People in three southern U.S. states are facing a health threat no one can explain: an abnormally high risk of suffering a fatal stroke – even among tourists just visiting the region.
Residents and visitors alike in near-coastal areas of North and South Carolina and Georgia have a stroke risk at least 10 per cent higher than people in other U.S. states.
And when local people leave the area, even for a short trip, their risk of a fatal stroke drops.
Since short visits don’t change a person’s weight, blood pressure or diabetic status, researchers are wondering whether there’s something in the local air or water.
The region takes in 153 counties, and some very popular tourist spots: Myrtle Beach, Savannah and Charleston.
So far, the evidence seems to shoot down every other explanation they’ve come up with.
Hot, humid climate? Florida has the same, but without the strokes.
Deep-fried, artery-clogging Southern cooking? Other Southern states have as much or more obesity, but with less stroke risk.
Attempts have also failed to account for the problem through smoking, another major risk factor for stroke, as well as through poorer health care, infectious agents, bad genes and toxins in the water or soil.
So what is killing the people of the coastal “Low Country” and their visitors?
“Nobody knows. I think if you ask any one person, they’ll have some sort of theory, especially people not in the profession,” said Ilan Shrira, a psychologist at the University of Florida. “You have lots of stereotypes among people who have never been to this area: diet or poverty or something. But among people who know the research … there’s no evidence for any one explanation.”
A wide area of the U.S. southeast has long been recognized as a stroke belt.
Poverty and obesity are often blamed. But the eastern parts of the Carolinas and Georgia form a smaller region within this belt – nicknamed the stroke buckle – with an even worse picture of health.
Using all U.S. death certificates from 1979 to 1988, researchers from three U.S. universities counted stroke deaths inside and outside the buckle. They also distinguished residents and non-residents of the region.
They found that visitors to the region were 11 per cent more likely to die of a stroke than were visitors to any other part of the U.S. As well, stroke buckle residents who temporarily left the area reduced their chances of stroke death by 10 per cent.
While the death certificates were not recent, doctors agree the same problem exists today.
So far the research hasn’t pinned down how long outsiders have to be in the region before they suffer strokes.
But the fact that visitors are affected points to some environmental cause, Shrira thinks. Strokes can be related to a wide variety of infections, from HIV to dental infections. But there again, no obvious solution to the Carolina-Georgia problem is popping up.
“I would guess it’s not something simple,” but rather an interaction of factors that makes the cause harder to find.
“We didn’t want to start a scare or have people avoid the region at all costs, but it’s so interesting,” he said. “Especially because it’s unknown, I guess.”
The findings are reported in a medical journal called Neuroepidemiology.