In order to develop townscapes that have at least some relationship to our evolutionary journey, our 'genetic-response' to nature needs examination. A crowded city is made more bearable because it has a park: it's not the just the physical open space (that could be a tarmac carpark), it's the grass and trees themselves. Town planners now have an increasing appreciation of this basic human need that "spaces incorporating urban greenery and water…contribute to mental health". In the search for urban wellbeing, there is therefore a clear role for town-planners to work within an 'evolutionary' brief in the design and provision not just of public and private buildings that function at a human level, but of urban greenspace, parks, sports facilities, pedestrianisation schemes, tree-planting and transportation systems.
The importance of urban greenspace can be shown to be more than window dressing: it has purposeful roles to play in the bettering of urban life. A cityscape that positively encourages walking and cycling as the normal modes of urban propulsion through quiet streets, parks and segregated routeways will have cleaner air, healthier citizens and a smaller NHS budget. The active promotion of sport with appropriate facilities and playing fields improves health, social cohesion and lowers crime rates. Allotments and residential gardens produce fresh food, while the psychological and therapeutic benefits of gardening, working with animals on care farms or keeping pets is well documented. But the importance of our continuing engagement with the natural world is even more important than that. Research by Professor Graham Rook's team (2013) demonstrates that there is a very basic biological reason for plants, pets and parks in urban life if our immune system is to operate effectively.
Proximity to urban greenspace is good for your health
Significantly, studies have shown that residents in the boroughs with the most greenspace have better physical health than those in the greyer regions (Mitchell & Popham 2008). The rise of the greener suburbs seems to have improved the health of its occupants: but what does the future hold for those living in the ever-denser conurbations of garden-less flats and six-lane highways, if that is the projected norm of tomorrow's cities?
All in the mind? The psychology of urban greenspace
The therapeutic benefits of nature in an urban environment can be shown by the expanding network of allotments, community gardens and the fifteen City Farms now operating in the Greater London area. These latter schemes, for example, are regularly visited by families and serve as valuable open-air class rooms for local school children, living far from the open countryside. These farms also show the socially-beneficial impact that physically working with animals and plants provides, with positive work-experience placements, and courses that accommodate those with autism, behavioural problems, the homeless, young offenders, the unemployed.
Or all in the body? The biology of urban greenspace
There is an additional evolutionary reason for needing a green town, as recent biological research by Professor Graham Rook and his team have shown. Continuing good health requires an effective immune system, but can the process of urbanization itself be detrimental to our body's ability to fight infection and disease? As long ago as 1820, Dr John Rostock observed that farmers (but more significantly their children) never suffered from Hay Fever: indeed it was seen as an aristocratic affliction of the urbane urban classes. What was not realized at that time is that it is from direct contact with animals and plants -particularly in the first weeks and months of life- that we derive the macro-organisms, micro-organisims and microbiota that live on our skin or in the gut, and these creatures have crucially co-evolved roles in the regulation of the human immune system. Without them, our susceptibility to allergies, autoimmuntity and inflammatory bowel disease is much increased.
These studies suggest a major reason why towns (or more correctly, reduced engagement with nature) could be bad for our physical health. But new research has shown that if our urban bodies cope ineffectively with inflammation, then there can also be negative psychiatric consequences. This is because the same organisms and processes that help our immune system combat inflammations also modulate brain development, cognition and mood. This crucial link between psychiatric disorders and chronic inflammatory disorders requires further detailed research by immunologists, epidemiologists, neuroscientists and psychiatrists. A possible solution suggested by Professor Rook's team may lie in the extended greening of conurbations, the keeping of pets and universal regular access to gardens, allotments and parks. In such ways, nature might improve our immune systems for us, given that we start early enough and that we identify which plants and which animals provide the greatest benefit.
Hine, R, Peacock, J & Pretty, J 2008 'Care farming in the UK: Evidence and Opportunities' National Care Farming Initiative
Mitchell, R & Popham, F, 2008 'Effect of Exposure to Natural Environment on Health Inequalities: an observational study', Lancet 372: 9650 pp 1655-1660 Rook, G, Lowry, C, and Raison, C, 2013 'Microbial 'old friends' , immunoregulation and stress resilience', Evolution, Medicine and Public Health (2013) pp 1-19 doi:10.1093/emph/eot 004