The largest-ever study of the link between city walkability and blood pressure has been held up as evidence of the “intangible value of urban design” in improving long-term health outcomes, say researchers.
The study of around 430,000 people aged between 38 and 73 and living in 22 UK cities found significant associations between the increased walkability of a neighbourhood, lower blood pressure and reduced hypertension risk among its residents.
The outcomes remained consistent even after adjustments for socio-demographic, lifestyle and physical environment variables, though the protective effects were particularly pronounced among participants aged between 50 and 60, women, and those residing in higher density and deprived neighbourhoods.
The paper was published in the International Journal of Hygiene and Environmental Health this week. With hypertension a major risk factor for chronic and particularly cardiovascular diseases, researchers at the University of Hong Kong and Oxford University said the findings demonstrated the need for public health interventions to factor in urban design.
“With the increasing pace of urbanisation and demographic shifts towards an ageing population, we become more vulnerable to chronic diseases,” said Dr Chinmoy Sarkar, an assistant professor at the Healthy High Density Cities Lab of the University of Hong Kong and lead author of the study. “Public health interventions must consider the intangible value of urban planning and design.
“We are spending billions of pounds in preventing and curing cardiovascular diseases – if we are able to invest in creating healthy cities through small retrofits in the design of our neighbourhoods to make them more activity-friendly and walkable, then probably, we will have significant savings in future healthcare expenditures.”
To measure a neighbourhood’s activity-promoting potential, researchers developed a composite index of walkability comprising relevant urban metrics, including residential and retail density, public transport, street-level movement, and proximity to attractive destinations.
Poorly designed spaces generally inhibited walking and physical activity, promoting sedentary lifestyles; and were detrimental to social interactions, and as such associated with poorer mental health and wellbeing.
Because walkability was “based on the underlying design of the city”, said Sarkar, cities could be modified or designed to encourage it. “Such investments in healthy design are likely to bring in long-term gains as they are enduring and all-pervasive.”
The study’s large and diverse dataset also presented an opportunity to examine the effects of walkability on blood pressure of specific subgroups of people which, Sarkar said could yield valuable insights into how to manage demographic changes.
He singled out the world’s growing urban population, with more than half (54.5%) of the total population currently living in cities. That figure is expected to rise to 60% by 2030, with one in three living in cities with at least half-a-million inhabitants.
In the UK alone more than 7 million people are estimated to be affected by cardiovascular disease, which accounts for nearly 160,000 deaths annually and £19bn in health costs.
Designing and retrofitting cities to promote active lifestyles could therefore have significant repercussions for the health of urban populations and governments’ related expenditure around the globe, said Sarkar. “Well-designed cities of today will be healthy cities of tomorrow.”
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