Association of Food Deserts and Food Swamps With Obesity-Related Cancer Mortality in the US

Abstract

Importance: Obesity-related cancers account for 40% of all cancers in the US. Healthy food consumption is a modifiable factor shown to reduce obesity-related cancer mortality, but residing in areas with less access to grocery stores (food deserts) or higher access to fast food (food swamps) reduces healthy food access and has been understudied.

Objective: To analyze the association of food deserts and food swamps with obesity-related cancer mortality in the US.

Design, setting, and participants: This cross-sectional ecologic study used US Department of Agriculture Food Environment Atlas data from 2012, 2014, 2015, 2017, and 2020 and Centers for Disease Control and Prevention mortality data from 2010 to 2020. A total of 3038 US counties or county equivalents with complete information on food environment scores and obesity-related cancer mortality data were included. An age-adjusted, generalized, mixed-effects regression model was performed for the association of food desert and food swamp scores with obesity-related cancer mortality rates. Data were analyzed from September 9, 2022, to September 30, 2022.

Exposures: Food swamp score was calculated as the ratio of fast-food and convenience stores to grocery stores and farmers markets. Higher food swamp and food desert scores (20.0 to ≥58.0) indicated counties with fewer healthy food resources.

Main outcomes and measures: Obesity-related cancer (based on the International Agency for Research on Cancer evidence between obesity and 13 types of cancer) mortality rates were categorized as high (≥71.8 per 100 000 population) vs low (<71.8 per 100 000 population) per county.

Results: A total of 3038 counties or county equivalents with high obesity-related cancer mortality rates had a higher percentage of non-Hispanic Black residents (3.26% [IQR, 0.47%-26.35%] vs 1.77% [IQR, 0.43%-8.48%]), higher percentage of persons older than 65 years (15.71% [IQR, 13.73%-18.00%] vs 15.40% [IQR, 12.82%-18.09%]), higher poverty rates (19.00% [IQR, 14.20%-23.70%] vs 14.40% [IQR, 11.00%-18.50%]), higher adult obesity rates (33.00% [IQR, 32.00%-35.00%] vs 32.10% [IQR, 29.30%-33.20%]), and higher adult diabetes rates (12.50% [IQR, 11.00%-14.20%] vs 10.70% [IQR, 9.30%-12.40%]) compared with counties or county equivalents with low obesity-related cancer mortality. There was a 77% increased odds of having high obesity-related cancer mortality rates among US counties or county equivalents with high food swamp scores (adjusted odds ratio, 1.77; 95% CI, 1.43-2.19). A positive dose-response relationship among 3 levels of food desert and food swamp scores and obesity-related cancer mortality was also observed.

Conclusions and relevance: The findings of this cross-sectional ecologic study suggest that policy makers, funding agencies, and community stakeholders should implement sustainable approaches to combating obesity and cancer and establishing access to healthier food, such as creating more walkable neighborhoods and community gardens.

Figure 1.. Flowchart of US Counties or County Equivalents Reporting Food Environment Measures

Figure 2.. Correlations Between Food Deserts and Obesity-Related Cancer Mortality and Between Food Swamps and Obesity-Related Cancer Mortality

A, Correlation between total percentage of people living in food deserts and age-adjusted obesity-related cancer mortality (ρ = 0.12). B, Correlation between food swamp scores and age-adjusted obesity-related cancer mortality (ρ = 0.08).