Blacks More Prone to Alzheimer's Disease
Increased risk of vascular disease may be to blame, research suggests
SUNDAY, Jan. 30, 2005 (HealthDayNews) -- Alzheimer's disease is a silent epidemic striking black Americans, who seem more susceptible to the brain-wasting condition than any other group of Americans, new research finds.
One possible explanation: Black Americans are at greater risk of vascular disease, such as high blood pressure and high cholesterol levels. And studies have found that people with a history of either high blood pressure or high cholesterol are twice as likely to succumb to Alzheimer's disease, according to the Alzheimer's Association.
Statistics are hard to come by because black Americans aren't well represented in studies on Alzheimer's. But recent research has found dementia is anywhere from 14 percent to 100 percent more prevalent among the black American population than among whites, according to Stephanie Johnson, a research associate at Duke University Medical Center's Bryan Alzheimer's Disease Research Center.
And, she added, nearly half -- 44 percent -- of first-degree relatives of black Alzheimer's patients are at risk for the disease.
"Highlighting the racial difference in prevalence rates for Alzheimer's wasn't really on the radar screen because of all the other health disparities we focus on. But when you start to put the pieces of the puzzle together, it makes sense," said Johnson, who is also a clinical associate professor at Duke's department of psychiatry.
Most telling, she said, is the high rate of vascular disease among black Americans, a known risk factor for Alzheimer's.
"Hypertension, type 2 diabetes and high cholesterol, which are highly prevalent among African-Americans, are significant risk factors for the development of Alzheimer's disease," Johnson said, and could be the reason first-degree relatives are at high risk for the disease as well.
According to a 2002 report by the Alzheimer's Association, 65 percent of black Medicare beneficiaries have hypertension compared to only half of white beneficiaries. And blacks have a 60 percent higher risk for type 2 diabetes than do whites.
But along with the clear medical risks associated with Alzheimer's disease are less quantifiable social and economic reasons, Johnson said. Less access to health care means that diagnoses often come when the disease has progressed to a serious stage. Also, socioeconomic status keeps poorer blacks from the best nursing care. And, among older black Americans, there's often a deep-seated distrust of doctors that can affect their medical care, Johnson said.
The Rev. Henry Edmonds is director of the African-American Community Outreach Program (AACOP) at Duke University. He sees this distrust of the medical profession as a major hurdle that must be overcome if black Americans are to get the care they need.
"Many patients remember when they couldn't come to Duke University Medical Center. They're very suspicious of doctors," said Edmonds.
To address these underlying obstacles to good medical care, Edmonds heads the statewide AACOP. It's an organization that includes community leaders, caregivers and church pastors that seeks to educate the black community about the high rates of Alzheimer's within its ranks.
"Building trust is a major focus of what I do, so we can find out why African-Americans contract Alzheimer's at a greater rate than the general population," he said.
Among his goals is to persuade black Americans to seek medical care, especially preventive care, to reduce their risk for the disease and to also persuade them to work with health professionals by participating in university and government-sponsored Alzheimer's studies.
"We try to use the church as our major recruitment," he said, because the church is a central and trustworthy institution in the lives of many black Americans.
Edmond's work is part of a program at Duke that's headed by Johnson. It includes having health professionals from Duke visit rural communities throughout the state for a period of seven months, during which time they work with local doctors to offer health screenings, medical services and information about diet and lifestyle changes that might reduce the risk of Alzheimer's.
"There is a feeling in the African-American community that health professionals and scientists 'use us as subjects, but don't leave anything behind for us,'" Johnson said. "So we are offering them tangible information."
Johnson hopes further research will help unlock the genetics of Alzheimer's for black Americans. Interestingly, current studies suggest the presence of the APOE genotype, which is associated with a higher risk for Alzheimer's among whites, might not be a risk factor for black Americans.
"We know what we're working with, social, medical and biological variables, but it's a complex problem," she said.
For more on blacks and Alzheimer's disease, visit the Alzheimer's Association.