Local green spaces are linked with better mental health

Green and blue spaces could improve mental health through the opportunities they provide to socialise and exercise; it could also be that these spaces improve air quality. But other factors, such as wealth, may explain this difference.

In this podcast, Helen Saul, Editor in Chief of NIHR Evidence, speaks with Sarah Rogers, Professor of Health Informatics at the University of Liverpool about the impact of green space on our mental health and her study aiming to tease out the impact of green and blue spaces alone, regardless of wealth or other factors.

Read a full transcript of the episode here.

The views and opinions expressed in this podcast are those of the host and guests and do not necessarily reflect those of the NIHR or the Department of Health and Social Care.

Transcript

2310_1238 Q1 BD Ambient greenness, access to local green spaces, and subsequent mental health: a 10-year longitudinal dynamic panel study of 2·3 million adults in Wales

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0:08

Helen Saul: Welcome to this podcast from the NIHR on the impact of green spaces on our mental health. Living near to green and blue spaces, such as parks, lakes, or beaches, is associated with better mental health. But exactly why is not clear. It could be that these spaces themselves reduce stress levels, encourage us to exercise and socialise, and improve air quality. Or it might just be that people living in these areas are wealthier and therefore healthier than others in the population.

Today we'll be discussing a huge study that set out to untangle these effects. 

My name is Helen Saul, and I'm the editor in chief of the NIHR Evidence website. I am speaking with author Professor Sarah Rodgers. Perhaps you'd like to introduce yourself, Sarah.

0:58

Sarah Rodgers: Hello, Helen! So I am, as you said, a Professor of health informatics at the University of Liverpool, and I've got a background in geography and epidemiology. So I thought this study seemed appropriate for me and my my background, thinking about how the environment impacts health.

1:18

Helen Saul: There's obviously been research previously on green spaces and mental health. Why was this study needed?

1:27

Sarah Rodgers: Existing studies mainly had small cohorts of people. So a few 100 or 1,000 and assessed changes over a short period of time. And they didn't really focus that much on the socio-economic inequalities as well. And so because those studies were cross sectional, we aren't really sure if the person's health caused them to move to a different environment because of their general life chances being impacted by poor health, for example, and wanting, you know to have to stay in the middle of an urban city where they didn't want to be, or they've proactively been able to move out to a green and nicer place already.

2:08

Helen Saul:  How did you address this in your study?

2:11

Sarah Rodgers: So, yeah. So the way we set up our current study allowed us to be sure that the exposure to green or blue space came before the outcome, so we could test more precisely if the green or blue spaces were preventing the ill health. And I think that was a really useful advance. So what we were able to do was use the household linkages from people's homes and then link the environment around their home to their health records. So, in this case we linked to the GP records in Wales for about 2 million people. So, we were looking for their health conditions over time, monthly or quarterly, we can, we can do that. And then this was with anonymised data, which means that all the identifiers, so their names and addresses were removed. And so, the researchers access the data without ever knowing who the person is or where they live. 

3:05

Helen Saul: And you were looking both at people's immediate surroundings at home, and their potential access to green spaces?

3:13

Sarah Rodgers: Yes, that's right. So, we thought that if we looked at a short distance from home, and we looked at the greenness, we called that ambient greenness around the home, within about 2 or 300 metres, people could actually see this from their front door, so they wouldn't have to make any effort to to get the benefits from it, it would just be there. But then we also looked at their access within about a mile of home. So that in that case, that's their sort of potential to access those green spaces because we weren't sure whether they actually would have visited that space at that time.

3:52

Helen Saul: So, what did you find? How did these 2 measures relate to mental health?

3:58

Sarah Rodgers: That was really interesting. We found the quite a strong association with the ambient greenness. So, when we looked at the routinely collected health data for more than 2 million adults, we saw that people's home surroundings and their potential to access green or blue spaces was associated with a reduction in anxiety or depression that they reported to their their general practitioner.

So, having the top third amount of greenness immediately from their sort of front door reduced their likelihood of anxiety or depression by 20%. So, they were a fifth less likely to need to go to their GP for help. And then we saw some reduction, a smaller reduction, but still a reduction of 7% in terms of the potential to access these green or blue spaces within a longer distance from home. So, for every 360 metres to their nearest space, there was a 7% increased likelihood of a common mental health disorder, the the anxiety or depression.

5:04

Helen Saul: And did the results differ for people who had a previous mental health diagnosis and those who didn't?

5:11

Sarah Rodgers: Yes, so umm they were different, we wanted to make to kind of look back at people, firstly, who'd had an anxiety and depression episode a long time ago to see what impacts this has had. And we found that adults who'd had an old diagnosis of up to 8 years earlier had an even lower chance of having a common mental health disorder. So, this was 32% less, compared to 16% for those who didn't have that old historical diagnosis.

5:44

Helen Saul: That's a huge difference within, presumably, a vulnerable population.

5:51

Sarah Rodgers: Yes, yes, that is, it is quite a massive difference, and we think this is a big advance because of how we structured the data, and how we were able to use all of those data more precisely to be able to look at their health condition and see whether their preceding exposure to green or blue spaces had an impact potentially on their on their health conditions.

6:17

Helen Saul: You also looked at different groups of the population. Which groups did you find were most likely to benefit from green surroundings and better potential access?

6:27

Sarah Rodgers: So, we looked at different stratifications of deprivation. So, what we found was there was an association of common mental health disorders and the likelihood of potential green blue space access for adults living in the most deprived areas. That was a 10% reduction. And that was a stronger association than for those living in the least deprived areas which only saw a 6% reduction. So that indicates that there were really great benefits, greater benefits to mental health for people living in the deprived areas with more green or blue spaces. So, they had, you know fewer overall resources but they had these green or blue spaces that they were taking, potentially, taking some advantage of which is good to good to see.

7:23

Helen Saul: Well, it's very interesting that the people who needed it most benefited most.

7:29

Sarah Rodgers: Yes, definitely, it's really interesting to see those patterns in terms of deprivation and inequalities, and to know that there is the potential to have nicer spaces making an impact on people who need these spaces the most.

What I'm trying to do now is work with local government and different stakeholders. So, when they are designing new spaces, we are trying to work out how we can help our local government engage with the local community, to empower the local community, to co-design those spaces with the people who need them the most, and maybe even so design those spaces with those people in mind, with those people themselves. 

8:29

And that's what we're doing with this new UK prevention research partnership called Groundswell that I'm involved with. So, we're taking the data a step forward and looking on the ground and working with people designing those spaces. So, I think the impact of the NIHR project that we were funded for is a really good baseline, and that's helping us now to work on the ground with people about this co-design element.

9:00

Helen Saul: 

Well, we’d like to wish you the best of luck with that important work, Sarah, and thank you very much, for joining me today - and for your description of an incredible study. 

This is an episode of the NIHR podcast, I'm Helen Saul, and thank you for listening. If you have thoughts or comments on this or any other episodes, please contact us at evidence@nihr.ac.uk, and do visit our website, which is evidence.nihr.ac.uk.

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