Analysis is interesting, but doesn't prove cause and effect, researcher says
THURSDAY, Feb. 19 (HealthDay News) -- Living in neighborhoods packed with fast-food joints could increase your risk for stroke by 13 percent, compared to residing in places where such restaurants are less plentiful, a new study suggests.
Whether the link proves to be causal is not known, though, said study author Dr. Lewis B. Morgenstern, a professor of neurology at the University of Michigan School of Public Health.
"The only thing we are certain about is, if you live in a neighborhood with a high fast-food restaurant concentration, you are at increased risk," Morgenstern said. He presented his study Thursday at the International Stroke Conference in San Diego.
Morgenstern's research team gathered data on stroke cases in Nueces County, Texas, finding 1,247 cases of ischemic stroke from January 2000 through June 2003. More than 700,000 strokes occur each year in the United States, and most are ischemic, in which blood vessels become clogged.
The researchers then determined the number of fast-food restaurants in the county -- 262 -- and zeroed in on 64 U.S. Census Bureau tracts to determine the number of fast-food outlets in each area. They counted only restaurants that had at least two of four characteristics: rapid food service, takeout business, either no or a very limited wait staff and payment made before receiving food. And they ranked the neighborhoods from most to least number of fast-food outlets.
Morgenstern said that it would be difficult to break down how many fast food restaurants per block or per mile were in the high-concentration areas. But each census tract included about 5,000 people, and the neighborhoods in the top 25 percent had 33 restaurants per tract, while those in the lowest had 12.
Their analysis determined that "there was a 13 percent increased risk of stroke in the top 25 percent compared to the lowest 25 percent," Morgenstern said. The study was funded by the U.S. National Institutes of Health.
"It's interesting, but we don't know if it is causal," said Dr. Ralph Sacco, chairman of the department of neurology at the University of Miami Miller School of Medicine and a spokesman for the American Stroke Association.
But the findings are plausible, said Dr. Dean Johnston, a clinical assistant professor of neurology at the University of British Columbia. "This suggests that diet and lifestyle factors are important for stroke prevention," he said. Fast food has been linked with obesity, and obesity increases stroke risk.
The bottom line for consumers? Anyone moving to a new locale should pay attention to the neighborhood, Morgenstern said, including the number of stores that sell fresh produce and the number of fast-food restaurants.
The American Stroke Association has more on stroke.
SOURCES: Lewis B. Morgenstern, M.D., professor, neurology and epidemiology, and director, stroke program, School of Public Health, University of Michigan, Ann Arbor; Ralph Sacco, M.D., professor and chairman, department of neurology, University of Miami Miller School of Medicine; Dean Johnson, M.D., clinical assistant professor, neurology, University of British Columbia, Vancouver; Feb. 19, 2009, presentation, International Stroke Conference, San Diego
All rights reserved