Feb. 12, 2013 -- The South is known as the "stroke belt," and a new study reinforces one of the key reasons why: its diet.
Those who ate the Southern diet about six times a week had about a 30% higher risk of stroke than those who ate it about once a month, says researcher Suzanne Judd, PhD. She is a nutritional epidemiologist at the University of Alabama, Birmingham.
This holds true even after taking into account factors such as age, race, sex, smoking, and physical activity.
The study defined a Southern diet as one rich in salty, high-fat fried foods and sugary drinks. The research was presented at the International Stroke Conference in Honolulu, Hawaii.
The study included more than 30,000 people ages 45 and older. There were an equal number of African-American and white people.
The people filled out detailed food questionnaires. From these responses, researchers came up with five dietary patterns:
- Convenience: Mexican and Chinese food, and mixed dishes with both meat and beans.
- Plant-based: fruit, vegetables, fruit juices, cereal, fish, and poultry.
- Sweets: added fats, bread, chocolate, desserts, and sweet breakfast foods.
- Southern: added fats, fried foods, organ and processed meat, and fatty milk.
- Alcohol: beer, wine, liquor, green leafy vegetables, salad dressings, nuts and seeds, and coffee.
In addition to being high in fried foods like chicken, liver, ham, and potatoes, the Southern diet includes lots of high-fat dairy, eggs, added salt, and sweetened beverages.
On the plus side, the diet does include green vegetables, like collard greens.
People following the Southern diet don’t just fry their food; they also use unhealthy oils -- for example, bacon grease instead of olive oil, says Judd. “Often in the South, you’ll see people render meat and keep the fat, the bacon fat, and fry okra or potatoes in it; so they’re getting the bacon in their bacon and in their vegetables, too.”
Gizzards, Organ Meats
The Southern diet includes meats high in saturated fat: things like organ meats and gizzards (the neck of poultry). "In a lot of Southern kitchens, people will use all parts of an animal -- to flavor broths and stews -- and they will use organ meats and cuts that you wouldn’t see in other places," Judd says.
Calorie-wise, the Southern diet does not differ that much from other diets.
The research shows that 10 states -- Delaware, Louisiana, Mississippi, Alabama, Illinois, Georgia, Missouri, Arkansas, Michigan, and Maryland -- followed the Southern diet the most.
Previous studies have shown a two- to four-times-higher risk of stroke among young African-Americans compared to young whites, Judd says. In this new study, the Southern diet explains about 63% of the racial variation in stroke risk.
"To me, the really interesting part of the study is that diet explains so much of the racial disparity between African-Americans and whites," she says.
Judd and her colleagues also ranked people according to how well they stuck to a plant-based diet. The groups that followed this diet the most showed a 20% lower risk of stroke. "As long as you were eating some (of the plant-based diet), it looked like it was protective," she says.
"We'd love to look at that next -- to find out whether it’s the bad foods or the lack of good food" that raises stroke risk, she says.
Judd and her colleagues also hope to look at how the Southern diet might affect mental skills. And they would like to learn whether being born in the South or moving there makes a difference to dietary habits.
When asked to comment on the study, Brian Silver, MD, a neurologist at Rhode Island Hospital, called it "fantastic."
"The authors have done their homework in trying to really analyze in great detail the effects of diet on stroke risk," he says.
Silver says he was surprised to learn that almost two-thirds of the stroke risk is due to diet. "That is novel information for certain. It tells us that we can’t just blame our genes necessarily; we definitely do have to make efforts to try to fix our diet."
He wondered if people are "pre-programmed" genetically to eat the way they do or whether dietary choices are more influenced by culture. "What we do know now though is that it's changeable, because people were not this obese 100 years ago."
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.