New Data from REGARDS Study Shows Southern Foods Increase Stroke Risk
By Peggy Noonan
May 28, 2013
- Summary: New research shows that stroke risk, including among those with atrial fibrillation, increases in direct proportion to amount of southern foods consumed
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A new study shows that the foods people eat can increase their risk of stroke, which applies to those with atrial fibrillation as well.
Frequency of stroke was directly proportional to the amount of Southern-style foods that people consumed, lead researcher Suzanne Judd, PhD, assistant professor in the University of Alabama Birmingham department of biostatistics, reported when she presented the study at the American Stroke Association International Stroke Conference 2013 in Honolulu, Hawaii (USA).
“People who ate Southern food had a 30 percent increased risk of stroke,” Judd reported. She explained that this category of foods includes fried foods, such as fried chicken, fried fish, fried potatoes, bacon, and ham; organ meats, such as liver and gizzards; and sugary drinks, such as Southern “sweet tea.”
At this point, researchers cannot say whether the primary cause of this extra stroke risk is due to a single element in this diet, a combination of elements, or all of the elements combined together at the same time, Judd says. But we do know that these foods all increase cardiovascular disease risk because:
- Fried foods are high in fat, and fatty foods are high in cholesterol
- Sugary drinks are linked to diabetes
- Salty foods promote high blood pressure
Judd’s team looked at diet habits and stroke incidence in black and white adult participants in the REasons for Geographical And Racial Differences in Stroke (REGARDS) study, an ongoing population-based study of more than 30,000 people aged 45 or older in 48 U.S. states. For this diet-focused aspect of REGARDS, they used data from the 20,480 participants who completed the Block98 food frequency questionnaire portion of the study.
Last year, REGARDS data identified stroke risk factors that account for half of racial disparity in stroke incidence in black and white Americans. That study found that high blood pressure, diabetes, atrial fibrillation, and heart disease accounted for about half of the higher number of strokes in blacks.
However, researchers said, the reasons that might explain the other half remained a mystery. To solve it, researchers would need to go “upstream” by investigating other factors such as diet, said REGARDS co-principal investigator George Howard, DrPH, professor of biostatistics at the University of Alabama at Birmingham. Howard is also a coauthor of this study.
We already knew from previous research that people in the Southern US are about 20% more likely to have a stroke than people in other parts of the country.
Other factors that pointed to a Southern connection include:
- While Southern-style foods are consumed throughout the US, consumption of Southern-style foods is about 20% higher in the South than in other regions of the country
- A majority (about two-thirds) of those in Judd’s study who ate the highest amounts of Southern foods lived in Southeastern states
- African-Americans are five times more likely to eat Southern foods than whites
- African-Americans have twice as high a first-time stroke risk as whites
Diet and sweet tea link
Judd’s team used mathematical models to analyze multiple aspects of data on REGARDS study participants. They found that stroke risk was higher wherever people ate the highest amounts of Southern foods, regardless of their geographic location.
Southern style foods were popular everywhere. “This diet pattern was eaten across the country,” Judd says. For example, she says, people in California ate lots of fried foods and although their “sugar-sweetened beverage might not be the sweet tea” that people in the South drank, “they are still drinking a lot of sugar-sweetened beverages.” She explains that it’s “the overwhelming quantity of sugar that we have in our modern American Diet,” rather than the specific beverage containing the sugar, that adds to stroke risk.
The term “sweet tea” may seem puzzling to those who haven’t been in the South. Judd explains this popular beverage is made by “a very, very different process” than is used to make tea in other parts of the country. Sugar and water are boiled together to make sweet tea, or boiled into already brewed tea, which allows the water to contain much higher concentrations of sugar than it can hold when sugar is added after boiling, such as by stirring a spoon or two of sweetener into already brewed hot or iced tea.
In other parts of the country, the equivalent “sugary drink” may be sugary sodas or other beverages, and those beverages may be made with sugar, corn syrup, high fructose corn syrup (HFCS), or other sweeteners, but the type of sweetener is not as important as the quantity because all sugars generally “behave the same in the liver,” says Judd.
Food and stroke facts
Although she notes that this research is an association study, the link between nutritional factors — sugars, fats, salt — and stroke risk is “pretty clear,” Judd says.
The study reported that stroke risk was:
- 41% higher in those who ate Southern foods about 6 times a week compared to those who ate Southern foods about once a month
- 63% higher in blacks who ate Southern foods than comparable whites
- 29% lower in those who ate fruits, vegetables, legumes (such as beans, peas, lentils), and whole grains about 5 times a week compared to those who ate the least of these foods (about 3 times a week)
On the plus side, the research also showed that a diet high in fruits and vegetables, whole grains, and lean proteins such as skinless baked (not fried) chicken “was associated with a pretty big reduction in stroke, almost 20 percent,” Judd says. “To me, it’s exciting that there are actually foods that seem to be helpful as well.”
Another bit of good news for those who don’t want to forego favorite foods forever was the finding that showed “you don’t have to eliminate it altogether,” Judd says, “just cut back.” People at low stroke risk still ate their favorite Southern foods but limited the indulgence to once or twice a month. For those who currently consume these foods several times a week, she recommends cutting back gradually, starting with once or twice a week, until you’re comfortable with once or twice a month, or less.
Also, she adds, health care providers need to teach patients about nutrition earlier than they do now and need to ask patients what they are eating, how often, how much.
What this means for people with Afib
Study coauthors Dr. George Howard (above) and Virginia J. Howard, PhD, associate professor of epidemiology at the School of Public Health at the University of Alabama at Birmingham, were asked how this study applies to people with afib.
Dr. George Howard said, “There is no reason to think that those with afib would have a different diet-stroke relationship.” He explained that in this type of research, “the general approach is to assume that unless there is some a priori reason to think that some subgroup, such as those with afib, would ‘act’ differently, it is assumed they would act the same.”
The findings should apply to all persons, with or without atrial fibrillation, added Dr. Virginia Howard.
Changing health futures
Judd is passionate about doing this type of research, partly because her family has a history of heart disease. “No man in my father’s family had ever lived to see his grandchildren.” They all died of heart attack or stroke.
When her father was in his 40s and learned what a difference a healthy lifestyle could make, he decided he wanted to be the exception, the first man in the family to live to see his grandchildren. He dramatically changed his diet, Judd says, began walking to work, bicycling, and making physical activity an everyday habit, and has lived to see four grandchildren.
Judd wants other people to have that chance, too. That’s why she says “it’s really important for me to keep doing the research and get it out there so maybe other people can live to see family members they might not have seen.”
Since those with afib are already at higher risk of strokes, it seems intuitive that cutting back on (or avoiding) these Southern-style foods could potentially decrease our stroke risk. While cutting them out entirely may not be necessary, decreasing them as much as possible seems to be the way to go.
In our conversations with her, Judd suggested that new studies are needed to focus specifically on questions such as:
- Does the combination of fat plus sodium in foods, which is typical of the Southern diet (e.g., fried eggs and bacon, fried ham, fried potatoes, collard greens flavored with bacon grease, etc.), increase craving for those foods and/or avoidance of healthier foods?
- Is it the fat alone that increases cardiovascular disease risk, or fat plus sodium, or fat plus sodium plus sugar, etc.?
- Could the increased stroke risk in blacks be reduced merely by adding more fruits and vegetables to the diet?
Answering these questions could transform our ability to moderate stroke risk with simple lifestyle modifications.
What about obesity? It was not mentioned in the factors here. The South is widely thought to be the most obese part of the US, but new data refutes that perception. People in the South are “generally more hypertensive and have higher rates of diabetes and stroke,” says Dr. George Howard, but new research showed that “people in the South were really not the fattest.” According to data from REGARDS, the West North Central part of the country leads with 41% obesity. That region includes North Dakota, South Dakota, Minnesota, Nebraska, Iowa, Kansas, and Missouri. He is one of the coauthors of a study published in Obesity.
While in our interviews Judd spoke of “fats” in general, it is important to know that there are different kinds of fats. In my book, A Woman’s Guide to Saving Her Own Life: The HEART Program for Health and Longevity, I characterized the different kinds of fats as “good, bad, and ugly.” Southern-style foods are typically fried in saturated fats (bad) and trans fats (ugly), both of which increase your risk of heart disease, strokes, and other issues (for example, trans fats have also been associated with macular degeneration).
Fortunately, in recent years, there has been a trend away from frying and toward preparing foods with good “healthier” fats, such as olive oil. For anyone with afib and other stroke risk factors, sticking to good fats seems a prudent way to go.
What I found a bit odd in the study, having grown up in the South, was how sweet tea was characterized as being made by boiling water and sugar together. That is not how it was done in my family, nor by my in-laws or my friends’ families; in fact, most made unsweetened tea and people added sugar at the table.
We were probably an anomaly as my Mother was into health foods and taught yoga decades before it became cool. Perhaps many families, and southern restaurants, boil the water and sugar together so their tea is super-saturated with sugar. And commercially-prepared beverages, such as sodas, are saturated with sugar, too.
Since I usually drink water (and rarely have unsweetened tea or soda), I really don’t know, but would love to. Is that how your family does/did sweetened tea?
Feel free to join the discussion of this on our StopAfib Discussion Forum. (To post or ask questions, you’ll need to register — here are the instructions for registering and getting started.)
To learn more about this study and related studies, see:
- Southern diet could raise your risk of stroke, American Stroke Association Meeting Report – Abstract 144, Feb. 7, 2013
- Abstract 144: Southern Diet Pattern Increases Risk Of Stroke While Plant-based Pattern Decreases Risk Of Stroke in the REGARDS Study, Stroke. 2013;44:A144