LISTEN: Researchers are recruiting people in their 50s and 60s with no symptoms of Alzheimer’s for a new study of the disease. The cognitive disorder mostly affects people late in life. GPB’s Ellen Eldridge explains.

PET scan results that are part of a study on Alzheimer's disease at Georgetown University Hospital in Washington

In this May 19, 2015, file photo, R. Scott Turner, Professor of Neurology and Director of the Memory Disorder Center at Georgetown University Hospital, points to PET scan results that are part of a study on Alzheimer's disease at Georgetown University Hospital in Washington. Government and other scientists are proposing a new way to define Alzheimer's disease. basing it on biological signs, such as brain changes, rather than memory loss and other symptoms of dementia that are used now.

Credit: (AP Photo/Evan Vucci, File)

Due in part to an aging population and the ability to detect Alzheimer's disease more accurately, more and more people are being diagnosed with this disease of dementia.

Alzheimer’s is the sixth-leading cause of death in the United States, killing more Americans than diabetes, and the number of Georgians living with Alzheimer's is expected to increase 46% over the next decade, according to the Georgia Department of Public Health.

Researchers understand changes in the brains of people with Alzheimer’s disease start as many as 20 years before experiencing memory problems.

Dr. Julio Rojas is an associate professor of neurology at the University of California, San Fransisco, and a member of the Alzheimer’s Clinical Trial Consortium (ACTC), a network of leading academic Alzheimer’s research centers funded by the National Institutes of Health (NIH) in partnership with the pharmaceutical company Eisai.

The main theory about what causes Alzheimer's disease is the accumulation of this junk protein called "amyloid" in the brain, Rojas said.

"This is the first change," Rojas said. "There's a cascade of changes that come after that. But, it seems like amyloid plays a very central role."

The AHEAD study wants to identify people who happen to have amyloid in their brains without having any symptoms of dementia.

"The key observation is that this brain accumulation of amyloid," he said. "We know because of their scientific progress that it starts occurring 15 to 20 years before people develop symptoms."

That's why centers worldwide are enrolling participants between 55 and 60s. People whose brain scans show amyloid may respond to existing Alzheimer's treatments such as lecanemab, which reduced the rate of cognitive decline by 27% as compared to a placebo in a study of nearly 1,800 people in the early stages of Alzheimer's.

Rojas said researchers with the AHEAD study are interested in the social aspect of dementia as well.

Despite representing roughly 13% of the U.S. population, Black Americans are twice as likely as white Americans to develop Alzheimer's, and face significant disparities in diagnosis, treatment and care.

"We are trying to create a study that really reflects what happens in society," Rojas said. "Unfortunately, prior studies that have studied or investigated drugs for Alzheimer's disease have recruited a very homogeneous (white) people, and they have not included historically underrepresented groups."

The AHEAD Study has approximately 100 study locations worldwide, including in North America, Japan, Singapore, Australia, and Europe — nearly 75 of which are in the United States and Canada.

The Columbus Memory Center and Emory University in Atlanta are currently enrolling eligible participants.