuchimba kwa mikono isiyo na glavu inaweza kuwa tiba mpya ya antidepressant." "Utafiti wetu unaonyesha kwamba kula, kugusa, na kupumua viumbe vya udongo huenda kukawa na uhusiano na ukuzi wa mfumo wetu wa kinga na mfumo wetu wa neva.""" "Lakini lazima uelewe kwamba tulikuwa tukitoa wanyama wetu zaidi ya kile ambacho unaweza kupata katika mchanga, ilikuwa kama kipimo cha dawa, kwa kweli, kitanda chote kilichoinuliwa katika bustani yangu hakina uwezekano wa kuwa na M. vaccae kama kile Jenks alikuwa akitoa kwa panya zake. """ Inaelekea kwamba hali yetu ya afya inategemea kuathiriwa mapema na mara nyingi na vikundi mbalimbali vya bakteria, kuvu, protozoa, na minyoo. "Kwa sababu ya kuwa nilitaka kupata matibabu ya kutosha, nilimpigia simu Jack Gilbert, mtaalamu wa mazingira ya majini, ambaye anafundisha katika Chuo Kikuu cha Chicago.""" Gilbert ni mwanzilishi mwenza wa Earth Microbiome Project na American Gut, miradi miwili ya ushirikiano wa kutamani kutafuta kuelewa jinsi wanadamu na wanyama wengine wanavyoingiliana na mazingira yao ya microbial. Gilbert alikuwa ameshiriki nami hapo awali kwamba utambuzi wa ugonjwa wa akili wa mwanawe ulikuwa umemfanya apendezwe na athari za uwezekano wa kudhibiti neva za vimelea. Nilipomwuliza ningeweza kuwapa wagonjwa wangu ushauri gani kwa kuzingatia matokeo hayo, alitoa pumzi. <unk>Kila hotuba ninayofanya, kuna wazazi wanaotaka kitu fulani. Mimi kabisa kupata ni. Tunataka kitu ambacho kitawasaidia watoto wetu kujisikia vizuri zaidi. "Utafiti huu wote ni wa kuvutia sana, lakini hatuna habari ya kutosha kufanya madai yoyote. "Ikiwa ningesema kwa kila mtu, ""Hamishieni shamba, nunua mbwa, na kula mboga zaidi mbichi,"" taarifa hizo zingekuwa tupu kutoka kwa mtazamo wa majaribio au kliniki. ""Kuzungumza na Jenks na Gilbert kunikumbusha kwamba M. vaccae si tiba ya kutengwa." Kwa kweli, ni moja tu ya aina nyingi za vimelea ambavyo vimekuwa vikishirikiana na kutokezwa pamoja nasi tangu siku zetu za mapema. "Ubora wetu wa kinga na kisaikolojia unategemea zaidi kuambukizwa mapema na mara kwa mara kwa kundi tofauti la bakteria, kuvu, protozoa, na minyoo kuliko kwa kiumbe chochote kimoja. """ "Mwanamume mmoja anayeitwa Graham Rooke, ambaye ni daktari, mtaalamu wa microbiolojia, na profesa wa emeritus katika Chuo Kikuu cha London, alimwita ""Rafiki wa Kale"" katika mkutano wa dawa ya mageuzi katika Chuo Kikuu cha Arizona, ambapo alitoa mfululizo wa masomo ya kuvutia kuunga mkono nadharia yake ya ""Rafiki wa Kale"" ya dysregulation ya kinga: kwamba kutofautiana kati ya DNA yetu na mazingira yetu ya kisasa ya microbe ni wajibu kwa ongezeko la hivi karibuni la matatizo ya afya ya muda mrefu, ikiwa ni pamoja na magonjwa ya autoimmune." Kwa hiyo ni nini ninachopaswa kuwashauri wagonjwa wangu? Ninakubaliana na Jenks na Gilbert. Utafiti wa microbiome bado uko katika hatua ya mwanzo, na kuna mengi ya kugundua kabla hatuwezi kufanya maagizo ya mwisho. Lakini kuna uthibitisho wenye kusadikisha kwamba tunahitaji aina mbalimbali za viumbe vinavyopatikana katika wanyama, mimea, udongo, maji, na hewa ili mfumo wetu wa kinga na mfumo wetu wa neva ufanye kazi vizuri. Sasa ninafananisha kuhifadhi utofauti wa ikolojia katika mazingira yetu na kulinda afya yetu wenyewe. Kwa kiwango kikubwa, tunaweza kuanza kufanya hivyo kwa kuongeza utofauti wa kile tunachokua katika mashamba yetu, kwa sababu kilimo, kinachofunika zaidi ya theluthi moja ya uso wa ardhi duniani, ni hifadhi ya wazi ya bioanuwai. Mfumo wetu wa kilimo kimoja umepunguza sana aina ya viumbe wanaojificha chini ya udongo, wanaoishi juu ya mimea, na wanaotembea-tembea mashambani. Dawa za kuua magugu na dawa za kuua wadudu zinazotumiwa katika kilimo kimoja hufupisha zaidi aina hizo. Tunaweza kuanza kuhamia mfumo wa kilimo uliobadilika zaidi kwa kuunga mkono mashamba ambayo hukua mazao mbalimbali na kwa kuwaelimisha marafiki, majirani, watoa huduma za matibabu, na wabunge juu ya umuhimu wa afya wa aina hii ya kilimo. Hata karibu na nyumbani, labda mahali pazuri zaidi kwa kila mmoja wetu kuanza ni na shamba letu la nyuma au sanduku la dirisha. Kupanda mbegu za mvua, kuepuka matumizi ya kemikali za bustani, kulisha udongo na nyenzo za mimea, kuchimba kwa mikono yetu, na kula zawadi - wakati haijahakikishiwa kuchukua nafasi ya dawa ya antidepressant - ni nafasi nzuri ya kutembea na "Rafiki wa zamani".