African Americans are about twice as likely to have Alzheimer’s disease as whites, and Hispanics are one and a half times more likely than whites to have the disease, according to a new report released today by the Alzheimer’s Association. Both groups are also less likely to know they have dementia, the report says.
Although researchers had known that African Americans and Hispanics were more likely to get the disease, this is the first time the association has collected and reported definitive numbers in a report.
An estimated 5.3 million Americans have Alzheimer’s disease, a number that is expected to grow as boomers age. For the special report on race, ethnicity and Alzheimer’s disease, the association convened a panel of experts who analyzed the prevalence of Alzheimer’s disease in the United States.
The findings are part of the Alzheimer’s Association’s annual report, “2010 Alzheimer’s Disease Facts and Figures,” a compilation of national statistics and information on that disease and other types of memory problems.
Although people tend to assume genetic factors explain the fact that African Americans and Hispanics are more likely to have Alzheimer’s disease than whites, Eric Larson, M.D., executive director of the Group Health Research Institute and a member of the expert panel that prepared the report, says there are no known genetic factors that can explain the significant difference in risk of getting the disease for these two groups.
Larson says the genetic differences among all people “are rather tiny when it comes to determining things like Alzheimer’s disease.”
High blood pressure, diabetes
But if there is no strong genetic link between Alzheimer’s disease and race, what accounts for the disparity among these groups? The authors of the report point to conditions such as high blood pressure and type 2 diabetes to help explain the increased risks of the disease—conditions that African Americans and Hispanics are more likely to have than whites.
“If we could help control the high blood pressure and diabetes issues, it would help reduce the disparity,” says Angela Geiger, chief strategy officer of the Alzheimer’s Association.
Larson says African Americans and Hispanics are getting the disease at younger ages than whites, which partly explains the higher rate of the disease.
“On the other hand,” he says, “this creates an opportunity for health care to do a better job to control these risk factors.”
About 80 percent of African Americans and nearly 70 percent of Hispanics with cognitive impairment—diagnosed memory problems—also have high blood pressure.
Geiger added that more research needs to be done before experts can know whether reducing the occurrence of diabetes and blood pressure among African Americans and Hispanics would make a difference in the number of Alzheimer’s cases.
The report said that a growing body of evidence finds that the health of the brain is closely linked to the overall health of the heart and blood vessels, adding that lowering the incidence of high cholesterol, diabetes, high blood pressure, smoking, obesity and physical inactivity may help avoid or delay the decline of the brain.