Diabetes Risk in Black Women: Where You Live

A long-term study of African-American women’s health has revealed yet another factor, in addition to poor diet, lack of exercise, and low income, that amplifies the risk of adult-onset diabetes. Yvette Cozier, an epidemiologist at the Slone Epidemiology Center and an assistant professor of epidemiology at the School of Public Health, says that where a woman lives may also add to the likelihood of her developing the disease.

The new study, which appears online in the American Journal of Epidemiology, is the first to determine if, and how, the type of area an African-American woman lives in contributes to her chances of developing type 2 diabetes. Cozier and her colleagues found that the rate of new type 2 diabetes for women in neighborhoods with average incomes of $15,000 was one and a quarter times that of women in neighborhoods with average incomes of $100,000. When they compared rates in the lowest income neighborhoods to rates in the highest, the number of women diagnosed with type 2 diabetes was 1.65 times higher in the former. They found that the discrepancy exists even among women who have more education and earn more money than their low-income neighbors.

Characterized by an inability to metabolize sugar because the hormone insulin becomes ineffective, type 2 diabetes affects 20.6 million people in the United States and accounts for 9 out of 10 cases of all diabetes. (In type I diabetes, the problem is low insulin, not ineffective insulin). Since 1995, Cozier and her colleagues working on the Black Women’s Health Study have followed the health of 46,382 participants between the ages of 30 and 69.

The results support what Cozier had long suspected: that no matter how well a black woman takes care of herself, her neighborhood may be undermining her health. A lack of available fresh produce, nonexistent recreation areas for exercising, and a proliferation of fat-laden fast food franchises all contribute to obesity, the main culprit in type 2 diabetes. Some less obvious factors include such things as poorly lit streets and high crime, which discourage even the most active women from the simple exercise of going out for a walk. And the sum total of these increases stress, another risk factor.

Sedentary and overweight African-American women over 40, especially with excess fat around the middle — in clinical parlance, “apple shaped” — are the most likely to develop type 2 diabetes, and those with a family history are at greater risk. People with Hispanic, Native American, or Asian backgrounds are also more likely to develop type 2 diabetes in connection with obesity, according to the American Diabetes Association.

The Black Women’s Health Study tracks its subjects with four-page questionnaires, distributed every other March, asking participants a range of health questions, from their smoking and drinking habits, the medications they take, their pregnancies or menopause, and how many hours of sleep they normally get, to questions about whether they’ve faced racial discrimination from businesses, health-care providers, or at work.

“My focus is social epidemiology, so I’m very interested in social factors,” says Cozier. “It’s different from mainstream epidemiology, which tends to ask, ‘What did you do wrong to cause you to have this disease?’ But a lot of things we do as individuals are shaped by our environment, by where we live.”

Even as a student Cozier suspected epidemiologists were underestimating the impact of neighborhood on health, although anyone trying to put together a healthful menu from shopping in small urban bodegas knows it’s difficult, if not impossible. “The provider can send a patient home saying, ‘Do this, don’t do that, eat better,’ and the person is sent home to a neighborhood where they can’t shop for food or take a walk,” says Cozier. “We’re totally ignoring the context.”

She offers an example close to home: a Super Stop & Shop supermarket that opened in 1992 on a vast, fallow lot in the largely low-income Jackson Square section of Jamaica Plain. The 45,000-square-foot store was the first Stop & Shop constructed in a U.S. urban neighborhood in more than 15 years.

It changed people’s lives, says Cozier, who has lived in Jamaica Plain for decades. “Before the Stop & Shop, if you lived in JP and wanted to buy food, it was the neighborhood bodega or a trip to Brookline,” she recalls. “You could go and get sugary canned peaches close to home, but not fresh peaches. That supermarket makes a huge difference.”

The long-term study’s recent results belie many researchers’ preconceived notion that educated, higher-income black women are somehow exempt from the health risks facing poor, uneducated women. “Even considering all the individual issues that may lower risk,” says Cozier, there is now strong evidence that “where you live affects your health.” She drives the point home to her students, who she hopes will get out the word that urban neighborhoods don’t need more Burger Kings to community organizations, city planners, redevelopment authorities, and politicians. (Grove Hall, the embattled neighborhood where Dorchester and Roxbury meet, lost a supermarket and gained a Burger King, which sits ironically next to a WIC center.) They need supermarkets and farmers markets, she says. “I tell my students, we produce the numbers; it’s up to the rest of you to move it forward.”

Susan Seligson can be reached at sueselig@bu.edu.