Southern Diet Might Explain the 'Stroke Belt'
Study found those who ate fried, salty foods and processed meats were more likely to have strokes
Thursday, February 7, 2013
Researchers say that diets that are heavy in fried and salty foods could be the most dangerous in terms of stroke risk.
The team conducted a nationwide survey of more than 20,000 white and black adults aged 45 and up and identified five common dietary patterns. They kept in touch with the participants over the next six to 10 years to find out which ones had a stroke.
The people who said they ate foods such as fried chicken and fried potatoes, processed meats and salty greens nearly every day were about 30 percent more likely to have a stroke than people who rarely consumed these foods.
In addition, black people and people in the southern states most frequently dined on this type of menu, which could help explain why blacks have higher stroke risks than whites and why this region of the United States is known as the "stroke belt."
"The Southern diet is probably the most commonly cited explanation that people give for stroke risk, but unfortunately, until this study was put together, there was not a way to look at a large enough sample to see," said study author Suzanne Judd, a nutritional epidemiologist at the University of Alabama at Birmingham.
The findings were to be presented Thursday at the American Stroke Association's annual meeting in Honolulu.
Stroke is the fourth leading cause of death in the United States, and there are about 800,000 strokes every year, according to the U.S. Centers for Disease Control and Prevention.
Black people are about twice as likely as whites to have a first stroke and are more likely die from a stroke.
"I tell my patients that if they're going to have fried foods, once or twice a month is OK, but avoid having more," said Dr. George Bakris, director of the University of Chicago Medicine Comprehensive Hypertension Center.
Fried and other characteristically Southern foods could pack a triple punch in terms of stroke risk, Bakris explained.
High fat and sodium content could increase cholesterol and blood pressure, respectively, and diets laden with fried foods tend to be low in potassium-rich foods such as tomatoes, melons and avocados, which can counteract the effects of sodium.
"The Southern diet probably accounts for about half of the difference in stroke risk between black and white people," Bakris said. Making matters worse, black people tend to be more salt-sensitive, so a small amount of sodium could lead to big increases in blood pressure, he added.
The current study included more than 20,000 people in the 48 contiguous U.S. states. Judd and her colleagues carried out surveys between 2003 and 2007, asking the participants how often and how much they consumed 108 foods and beverages.
The researchers found that people who ate some items were more likely to eat others, and grouped these items together into five dietary patterns: the Southern diet, consisting of fried and processed meats, greens, and sweetened iced tea; the convenience diet, made up of pasta, pizza and Mexican and Chinese food; the sweet diet, which is high in desserts and sweetened snacks; the plant-based diet, which is high in fruits, vegetables and legumes; and the salad and alcohol diet.
"The biggest surprise was that there was a Southern pattern," Judd said, adding that with migration and traveling she expected all regions of the United States to partake similarly in this type of diet.
Judd and her colleagues found that people in Arkansas, Louisiana, Mississippi, Alabama, Georgia, North Carolina, South Carolina, Tennessee, Delaware, Michigan and Illinois were the highest consumers of the Southern diet.
There also were racial differences between the people in the top 25th percentile for Southern diet consumption, who ate these foods every day or almost every day, and those in the bottom quartile, who ate them about once a month.
Black participants made up about 58 percent of the top quartile of Southern diet consumers, even though they made up only about half of the participants in the study, Judd said. On the other hand, only about 9 percent of the bottom quartile was black participants.
Judd and her colleagues followed up with the participants twice a year after their food surveys through April 2012 to find out about their stroke history. The researchers found that people who were in the top half for consumption of the Southern diet were about 30 percent and 12 percent more likely, respectively, than those in the bottom quartile to have had a stroke.
These differences in stroke risk were found even after the researchers took into account whether they smoked, exercised or had a history of heart disease.
It remains possible, however, that other health aspects -- such as obesity, diabetes and high blood pressure -- were different between these groups, either because they ate more Southern diet foods or because of other lifestyle differences that could have contributed to variations in stroke risk, Judd said.
The researchers also found that a plant-based diet could protect against strokes. The participants in the top three quartiles had between 15 percent and 26 percent lower stroke risk than those who consumed only fruits and veggies about once a week, Judd said.
There did not appear to be a relationship between the other three diets and stroke risk.
Research suggests that 80 percent of strokes can be prevented, but lifestyle factors in addition to diet should also be considered, Bakris said. "There is no question that if you can exercise more and stop smoking, your stroke risk is going to be reduced dramatically," he said.
Research presented at medical meetings should be considered preliminary until it is published in a peer-reviewed medical journal.