Texas’ border counties have higher rates of Alzheimer’s disease among older adults than other areas in the state, according to a new study estimating county-level prevalence of the neurodegenerative disease.
An estimated 15% of people 65 and older in El Paso County have Alzheimer’s, making the county the 10th-worst in the nation when compared to counties with at least 10,000 residents older than 64. Miami-Dade County, Florida, Baltimore County, Maryland, and Bronx County, New York, tied for the highest prevalence rate, with 16.6% of older adults in each county having the disease.
A county-level database is a helpful tool for researchers looking at which populations are most affected by Alzheimer’s, although it doesn’t answer some of the biggest questions surrounding Alzheimer’s research, including why some groups are more likely to develop the disease than others.
“We know unequivocally that the environment impacts brain aging,” said Sid O’Bryant, executive director of the Institute for Translational Research at the University of North Texas Health Science Center, who is not involved in the study. “We don’t know very well why and how, and we’re teasing apart what things are most impactful.”
Dallas County has an estimated Alzheimer’s prevalence of 12.6%, while Tarrant, Collin and Denton counties have prevalence rates of 11.3%, 10.2% and 9.9%, respectively.
Among Texas’ other major metropolitan counties, Harris County has a prevalence rate of 12.2%, Travis County has a rate of 10.7% and Bexar County has a rate of 13%. The statewide prevalence rate is estimated at 11.9% of people 65 and older.
Authors of the study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, used cognitive data from the Chicago Health and Aging Project and population numbers from the National Center for Health Statistics to estimate Alzheimer’s prevalence rates.
The more-granular data illustrate how variably the devastating disease impacts communities across the U.S. They also offer public health experts direction for where to target preventive measures and support options, both for patients and their families.
“This information, in addition to raising awareness of the Alzheimer’s crisis in specific communities, may help public health programs better allocate funding, staffing and other resources for caring for people with Alzheimer’s and all other dementia,” said Kumar Rajan, lead author of the study and professor in the Department of Internal Medicine at Rush Medical College in Chicago.
Announcement of the county-level data comes less than two weeks after the Food and Drug Administration fully approved a drug, called Leqembi, meant to slow the progression of the disease for the first time. The Alzheimer’s Association reports an estimated 6.7 million older adults in the U.S. have the disease, which has no cure.
Older Black Americans are twice as likely to have Alzheimer’s or other forms of dementia than older White Americans, while older Hispanic Americans are one-and-a-half times more likely to have the disease than older White Americans, according to Alzheimer’s Association data. Age and environmental exposures also impact whether someone will develop Alzheimer’s.
Texas’ racial, ethnic and topographical diversity could explain why some counties have higher Alzheimer’s rates among older residents. Exposure to air pollution, water pollution and noise pollution can negatively affect the brain, as can stress and education levels.
“Where you live matters. Where you come from matters,” O’Bryant said.
O’Bryant’s team is currently leading one of the largest-ever studies of Alzheimer’s across the three largest racial and ethnic groups in the U.S.: African American, Mexican American and non-Hispanic White.
There hasn’t yet been research into why Dallas County has a slightly higher Alzheimer’s prevalence rate than nearby Tarrant, Collin and Denton counties, said Mark Denzin, executive director of the Dallas and Northeast Texas chapter of the Alzheimer’s Association.
While researchers are still determining why certain factors influence Alzheimer’s development, there are steps people can take to decrease their risk for the disease. Medical professionals recommend regular sleep and exercise schedules, prioritizing socialization and challenging the mind at every age.
Members of the Alzheimer’s Association leadership in Texas said they will evaluate the data in the coming weeks to determine which areas of the state could use more resources.
“This is the opportunity that maybe hasn’t been there in the past for us to become more granular in how we’re effecting positive change in the Alzheimer’s and dementia communities,” Denzin said.
