Neighborhood racial composition, neighborhood poverty, and food access in metropolitan Detroit: Geographic information systems and spatial analysis.

摘要

Inadequate access to a good selection of high-quality nutritious foods may be a barrier to healthy eating in impoverished, African-American neighborhoods and contribute to higher morbidity and mortality. In this study, I examined the spatial distribution of nutritional resources according to the racial and economic characteristics of neighborhoods in metropolitan Detroit. I first tested the extent to which large "chain" supermarkets are less accessible in neighborhoods with greater proportions of African-American residents using three spatially explicit measures (Manhattan Block distance to the nearest supermarket, number of supermarkets within a three-mile radius, and potential supermarket accessibility based on an inverse distance function) and whether neighborhood poverty mediates or moderates the association. Adjusting for spatial autocorrelation, the relationship between neighborhood racial composition and supermarket accessibility depends on neighborhood poverty level. For all three accessibility measures, supermarket accessibility is similar in low-poverty neighborhoods across the three tertiles of percentage African-American residents. Among the most impoverished neighborhoods, however, high African-American neighborhoods, on average, are 1.17 miles further from the nearest supermarket, have 2.95 fewer supermarkets within a three-mile radius, and have 0.70-units poorer potential supermarket accessibility when compared to predominately white neighborhoods. This study also compared the spatial distribution of several types of retail food stores (chain, large independent, mom-and-pop, specialty, convenience, and liquor) and the availability, selection, quality, and cost of fresh fruits and vegetables at these stores in four geographically-defined communities in and near Detroit: a poor, predominately African-American community a poor, racially heterogeneous community a middle-income, predominately African-American community and a middle-income, racially heterogeneous community. The poor, predominately African-American community has particularly poor access to nutritional resources. It has considerably fewer large grocery stores, a smaller proportion of retail outlets selling fresh produce, and significantly lower quality produce than the middle-income, racially heterogeneous community, as well as the greatest number of liquor stores of the four communities. Overall, results of this study indicating unequal distribution of nutritional resources according to an interaction between the racial and economic characteristics of neighborhoods lend support for racial residential segregation and neighborhood poverty as fundamental causes of disease (Link and Phelan 1995) in metropolitan Detroit.