Too Much Fried Fish Might Help Make South the 'Stroke Belt'
Researchers find clue to region's high rate of 'brain attacks'
WEDNESDAY, Dec. 22, 2010 (HealthDay News) -- Southerners living in the area of the United States known as the "stroke belt" eat twice as much fried fish as people living in other parts of the country do, according to a new study looking at regional and ethnic eating habits for clues about the region's high stroke rate.
The stroke belt, with more deaths from stroke than the rest of the country, includes North and South Carolina, Georgia, Mississippi, Alabama, Arkansas, Tennessee and Louisiana.
Consuming a lot of fried foods, especially when cooked in animal or trans fats, is a risk factor for poor cardiovascular health, according to health experts.
"We looked at fish consumption because we know that it is associated with a reduced risk of ischemic stroke, [which is] caused by a blockage of blood flow to the brain," said study author Dr. Fadi Nahab, director of the Stroke Program at Emory University in Atlanta. "More and more data is building up that there is a nutritional benefit in fish, specifically the omega-3 fats, that protects people."
The study, published online and in the Jan. 11, 2011 issue of the journal Neurology, measured how much fried and non-fried fish people living inside and outside of the stroke belt ate, to gauge their intake of omega-3 fats contained in high amounts in fatty fish such as mackerel, herring and salmon.
In the study, "non-fried fish" was used as a marker for mackerel, herring and salmon.
Frying significantly reduces the omega-3 fats contained in fish. Unlike omega-3-rich fish, lean varieties like cod and haddock -- lower in omega-3 fats to start with -- are usually eaten fried.
People in the stroke belt were 17 percent less likely to eat two or more non-fried fish servings a week, and 32 percent more likely to have two or more servings of fried fish. The American Heart Association's guidelines call for two fish servings a week but do not mention cooking method.
Only 5,022 (23 percent) of the study participants consumed two or more servings of non-fried fish per week.
The study used a questionnaire to determine total omega-3 fat consumption among the 21,675 respondents who were originally recruited by phone. Of them, 34 percent were black, 66 percent were white, 74 percent were overweight and 56 percent lived in the stroke belt region. Men made up 44 percent of the participants.
Blacks, who have a four times greater risk of stroke, ate about the same amount of non-fried fish as whites, but whites had higher total intake of omega-3 fats, the study found. Omega-3 fats can also be found in other foods including canola oil, flaxseed oil, walnuts and soybeans, Nahab said.
"I grew up in California, and when I moved here [Atlanta] I became aware of noticeable dietary differences between there and the South," said Nahab.
In southern California, few people in their 30s or 40s suffered strokes, he said, adding that in those cases "we looked for rare genetic disorders or some other unusual cause that could account for this." Now, Nahab tells his students to always ask stroke patients about their diet.
In the stroke belt, people tend to fry more food than in the rest of the country, said Nahab, also an assistant professor of neurology at the school.
Stroke belt patients also report frequently eating breakfasts of grits with butter, bacon and eggs, and toast, also with butter. In southern California, breakfast more likely included cereal with milk and fruit, said Nahab.
Another expert said he was not surprised by the findings.
"It reinforces what we know about the 'stroke belt' and the less favorable dietary factors that might be one part of the explanation as to why they have higher stroke rates, as opposed to the rest of the country," said Howard Sesso, an associate epidemiologist at Brigham and Women's Hospital in Boston.
Calling the study a "nice snapshot" of eating habits around the country, he said it "does a nice job of characterizing fish intake by ethnic and geographic factors."
But Sesso, who is also an assistant professor of medicine at Harvard Medical School, said drawing conclusions from the study is difficult.
"The implications are still very unclear. They didn't actually look at health outcomes such as strokes," he said.
The study is "insightful, but doesn't address specifically which fried food is actually linked to a risk of stroke in this population," said Sesso.
For more on stroke, visit the National Stroke Association.