Summary: Where you live in Canada can influence your risk for major chronic diseases such as heart disease, diabetes and some cancers, according to new research that maps community-level environmental factors.
Source: McMaster University.
Your postal code may affect your health: neighbourhood factors linked to cardiovascular disease, diabetes and cancer risk
Researchers at McMaster University examined how community features—from grocery store offerings to public transit and tobacco marketing—vary across Canada and how those differences may shape health risks. Their analysis identifies patterns in access to fresh produce, food and tobacco pricing, the prevalence of unhealthy food and drink promotion, and how restaurants present healthier options.
The study, which drew on detailed audits carried out across all 10 provinces between 2014 and 2016, is published in the journal Cities and Health. The project includes an interactive public map that displays the collected data by postal code for communities across Canada.
“We found meaningful differences in contextual factors that influence health, and those differences depended on whether a community was urban or rural and whether it was located in eastern, western, northern or southern regions of the country,” said Russell de Souza, the study’s lead author and assistant professor in the Department of Health Research Methods, Evidence, and Impact at McMaster.
De Souza is also a research associate at the Population Health Research Institute (PHRI) at McMaster and Hamilton Health Sciences. He and his colleagues emphasize that many environmental influences on health are beyond an individual’s control and vary with location.
Key findings
- Availability and selection of fruits and vegetables vary by province and between urban and rural communities. Advertising practices differ more across provinces than between urban and rural settings.
- Rural communities tend to face higher food prices, greater seasonal variation in produce selection, and fewer promotions for healthy restaurant choices and less nutritional information available in restaurants compared with urban areas.
- In-store advertising for sugary drinks and snack foods is more common than in-store advertisements promoting tobacco products.
- Cigarette prices are generally lower and the variety of brands greater in urban tobacco retailers than in rural ones; central Canada shows the lowest cigarette prices, along with more in-store cigarette advertising and more signs prohibiting smoking in stores.
- Alcohol prices were found to be lowest in Quebec.
The research team collected more than 2,000 field audits using a standardized assessment adapted from the Prospective Urban and Rural Epidemiological (PURE) study. Trained auditors completed on-the-ground evaluations of community features such as public transportation, grocery variety and prices, alcohol and tobacco availability, and the presence of health-promoting options in restaurants. Duplicate audits were conducted to check reliability.
De Souza said the study was motivated by growing concern over rising rates of overweight and obesity across Canada and the related increases in hypertension, diabetes and other chronic conditions that could reverse decades of progress in reducing cardiovascular deaths.
“We still have knowledge gaps about how the built environment—the human-made physical features around us—affects the development of risk factors like high blood pressure,” he said. “This study describes how those built environments vary across regions and between urban and rural communities.”
The patterns the researchers identified correspond with previously observed health trends. Prior studies have shown higher heart disease risk in eastern Canada versus western regions, and generally poorer health indicators in rural versus urban populations. By documenting the contextual drivers—what the team calls the “causes of the causes”—the study offers clues about why chronic disease risks differ by place.
De Souza and colleagues intentionally made their data available through an interactive online map so policy makers, public health professionals, researchers and community members can identify local priorities and plan interventions. “If healthy food is unaffordable or stores are far away, individual counseling alone is insufficient,” he said. “We need environments where healthy choices are accessible and affordable.”
The study is part of the Canadian Alliance for Healthy Hearts and Minds (CAHHM), led by Sonia Anand at McMaster. CAHHM is a multi-ethnic cohort study that investigates how social, environmental and contextual factors—such as nutrition, activity, tobacco exposure and access to health services—relate to cardiovascular and other chronic disease risk.
“Place matters,” said Anand, who holds the Heart and Stroke Foundation / Michael G. DeGroote Chair in Population Health Research at McMaster. “This work allows comparisons across communities, provinces and regions and helps identify where interventions could reduce inequities in health.”
De Souza noted that the three Canadian territories were not included in the audits due to logistical constraints for the research team. The researchers hope the data will inform policies that reduce barriers to healthy behaviours—such as improving access to affordable fresh produce, strengthening nutrition information in restaurants, and creating environments that discourage tobacco and excessive alcohol use.
Advocates and public health leaders responded to the findings by highlighting persistent inequities. Anne Simard of the Heart and Stroke Foundation of Canada emphasized that rural and remote communities still face challenges in accessing healthy foods and nutrition information, underscoring a need for targeted policy action. Craig Earle of the Canadian Partnership Against Cancer noted that the findings reveal disparities that contribute to different health outcomes and called for collective measures to address them.
Contributors to the study include researchers from McMaster University and the Population Health Research Institute, as well as collaborators from Université de Montréal, Simon Fraser University, Ottawa Hospital Research Institute, Harvard University, University of Toronto, Institute for Clinical Evaluative Sciences, St. Michael’s Hospital, and Sunnybrook Research Institute.
Funding: The CAHHM project received support from the Canadian Partnership Against Cancer, the Heart and Stroke Foundation of Canada, and the Canadian Institutes of Health Research through the Canadian Urban Environmental Health Research Consortium.
Media contact: Veronica McGuire, McMaster University.
Original research: De Souza et al., “Environmental health assessment of communities across Canada: contextual factors study of the Canadian Alliance for Healthy Hearts and Minds,” published in Cities and Health (2018). The study audits more than 2,000 communities and presents an online map for public use.
Environmental health assessment of communities across Canada: contextual factors study of the Canadian Alliance for Healthy Hearts and Minds
Rationale: Cardiovascular risk varies across Canadian communities, and community-level contextual differences may shape the development of risk factors.
Methods: Audits of urban and rural communities used a standardized instrument to collect objective measures on demographics, public transport, tobacco availability and advertising, grocery selection and prices, alcohol pricing, and healthful restaurant options. Duplicate audits assessed reliability.
Results: Between 2014 and 2016, 2,074 community audits were completed, most in urban settings. The study documents provincial and urban-rural differences in fruit and vegetable availability, higher food prices and seasonality in rural areas, more frequent advertising for sugary drinks and junk foods than for tobacco, and regional variation in tobacco and alcohol pricing. Audit reliability was high. An online map was created to share results.
Conclusions: Contextual determinants of health vary by province and by urban versus rural location. Public health, built environment professionals and government agencies can use these data to inform coordinated strategies that aim to reduce the chronic disease burden across Canada.