Indirect link between income and healthy eating

Jun 2 2005

A new study of 266 African-American women in Detroit concludes that those who shop regularly in supermarkets eat more fruits and vegetables than those who shop in independent neighborhood markets.

Women who were happy with the selection and quality of fresh produce at their market also ate more fruits and vegetables than others in the study, regardless of the cost and type of store. The study appears in the July issue of the American Journal of Preventive Medicine.

More than 75 percent of the women who shopped in the city frequented independent grocers, while 85 percent of those who shopped in the suburbs used supermarkets and none used an independent market. The women in the study lived about 2.5 miles from the nearest Detroit supermarket and four miles from the nearest suburban supermarket.

The findings may point to an indirect link between income and healthy eating, since “women with higher per capita incomes were more likely to shop at supermarkets than at other stores,” according to Shannon Zenk, Ph.D., of the University of Illinois at Chicago and colleagues.

The researchers found no direct link between income and fruit and vegetable consumption.

Zenk and colleagues asked women in the study about where they shopped most often, how they would rate the selection, quality and affordability of the fresh produce at the store where they shopped and how often they ate fruits and vegetables.

Women who shopped at supermarkets ate one more serving of fruits and vegetables daily than those who shopped at independent markets, Zenk and colleagues concluded.

In the study, supermarkets included full-service grocers in a national or regional chain; specialty markets included markets dedicated to selling one type of food like meats or produce; and independent markets were full-service grocers not affiliated with any chain.

Zenk and colleagues say it is difficult to tell, based on their data, whether the women were shopping at a particular type of store in a particular location because they preferred that store or whether they were limited by their transportation options to rely on certain grocers.

“The frequency of women’s intake of fruit and vegetables may have influenced their decisions on where to shop and their perceptions of the selection and quality of the produce for sale,” Zenk says.

“Nevertheless, it appeared that those women with the ability or resources to get to suburban supermarkets chose to shop at supermarkets, while those without the ability or resources were restricted to independent neighborhood markets,” she adds.

“Given that women are often the main household food shoppers, the stores and foods to which they have access may not only affect their personal nutrition, but also the nutrition of other household members,” the researchers conclude.

All of the women lived in an area of Detroit that was 97 percent African-American and had 35 percent of households living below the poverty line in 2000. A survey of the greater community area found no chain supermarkets, 13 independent grocery stores and 93 liquor stores serving about 90,000 residents.

In contrast, a nearby mixed white and African-American middle-income community had 19 grocery stores, including eight chain supermarkets and 18 liquor stores for 78,000 residents.

Other researchers have documented the lack of supermarkets in poorer communities. For instance, a 2002 study of 216 communities in Maryland, Minnesota, Mississippi and North Carolina found three times as many supermarkets in high-income neighborhoods compared to low-income neighborhoods, and four times as many supermarkets in mostly white neighborhoods as in mostly African-American neighborhoods.

The study was supported by the Centers for Disease Control and Prevention and the National Cancer Institute.