Written evidence submitted by Dr Janie Corley (UGS0023)
Written evidence submitted by Dr Janie Corley,
Lothian Birth Cohorts, University of Edinburgh
1. About the Lothian Birth Cohorts
1.1 The Lothian Birth Cohorts studies, based at the University of Edinburgh, are world-leading, longitudinal studies of ageing (https://www.ed.ac.uk/lothian-birth-cohorts), dedicated to understanding the changes in brain function and cognitive abilities over the life-course. These studies investigate genetic, developmental, and environmental factors influencing healthy ageing.
1.2 At the core of their research are the Lothian Birth Cohort of 1921 (LBC1921) and Lothian Birth Cohort of 1936 (LBC1936). These unique cohorts of individuals sat a nationwide intelligence test at the age of 11 and continue to be studied into their later years, providing insights into changes in mental abilities over time. Commencing with initial samples of 550 (LBC1921, beginning 1999) and 1,091 (LBC1936, beginning 2004), cohort members have been invited to participate every three years. The LBC1921 has yielded five waves of data, while the LBC1936 has six waves of data with a seventh scheduled to begin in 2024. They are the longest follow-up studies of cognitive ageing in the world.
1.3 Alongside cognitive assessments, participants are surveyed about their health, medical history, lifestyle, social background, and demographic information. These surveys have included questions about individuals' interactions with green spaces. In addition to self-reported information, a range of biomedical measures are collected, providing objective as well as subjective health data.
1.4 Data from the Lothian Birth Cohorts have been linked with geocoded information, connecting participants' complete residential address histories with detailed geographic data. This provides information on exposure to green spaces and air pollutant concentration levels throughout individuals' lifetimes. The historical nature of this data enables researchers to examine how exposure impacts individuals across their life span. It also allows the investigation of whether the effects of these exposures accumulate gradually over time or if there are specific critical periods in which benefits or risks become more pronounced.
1.5 The submission directly addresses questions posed by the Environment, Food and Rural Affairs Committee, incorporating relevant research from the Lothian Birth Cohorts. It emphasises the multiple benefits that green spaces offer to the ageing population and underscores the importance of preserving and establishing urban green spaces as a fundamental aspect of age-friendly communities. Key findings from this research will be presented— drawing upon the collective expertise of their research group and collaborators from the University of Edinburgh School of GeoSciences—which support the notion that green spaces can have a significant positive impact on the lives of older individuals and society in general.
2. Inquiry responses
Q2. What environmental challenges are urban areas facing, and how could wider access and inclusion to green spaces (including dog-friendly spaces) address these challenges? Areas to consider but not limited to: …
2.1 Environmental challenges in urban areas
Designing cities to maximize human health is an urgent global priority. Rapidly increasing rates of urbanisation in developing countries has resulted in considerable reduction in green open space because of pressure for provision of housing and related essential infrastructure. Urban areas face numerous environmental challenges such as air pollution, noise, heat, and flooding, while urban lifestyles are linked to reduced physical activity, increased exposure to crime, and poorer psychological health. As urbanisation continues, and cities grow more dense, congested, and polluted, providing healthy liveable urban environments has become increasingly important.
2.2 Importance of green spaces
Green space fulfils several critical functions in an urban context that benefit both the natural environment and human health, including pollution and climate change mitigation, social cohesion, enhancing physical and psychological well-being, and improving quality of life.
At an individual and population level, green spaces have been associated with improved mental and physical health and well-being and are increasingly recognised as a mitigation measure to buffer the aforementioned adverse health effects of urban living. Exposure to green spaces is associated with better perceived and objectively measured general health, improved mental health, enhanced brain development in children, reduced risk of chronic diseases, and lower mortality rates. The precise mechanisms underlying these health effects remain uncertain, but potential pathways include stress reduction, abatement of adverse environmental exposures, social interaction, physical activity, and the therapeutic impact of contact with nature.
2.3 Urban Green Space Benefits for the Ageing Population
● Increasing life expectancy and a growing proportion of individuals aged 65 and older have led to a rise in age-related chronic illnesses, cognitive impairment, and dementia. This demographic shift underscores the need to design age-friendly neighbourhoods with accessible urban green spaces tailored to the needs of older residents.
● Access to green spaces can foster engagement in physical and social activities among the elderly, providing opportunities for exercise and interaction. This is especially valuable as physical activity tends to decline with age, and green spaces can help older adults reach recommended activity targets, which, in turn, has numerous health and mood-related benefits.
● Urban green spaces offer an environment conducive to social interaction and mental stimulation. This is particularly significant for older individuals who may live alone, as it can help combat loneliness and enhance cognitive well-being.
● Natural green spaces provide psychological restoration and may serve as a refuge from the stresses and challenges of everyday life, such as chronic pain, family and health concerns, and social isolation.
● Urban green spaces also facilitate access to fresh air and sunlight, which is a natural source of vitamin D, contributing to overall health and well-being, and improved sleep.
● Notably, urban green spaces are typically free of charge and accessible to everyone. This accessibility is particularly beneficial for older individuals who may have financial concerns, allowing them to escape the confines of their homes, meet friends, and enjoy these spaces without incurring significant costs.
Making urban green space accessible to older people has significant health, social, and economic implications for society. Research using LBC data, outlined in the following section, shows that older individuals exposed to higher levels of air pollution and less green space tend to have worse health outcomes. In facilitating widening access, important points to consider are, how to improve air quality in our cities, and to address the barriers which many older people face in using urban green spaces.
2.4 Impact of air pollution
● Air pollution has been measured across the life-course in the LBC studies using historical air pollution concentrations linked to life-course residential addresses.
● In the LBC1936, higher levels of air pollution (fine particulate matter (PM2.5)) when participants were in utero, were associated with less favourable change in cognitive abilities over the life-course from age 11 to age 70.1. This is the first study to have examined life course air pollution exposure in relation to cognitive health.
● Air pollution, including fine particulate matter (PM2.5), sulphur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3) has also been linked to accelerated biological ageing, with a critical period of vulnerability being young-to-middle age exposure.2 Additionally, air pollution was associated with shorter telomere length, a DNA biomarker of ageing. Critical life periods for telomeres were found to be middle adulthood for men, and around time of birth for women. Findings were more consistent for the pollutants PM2.5, SO2 and NO2. These results suggest that air pollution levels are associated with older-appearing biomarkers of biological ageing in later life.
● This research sheds light on the connection between air pollution and ageing-related health effects.
Q4. Will the Government achieve its aims to increase the amount of green cover to 40% in urban residential areas? What other additional measures should the Government take to increase green urban space?
2.5 Home gardens: an important component of green infrastructure
● Private (domestic) gardens are a major component of the total green space in many UK cities, yet frequently overlooked in research. If public green spaces are expected to substantially decline then home gardens may take on more prominence in terms of promoting well-being. Here, we highlight that we should not underestimate the significance of domestic gardens, especially for older people.
● In the LBC1936, spending more time in home gardens during the COVID-19 lockdown period was associated with better physical and emotional well-being among older people.3 Individuals spending more time in their gardens over this period of self-isolation, reported better physical health, better emotional and mental health, and better sleep quality. Overall time spent in the garden, rather than any specific activity, was the most important indicator of well-being.
● Access to a garden also opens up opportunities for engaging in gardening activities. In the LBC1921 (manuscript is currently under peer review), gardening was found to boost healthy cognitive ageing in later life.4 Compared with non-gardeners, gardeners scored better on tests of intelligence, reasoning and visuospatial ability. Gardeners were more physically active in general, but having a higher physical activity level did not explain the positive association of gardening with successful cognitive ageing. Overall, those who garden more frequently performed better on cognitive tests.
● Private domestic gardens provide significant habitats and enhance the overall functional size of green space networks by functioning as corridors and patches. Therefore, the regulatory framework of public policy for future urbanisation of the UK should build strong incentives to encourage development of housing stock with sufficient garden space (private or community shared).
2.6 Other sources of urban green space
● In addition to home gardens, the government is also encouraged to address other various sources of green space to support the health of the ageing population.
● Allotments are also beneficial for health and well-being, and have the added advantages of providing social interaction, physical exercise, and access to fresh produce. Gardening, whether at home or on an allotment, can provide structure and routine and help foster a sense of pride and achievement.
● Other urban green spaces near schools, workplaces, and commuting routes, for example, should also be considered by urban designers and landscape planners as they contribute to a person's overall exposure to green space throughout their lifetime.
● Even viewing greenery from a window has benefits for health and mood. Urban street greenery is a crucial aspect to be incorporated into the design of age-friendly neighbourhoods.
Q5. Is access to urban green spaces equally distributed across all sectors of society? Do the environmental and associated health risks disproportionately impact certain groups? What barriers to access exist and how can they be addressed?
2.7 Urban green space can buffer the adverse health impacts associated with socioeconomic disadvantage in later life
● In the LBC1936, it was found that the presence of green spaces during childhood is linked to better mental health outcomes in later years, especially for individuals living in socially disadvantaged areas. Residents of neighbourhoods with higher levels of social deprivation who had more exposure to green spaces during their lifetime had a 19% lower anxiety score in later life.5
● These results suggest that lifelong exposure to green spaces may help protect against future mental health issues.
● These findings show that the positive impact of green spaces on mental health may be more significant for those in socially disadvantaged areas demonstrating that the environment's design can counteract the link between socioeconomic disadvantage and poor health outcomes.
2.8 Urban green space benefits for healthy cognitive ageing
● In the LBC1936, better cognitive ageing was linked to more green space - greater public park provision - in childhood and adulthood. The association was strongest in women compared with men, and among individuals with lower socio-economic status.6 These results suggest that having greater access to public parks throughout one's life may help slow down cognitive decline in later years. However, it's noted that individuals with lower socioeconomic status tend to stay closer to home, potentially limiting their access to such green spaces. This study is the first of its kind to explore the role of green spaces in influencing cognitive ageing, supporting the idea that aspects of the physical environment can have a protective effect on cognitive health as people age.
2.9 Barriers to green space access for older adults
● Access to urban green spaces should be equitable across all sectors of society. However, barriers do exist, particularly for older people
● The main barrier identified in a recent LBC1936 survey (preliminary unpublished work) was mobility issues, which limit how far older individuals can travel. Therefore, the presence of nearby urban green space is crucial for the 70+ age group.
● Other obstacles relate to perceived safety and comfort and include concerns about antisocial behaviour, physical challenges like uneven paving and the lack of dropped curbs and paths, lack of seated areas, limited access to toilets, inadequate lighting, and the absence of sheltered spaces like cafes.
● To address these barriers, involving older people in the consultation process for green space design and conservation is recommended. The LBC1936 survey also highlighted that many older individuals visit green spaces to observe nature, such as birds and flora and fauna, suggesting that the aesthetic function of public parks should not be overlooked. Designing rich plant communities also helps support the biodiversity of green spaces and supports air purification. To make urban green spaces more appealing, suggestions include adding information boards for wildlife and viewing platforms. Community planting projects are excellent opportunities to engage older people and foster community cohesion. Finally, guided nature walks can provide a specific purpose for older individuals to visit parks and gardens.
One of the most pressing challenges we face today is safeguarding human well-being by fostering clean air and healthy living through the preservation and rejuvenation of urban green spaces. The increasing prevalence of physical and mental disorders among the ageing population has substantial economic and social ramifications for society, public health, as well as implications for individuals and their families. Research from the LBC studies underscores the critical importance of green space provision for the health and well-being of older individuals. Expanding urban green space availability, and tackling the barriers affecting how older people engage with these spaces, has the potential to mitigate the growing burden of age-related diseases, thereby enhancing quality of life for older adults.
The findings from the LBC studies make an especially valuable contribution to understanding how aspects of physical environment can act as protective factors against cognitive decline. Moreover, these findings are amongst the first to shed light on the lifelong impact of early-life environmental circumstances, particularly the accessibility of local parks. These effects are particularly noteworthy for women and those in lower socioeconomic groups during adulthood. This research underscores the necessity of ensuring consistent and equitable access to urban green spaces throughout one's life to safeguard our future health.
As urbanisation continues to expand, the government's commitment to increasing green cover in urban residential areas is commendable. However, additional measures should be explored, including the incorporation of sufficient green spaces in new housing developments, either as private or community-shared plots, and the expansion of allotment provision. Furthermore, addressing barriers to access and promoting inclusivity in urban green spaces will be essential to realizing the full potential of these spaces for the well-being of all citizens.
October 2023
4. Further details
The LBC studies are primarily funded by the Biotechnology and Biological Sciences Research Council and Age UK, and have received funding from a number of other sources including the Medical Research Council, Economic and Social Research Council, Chief Scientist Office of the Scottish Executive Health Department, National Institutes of Health, and the University of Edinburgh.
5. References
1. Russ, T. C., Cherrie, M. P., Dibben, C., Tomlinson, S., Reis, S., Dragosits, U., ... & Pearce, J. R. (2021). Life course air pollution exposure and cognitive decline: modelled historical air pollution data and the Lothian birth cohort 1936. J Alzheimer's Dis, 79(3), 1063-1074.
2. Baranyi, G., Deary, I. J., McCartney, D. L., Harris, S. E., Shortt, N., Reis, S., ... & Pearce, J. (2022). Life-course exposure to air pollution and biological ageing in the Lothian Birth Cohort 1936. Environ Int, 169, 107501.
3. Corley, J., Okely, J. A., Taylor, A. M., Page, D., Welstead, M., Skarabela, B., & Russ, T. C. (2021). Home garden use during COVID-19: Associations with physical and mental well-being in older adults. J Environ Psychol, 73, 101545.
4. Corley, J., Pattie, A., Deary, I. J., & Cox, S. R. (under review). Gardening and cognitive ageing: longitudinal findings from the Lothian Birth Cohort of 1921.
5. Pearce, J., Cherrie, M., Shortt, N., Deary, I., & Ward Thompson, C. (2018). Life course of place: A longitudinal study of mental health and place. Trans Inst Br Geogr, 43(4), 555-572.
6. Cherrie, M. P., Shortt, N. K., Mitchell, R. J., Taylor, A. M., Redmond, P., Thompson, C. W., ... & Pearce, J. R. (2018). Green space and cognitive ageing: A retrospective life course analysis in the Lothian Birth Cohort 1936. Soc Sci Med, 196, 56-65.