LISA:
Welcome to Brainwaves a podcast about big ideas, produced at the University of Colorado Boulder.
I'm your host Lisa Marshall.
This week: gardening.
One in three households now grow their own food. That's up 200% from a decade ago, according to the National Gardening Association. And the under 35 crowd is among the fastest growing groups.
What's the draw?
As it turns out rolling up your sleeves and getting some dirt under your nails can be really healthy for you and your community.
We'll talk about some surprising reasons why, but first let's tag along with Brainwaves’ Dirk Martin.
He recently toured the Magnificent Fortune Garden, one of eleven community gardens in Boulder County with gardener John Day.
JOHN:
Okay, well we’re just coming up the alleyway and on our left is Fortune Park, and there are one, two, three, four... my math is not so good, but there are 18 lots here.
And this is all part of the Boulder Growing Gardens community garden system.
We're quite lucky here this is a very small garden, and we're pretty independent from the rest of the other gardens within the organization.
And I'll explain, here we have a lock, and the fence here serves several purposes, the main one: keeps the animals out.
And even when animals do get in, they tend to get out sometimes.
So, we've had deer in here and occasionally a dog, as you see coming along here: a beautiful dog.
Anyway I've opened the gate, and I'm gonna go over to my plot. Each lot is about ten foot square, and we're responsible for maintaining them. There are no real rules on what we can actually farm.
Generally most people, as far as I know, grow vegetables.
DIRK:
How do you garden?
JOHN:
Well, I basically do the Gandhi squat and get my hands in the soil. I can just get underneath there and break the soil up by hand and, well it's a little bit wetter than normal.
DIRK:
You're breaking up the soil, what does that do for it?
JOHN:
Well, it lets the air in. It lets the microbes do their job, breaks down the nutrients, and for me, it feels very, very good.
DIRK:
So what are your favorite vegetables to grow?
JOHN:
I normally have a process: beginning of the season, radishes goes in, spinach goes in, lettuce goes in. And then right about this time of year, maybe a little earlier, and in normal year start putting in the zucchini, the tomatoes and the beans.
DIRK:
What inspired you to get into community gardening?
JOHN:
Relaxation.
When I start gardening, I just go into my own little world. There could be a nuclear war going on, but I wouldn't know anything about it. I find it quite therapeutic. I also like to get my hands dirty, for me that also feels good.
So in a way you really connected with nature when you can do that yourself. It's good exercise. And then, of course, the bonus is you get some produce from the garden, and I come up here in the summer nearly every day and pick my vegetables.
Nothing like fresh food and when you grow your own, it's about as good as it gets.
[Music]
LISA: If you're a gardener, you probably already know this, but dirt can reduce stress: why?
And wouldn't it be great if you could bottle that stress relief?
One CU Boulder scientist has been working for decades to do just that, here's the story.
Ask any gardener, and they'll tell you: the minute you dig your hands into that rich black soil you start to relax. But why exactly is that?
CHRIS LOWRY:
So there's a lot of things about gardening that are likely to improve mood and psychological outcomes, including light exposure, physical warmth, somatosensory stimulation from touching the soil, feeling the soil, light breeze on exposed surfaces of your skin. But our work suggests that there's also something that's unseen that might also be impacting our mood.
LISA:
That's Chris Lowry, an associate professor of integrated physiology at CU Boulder.
For about 20 years, Lowry has focused his attention on one particular unseen ingredient: a bacterium hidden deep in the soil.
He has a radical idea in mind. He wants to use it to develop a stress vaccine.
CHRIS:
The original identification discovery of mycobacterium vaccae was in the early 1970s. It's a story related to immunologists and their understanding of vaccines.
LISA:
The year was 1971.
British scientists noticed that people living near Lake Kyoga in Uganda responded much better to certain vaccines than other people did.
They suspected there was something in the environment at play. When they investigated, they discovered an orange slime stretching across the lakeshore soil.
CHRIS:
They reasoned that the presence of mycobacterium vaccae in the soil, in the mud and the water in Lake Kyoga was acting as an environmental factor, as an adjuvant to boost the efficacy of the vaccines.
Later they learned that not only could it interact as an adjuvant with with these vaccines, but this bacterium also had what we call the amino regulatory effect, or anti-inflammatory effect, and in other words what this bacterium can do is interact with our immune system.
LISA:
Fast forward to 2007 when Lowry published his first study about the bacterium. It showed that when it was injected into mice, it acted a lot like an antidepressant.
CHRIS:
The press release came out on April Fool's Day. A lot of people thought well this must be an April Fool's joke.
CHRIS:
Since then, Lowry has published many more studies showing that exposure to beneficial bacteria in soil can boost human health.
One showed that kids raised on a farm, surrounded by animals and dirt, grow up to have more stress resilient immune systems and fewer mental health problems than people who dwell in the city. Another found that when mice are exposed to dirt dwelling bacteria, it reduces inflammation throughout the body and brain. That's important, because inflammation fuels disease, including depression.
CHRIS:
This is all in line with the hygiene hypothesis; the idea that as humans have moved into urban environments and away from rural or agricultural environments, we've lost contact with these types of microorganisms. As a consequence, we're at higher risk.
LISA:
Ultimately, Lowry wants to harness and bottle the secret ingredient in the soil and other bacteria like it to develop a sort of vaccine against stress-related disorders.
CHRIS:
The next step is to conduct clinical trials with high risk groups to see if treatment with the bacteria can prevent either depression or onset of PTSD after trauma exposures.
And this could be done either using the current strain, as a drug, in other words, as an injection, and in fact, thousands of people have been injected with this particular strain in different clinical trials, just not in psychiatry. And another approach might be to develop related strains that are also derived from soil from the environment that have similar properties and develop them as immune or nutritional supplements.
So in other words something that would be taken orally or as a nasal spray.
LISA:
Until then, if you want to get reacquainted with that healthful dirt we've lost touch, with head to the garden.
Stress relief aside, gardening can also be good for your community and even your weight.
We talked to Jill Lit an environmental health researcher at CU Boulder who has traveled from Boulder to Barcelona studying how community gardens impact our bodies and our neighborhoods.
LISA:
I know that you're in Spain right now and you've also done some research in France and other areas of Europe. When you ask people all over the world why they garden what do they tell you,is there sort of a universal answer that you get?
JILL:
As a health researcher I would expect people to say that they garden because they can eat better it's about health is about nutrition but what's interesting about what all gardeners say, no matter where they are across the globe, is that they garden because it makes them feel good, and they garden because they like to get their hands dirty, and they garden because they like to hear the sounds of nature.
LISA:
Can you just talk a little bit about what you found, how it benefits people to participate in a community garden?
JILL:
First, they provide an opportunity for social connection, second they provide a way in which gardens give people access to nearby nature. It is something that doesn't cost money, it is very close to where people live and it's very meaningful work. But it also gives people this access to fresh air, clean soil, a time to relax, a place that's beautiful. So people often talk about how beautiful these places are that they really feel different when they enter into the garden setting.
LISA:
Aside from the social connection piece, does it change the way people eat? I mean does it change how much they weigh or how active they are things like that?
JILL:
We saw that people who participated in gardens ate two times the amount of fruits and vegetables than people who did not garden.
We were able to compare Denver residents--people who didn't garden, people who gardened at home and people who gardened in the community context--and we saw this twofold increase.
This is more than almost all interventions that try to improve diets, so we see that there is this potential for changing diet. We also learned that people spend, on average, over an hour every time they visit the garden being active. They walk to the garden, participate in the garden, they walk home.
It's a way in which we get people to change their life activity behaviors. So they're less sedentary when they participate in the garden.
We also saw that people who garden had lower body mass index, a metric we use to monitor health in the population and particularly weight status, so we saw a difference between community gardeners who had the lowest body mass index, on average it was about 24, compared to those who did not garden and that average was about 27.
LISA:
I just wonder if you, anecdotally, if you could share anything about people being connected with one another through a community garden.
JILL:
People talk a lot about the relationships they build through seeking help and giving help. So this idea of reciprocity. People learn from their neighbors in the garden context. So, they look over at their neighbor’s plot, and they see how they're doing something, and then they might try it. And while that might feel very simple, these are the important ways in which people build feelings of confidence, feelings of belonging, feelings of purpose, all of these things that are really important for well-being.
LISA:
So I understand you have gotten some funding from the American Cancer Society. Can you just talk a little bit about that study that is ongoing now, and what you hope to find out?
JILL:
We received an award from the American Cancer Society to basically run a randomized control trial of community gardening. And in the study, our main focus is looking at changes in nutrition, changes in physical activity and changes in social connection.
LISA:
If you're someone who wants to reap the benefits of gardening and you've never done it before, is there any advice you would have on just an easy way to get into it?
JILL:
I think start small and choose a reasonable area of land. Or maybe start in containers, if you're not so sure.
Reach out to your garden stores, because they have a wealth of knowledge.
There's also master gardeners who can help give advice on what to grow in the places where you live, and the kind of environment you have to support plants. So, how much sun, shade and that kind of balance. And ask your neighbors, because amazingly over 70% of people say that they like to garden, so there is a wealth of knowledge in your community.
LISA:
Well great, well thank you so much for doing this we appreciate the time you've taken.
JILL:
Thank you.
LISA:
That's it for this week's episode, join us next week when we look back at the 50th anniversary of the first Moon landing, and some of the Moon science we've yet to figure out in the decades since.
Dirk Martin, Cole Hemstreet and Paul Beique produced today's show.
Sam Linnerooth is our digital producer.
Andrew Sorensen is our executive producer, and I'm Lisa Marshall.
Thanks for listening.
We'll see you next time on Brainwaves.