• Posted July 27, 2023

Minorities Miss Out on Brain-Imaging Studies for Alzheimer's

Americans in ethnic and racial minority groups are underrepresented in Alzheimer's research, a new study finds.

Still, the review of U.S.-based Alzheimer's disease brain imaging studies found the gap is closing.

Compared with white patients, Hispanic Americans are nearly two times more likely to develop Alzheimer's as are Black Americans.

For the study, researchers analyzed nearly 12,000 published studies on Alzheimer's brain imaging.

They found that about 84% to 87% of the participants were white.

"As far as we know, this is the most comprehensive review of representation in the Alzheimer's disease neuro-imaging literature," said review co-author Duke Han, director of neuropsychology in the Department of Family Medicine at the University of Southern California's Keck School of Medicine.

"It gives us a good sense of the current state of the literature and what needs to be addressed moving forward," he said in a school news release.

Specifically, the researchers examined more than 700 studies that reported participant race or ethnicity directly and more than 1,700 studies that included databases where race or ethnicity was reported.

Among studies that reported race, 87% of median study participants were white, 7% were Black, 3% were Hispanic and 0% were Asian, Native Hawaiian/Pacific Islander, American Indian/Alaska Native, multiracial or another race.

Among studies derived from larger databases, median representation of 84% of participants were white, 12% were Black, 5% Hispanic and 2% were Asian American. In all cases, minority groups were underrepresented based on their share of the U.S. population, the researchers noted.

The report was published July 25 in the journal Communications Medicine.

"This is a pretty big deal, especially as we look toward the future, where an increasing proportion of the U.S. will be ethnic minority groups," co-author Aaron Lim, a postdoctoral fellow at USC, said in the release. "If their representation isn't adequately captured, then this disparity in research will grow and grow."

Improving representation in Alzheimer's disease neuro-imaging will require a two-pronged approach, said Han. First, large studies need to recruit more diverse samples. Meanwhile, smaller studies that focus on collecting brain scans from people in minority groups are also key, Lim said.

Some of this is already happening, the researchers noted.

"In the past, some researchers were so focused on recruiting large groups of participants, that it took priority over the importance of representation," said Han. "Now, there's an increasing focus on balancing numbers with representation. This increased emphasis on diversity in neuro-imaging is a welcome sight."

More information

The Alzheimer's Association has more on Alzheimer's research.

SOURCE: University of Southern California, Keck School of Medicine, news release, July 25, 2023