Geographic disparities in stroke mortality have been charted for decades. The term "stroke belt" was coined to describe the higher rate for men, women, blacks and whites in the southeastern United States. Researchers once thought geography held the answer, theorizing the South might have different chemicals, both good and bad, in its water, soil and air. But over the past 25 years, high stroke rates in counties in North Carolina, South Carolina and Georgia have shifted. New concentrations of stroke deaths appeared in counties in Mississippi, Arkansas and North Florida.

Researchers now suspect socioeconomic conditions, availability of health care and migration patterns are much more important than once thought.
—Susan Aschoff, "Mapping out stroke deaths," St. Petersburg Times, March 18, 2003

Three physicians from China traveled to America's southeastern coastal plains to get a country doctor's views on a problem they all encounter in their work — unusually high rates of cardiovascular disease.

Forms of the disease are high in China's Kishan Province — and in the flat coastal lands of North Carolina and South Carolina. ...

Until a few years ago, adolescents and young women in Kishan Province died at alarming rates from Kishan's Disease, which causes congestive heart failure and pulmonary edema.

People in the province, as well as the "stroke belt" of Georgia and the Carolinas, have an unusually low level of the trace element selenium in their diets, Hames told his visitors.
—"Study Heart Disease In Georgia, Carolinas," The Associated Press, March 22, 1983