Our health is a function of where we live

Our health is a function of where we live

Comment Our health is a function of where we live almost two-thirds of physically inactive people would fulfil international guidelines if they added ...

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Our health is a function of where we live almost two-thirds of physically inactive people would fulfil international guidelines if they added 10 min of MVPA every day (Cerin E, University of Hong Kong, personal communication). According to Lee and colleagues,4 3·6 million deaths would be prevented each year worldwide if two-thirds of inactive people increased their activity to the level recommended in the guidelines. Given that Sallis and colleagues noted a difference of 68–89 min of MVPA per week between the least and most supportive built environments and given that the current environment of all participants might vary across a spectrum of supportive and unsupportive of physical activity, we estimate that total health gained by changing to optimal activity-friendly environments will be close to 2 million fewer deaths and around 3% fewer non-communicable diseases (in other words, about 50% lower physical activity associated noncommunicable diseases). Traditionally, some of the most pedestrian-friendly, physical activity-friendly, and cycle-friendly cities in the world were built or developed not for specific physical activity or health considerations, but for larger public good, and common civic sense. Wide pedestrian pathways (shaded with trees to counter the hot weather in tropical countries), cycling or bike lanes, green spaces for walking, and parks and community or sports centres were constructed many decades ago for public good. Delhi and Mumbai in India were such cities: they were beautiful pedestrian-friendly cities, but rampant

www.thelancet.com Published online April 1, 2016 http://dx.doi.org/10.1016/S0140-6736(16)00348-2

Published Online April 1, 2016 http://dx.doi.org/10.1016/ S0140-6736(16)00348-2 See Online/Articles http://dx.doi.org/10.1016/ S0140-6736(15)01284-2

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In The Lancet, James Sallis and colleagues1 report significantly higher physical activity levels among residents where the built environment is supportive of physical activity. This study is the largest to date and includes data from five continents (6822 adults) and makes a completely objective assessment of both the attributes of the built environment and the physical activity outcomes. The following four built environments were positively and linearly associated with higher physical activity levels in the single environment model: more public parks within walking distance (0·5 km) from residence, which were free and open to all; higher density of public transport such as number of bus, rail, or ferry stops and stations divided by the land area; higher net residential density; and higher number of street intersections that are pedestrian accessible. Sallis and colleagues’ Article is uniquely different, rigorous, and robust, when compared with previous published studies. Earlier studies of built environment and physical activity2 have struggled with methodological shortcomings: single country or continent, small sample sizes, and use of self-reported physical activity and perception of environment, which do not allow for an accurate quantification of either physical activity or structural environmental attributes, which increase or hinder physical activity.2 Self-reported physical activity levels are influenced by age, sex, culture, and recall bias. Sallis and colleagues used measurements from geographic information systems and accelerometers to assess environment and physical activity objectively. They noted a difference of 68–89 min of moderate and vigorous physical activity (MVPA) per week between the least and most supportive built environment areas, a substantial difference that translates into 45–59% of MVPA recommended per week by WHO.3 Lee and colleagues4 estimated in a conservative calculation that physical inactivity caused 9% of premature mortality, that is, more than 5·3 million deaths in 2008. A similar percentage of non-communicable diseases can be attributed to physical inactivity, such as coronary artery disease (6%, 95% CI 3·2–7·8), strokes and diabetes (7%, 3·9–9·6), breast cancer (10%, 5·6–14·1), and colon cancer (10%, 5·7–13·8).4 On the basis of the physical activity distribution in Sallis and colleagues’ Article,

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new construction has undermined their pedestrian friendliness and cycling friendliness.5,6 Similarly, the well known Danish bike lane system—which enables 25% of the population to cycle to work7—provides substantial health benefits. Mortality is 30% lower in cycle commuters compared with those who use passive transport.8 Most bike lanes were constructed 50 years ago because visionary politicians realised that cyclists caused less pollution and less traffic congestion than cars, and new cars were taxed 180%. Large sums of public money are spent on building or remodelling roads, cycling, and walking paths for good or ill. For example, the contentious so-called bus rapid transport in Delhi cost US$22·5 million.9,10 Similarly, the small city Førde, in Norway, has assigned $150 million to build bike infrastructure with no money for evaluation. Well planned multiperspective assessments (or evaluations) should be done for all new, existing, and old urban environment projects. Historically, town planning and built environments have had major impacts on infectious diseases such as cholera, rheumatic fever, and tuberculosis.11 Today’s reality is that large-scale and rural–urban migration, often of people in distress, is leading to unplanned overcrowded habitation and poor sanitation in many developing countries, contributing to outbreaks of infectious diseases and also increasing rates of noncommunicable diseases.6,12,13 Sallis and colleagues present clear evidence for the role of the urban built environment in enhancing physical activity levels of entire populations, across socioeconomic classes and cultures, and thereby preventing non-communicable disease. This evidence puts greater responsibility on town planners. Other vital attributes of the built environment that support physical activity and are taken for granted in all the countries of Sallis and colleagues’ study, might not be noted in many other developing countries and need urgent attention— safety, pedestrian priority, availability of adequately wide, usable, unencroached pedestrian pathways, convenience and safety in cycling, and adequate capacity in public transport. Ongoing and long-term multiperspective evaluations of existing urban built environments should be an

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integral part of urban planning and governance. We need interventions to counter the rapidly growly inactivity that urbanisation leads to, by providing environments that change the way we live our daily lives. It is high time that built environments provide the quadruple boost towards health, environment, equity (or public good), and habitat. *Shifalika Goenka, Lars Bo Andersen Centre for Chronic Conditions and Injuries, Public Health Foundation of India, Indian Institute of Public Health, Delhi, India and Centre for Chronic Disease Control, Gurgaon-122002, Haryana, India (SG); and Faculty of Teacher Education and Sports, Sogn og Fjordane University College, Sogndal, Norway (LBA) shifalika.goenka@phfi.org We declare no competing interests. 1

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Sallis JF, Cerin E, Conway TL, et al. Physical activity in relation to urban environments in 14 cities worldwide: a cross-sectional study. Lancet 2016; published online April 1. http://dx.doi.org/10.1016/S01406736(15)01284-2. McCormack GR, Shiell A. In search of causality: a systematic review of the relationship between the built environment and physical activity among adults. Int J Behav Nutr Phys Act 2011; 8: 125. WHO. Global recommendations on physical activity for health. Geneva: World Health Organization, 2010: 1–57. Lee IM, Shiroma EJ, Lobelo F, Puska P, Blair SN, Katzmarzyk PT. Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of burden of disease and life expectancy. Lancet 2012; 380: 219–29. Sen J, Chattopadhayaya V, Chandola P, Jamwal N, Seth B. Footfalls: obstacle course to livable cities. Delhi: Centre for Science and Environment, 2009. Goenka S, Ajay V, Jeemon P, Prabhakaran D, Varghese C, Reddy KS. Powering India’s growth. New Delhi: IC-Health, Center for Chronic Disease Control, World Health Organization Country Office, Public Health Foundation of India, 2007. http://ccdcindia.org/Powering_India’s_growth. pdf (accessed Feb 24, 2016). Hallal PC, Andersen LB, Bull FC, Guthold R, Haskell W, Ekelund U. Global physical activity levels: surveillance progress, pitfalls, and prospects. Lancet 2012; 380: 247–57. Andersen LB, Schnohr P, Schroll M, Hein HO. All-cause mortality associated with physical activity during leisure time, work, sports, and cycling to work. Arch Intern Med 2000; 160: 1621–28. The Times of India. Delhi govt approves Rs 11 crore to scrap 150 crore BRT project. The Times of India (Mumbai) Oct 3, 2015. Central Road Research Institute. Evaluating bus rapid transit (BRT) corridor performance from Amebedkar Nagar to Mool Chand intersection. New Delhi: Central Road Research Institute, 2016. http:// www.crridom.gov.in/content/evaluating-bus-rapid-transit-brt-corridorperformance-amebedkar-nagar-mool-chand (accessed Jan 26, 2016). Perdue WC, Stone LA, Gostin LO. The built environment and its relationship to the publics health: the legal framework. Am J Public Health 2003; 93: 1390–94. Peer N. The converging burdens of infectious and non-communicable diseases in rural-to-urban migrant Sub-Saharan African populations: a focus on HIV/AIDS, tuberculosis and cardio-metabolic diseases. Trop Dis Travel Med Vaccines 2015; 1: 1–8. Remais JV, Zeng G, Li G, Tian L, Engelgau MM. Convergence of noncommunicable and infectious diseases in low- and middle-income countries. Int J Epidemiol 2013; 42: 221–27.

www.thelancet.com Published online April 1, 2016 http://dx.doi.org/10.1016/S0140-6736(16)00348-2