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31/01/2018

How modern cities are killing our ancient bodies – and what planners can do about it

Words: Gustav Milne

Modern cities are killing our Palaeolithic bodies, argues Gustav Milne. Although we can’t change our biology, we can change our living environments

Once zoos were just penal colonies for captured animals wrenched from their natural habitat. Unsurprisingly the poor creatures exhibited problems, rarely breeding successfully in captivity. Today, the well-being of animals in our zoos and wildlife parks is better understood and catered for, with attempts to mimic elements of their lost environment. The better the surroundings simulated their ‘natural’ habitat, the healthier they were.

Given that we humans are also primates, might there be a lesson for us here, too? After all, some 3.4 billion people (50 per cent of the world’s population) are already urbanised, living in our own concrete zoos. But towns are not our natural habitat: for the majority of the last few million years, we and our immediate ancestors survived as hunter-gathers, living off the land in small tribal societies, working closely with nature.

Culturally, society is clearly evolving at remarkable speeds, with its new towns and new technologies. But biologically, significant evolution has been much, much slower: our bodies are still broadly Palaeolithic, much as we were long before extensive agriculture or the first towns were developing, 5,000 to 10,000 years ago.

Consequently there is a real mismatch between modern urban living and that ancient part of our genome that supported ‘hunter-gatherer’ lifestyles. The long period of gradual human evolution is still stamped deep into our DNA as our genetic ‘normal’. Our uncivilised teeth and our digestive system still reflect an omnivorous need for fresh fruit, vegetables, roots, nuts, berries, meat and fish, rather than the abnormal pre-packaged, over-processed, sugar-enhanced products. 

Our uncivilised lungs still only operate effectively with fresh air, not with abnormal exposure to toxic fumes, tobacco or diesel particulates. Our bipedal physiology still demands a daily workout, based on an ancestral lifestyle of regular walking, carrying, climbing and bending, rather than abnormally sedentary lives. 

“Our bodies are still broadly Palaeolithic, much as we were long before extensive agriculture or the first towns were developing”

And then there’s our uncivilised immune system: this still needs the microbiota obtained externally from plants, trees, animals, soil to function effectively, and we still need to top up our vitamin D levels by working outdoors.

An enhanced understanding of the innate and immutable evolutionary determinants of our health should have a much more central role in modern urban design. How might we reconfigure our townscapes and buildings on lines better suited to the physiology and psychology of the proxy hunter-gatherers that, biologically, we still are? 

If were able to achieve this, our urban well-being would be improved, the scourge of ‘Western lifestyle diseases’ contained, and the cost to the National Health Service diminished. As in a modern zoo, the better our urban surroundings simulate our ‘natural’ habitat, the healthier we urban apes will be. 

Are modern towns killing us?

For the first time in human history more people across the globe now live in cities than in rural communities. And more towns will have to be built to accommodate a population estimated to rise from 7.2 billion to 9.6 billion by 2050. 

But the fundamental question is this: are these artificial environments called towns bad for us? Indeed, is urbanisation actually killing us? 

Although there are major benefits to city living, there are also major costs, such as the seemingly unstoppable rise in obesity, coronary-related problems, type 2 diabetes, Alzheimer’s, and various types of cancer. 

The World Health Organisation lists all of these in the 10 most common causes of death in modern, urbanised societies. Do these deaths represent that mismatch between human biology and urban culture, or are they just an inevitable result of the ageing process? 

There is compelling research that challenges the inevitability of death by Western lifestyle diseases, suggesting that living in such artificial environments may well be exerting an unanticipated negative impact on modern urban well-being. 

“As for the Romans, they not only introduced the civilising concept of urbanisation to these islands 2,000 years ago, but also scurvy, rickets, rheumatoid arthritis and leprosy”

A major long-term study by Staffan Lindeberg showed that ALL those fatal ‘Western’ conditions are rare or non-existent in un-urbanised communities that still maintained an ‘ancestral’ lifestyle, such as that in Kitava, Papua New Guinea (Lindeberg 2010 Food and Western Disease: Health and Nutrition from an Evolutionary Perspective) Detailed archaeological studies show graphical support for this contention, demonstrating how 5,000 to 10,000 years ago the transformation from ancestral practices to farming and urbanisation damaged our collective well-being.

That Neolithic period is associated with the first evidence, not just of intensive farming, but also of tumours, anaemia, diffuse idiopathic skeletal hyperostosis (DISH, a proxy for obesity) and osteoporosis. 

As for the Romans, they not only introduced the civilising idea of urbanisation to these islands 2,000 years ago, but also scurvy, rickets, osteomalacia, gout, rheumatoid arthritis, tuberculosis, osteitis, poliomyelitis and leprosy. None of these conditions were seen in the prehistoric, largely un-urbanised tribal populations that lived here before the Roman invasion of AD 43 (see, e.g. Health and Disease in Britain, from Prehistory to the Present by Charlotte Roberts and Margaret Cox, or Brenna Hassett’s Built on Bones).

Urbanisation was, and often remained, a mixed blessing.


How to build a better human zoo

 

  • Provide fresh water and sound sanitation systems.
  • Ensure good air quality (e.g. ban vehicles that emit diesel particulates).
  • Put human locomotion at heart of transport policy/street design (e.g. traffic-calming measures, cycle tracks, pedestrianisation).
  • Develop integrated public transport systems that help limit car use.
  • Develop designated safe cycle and pedestrian route-ways.
  • Extend urban green space – pocket parks as well as central parks.
  • Promote/develop participatory urban green space (e.g. allotments, community gardens, city farms).
  • Promote sport through development of pitches and maintained sports facilities.
  • Develop programmes of street greening and promote roof gardens and green walls.
  • Limit development for high-rise buildings for residential use (maximum six storeys preferable)
  • Encourage street-based neighbourhoods rather than enclosed estates.
  • Ensure that residential buildings have adequate natural light and access to some outside space (garden, patio, terrace or balcony).

Evolutionary-concordant urban design 

Approaches to urbanisation that attempt to address this real challenge and specifically incorporate well-being include Ebenezer Howard’s Garden Cities, New Urbanism that developed in the 1970s and the Healthy Cities movement, which originated in Toronto in 1984. Less than 20 years after its foundation, 1,300 cities in 29 countries had signed up to the Healthy Cities movement. 

An evolutionary-concordant urban design protocol not only builds on those ideas but also, more importantly, underpins them.

It is appreciated that we have a personal responsibility for our own dietary and activity regimes, should we wish to follow a proxy Palaeolithic path. But it’s not just our individual lifestyles that need reconfiguring, as change is also needed in town planning, in the fabric, design and layout of our cities. All need to operate on evolutionary-concordant lines to make a real difference to tomorrow’s urban well-being. 

An evolutionary-concordant town would promote the idea of ‘greened cities’, not just with large central parks, but also with smaller ‘pocket parks’, tree-lined streets, roof gardens, green walls, and the greater provision of pitches, sports fields and allotments. These elements are essential not only for biodiversity, but also for fostering our uncivilised immune systems, dependent as they are on microbiota absorbed from the natural environment. 

Further, active lives can also be encouraged and promoted through increased pedestrianisation, riverside paths, designated cycle lane schemes and coherent public transport provision. 

"If we are really to achieve healthily human-friendly cities, we may need a step change in attitude"

Another major inducement for all those contemplating urban walking or cycling is the banning of fatal diesel particulates and other noxious emissions. The protection of our uncivilised lungs and respiratory systems (designed solely to cope with fresh air) is essential. Every year, some 400,000 people across Europe die prematurely as a consequence of their long-term exposure to such pollution: an unnecessary and shameful statistic.

If our streets, parks and buildings genuinely facilitate active commuting, then a major report by Lucy Saunders (Transport for London) lists the benefits. It estimates that, in London alone, more than 4,000 premature deaths, nearly 800 more cases of breast cancer, up to 500 more cases of colorectal cancer, 1,500 extra cases of coronary heart disease and nearly 45,000 more cases of type 2 diabetes could be avoided simply by increasing activity levels. Such basic changes in our cultural and health behaviours, supported and promoted by relevant town planning initiatives, really would save lives.

As Professor Stephen Marshall has argued, if we are really to achieve healthily human-friendly cities, we may need a step change in attitude. The health and well-being agenda should be no less deserving, strategic or systematic than the safety or accessibility agendas.

Just as policymakers would not knowingly create an unsafe road layout nor install a public building without wheelchair access, arguably no planning or transport policy should knowingly be implicated with unhealthy urbanism (Marshall et al, Town and Country Planning Journal, 2015 pp125-129). At the very least, such a necessarily wide-ranging agenda should include closely integrated considerations of urban green space, human locomotion and clean air as standard.

We need to build a better zoo to secure our collective well-being. Many unrelated bodies following different lines of enquiry reached similar conclusions as to the potency of the evolutionary determinants of health and urban design. Although most had little concept of the underpinning deep genetic imperatives, all could see positive results. 

These include health professionals constructing beneficial activity regimes, as well as the walkers and cyclists who had long practised them; social workers looking at the benefits of urban sport; the NHS contemplating the ever-rising costs of the obesity epidemic; architects designing buildings for humans; community groups pressing for better streetscapes; town planners working with public health officials; urban designers who value green space. 

The unifying paradigm underpinning all such varied initiatives is the deeper concept of evolutionary concordance. For all those who are trying to make urbanisation work, a better understanding of our shared deep past will materially assist the construction of a more normal, healthier future. Homo Sapiens are not best adapted for living in modern towns: we can’t change our biology, but we can change our towns.  

Gustav Milne is an archaeologist and lecturer who coordinated research for University College London’s Evolutionary Determinants of Health and Urban Wellbeing project. He is the author of Uncivilised Genes: Human Evolution and the Urban Paradox, published by Crown House Publishing

Illustration | Chris Malbon

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