446-How Nature Heals Us, with Kathy Willis, Ph.D.

Hi everybody, this is Joe Lample, the Joe Behind Joe Gardener, and welcome to the Joe Gardener Show. Today I'm excited to welcome someone whose work sits right at the heart of what we talk about on this show, the relationship between people, plants, and the natural world. You know that feeling you get after walking out into the garden and spending even a small amount of time there? Our stress levels go down, our creativity goes up, and we're reminded of that awe-inspiring feeling all around us. And that's exactly what our guest today, Professor Kathy Willis does with her new book, Good Nature. It digs into the science behind something gardeners have always felt instinctively. Overall, Good Nature is a book about how nature influences human health and well-being, where plants are the stars of the show. Suffice it to say, Professor Willis brings the science behind that to life, and it opens up a whole new way of thinking about the gardens and natural spaces that we interact with every day. Because we love geek alerts so much on this podcast, you'll be happy to know this episode is certainly worthy of that. Now a little bit about Dr. Willis. She is one of the leading plant scientists and biodiversity experts of our time. She's a professor of biodiversity at the University of Oxford and the former director of science at the Royal Botanic Gardens, Q, where she helped advance global research on plant conservation and ecosystem resilience. So let's get started with my conversation with Kathy Willis, and as we do, thanks to our sponsor for this episode, the Ultimate Gardening Sheet, just in time for the gift-giving holiday season. The Ultimate Gardening Sheet is the one piece of gear that truly changed the way that I garden. After years of juggling my pruners, soil knife, and micro snips, I co-created this sheet to keep everything secure, comfortable, and right where I needed it, and based on your feedback, it's done the same for many of you. And with the holidays here, it's perfect timing. The Ultimate Gardening Sheet is also the Ultimate Gardening Gift. If you want something unique, beautifully handcrafted, and built to last for years, this is it. And now, through December 31st, you get the Pro Series Edition, which includes the UV marking pen, plant tags, and stainless steel carabiner at no additional cost, a free $15 upgrade. Hand-made in North Carolina by a skilled leather artisan, this sheet is practical, durable, and one of a kind. It's available exclusively at joegardner.com slash UGS. To learn more and order yours today, visit joegardner.com slash UGS. Professor Kathy Willis, thank you for being here. I really enjoy reading good books, especially when they're sciency related to gardening and nature. Ironically, in my podcast theme, we always talk about the connection between people and the natural world. And plants, of course, is the centerpiece. And your book seems to really encompass all of that together. So I'm very excited to have this conversation. So I really do appreciate you being here. Thanks for taking the time to do that. I'm really put to this. Good. Good, good. Well, thank you. All right. So I want to ask your kind of your journey to you've got some really prestigious work and job titles and things that you do now and have done for years. Give us kind of the overview of you wherever you want to begin. Well, I always just like being outdoors always, even though we grew up in London, but we grew up in a sort of northern part of London, which is quite leafy. And my mother was of the generation that was evacuated during the Second World War from central London into the countryside, into the Leicestershire countryside, which is still really beautiful. And so she knew all the plant names and she knew all these sort of things about landscapes. And I think that just rubbed off onto me. And whenever we went on holiday, she'd always be pointing out the flowers in the hedgerows. And so I got very attached to the environment. And one is at school. I just, the subjects I most liked were things like biology, but it was more the sort of whole organism plants and those sorts of things. And I also liked geography and I liked chemistry and the interaction of the natural world. And so I went to do an environmental science degree originally. And I was the first generation in our family to ever go to university. My sister had gone. She'd sort of she'd cut the way through and I got to university, but I chose environmental science. And at that point, that was at the point where people really weren't thinking about climate change. And I was just as 1982. And my father was very bemused because he hadn't been to university and left school at the age of 12. So he sort of thought, what earth is this in from? You know, it's sort of food science. But I persisted. And when I got to university, that's university Southampton. And when I got there, I realized that I loved that course. So it spent a lot of time in the New Forest, which is absolutely beautiful. A lot of the coursework was outdoors. And from there, I went on to do a PhD in Cambridge in Botany. But again, looking at vegetation and how vegetation responds to climate and other environmental drivers stayed there for 13 years in the end. And then I had one year as a plant sciences editor at Cambridge University Press. And I was terrible at that terrible. It's like this is not the job of me. It's my fault. I mean, I just I'm not very good being indoors with books. I don't know why I thought I should even apply for it, actually. So after after spending this time at the publisher for one year, I then went back into research. But it was a very good year out because it made me decide what I did want to do around just carrying on. And then I got to a particular point in my career where I still in Cambridge. And I suddenly realized that I was on soft money, research money. And I saw a permanent job being advertised in Oxford in geography. And I thought, oh, I can teach geography. It's sort of it's environmental. And I got and I got to Oxford and found it was a lot of it was not environmental science. So I the learning curve was very steep. Let's put it that way. And I but I learned huge amounts about subjects I'd never really embraced before about human nature, interactions about landscapes. It was very, very interesting. And also I had to I had to teach tutorials on first year climatology. And as a result, I used to go sit at the back of the lecture. So I was always one stage ahead of the lecture when I then did my small group teach for the students. I'm sure any thought students is like this. Anyway, a long, long story short, I sort of carried on in geography until I got to a point where I was running a big masters program on biodiversity conservation. They advertised a job in zoology in Oxford for a chair, a professor in biodiversity conservation. I thought, oh, well, I can do that. And I applied and got it. Of course, I did exactly the same as I did before I jumped from a department that I was quite comfortable in the area that I've never worked on animals, never will. But zoology in Oxford is really much more about whole organism. And now it's become a department biology. And from there, I was asked if I would go and be the first director of science at Q Gardens in London to set up this whole new structure that they were having. And I decided to do I did that on sabbatical from from Oxford for five years. It was a tough job. Are there 400 scientists there? You're a response. I was responsible for all of these major collections like the Herbarium, the Fungarium, the Millennium Seed Bank, the Molecular Records and the scientists that work on them. And they have so many international partnerships. And then after five years, Oxford said, are you coming back? And Q said, are you staying? And so I went back to Oxford and I've been running a college, one of the undergraduate colleges and resumed my research in Oxford. And then my most recent thing I've done about three years ago, we have two legislative houses in our in our parliament. We have a lower house, which is basically the elected house. And we have a second house called the House of Lords, which scrutinizes an immense legislation to make it better effectively or try and make it better. And so I've gone into the House of Lords as what is known as a crossbench pair, which means I'm nonpolitical. And I work on legislation. I very much on nature, climate, health, education. So I do that alongside the other two jobs. So I had this sort of I'm always juggling these three hats. They're all great and really interesting. Sometimes they all crash into each other. And then everyone does many jobs now. So I mean, I'm not alone in that. But that's that's where I've got to. And the book that I'm talking about is very much it sort of pulled together many different strands of my life into writing a book. And it's partly driven by a frustration that I kept coming across, particularly in policy, where the minute you talk about nature, people always put it into sort of a fluffy bunny, pretty flower bucket. And they never see it as being a scientific relationship between health and nature, what's going on in our bodies when we interact with nature. So that's why I sort of wrote the book from both a policy policy perspective, but also using my scientific knowledge as well. And when did you decide to write the book? And was there anything that was the catalyst to finally get you to do it? Clearly, you had been, you know, mulling these thoughts over for a while as you went about your business. But at some point you said, I need to write this book and then you did it. Anything you can pin to that that led you to start it? Well, I was working before I went into the House of Lords, I did quite a lot of working on big international projects. And there's one I was working on, which is called the International Panel on Bar, Diversity and Ecosystem Services, long name, many, many countries involved. And my role in that, we're doing a global assessment on nature and and it's how it underpins so many functions that we all rely on. And my role or one of my roles was to find out the relationship between nature and human health. And I imagined it would be sort of stuff like, you know, shade from trees and streets, make the streets cooler, you know, this urban heat island that affects the stuff. And in fact, the paper I kept coming across was this paper that was published in the American Journal of Science in 1984, which showed the people who looked out of hospital window beds, those that looked onto trees, they had the all these people had gallbladder operations. And in those days, you stayed in hospital for like 10 days. OK. The people that looked onto the brick wall or the people who looked onto trees and not brick walls, they had they had less pain relief and they need less pain relief. They recovered faster, they were happier and they went home two to three days quicker. And I thought this is really odd, A, that's published in Science, B, that they've obviously got enough scientific data to show this, but also the whole concept that just looking at something to trigger these different pathways in the body that result in these responses. And that and I it made me sort of think, well, what else is there out there? What are the mechanisms of action that are going on in our bodies when we interact with nature? Right. Right. And so that's where I really started this journey of looking. And the more I looked, the more I found so much evidence out there, but not published in the sort of journals that most people are looking at or not biologists. You know, these are in the top medical journals like the Lancet, the top psychiatry journals and all over the place. These, you know, but actually a big, big body of literature that's been emerging in the last 15 to 20 years. That is fascinating. And I am familiar with that study. I've come across it several times in my work as well. And I really loved seeing that you you mentioned that in your book. And that's kind of what started it. And thank you for sharing that in your research and in putting this book together. Did you recognize anything about yourself that had changed or maybe an observation that related to how these patients were healing faster from just looking at, you know, something pretty rather than a wall? Did you see anything in yourself that made you think, yeah, I get that because I remember this about me or I recognize this. So one of the things that I when I started doing this and it's I still work at Q at that point was I had already realized that if I went walking in the gardens at lunchtime for half an hour, I was always in a much tough job. And I was always in a much better mood in the afternoon. And if I'd walked the same amount of time, but I'd walked to the local shops, you know, you're walking down the street, you've got you've got cars, you've got traffic, but I'd never given it any thought at all really. But every time within the book, every time I've read and researched a section because I've split it up into OK, the different senses outside. And I'll touch out, taste up, you know, the fire, all these main senses. Every time I've researched and came across these studies, stuff started to build up in my house. I'm sitting in my study now, I'm surrounded by plants. I have diffusers down the other end of the room. You know, I look out the window onto green. My computer screen saver is now of trees. Oh, all of these things that we don't need to wait. You know, there's the whole thing about forest bathing and you can go and lie in the forest for two hours. But how many of us have got time to go and lie in the forest? Very few. But there are so many small tweaks you can make within your own lifestyle, your own daily interactions that can absolutely trigger these physiological and psychological changes in our bodies that really do bring about health benefits. And whenever I talk to people, oh, that's obvious. Yeah, I knew that. I knew that. But then suddenly they think, oh, I didn't know that. I didn't know that. So there are also some other things that people just none of us. I certainly knew some of this stuff. Well, this is fascinating in the perfect segue because I did want to talk to you about some of your observations related to the senses, such as sight, smell. And then we can go a little geekier with the environmental biome because that's always something that doesn't get talked about enough. But if you're open to that, I'd love to talk to you about the section under senses and maybe start with sight. Tell me some of the things there. Well, the really interesting thing with sight was two, I think, three interesting aspects. So because it's both the shape and the color and the fractural dimension. So shape and color, you might guess, fractural dimension sounds like a nightmare, but I will unpack it. Good, good. So with just even looking out the window, they have very or even on a computer screen with trees or no trees. Lovely experiment where they have participants just sat there being they were wired up so they measuring their heart rate and heart rate variability. Just very simple measurements of stress. And also they did psychological well-being questionnaires at the end of the experiment at the beginning and end. And just 90 seconds of looking at trees on your computer screen compared to looking at an urban skate like the New York Skyline. 90 seconds, you get a significant lowering of your blood pressure. But also if you look at if they were up the sort of the one of the skull caps where they're finding out where the blood flow is in the brain, they find that the blood is actually going to those parts of the brain that are more associated with physiological calming. So you are calmer by looking at an image of trees on your computer screen than you are of an urban environment. And the same is when you look out the window, if you look out the window onto trees rather than onto bricks, then you have a very, very good reaction. And really interesting, if you're really stressed, it's a good idea to look out the window onto something green because they're showing them when they automatically stress people. I wouldn't do this experiment, but you can stress people with an electric shock to their finger. Doesn't sound good to me, but you can. And when they did this and then they measured at their heart rate, how they calmed down, those that glanced out the window were able to look onto green, recovered much faster than those who didn't. So that's a really interesting aspect of it. But then the next set of things, people looked at color and they used them Ivy Leaves, which are beautiful. The Hedra Helix, it's a slightly different to the American Ivy, but it looks similar. Anyway, that's as you know better than anyone, that you get these very hybridizers really easily. So you get red, greens, orange, gold. So they use these different color leaves and then they've got people to look at these different color leaves all the same shape, same shut size and wired up their brains again and measured blood pressure and the like. And again, it was the green and yellows and the green and white leaves that induced the greatest amount of physiological and psychological calming when you look at them. And so you think about what plants you have in your desk. That's a really interesting, because even a single white rose with green leaves on your desk versus none, they've shown, the experiments shown that people's blood pressure goes down. So I can't see no plants in your background, I have to say. Wait now, that's because it's blurry. I have, I have. Oh, I can see that. Yeah. OK. Yeah. So I've got about four here and they're all, I mean, the noble. And a rescue aloe right here. I'm working on it. Yeah, I've got a dead, a fairly dead spider plant just above me here, so I'm hanging down. But so that's really interesting. Whereas red, red leaves in particular seem to, certainly in the psychological assessments, can cause quite a lot of rise in irritation. That's slightly cultural. That one, there is a cultural bias in that colour. But the thing that has that's got really interesting, this is the third thing is the fractured dimension. So the fractured dimension is when something divides into itself more and more and more. So if you think, you know, if you can get a computer-generated picture that keeps going in and in and in and in and in. OK. But actually nature is very, lot of nature is very fractal. So if you think about a shoreline and then on a coast and then what you have is you have the inlet and then you have smaller inlets and smaller inlets. And so that's a fractural pattern. OK. And trees are another one. If you think of a branch, then you get a smaller branch, then you get a smaller branch, you get a twig. So that same pattern is being repeated through and through. And what they showed is that actually when people look at different fractural dimensions, that you get different responses. And when we look across a horizon, what happens is our eyes are picking out the fractural dimension of the horizon. So if you think about a horizon, you think about a conifer horizon. So you've got lots of pointy pine trees on it. So it's going up and down and up and down and up and down. So that's quite a regular fractural pattern. You think about a more open savanna landscape. You've got a few trees interacted on an open landscape. That's not as fracturally sort of regular. Right. So that's a more open landscape. And that's got a fractural dimension, a mid-level, about 1.3. And then you think about someone like New York's Skyline. That actually doesn't have any fractural dimension or very little because it's all square and different shapes and different heights. So when they wired people up and got them to look at these different fractural dimensions, they found that the greatest physiological relaxation in terms of measuring from brainwave activity and other metrics was when people looked at that mid-level, the more open landscape, the savanna trees, on a scattered landscape. Now, the interesting thing is when you think about it, how many pictures do you see on walls where it's a more open landscape with a few trees? And you think about the earliest gardeners like Capability Brown. What did they create? They created an open landscape with a few scattered trees on it. And so I think inherently we probably know that that is the landscape we most enjoy seeing, but it also seems to trigger the greatest physiological reaction to it and makes people more relaxed when they're looking at it compared to these other landscapes. I find this shape thing really fascinating because once you start to think about it, you think, gosh, that's a really interesting dimension that probably makes sense. You know, I think about when we design landscapes, we plant in odd numbers because to our eye, that just seems to work better than even numbers of clusters of the same plant. Intuitively, our body tells us that we like that better visually and that reminds me of what you're saying there. Very interesting there. Back to sight, for example, and the colors. I found that very interesting because to me, just personally, yellow doesn't seem that calming to me, and yet I still love a nice area of daffodils and a lot of that. But I read, did you mention the autumn paradox maybe? Yeah. So it is funny, we're quite fickle about color. So just going back to your yellow comment before, I think the most important thing on the most clear point that came across me from looking at all of these studies is what's happening is when we see these things, we see these colors, we see this is automatically happening in our bodies. So it's not linked to preference. It's linked, it's an automatic process that's happening, like automatic nervous system, our hormonal system, our endocrine system. All of these, it triggers these pathways. You don't have to go into nature and think, I'm in nature, I must now be calm, or I like the color of that flower. It seems the yellow and white flowers are the ones that automatically trigger these changes that occur. But it's quite interesting. So in terms of preference, they haven't actually measured whether or not this actually comes through to these automatic processes. In terms of preference, people, they much prefer the green, green, green, green until you get autumn. And then all of a sudden, preference levels for reds and oranges, if you talk. But then when you get back to the end, after autumn, after the leaf fall, it goes back to being green again. So we're quite fickle with color, I think. So color is a tricky one. Yeah. And I was saying, there are some cultural differences that have been detected as well with color. And so it's one of those ones where you sort of, there needs to be, many of these things, there needs to be more research on it, particularly if you're using color and colored plants in particular environments to induce calmness then we really do need to understand what colors we're using. What about our sense of smell? How does that play out? Oh, well, smell is the one that most, most really surprised me because I'd always rather assume that you just, it was just a nice scent. I didn't really think much more in the how that lavender smells nice. Your grandmother told you it made you sleep well and you know, we have all these stuff to spray around. Until I realized that first of all, when you breathe a smell in, what's making that smell is effectively, it's called a volatile organic compound. It's a carbon compound that when it hits air, it turns into gas, evaporates. And that's the smell you get. And when you breathe it in, it passes across the membrane in both your nose, but also in your lungs, into your bloodstream. So how do they know that? They've measured people's bloods before they walk in a forest, a pine forest. They've measured the ambient air in a pine forest and found it's high in pineene. That's the compound that creates that piney smell. And then they measured the people once they'd done, before they walked, they measured it in their bloods, at very low levels. They walked for 20 minutes, measured the bloods again, great spike of pineene in their blood. Now, why is that relevant? Because what they find is many of these compounds, or there's a number of them, where those compounds interact once they're in your bloods, they interact the same biochemical pathways as if taking prescription drugs. Wow. So lavender does make you sleepier and it makes you sleep, deeper sleep and for longer intervals of sleep. And they've shown that through clinical experiments as well. Rosemary makes you more awake. Wake affects that, a particular biochemical pathway makes you more alert. So does peppermint. So think about chewing gum and sucking mints. People suck mints to keep awake. Yeah, and it would work because it's doing that. And then there's some really curious ones. And one of the most interesting ones, I think, and is now being picked up in oncology journals, is the heavier smell that's attached to cedar and things like the Japanese cypress. It's called Hinoki oil. If you've taken the pure ointment. And they've shown, they show first of all, in clinical studies, when people inhale this for three nights when they're sleeping in a room with that, they found their adrenaline hormone went right down, but they also found a really elevated level of natural killer cells in their bloods. Now, these are the cells that attack cancers and virus cells. We all want elevated levels. And I also thought it was a really interesting experiment, but even more interesting, a follow-up that's been published a couple of years ago and published in this journal on Cotarget. They had one group of people. They first of all looked at people who lived right near to a cedar forest or lived in it right around the edge versus the same number that lived further away. And they looked at their natural killer cells in their bloods. And sure enough, those that lived in the forest had much, much higher level, statistically significant higher levels, and those lived further away. But also they sent another group of people walking in this forest for five days. And after five days, they had these really high levels of natural killer cells in their bloods. But even more importantly, five days later, they still had the elevated levels. So it's not like it just elevates and then goes back down again. And so therefore that sort of building up a sort of an immune sort of a resilience within your body by actually just inhaling these smells. And then the other one, limonene, the one you get from citrusy fruits is being shown to reduce inflammation in the soft cusin and in this whole sort of respiratory part of the body. And there's clinical trials on that. That's early days. But there's so much that we ignore about plants and smell. And I'd always just, as I say, I now have a whole research project on smell and volatiles because you suddenly realize, well, if it's really pouring with rain and horrible outside, can you get the same benefits for going standing in a glass house in a botanic garden? For example, we had students doing, looking at, we've measured them after they spent 20 minutes sitting in different glass houses compared to a control room. And there's a statistically significant difference in physiological and psychological calming when they sit in a glass house, which is full of smells of citrus fruit or whatever, versus if they sit in just a normal classroom. One more reason to love a glass house, like you need to. I love glass houses. Yeah, I mean, why? Any day. Any day with or without those scents, but yeah. Another case, have they been able to replicate or extract the enzymes or whatever it is, the VOCs and the Hinoki Cypress to be able to take advantage of that without having the plant in your house or your garden or your glass house? So a lot of these experiments, I mean, then that's what I do. I mean, you can buy little bottles of Hinoki oil, which you can just drop into a straightforward diffuser. And you can use it yourself. I mean, every, I don't know, 10 days or so, I'll just switch this thing on, have a sort of study, have a quick puff of it. It wasn't any harm, but it certainly, we'll almost certainly do some good. We're talking about the senses right now, but I did wanna ask you one question. You were talking about, did you say killer cells? Yeah. Is that the word? Okay, just wanna clarify that. It's called natural killer cells. Okay, good. Do you wanna move on from that to environmental microbiome or do we? Yeah, yeah. Okay. Yeah. Go for it. I'm having to talk about that. I mean, this is, this one is a extraordinary really, again. So I didn't know much about the smell. And so smell was one of those, one of those sort of moments you think, this is just extraordinary. And then I got onto the environmental microbiome and somebody, every time I talked about this, somebody had said to me, every time I talked about sort of health and I had, some people saying, what about in the soil? What about the microbes in the soil? And I just tended to ignore all these people. I just thought, oh, you know, it's, and then I started to look around and I, there was a paper that was published about 15, 16 years ago by an absolutely top notch ecologist who's now sadly passed, but in Finland, in Helsinki. And he had worked with these two top, top medics. And they wrote a paper called The Biodiversity Hypothesis, which said that since we have lost more and more nature from our environments, from our cities, we've had a massive increase in all of these autoimmune diseases and inflammatory diseases. They are the non-communicable diseases like asthma and strokes and all the other stuff. And they said, it's because we've lost our environmental microbiome. And I thought, what else is going on about? And they hypothesized that when you spend time in nature, that your body adopts the good bacteria that is all around us in nature. Now that was a hypothesis, but over the last 15 to 20 years, more and more people have shown this. So what I hadn't realized is in terms of our own gut microbiome, only 7% of it is inherited, 93% of it is due to our environment, which is why people are drinking probiotics and doing all these other things to try and change their gut. Because we now know that microbiome in our gut is such an important part of our whole health structure. And some people call it the fourth organism or whatever. And what they've shown now is that certain environments, even outside in your front garden, if you've got plants in your front garden, you will have this wonderful good bacteria being zuded from the plants. And plants and soil in particular will then, if you spend time in that, your body adopts the signature of that microbiome. And the most interesting experiment to prove this was a sort of a double-blind, perfect clinical study that was carried out on nursery school, kindergarten, aged children, in Finland, where they basically gave one set of children played in a sandpit, which they'd put whole little soil in it from the local forest. And then the other sandpit was sterile. And they did number it's term, it's like this with Matt and everything else. And they measured their gut bacteria, they've got microbiome and their skin microbiome, but they also measure their bloods. Because of course, there's lots of studies showing when your gut bacteria gets better, your blood's improved and your inflammatory marks go down. And sure enough, after 28 days, the children that played in the sandpit with soil had a completely elevated gut floor, really diverse, full of really good things, only because they'd played in the sandpit with this soil, which had given them the dirt, had given them the... But also that when they measured their bloods, the T cells, which are really good indicator of inflammatory change, showed a significant reduction. So that you can see that actually these things are linked together. So then they tested it on other people, where even just having a green wall in an office, and they looked at these office workers, you have one of those living green walls behind them in the office, and they looked at their bloods, and they looked at their gut flora and their skin, the bacteria in their gut and the skin. And sure enough, again, after 28 days, those that had the living green wall in the office had this greatly improved gut and skin bacterial, full of the good stuff, the stuff that you drink, a probiotic drink to have. But again, they showed a really important change in their T cells and their bloods, indicating a reduction in their levels of inflammation. And then people have measured, like they've measured the bacteria loads or the microbiome across a park, like an urban park in Adelaide. And if you go from like a soccer pitch, where fairly low levels as you'd imagine, but as you move towards the edge, where you've got more and more trees and more and more biodiversity, you get this increase, significant increase, in the levels, in the diversity of the microbiome. And therefore, those are the sort of environments you want to spend time in. And soils, especially organic soils, where you're gardening and doing, you know, growing your own crops, absolutely jam packed full of bacteria. So we should be gardening without our gloves on. We should not be putting chemicals on the soils that are going to kill all these wonderful bacteria. And we can get so much. And this is why so many gardeners are healthy. And I'm sure of it now, sort of like, you know, they're there, they're touching, they're smelling, they're absolutely surrounded by this wonderful, healthy environment that really, really does make a difference to our health. It's not just voodoo science. And that's that's the most important thing that these are these are affecting the same pathways that we're, you know, we're often being told prescription drugs are the only answer. They're not interacting with nature. Can, in many cases, bring about the same outcomes as taking a prescription drug. But it's free and it's good for you. And so therefore, this whole link to garden is just, you know, we should all be there. I have a huge, as you can see, I have a huge smile on my face. And I know probably 99.9% of everyone listening right now is feeling the same way because we're an audience of gardeners for the most part. And that was a beautiful segue because I was curious to know of all these really simple activities that we should be doing anyway. And many of us love that and spend a lot of time doing some of those things like being outside and, you know, playing in the garden. Is there prescription? That's the word you said a minute ago, kind of like medicine. What would be the guidelines for, you know, how much is enough? And is it possible to have too much? Or is it do we lose the value of more time versus a certain amount of time, etc? So there's some lovely studies where they've looked at people, like how long do you need to be in outdoors to get the benefits? And there's a lovely study done by the University of Michigan where they gave members of staff a choice. You can walk for any length of time you like, need to be doing daylight. And people would walk, sit, run, whatever in the park. And they measured the salivary amylase, the salivary amylase before and after the time spent in nature and cortisol in this again, from swaps, salivary swaps. And the really interesting thing is what they found is that 20 minutes, 20 to 30 minutes was when you got the maximum reduction in cortisol and salivary amylase. So that's when you get the maximum stress reduction through those enzyme and hormonal responses. 30 minutes, you didn't get much more difference. Less than 20. So there's a sweet spot. And beyond that, you're not going to get much more. But what I really liked about that study was that the greatest benefits were found with people who are sitting and walking rather than running. I'm not a great runner. Now, I'm sure when you run, you get all other sorts of benefits. But the idea that those benefits of nature are very much coming through from, you know, the sort of the more sort of sedentary approach to being outdoors. But it has changed me because sometimes when I'm walking my dogs and I just think, oh, 10 minutes around the park, that's enough. And now I don't. Now I think now I'm going to do 20 minutes around the park. Right. Small change. And then also, you know, again, there's lovely studies where they've shown that going back to what I said in the beginning of the queue that, you know, if you've only got 20 minutes lunchtime, walk around the edge of the park, walk near some trees, don't walk on a, don't go to somewhere that doesn't have that nature because it makes such a big difference. And it's a small change that can make a very big difference. Change your route to work. You know, they're really small changes, but can make a very, very big difference to your overall health. I'm sure that is also music to people's ears that are challenged for time as most of us are. And you already acknowledged that. And for the ones that are non-runners who can get the benefits by just sitting and enjoying the scenery from a bench or sitting even better, right? That's all good news. Yeah. You did a study, or you referenced a study about depression and anxiety and exposure to nature really got people back to work faster than not having that exposure. Do you remember that study? Yeah. That's a really interesting study. It's carried out with the University of Copenhagen and they had, they wanted to actually understand the efficacy, you know, which one is better. It's nature, interactive nature. Is that the same or worse than doing something like cognitive behavioral therapy, which is a well prescribed therapy for depression? So they took a group of clinically ill people with health, mental health issues who'd been off work because of them for a year and they split them in two. And one half did two times a week. They did cognitive behavioral therapy with a trained therapist. And the other half went into the university's gardens and joined in with gardening activities for two times a week. And after the 10 weeks, they looked at how many people were back at work, but also how many visits they had to their doctor. And they found similar results that 80% were back at work. So it seemed that even though the gardening was really much, much cheaper, much cheaper. Much. You've got the same, you've got the same, the same result. But the really interesting thing from that study, a year later, they went back to look at who was still at work. Now, I had assumed those who had got the cognitive behavioral therapy had learned mechanisms to cope with things. But it was the other way around. It was those that had garden and done the gardening. There were some like 70% of those were back at work compared to 60 who'd done the cognitive behavioral therapy. So there's a really interesting cost benefit and a long term efficacy result in there. And the real problem I think right now is that I can count on one hand the number of studies that have done that sort of comparative work that's really needed. Yes. If we're going to persuade the health professionals to actually take this seriously, we have to treat nature and the experimentation we do on nature and its impact on health in the same way, in the same framing. But right now we tend to, because it's nature, you attend, people seem to mean it, you talk about nature, it has to be into the, I've said it before, but it goes into this very sort of very touchy, feely bucket. And therefore you lose sight of the quantitative evidence base that's needed to persuade clinicians, but also those funding, you know, if I think in the UK or any healthcare practitioner who's having to find the money to pay for these things. Yeah, it's always that. You need to be able to demonstrate this is a cheaper and as effective way of getting these outcomes. Mental health doesn't get, I don't believe it gets enough attention. And I think when you try to put nature into that equation, it's like woo woo. It's like they're not, they don't take nature, the nature part seriously enough to give it its due. The other really interesting thing that I find, there's a lot of these population level studies now done where they look at how close people are to living to nature, how close the home is to nature, and they compare it to their mental health records. And there's a study carried out in Wales last two years ago published in a big top medical journal, and they looked at a huge number of people, millions of people. And they showed very clearly over a 10 year period, it's three million people over a 10 year period. And they showed that for every 350 meters from green space, away from green space, they lived the higher the incidence of common mental disease. And it didn't do what your socioeconomic background was. In fact, if you were poorer, you got more benefits, health benefits and mental health benefits than if you were richer from living close to green space. Is that because they're more reliant or less able to use other sources such as pharmaceuticals or things like that? What was the relationship to that? Possibly. I don't know. They haven't looked at that other than to show that there's this a really, really big difference. And this is over a 10 year period. Now, if there were any other public health data that was not linked to nature, it linked to something else, you would immediately have every healthcare professional looking all over this. But this study is sitting there and there are many, many of them. There are some in the state showing the same. If you need the closely lived to green space, the better your mental health outcomes on a longer term, the less prescriptions you need to have for mental health and less mental health problems you have. And so the links are there. But of course, that is just a correlation. That's not showing you what's going on. That's why it's so important to have this data underneath to say, what are the mechanisms then happening in physiologically, psychologically that are bringing about these changes? Speaking of correlations, you just reminded me of something else I read. And that was the allotment advantage. There was, there's a benefit, of course, to being outside and being in a garden, but there was a study that you referenced that showed that people that had allotments tended to be healthier than maybe somebody gardening solo. Talk about that one. Well, it's an interest. They compared things like hot tax, strokes, mental health, the whole lot. And it was a big meta data, big meta analysis of many, many studies. And they looked at front gardens, back gardens and allotments. And they showed that those people who garden in the lot had allotments and garden for allotments were the healthiest. And they concluded it was partly the diversity of different plants in the garden, when they looked at, you know, what can you wear the correlations in here? They did mention in there that they again, coming back to the soil, the environmental microbiome, the sounds and everything else. But also, I think we do have to recognise that some people find a backyard stressful, especially if they're by themselves. So therefore, you know, this is not always going to be brilliant to have your own green space. It's better to go and walk in someone else's. And I can relate to that. Me too. I mean, I've sort of, I've got to point now where I don't worry about it as much. But, you know, there's something in us that things are, we must make that tidy, we must do that. And all of a sudden, because of Chor, he ceased to be relaxing. So and also the other thing is the front garden is more important than the backyard. And they showed even with people who are really quite mentally ill and quite poor, that a few pop plants in the front garden can make a very big difference to them. And again, it's because you go in and out your front door every day, whereas you don't always go into your backyard. So it's an interesting, you know, so it's having these pop plants, even a few, just a few pots there. Unfortunately, what many of us do now is we, you know, we pave over our front gardens or our front yards and put a car on it. So there's still space, even if you've done that, there's still space for a few pots. Yeah, absolutely. Anybody can have a few pots on their balcony or their front yard or whatever it is. OK, a couple of questions back to you and your, your relation to your years of experience and applying this information that you've learned in writing the book and your research. Do you have like a single best prescription? We've talked about, you know, all of these benefits. If you were giving advice to somebody that said, you know, is there one thing I can do or focus on of the things that we've talked about today that would really give me the best advantage using nature as my pharmacy? Yeah, I mean, well, I'm always, I'm a great supporter of the noble spider plant. So the spider plant, first of all, it's got green and white. Yes, it does. Secondly, they did this lovely experiment where they shut this poor spider plant in a room, in a sterile room, and then they went back and measured the microbiome in the room. And this single plant had seeded the air, it seeded the air, the ceiling, the walls, everything within eight weeks. All is full of good. So it gives this gives you that good microbiome. They're hard to kill. You're having to constantly sort of touch the plant because you're trying to stop the thing, you know, you have to be sprouted out. So your hands are getting. So a single little spider plant on your desk can make a huge difference. And that would be my one piece of advice. Well, when I was, when I discovered my love of gardening at eight years old, I was planting everything, anything and everything I could get my hands on. I grew up in Miami where it was very tropical and we had a patio screened in patio and I had my share and then some of spider plants. And of course, you know, you can easily propagate them. So every week I was making more. Yeah. There's something very satisfying about spider plants. I've just got a couple of round meat right now. And they, they, they went out of fashion there a bit like sort of 1970s hangover. Some people was like, you know, but actually, you know, now when you look at them, you think, oh, these are, these are fantastic plants. They, I've got one in my bedroom that I've had for 45 years. Really? Keeps going, keeps going. So isn't that interesting? And speaking of retro plants, the Sands of area, the one that you can't see in the background over here, it's, it's such a bulletproof plant. You can't kill that either. And in fact, when I first bought that one, I forgot I bought it when I stuck it back there, because it's kind of out of sight out of mind. And the first time I realized I had it was eight months after I bought it. And I had, obviously hadn't watered it, but it's under that, those LED lights. And it was as if I had pampered it. It was perfectly healthy, slightly wrinkly, but a little bit of water. And it was back to normal. So yeah, two more questions. I'm going to let you go again, back to this experience of writing your book. And you've actually kind of shared about your walking your dogs and going from 10 to 20 minutes. Can you peg any other activity changes for you that have been a direct result of your research in writing this book that you do? Yeah, I think it will. I have, I certainly, as well as having house plants, I now diffuse different scents and different rooms. I have lavender in my bedroom. I have cedar in the hall when people, you know, they're, so I do that now, sort of fairly routinely. I'd never did that before. And I think I'm much more, I think you can do an awful lot indoor, because you don't have to go outside to do these things. There's like a saying, change my computer screen. We can help ourselves. It's preventative. We don't have to wait to get sick. We can start doing this now. We don't have to wait for it to be prescribed even you can do it yourself. And that's what I think is the really important thing. And it doesn't matter if the plant dies, you have to buy another one. You know, it's not, this is not, this is not the Chelsea Blanche show. This is about working with plants, enjoying plants because of the incredible health benefits they provide us with. Oh my gosh, I could just end right there. That's a beautiful finish. And I talk about that. That's a good example related to gardening or with anything, but always with gardening, I talk about the benefits of being proactive rather than reactive. Absolutely. It's the same, you know, and like you say when you're a child, I mean, my gardening is chaotic. I would say I go and if it dies, I put something else in the ground. Right. Because I just enjoy now in the garden in my own garden as well. The other thing I realized that it's the cut, it's the different shades of green that are really important. So I've stopped worrying so much about having some fantastic herbaceous border. I've got, you know, outside of my, that's my window, but I've got a whole sort of fernary section now. And then I've got sort of different shapes on the other end. And I've got some, just all sorts of different shapes and sounds and things that bring in the birdsong. So you can pick up this beautiful, tuneful birdsong. There are so many things you can do without having to be a brilliant gardener, but just, just enjoy it. And in that realization alone, if there was one mental change that you could make is just giving, cutting yourself some slack and having more fun and not being so hard on yourself. That alone can reduce tremendous amount of stress. Absolutely. We're all very good at beating ourselves up all the time. Yes. And it just, you just go into a spiral. And so I think sometimes you have to step back. And I think when you're stepping back, that's the time is to go and breathe the air outside. And it just, that action alone, or just doing a digging or a bit of mudding around. As I say, I never wear garden gloves anymore because I know that touching the soil is just such an important part of it. And even, I mean, we haven't talked about touch really, but one of the studies, there aren't that many studies on it, but those that have looked where if you stroke wood, it can, a particular knotty wood, quite smooth wood. Yeah. And it does affect your blood pressure. And once you realize that, you get, and if you go into, you know, a home store and you see people choosing kitchens or tables, the first thing people do is stroke the surface. And once you start to realize that you think, gosh, you know, and so it's even, even just stroking something like a piece of wood. How about that? The very last thing, and you already mentioned an important point in that, that is you don't have to walk outside to benefit from any of the things that we've talked about, but it's always good to get outside and get a breath of fresh air. But if you were to mention one thing that we could all do when going outside to strengthen our connection to the natural world. Would it be as simple as just getting outside for 20 minutes, or would you add to that? Yeah, I think, I mean, I think the thing that we can all do is once you get outside is it is make sure you're, you're somewhere that's green, but I often, I often now go and touch the plants, touch the leaves. I think that links you back to them. And then, and you suddenly start to feel these different shapes and textures. And it brings the whole thing alive. You're not just looking at your feeling, you're touching it, you're smelling it. Those are really, anyone can do that. And you can do that in two minutes. And you will absolutely get the benefits from it. Well, I hope you enjoyed that. But one of the many things I enjoyed about this conversation was that Dr. Willis really brought more of the science to some of those studies that we may have heard about in the past, such as patients that were hospitalized in a room without a view to natural spaces outside and recovered less quickly than those who had a nature view. Fascinating information, along with many other examples in our conversation today. And of course, if you'd like to go back and re-listen to this episode or check out the show notes that we've prepared for you exclusively from this conversation, you can do that from our website at joegardner.com. Under the podcast tab, just look for episode 446. And of course, now you can go actually watch this episode on our YouTube channel at joegardnertv. And I think you might enjoy that because they're a little more laid back, less edited and kind of fun to watch too. As for other announcements, there are two. First is the annual holiday gift guide that we update every year ahead of the holiday season. It's a summary of my favorite gardening tools, gear and gadgets that you might want to know about for yourself. I call it the best of the must haves. And again, with this being the gift giving holiday season, maybe it's something special for that gardener in your life. It's a one stop shop of all things I use and love and think are definitely worthy of your consideration also. And you can check out the guide from our website at joegardner.com. Slash gift guide. That's all one word. Again, joegardner.com slash gift guide, no spaces. Also, if you've been following my brand new raised bed rebuild project that's been going on now for almost three weeks, we've had great interest online, mainly on Instagram and Facebook. And you can follow the action there on Instagram. I'm at Joe Gardner and same with Facebook. And that's where we've been posting, but so many of you have had questions that have come up and we are going to do a YouTube live event to answer all of those questions and share pictures of it all and take your questions live as well. If time permits. And this is going to happen on Tuesday, December 16th at 12 noon Eastern time on our YouTube channel, which is Joe Gardner TV. So be looking out for more information on that, but please join us. If you were at all interested in this project or maybe are thinking that someday in the near future, you may have to replace your existing raised bed garden like I just did. Hoof. Anyway, I think this round, they're built to last longer than I'll be around. And that's a good thing. But this YouTube live is being set up on our channel now as an upcoming event. So keep an eye on the channel for that. And again, the date to know is December 16th. That's a Tuesday at 12 noon Eastern time. And if you miss it, of course, you can go watch it after that. It'll be permanently there on the YouTube channel, but for your chance to ask questions live, if you can attend it live, that would be the best opportunity. Otherwise you can just leave comments or questions in the YouTube post there. And I will be sure to respond. So that's going to do it for today. Thanks as always to Amy Princess, Brendan O'Reilly and Christine Lafond, for their help on the podcast team. And thank you for joining me today. If you're a regular listener, I so appreciate that. And if you just found us welcome and thanks for being here. If you didn't notice sometimes these episodes are a little geeky, but we like that. But my goal for every episode is to help you take the guesswork out of gardening by teaching you the why do behind the how to so that you can become a better, smarter, more confident gardener. I'll be back here again next Thursday for another episode of the Joe Gardner show. And I look forward to having you right back here to join me for that. Until then, have a great week. Take care and I'll see you back here really soon. Thanks for listening to the Joe Gardner show, the podcast where it's all about gardening and learning to grow like a pro, no experience required. For more information, podcasts and how to videos, visit us online at Joe Gardner dot com.