People living in neighborhoods where fast food restaurants are plentiful appear to have a higher risk of stroke than those living where such restaurants are scarce, a new study says.
Fast food consumption has previously been linked to higher rates of heart disease and organ damage. In this latest study tying fast food restaurants to cardiovascular ills, researchers studying neighborhoods in one Texas county found that people living in regions with 33 fast food restaurants or more had 13 percent greater odds of stroke than those living in neighborhoods with the fewest fast-food joints.
The study also showed that each additional fast food restaurant in the neighborhood increased the chance of stroke by 1 percent. The results of the research were presented at the International Stroke Conference in San Diego on Thursday.
"This study suggests that those living in neighborhoods with a high density of fast food restaurants have an increased stroke risk," said Dr. Lewis Morgenstern, lead author of the study and director of the University of Michigan's stroke program in Ann Arbor.
But he cautioned that the findings are purely associative and do not necessarily point to a direct link between the restaurants' offerings and potentially deadly stroke.
"I can't tell you that anybody who had a stroke in this study has ever had a burger in their lives," Morgenstern said. "But I can tell you that these neighborhoods on the whole have factors that increase the risk of stroke."
Keith Thomas Ayoob, a pediatric nutritionist at the Albert Einstein College of Medicine in Brooklyn, N.Y., agreed that the results of the research did not lend themselves easily to an interpretation that fast food was the true stroke culprit.
"It's hard to know whether this is a chicken or egg thing," he said.
While the exact reasons for the association may be difficult to pinpoint in this study alone, Dr. David Katz, co-founder and director of the Yale Prevention Research Center, said the data could be viewed as a further implication of fast food.
"Among the many ills of fast food is an extremely high sodium content," said Katz, who was not affiliated with the study. "A highly processed fast food meal may provide a full day's sodium requirement, or more.
"Sodium is a contributor to hypertension, hypertension is a contributor to stroke."
In a country where many of the risk factors for stroke are on a steady rise, the findings of the study may seem particularly relevant.
Each year, nearly 800,000 Americans suffer a stroke. Known risk factors for stroke include advancing age, smoking, high blood pressure and diabetes. Other factors, such as air pollution and stress, have also been linked to the condition.
Researchers have speculated that easy availability of high-fat, high-salt food may lead to poor dietary choices, causing more obesity and greater stroke risk.
However, the authors of this study say it's also possible that fast-food restaurants cluster in neighborhoods where more people make unhealthy choices such as smoking, drinking excessive alcohol and not exercising.
For example, Morgenstern said, such neighborhoods may have fewer parks and green spaces for exercise. They may have a higher level of air pollution -- another determinant of an increased stroke risk. Or they could be poorer areas, with more crime and other stressors that could bump up stroke risk among inhabitants.