Escape from Poverty Helps Explain Diabetes Epidemic in the American South

The strikingly high prevalence of Type 2 diabetes in the American South can be partially traced to rapid economic growth between 1950 and 1980, new research suggests.

The study tests the “thrifty phenotype” hypothesis, which suggests that if economic conditions present during fetal development improve dramatically during a person’s childhood, the prospects of poor health in adulthood increase.

According to the hypothesis, children whose parents endured being poor were unprepared biologically to manage the riches of processed foods and the more sedentary life that accompanied higher incomes. The resulting obesity leads to a high risk for multiple diseases.

In the South, and particularly for African Americans, poverty was rampant for several generations until industrialization took hold in the 1950s and ’60s, leading to rapid economic growth. The benefits of prosperity and the South’s large African American population – also at higher risk than whites for diabetes – both help explain the region’s current poorer health.

“It’s a clash between anticipated lifestyle and the lifestyle that’s realized,” said Richard Steckel, distinguished university professor of economics, anthropology and history at The Ohio State University and author of the study. “If the thrifty phenotype hypothesis is correct, people with diabetes today should have had a socioeconomic history of moving from poverty to prosperity.”

And that is what Steckel’s study showed. He investigated the relationship between state-based per-capita income growth and diabetes prevalence by state. The analysis indicated that the most dramatic improvements in household income from 1950 to 1980 were clearly associated with a higher prevalence of Type 2 diabetes, and Southern states topped both of those lists.

If future rates of diabetes can be predicted based on income history, “this message is dire for historically poor countries undergoing rapid growth,” Steckel said. He also said the research has health-care implications, suggesting that doctors should collect data on patients’ socioeconomic background at the same time they take medical histories.

The research is published in the July/August issue of the American Journal of Human Biology.

Steckel specializes in the study of slaves’ health, so he is an expert on the economics of the South. In the course of his work, he examined a map outlining Type 2 diabetes prevalence in the United States. Without a single word, the map told a story: Southern states have far higher percentages of people with this disease than do states to the north and west.

In many areas of the South stretching from Oklahoma to West Virginia, more than 10.6 percent of the adult population had Type 2 diabetes in 2009, according to the Centers for Disease Control and Prevention (CDC). Percentages were lower in all other states, except in select portions of several states in the West and in pockets of Ohio, Indiana, Michigan and Pennsylvania.