13. Benefits of nature for human health

Question 1

Structure of the lecture

Answer 1

1. The potential of green prescribing
2. Finding the specific interactions
3. Understanding the mechanism
4. Finding a dose
5. Understanding the cost
6. Coming up with a solution

Question 2

What did Hutson et al., 2016 show about indirect health benefits and nature?

1.1

Answer 2

Increased green spaces can lead to improved public health outcomes

Green spaces are positive for exercise (good for improving cardiovascular/respiratory health), reducing pollution (improving pollution and allergens) and heat reduction (reduces overheating and heat stress)

Question 3

What did Kardan et al., 2015 show about the direct impacts of nature on human health?

1.2

Answer 3

Study performed in Toronto that measured every tree in the city to generate a BioBank to map the health of all individuals alongside the number of trees. Found that people living in streets with higher numbers of trees tend to have fewer cardiometabolic conditions

Question 4

What did Donovan et al., 2013 show about tree death and human mortality?

1.3

Answer 4

Found that the spread of the Emerald Ash Borer from 1990 to 2007 resulted in the death of 100 million ash trees across 1296 US counties. This decrease in ash trees was correlated with a significant increase in human deaths from cardiorespiratory illnesses

Question 5

What did Sarkar et al., 2018, show about NDVI and health outcomes?

1.4

Answer 5

Ambient greeness exposure over time was associated with lower odds of subsequent Common Mental Diseases (CMD). Every extra 360m to the nearest Green Blue Space (GBS) was associated with higher odds of CMD. The impacts of GBS was highest in the most deprived areas

Question 6

What are the 3 main mechanisms for us to understand the health outcomes of green prescribing?

3

Answer 6

Sight
Smell
Environmental microbiomes

Question 7

What 3 papers can we look at to understand the impact of SIGHT from green prescribing?

3.1

Answer 7

Song et al., 2015:
Elasdek et al., 2017
Taylor et al., 2011

Question 8

What did Elasdek et al., 2017 show about the impact of SIGHT from green prescribing?

3.1.2

Answer 8

Found that yellow and green plants are the most calming to look at, and are the most indicative of relaxation via blood flow to the brain

Patients also pay more attention to yellow-green and bright-green plants compared to other shapes

This is aside from during autumn, when humans are more attracted to red/orange plants

Question 9

What did Song et al., 2015 show about the impact of SIGHT from green prescribing?

3.1.1

Answer 9

Compared brain activity and psychological wellbeing when viewing urban/natural scenes, and found significantly higher relaxation, lower blood pressure and lower heart rate in natural environments

Question 10

What did Taylor et al., 2011 show about the impact of SIGHT from green prescribing?

3.1.3

Answer 10

Found that the fractal dimensions and shape of natural patterns, particularly along the horizon has a strong impact on peace/focus, with more open landscapes providing the optimal effect

Question 11

What are the 4 papers we can look at to understand the impact of SMELL on green prescribing?

3.2

Answer 11

1. Joung et al., 2014
2. Kim et al., 2019
3. Li et al., 2009
4. Tsao et al., 2018

Question 12

What did Joung et al., 2014 show about the impact of SMELL from green prescribing?

3.2.1

Answer 12

Found that the impact of VOCs found in local nature, such as Alpha-pinene and limonene lead to enhanced parasympathetic nervous response, slowed heart rate, increased comfort, and calmed physiological/psychological responses

Question 13

What did Kim et al., 2019 show about the impact of SMELL from green prescribing?

3.2.2

Answer 13

Found that VOCs from nature can pass into our blood stream from so much as a 10-minute walk

Question 14

What did Li et al., 2009 show about the impact of SMELL from green prescribing?

3.2.3

Answer 14

Found that some of the most important health benefits occur once VOCs enter the bloodstream.

For example, VOCs from the Hinoki cypress tree have been found to decrease stress

Question 15

What did Tsao et al., 2018 show about the impact of SMELL from green prescribing?

3.2.4

Answer 15

The influence of scent from the Japanese Cedar in everyday life (such as reed diffusers, shower gel, perfume) can influence the immune response (via improved, longer lasting NK cell response and anti-inflammatories), and increase cardiovascular health

Question 16

What are the 5 studies we can look at to understand the impact of nature on the MICROBIOME?

3.3

Answer 16

Von Hertzen et al., 2011
Roslund et al., 2020 and 2022
Selway et al., 2020
Soininen et al., 2022
Robinson et al., 2021

Question 17

What is Van Hertzen’s Environmental Microbiome Hypothesis?

3.3.1

Answer 17

States that biodiverse environments are naturally high in ‘good’ environmental microbes, and will:

1. Increase the diversity of human microbiomes
2. Provide microbes that allow us to deal with daily functions like digestion, immune function and autoimmunity

Question 18

What did Roslund et al., 2020/2022 show about the impact on ENVIRONMENTAL MICROBIOME from green prescribing?

3.3.2

Answer 18

Found that children who played in more microbially diverse soils had significantly improved skin and microbial diversity after 28 days and increase IL10 T-cells, suggesting enhanced immune functioning

Question 19

What did Selway et al., 2020 show about the impact on ENVIRONMENTAL MICROBIOME from green prescribing?

3.3.3

Answer 19

Found a significant increase in diversity and abundance of microbiota on participant’s noses and skin after spending time in green, urban, and biodiverse spaces, compared to urban ones. This also tracks along a transect.

Question 20

What did Soininen et al., 2020/2022 show about the impact on ENVIRONMENTAL MICROBIOME from green prescribing?

3.3.4

Answer 20

‘Living walls’ in offices can provide ‘good’ skin bacteria and lower the inflammatory markers of office works.

Question 21

What did Robinson et al., 2021 show about the impact on ENVIRONMENTAL MICROBIOME from green prescribing?

3.3.5

Answer 21

The more biodiversity-dense an environment, the higher the benefits derived. Modelled this linearly

Question 22

How LONG should a nature interaction last for?

4.1

Answer 22

Hunter et al., 2019

Around 20 minutes SITTING in nature, multiple times per week helped to provide maximum health benefits.

Tested with 36 participants from University of Michigan and measured salivary amylase for multiple activity/times in nature

Question 23

How can we asses the benefit of nature-based therapies against other therapies/drugs?

5

Answer 23

1. Comparison to other therapies, like CBT (Stigsdotter et al., 2018)
2. Assessing economic value (Pretty and Barton, 2020)

Question 24

How did Stigsdotter et al., 2018 assess the effectiveness of nature-based therapies?

5.1

Answer 24

Comparison to CBT in clinically stressed individuals.

Tested 84 Danish Participants, all of whom were out of work due to clinical stress.

Half given CBT, half given NBT

Both found to be significantly effective against stress

77% of those who did NBT were back at work a year later, compared to 60% who did CBT

Could a combination of the two be most effective?

Question 25

How did Pretty and Barton, 2020 assess the economic value of nature therapies?

5.2

Answer 25

Tested 642 participants over 4 years with therapies like woodland therapy, horticulture therapy, green care and Tai Chi

Concluded that the net economic benefits of ‘green prescribing’ could be up to £31,500 per year, per person

Question 26

What are the two major ways that we are beginning to integrate NBTs?

6

Answer 26

Target 16 of the CBD
UK Environmental Improvement Plan

Question 27

What is Target 16 of the CBD?

6.1

Answer 27

To significantly increase the area and access to greenspace in urban areas to improve human health and wellbeing

Question 28

What is the UK Environmental Improvement Plan?

6.2

Answer 28

The public should be able to access green space or water, such as woodlands, wetlands, parks and rivers within a 15-minute walk

Question 29

What are the 3 major benefits of green prescribing?

6.3

Answer 29

1. Reducing harm: stress, post-operative pain, recovery rates etc.,
2. Building resilience: Increase in NK cells, anti-inflammatory compounds, improve gut/skin
3. Restoration: Attention span, cognitive function, stress recovery etc.,