This diagram shows food deserts (black) and service areas (white) around low- and high-cost supermarkets defined as baseline (1 mile) and 10-minute walking, riding transit, and driving network distances in Seattle–King County, Washington. For a larger version, please click the diagram or download the study at the top of the story (it is on pg. 6).
Car access and supermarket costs play a big role in King County food deserts, UW study finds
A group of University of Washington researchers, in a study published in the American Journal of Public Health, took a closer look at the challenges facing vulnerable populations in King County food deserts, and the information provides insight into the struggles of those in our own backyard, including Highland Park and North Delridge.
They found that access to a car and the cost of nearby supermarkets are large determinants in defining a food desert.
Food deserts are areas with limited access to healthy food options (AKA a supermarket), where the quickest way to a meal is often a fast food restaurant or shelves of processed, prepackaged food common in convenience stores.
Researchers looked at vulnerable populations in their study, defined by the Robert Wood Johnson Foundation as “….populations including the economically disadvantaged, racial and ethnic minorities, the uninsured, low-income children, the elderly, the homeless, … (and) those with chronic health conditions.”
Taking into account car ownership and proximity to low-to-medium cost supermarkets, researchers found that one-third of King County’s vulnerable populations could walk to a nearby supermarket within 10 minutes, but only three percent could walk to a low-cost market in that time (they operated on the assumption that low-income populations need to access to low-cost markets).
"Most of the research (done in the past) assumes that everybody has a car to go to and from the supermarket, which is not really true," Anne Vernez Moudon, professor of urban design and planning at UW and one of the paper’s authors said in a statement.
"We have 5 to 8 percent of the population that doesn't have a car,” she added. “And if you take a family of four and you have one car, not everybody has access to the car all the time."
The study found that while access to public transit (and therefore a route to a market) is widespread in the county, “individual shopping needs don’t always coincide with transit routes or times.”
“Having access to a car was the best guarantee of the majority of the vulnerable populations to reach any supermarket within 10 minutes, making food-shopping a car-dependent activity,” they found.
By taking into account high, medium and low-cost supermarket options, they found the areas defined as food deserts spread dramatically.
A diagram (found on page 6 of the study attached at the top of the story) shows the contrast. When only walking to a low-cost market is taken into account, nearly all of West Seattle is considered a food desert. Looking at using transit or a personal vehicle, the desert lessens, but only in the northeast section of the peninsula. Southeast West Seattle (including Highland Park) remains a food desert.
Moudon said the results of their study could prove useful to city planners and public health authorities. Historically, she said, they have left access to low-cost, healthy food up to the private sector which inevitably leads to areas without options.
"The public health people are saying to the planners, 'Don't let people develop in areas unless you bring a food source,'" Moudon concluded.
Moudon worked with co-authors Philip M. Hurvitz, Adam Drewnowski and Jared Ulmer of the UW and Junfeng Jiao of Ball State University on the study.