Roger: 0:02

Talking Trees with Lillian Jad. Welcome to Talking Trees. Today, we explore two studies examining the relationship between green spaces and cancer. O'callaghan-gordo et al chur, 2018, investigated the link between residential proximity to green areas and breast cancer risk in Spain, while Sakviti et al 2022 conducteda systematic review and meta-analysis on the influence of green spaces on cancer incidence, prevalence and mortality. Both studies highlight the need for further research to fully understand these connections.

Jad: 0:41

Hey everyone and welcome to another Deep Dive. Yeah, a lot of people wonder about this and we're going to dive in today. Can green spaces actually lower our risk of cancer?

Lilly: 0:52

Oh, it's a fascinating area of research for sure, and I think we've got some really interesting sources you shared to break down what the science actually says.

Jad: 1:00

Yeah, for sure. We've got this big study from Spain focused on breast cancer, and then we also have a meta-analysis, which you know. Those are always nice because they combine data from a bunch of different studies so we can kind of see a bigger picture.

Lilly: 1:12

Yeah, like getting that panoramic view instead of just little snapshots, and I think when we're talking about something as complicated as cancer, it's really important to have that.

Jad: 1:20

For sure, yeah. So our mission today is definitely to figure out, like what do these studies tell us, where is the evidence strongest and you know what questions are still out there?

Lilly: 1:30

Yeah, sounds like a plan.

Jad: 1:31

All right, so let's jump in First up. We've got this Spanish study. They decided to focus on breast cancer and you know this is obviously a major concern globally. In Spain alone, they see thousands of new cases and deaths every single year.

Lilly: 1:46

Yeah, absolutely. It really reminds us of the huge impact of this disease and why. You know why research like this is really important.

Jad: 1:53

Yeah, no, I totally agree. So this Spanish study officially it's called the MCC Spain Study. They had over 3,600 women involved across 10 different provinces, and one of the things that really jumped out at me was they weren't just looking at where these women live now, but also how long they'd lived there.

Lilly: 2:10

Oh, that's a really good point. You know, I think, residential history it's often kind of overlooked, but it can really make a big difference when you're trying to understand, you know, the impact of the environment over a long period of time and in this case, they found that 75% of their participants had lived in their current home for at least 10 years and two thirds of them it was the place they'd lived the longest.

Jad: 2:30

Wow, that's, that's wild. Like. That's a lot of consistency. It seems like that would really help them, you know, be more confident about whether there's a true link between their surroundings and their risk of breast cancer.

Lilly: 2:42

Yeah, definitely, because it makes it less likely that the what they're seeing is just because people are moving around a lot, right?

Jad: 2:48

Right, okay, that makes sense. So how did they actually measure exposure to green spaces in this study?

Lilly: 2:54

Well, they used something called the Urban Atlas, which maps out where green spaces are, and what they did was they basically drew these different size circles they call them buffers around each participant's home, and then they basically check to see if any green spaces fell within those circles.

Jad: 3:09

Oh, interesting. So it's not just like you know, do they live near a park, but more like how much greenery is kind of surrounding them in general.

Lilly: 3:15

Exactly yeah. It gives you a much more kind of complete picture of their green space exposure.

Jad: 3:21

Gotcha, but I'm curious did they talk about any limitations of using that method? It seems like it could get a little tricky, especially if someone lives right on the edge of a city or something like that.

Lilly: 3:30

You're right to be thinking critically about that. They did mention some limitations. In particular, they said that they weren't able to get data for people who lived in less populated areas, which could have introduced some bias.

Jad: 3:44

Okay, so it's not a perfect system. What about other studies in this field? Do they use similar ways of measuring this green space exposure?

Lilly: 3:52

There's some variation, for sure, but a lot of studies. They use something called NDVI, which stands for Normalized Difference of Education Index.

Jad: 4:01

NDVI, that sounds pretty technical.

Lilly: 4:03

It is, but you can think of it basically as scientists using satellites to actually measure, like how green an area is. They're giving a greenness score basically from space, and that helps ensure it's objective right. They're relying on data, not just people's perceptions.

Jad: 4:18

Okay, that's actually pretty cool. So, from maps to satellites, it sounds like researchers are really trying to understand this connection, this connection between green spaces and health. They're using every tool they can. Huh.

Lilly: 4:28

Yeah, they're really committed to this. And, speaking of getting a brawler perspective, maybe we should shift gears a little bit and talk about that meta-analysis that you mentioned.

Jad: 4:36

Yeah, let's do that Before we dive in, though. I'm curious what types of cancer outcomes were they actually looking at in this meta-analysis?

Lilly: 4:44

Well, they examined a few. You know, things like the incidence of cancer, so that's like new cases, the prevalence, which is existing cases, and then also mortality, which means deaths from cancer.

Jad: 4:56

OK, so they're getting a pretty comprehensive look at how cancer is affecting populations over time. All right, that's a good foundation to have. Now let's get to the heart of it. What did these studies actually find?

Lilly: 5:06

Well, the Spanish study, you know. It seemed to suggest that urban green spaces might actually be protective against breast cancer, but the meta-analysis, which remember combined data from 18 different studies, it painted a bit of a more nuanced picture.

Jad: 5:21

Oh, so it wasn't just like you know more greenery, less cancer.

Lilly: 5:24

Not exactly. For some cancers, like breast cancer, the evidence was kind of inconclusive when you put it all together. Like some individual studies suggested, there might be a benefit, but it wasn't a slam dunk across the board.

Jad: 5:35

Interesting. So it seems like with breast cancer in particular, there's still a lot more to learn. Huh, what about other types of cancer? Did the meta-analysis you know show any clear connections there?

Lilly: 5:45

You know, not really For lung cancer, prostate cancer and colorectal cancer. They just didn't find consistent evidence that there was a strong connection with green space either positive or negative.

Jad: 5:56

Huh, that's kind of surprising. I guess I kind of just assumed that more green space would automatically be good for everyone's health.

Lilly: 6:03

Yeah, it's a it's a reasonable assumption, but you know, it turns out that the human body and how it interacts with the environment is incredibly complex. And it gets even more interesting because some studies actually suggested that green space might be associated with a higher risk of skin cancer.

Jad: 6:19

Whoa wait a minute. Hold on how. How could that be?

Lilly: 6:22

It probably comes down to sun exposure. People who live near green spaces they might spend more time outside right and that could lead to greater UV exposure and then, you know, down the road, an increased risk of skin cancer.

Jad: 6:34

Oh, okay, yeah, that makes sense, like it's almost like too much of a good thing, right, like you want to enjoy the outdoors, but you also have to be smart about protecting yourself from the sun.

Lilly: 6:45

Exactly, and it's a good reminder that you know it's always important to look at the whole picker and not just jump to conclusions based on one or two findings.

Jad: 6:49

Yeah, very good point. So if the results are kind of mixed like this, what could explain these inconsistencies? What makes this link between green space and cancer so tricky to figure out?

Lilly: 6:59

Well, the meta-analysis actually gave us some clues about this. So, first off, it's really important to realize that not all green spaces are the same right, Like urban parks and agricultural areas, for example. They could have totally different effects on our health.

Jad: 7:12

Oh right, Because of like pesticide use and stuff in farming.

Lilly: 7:15

Exactly, pedicide exposure is definitely a potential risk that you have to consider when you're studying the impact of green spaces, especially those that are in agricultural settings. Another thing is that there's a lot of variation in those buffer sizes that we talked about. Right, like some researchers might look at green space within, you know, 500 meters of someone's home, others might use a kilometer.

Jad: 7:36

Oh, so it's like they're using different measuring sticks, which makes it hard to really compare the results directly.

Lilly: 7:41

Right, exactly, it's like trying to bake a cake using two different sets of measuring cups. You know it's just not going to work. And finally, we can't forget about all the other factors that could be influencing both cancer risk and access to green spaces.

Jad: 7:55

Right like air pollution. How much physical activity someone gets even just you know socioeconomic factors.

Lilly: 8:01

All of those. Yeah, for example, you example people with more money. They might be more likely to live in neighborhoods that have lots of green spaces, but they also tend to have better access to health care. So it can be tough to really isolate the specific impact of the greenery itself.

Jad: 8:14

Yeah, it sounds like researchers are dealing with a pretty tangled web here.

Lilly: 8:18

Definitely, and it really takes careful planning and analysis to tease apart all these relationships. It's not about proving or disproving a simple link. It's more about understanding all the nuances.

Jad: 8:29

Yeah, that makes sense. So we've established that the link between green spaces and cancer. You know it's not exactly clear cut, but let's switch gears a little bit, even if that connection is still a little murky. What about some of the other potential health benefits of being out in nature? Are there areas where the evidence is a little stronger?

Lilly: 8:47

Oh, absolutely, and this is where things get really exciting. There's a growing body of research that suggests that green spaces can actually have a really positive impact on all sorts of aspects of our health, from reducing stress to improving air quality.

Jad: 9:00

Okay, now I'm definitely interested. Tell me more Well, for starters, there's a very strong connection between spending time in nature, reducing stress to improving air quality.

Lilly: 9:05

Okay, now I'm definitely interested. Tell me more. Well, for starters, there's a very strong connection between spending time in nature and lower stress levels. Studies have actually shown that being in green spaces can have a very calming effect on our nervous systems.

Jad: 9:15

So it's not just about feeling better because you're, you know, away from the hustle and bustle, like there's an actual physiological response going on.

Lilly: 9:22

Exactly. Studies have found that exposure to green spaces can lead to measurable changes in our bodies, like reductions in heart rate, blood pressure and even the levels of stress hormones, like cortisol, that are circulating in our blood.

Jad: 9:34

Wow, that's pretty amazing. I think I read somewhere that spending time in nature can even boost your immune system. Is there any truth to that?

Lilly: 9:42

You know there's definitely a connection there. It's still an area of active research, but some studies have suggested that being exposed to natural environments can actually enhance our immune auction. One theory is that the diverse microbes that are found in nature, like those in soil and plants. They may actually help to diversify our microbiome. You know the community of bacteria that live in and on our bodies.

Jad: 10:04

Oh, so it's almost like our bodies are getting a little dose of nature's probiotics.

Lilly: 10:07

I like that. That's a great way to think about it, and a more diverse microbiome is generally considered a good thing for overall health, so green spaces might actually contribute to that.

Jad: 10:19

Wow, fascinating. So it's not just about like the sights and sounds of nature. There's a whole invisible world at play that could be impacting our health. Okay, shifting gears a bit, let's talk about physical activity. It seems pretty intuitive that people who live near parks and green spaces would probably exercise more, right?

Lilly: 10:38

Yeah, that makes sense. Green spaces are great for all sorts of activities walking, jogging, biking, team sports, the list goes on. But what's really interesting is that just being exposed to green spaces might encourage people to be more active, even if they weren't planning on it.

Jad: 10:52

Oh, really. So even if you're not like consciously thinking I'm going to go for a run in the park, just seeing those trees in green areas could, like subconsciously, motivate you to move more.

Lilly: 11:02

That's the idea. It's like a little invitation from nature to get out there and explore, and there is some evidence to support this. Studies have shown that people who live in greener neighborhoods tend to be more physically active, even when you account for other things like age and income.

Jad: 11:16

Wow, that's. That's pretty powerful. I'm starting to see how all these you know little everyday interactions with nature can add up over time. Ok, so we've got stress relation, cleaner air, maybe a little boost to the immune system, more physical activity, all potentially linked to green spaces. What about the social aspect? I think you mentioned that earlier.

Lilly: 11:41

Right. Well, green spaces often act as these kind of community hubs, bringing people together and helping them build social connections. You know, think about parks, community gardens, even just streets that have lots of trees. They all create these opportunities for people to connect, whether it's through organized activities or just, you know, bumping into each other.

Jad: 11:53

Yeah. Yeah, I've definitely noticed that, like I, when I walk my dog in the park, I always end up chatting with the other dog owners. It's a nice way to you know, connect with my neighbors.

Lilly: 12:02

There you go and those social ties. They're incredibly important for our well-being. They give us a sense of belonging, they reduce feelings of loneliness and they can even contribute to better physical health.

Jad: 12:13

It's amazing how all these pieces kind of fit together. So so far it seems like we have a pretty strong case for the benefits of green spaces, even if you know that link to cancer prevention is still being figured out. But you mentioned earlier that not all green spaces are created equal, right? What are some of the things that make a green space truly beneficial?

Lilly: 12:33

Ah, that is a great question. Researchers are definitely digging into that right now, and, while we still have a lot to learn, there are a few key factors that seem to be emerging. One is biodiversity, which is basically the variety of plants and animals that you find in a given space, like a park that has a mix of different kinds of trees and flowers and other vegetation is likely to offer more benefits than you know a space that's just dominated by a single species.

Jad: 12:59

So it's kind of like a healthy diet for our surroundings the more diverse, the better.

Lilly: 13:07

I love that analogy because it's true, right. Just like a diverse diet supports a healthy gut microbiome, a diverse environment probably supports a healthy ecosystem, which in turn can benefit us.

Jad: 13:14

Yeah, that makes a lot of sense. What about the design of the space itself? Does that play a role in how beneficial it is?

Lilly: 13:21

Absolutely. Walkability is huge. A green space that has well-maintained paths you know, trails, sidewalks that encourages people to get out there and move around, Whereas a space that's really hard to navigate might actually discourage physical activity.

Jad: 13:36

So it's not just about having green spaces, it's about making them easy and enjoyable to use.

Lilly: 13:40

Right, exactly, and accessibility is important too. A truly beneficial green space should be accessible to people of all ages and abilities, you know, regardless of any physical limitations.

Jad: 13:52

Yeah, I hadn't thought about that, but that's so true. Everyone should have the opportunity to experience the benefits of nature.

Lilly: 13:58

I completely agree. I completely agree. And we shouldn't forget about those little deshells that can have a big difference too, like having benches for people to rest on, shade structures to protect people from the sun. You know, even water features those can add a nice touch.

Jad: 14:13

Yeah, those are all great points. It seems like creating a truly beneficial green space. It's almost like an art form, isn't it Like combining nature with thoughtful design to really maximize that positive impact on people.

Lilly: 14:25

Yeah, it definitely is, and it's something that requires collaboration, you know, between researchers, urban planners, landscape architects and the community itself.

Jad: 14:35

This has been such an interesting conversation. We've learned so much and hopefully you've come away with a better understanding of this complex relationship between green spaces and human health. There's still a lot to learn, but it's clear that nature has a lot to offer us.

Lilly: 14:49

Definitely, and I hope you'll continue to be curious. Keep exploring nature, keep asking questions and keep making choices that support both your own well-being and the health of our planet.

Jad: 14:59

Couldn't have said it better myself. Thanks for joining us on this deep dive and until next time, keep exploring.

Roger: 15:08

Thank you for joining us. Today we discussed two studies exploring the relationship between green spaces and cancer, including one on breast cancer risk in Spain and another comprehensive review on the broader impacts of green spaces on cancer incidence and mortality. These studies underscore the importance of continued research into this potential connection. We appreciate your attention and look forward to our next episode.