By Amy Norton
Experts have long known that blacks are more likely to die of heart disease and stroke than whites -- and that rates of high blood pressure explain a lot of that disparity. But why are blacks more likely to develop high blood pressure?
The new study suggests the key factor is the traditional Southern diet -- with its deep-fried foods, pecan pies and other tasty but nutritionally dubious fare.
In fact, the diet explained more than half the excess risk of high blood pressure among black men, versus white men. Among women, the eating pattern was less important, but still explained almost 30 percent of the disparity between black and white women, according to the findings.
Diet has a critical effect on blood pressure, regardless of race, said lead researcher George Howard, of the University of Alabama at Birmingham.
But this study, he said, shows that it accounts for much of the black-white racial disparity in high blood pressure.
"We were absolutely surprised by how important this factor was," Howard said.
And that can be seen as good news, he added.
"Diet is something you can change," Howard pointed out. "This is not all because of underlying genetics or other factors you can't change."
The research is based on nearly 6,900 older U.S. adults who were followed for roughly nine years. At the outset, they were 62 years old, on average, and free of high blood pressure.
By the end of the study, 46 percent of black participants had been diagnosed with high blood pressure, versus one-third of whites.
When Howard's team looked for explanations for the discrepancy, they found that the Southern diet seemed to be the single most important one.
The impact was clearer among men. There was no major difference in body mass index (BMI) or waist size between black and white men, Howard said. On the other hand, Southern-style eating explained 52 percent of the racial disparity in high blood pressure risk.
The picture was somewhat different for women. Black women had a higher average BMI and waist size than white women -- and those were two key factors in their higher blood pressure. (BMI is a measure of weight in relation to height.)
However, the Southern diet explained 29 percent of the racial disparity in women's risk of high blood pressure.
The diet mattered independent of any effects on weight and belt size. So its nutritional components may bear much of the blame, according to the researchers.
Besides deep-fried fare, the traditional Southern diet is heavy in processed meats, eggs, high-fat dairy, sugary treats and bread.
"There's no doubt the Southern diet is like a sodium pill," said Howard, adding he grew up on it himself.
The study was published Oct. 2 in the Journal of the American Medical Association.
Cordialis Msora-Kasago is a registered dietitian and spokesperson for the Academy of Nutrition and Dietetics. She, too, was surprised by the findings.
"The figures were really striking," Msora-Kasago said. "And this is good news, because diet can be modified."
That does not mean people have to abandon comfort foods to become vegetarians, added Msora-Kasago, who was not involved with the study.
"The Southern diet isn't just an eating pattern," she said. "It's called 'soul food,' because it's part of a culture and tradition."
Fortunately, she said, it's possible to make healthier versions of Southern favorites. People can cut down on salt, and season with herbs and spices instead. They can reduce the amount of meat in dishes, and add more vegetables.
"It's important that the changes fit into a person's lifestyle so they are sustainable," Msora-Kasago said.
African-Americans are at "extraordinary risk" of heart disease and stroke, Howard said, noting that's largely due to high blood pressure.
"So preventing high blood pressure," he said, "is the key to reducing that disparity."