Blacks and Hispanics seem to be at a higher risk for Alzheimer’s disease than whites, according to two studies released yesterday.
One study, presented at the ninth International Conference on Alzheimer’s Disease and Related Disorders, which concludes today in Philadelphia, found that Hispanics tend to develop Alzheimer’s almost seven years earlier than whites.
The other study analyzed Alzheimer’s records in South Carolina and determined that prevalence of the brain-killing disorder was three times higher among middle-aged blacks than among whites in the same age group.
“As minority populations get older, they will see a dramatic rise in Alzheimer’s disease. This will overwhelm their families and communities, unless we take action now,” said James Jackson, a member of the Alzheimer’s Association advisory council, which sponsored the conference. “Studies like this should serve as a wake-up call to Congress and the nation.”
Alzheimer’s is a major public health concern, affecting about 4.5 million Americans, most of them elderly. With the dramatic aging of the U.S. population, the number of Americans with the disease is projected to reach 16 million by 2050.
Figures available do not show how many Alzheimer’s patients are black or Hispanic, said Dr. Neil Buckholtz, who heads the National Institute on Aging’s (NIA) dementia program.
“But Alzheimer’s is clearly not just a disease of whites. It’s an age-related disease that affects everybody,” and some minorities may be at increased risk, Dr. Buckholtz said yesterday.
A report released earlier this year by the Alzheimer’s Association estimated the number of Hispanics living with the disease at fewer than 200,000. That report predicted the number of Hispanics with Alzheimer’s will increase to 1.3 million during the first half of the 21st century.
Several studies presented at the conference this week indicated that cardiovascular risk factors, such as obesity, high blood pressure and high cholesterol, also can increase the risk of Alzheimer’s, a disease marked by destruction of brain cells and a loss of cognitive function.
Minorities are at higher risk than whites for conditions that make them more vulnerable to heart disease and stroke, and researchers say this may explain minorities’ greater risk of Alzheimer’s.
James N. Laditka of the University of South Carolina, whose study added to the meager data available on racial differences in Alzheimer’s risk, agreed. Mr. Laditka points out that South Carolina is the “only state that keeps a comprehensive database of people with a diagnosis of Alzheimer’s” and that his research team is following 37,000 Alzheimer’s patients.
His study determined that blacks ages 55 to 64 were three times more likely than whites that age to have the disease. It also showed that blacks ages 65 to 84 had double the risk of whites. “Even over the age of 85, African-Americans had an Alzheimer’s rate nearly 1.5 times higher,” Mr. Laditka said.
Mr. Laditka pointed out that he and his colleagues found the highest Alzheimer’s rates clustered in South Carolina counties where residents were more likely to be overweight.
“In South Carolina, we may be anticipating what will happen in the rest of the U.S. as the country grows in girth,” the researcher said.
The study of Hispanics, led by Dr. Christopher M. Clark of the University of Pennsylvania School of Medicine, evaluated 119 Hispanic and 55 non-Hispanic, white Alzheimer’s patients at five NIA-sponsored Alzheimer’s disease centers nationwide. Researchers interviewed family members of the patients to determine when the first symptoms of the disease appeared.
They found, on average, that the first symptoms of Alzheimer’s began at 67.6 years for Hispanics and at 73.1 years for non-Hispanic whites.