Older Black Americans are twice as likely as older white Americans to have Alzheimer's disease or dementia, yet they remain some of the most underrepresented participants in the clinical trials designed to find treatments. In Georgia, that risk is showing up in the numbers: 19% of Black adults age 45 and older now report cognitive impairment, compared with 18% of white adults and 18% of Hispanic adults in the same age group.
That 19% figure is a sharp jump from just a few years ago. As reported by Atlanta News First, only 12% of Black Georgians in that same age bracket reported cognitive decline back in 2021. Dr. Antoine Trammell, with Emory School of Medicine, is among the researchers trying to close the gap between who gets sick and who gets studied, including through monthly sessions engaging Black men in Atlanta.
A Research Field Built Around a Narrow Slice of Patients
The problem Trammell is working against is not new, but it is stark. Atlanta News First reports that Alzheimer's studies have largely centered on well-educated, wealthier white participants who have the time and financial flexibility to take part, a dynamic that has shaped decades of findings even as the disease disproportionately threatens Black communities.
National data backs up the scale of the imbalance. Nearly 40% of Americans belong to a racial or ethnic minority, but according to the Alzheimer's Association, clinical trial participants are typically 80% to 90% white. More than 6 million people are living with Alzheimer's dementia in the United States, per the same source, making the mismatch between who is affected and who is studied a significant blind spot for treatment research.
The pattern shows up trial by trial. In the Phase 3 TRAILBLAZER-ALZ-2 trial, 92% of participants were non-Hispanic white, according to Alzforum. In the Phase 3 CLARITY-AD trial, that outlet reports 76% of participants were non-Hispanic white, 12% were Hispanic and 2.5% were Black. About 90% of participants in the IDEAS amyloid-scan study were white as well, per the same account.
Why So Few Black Patients Make It Into Trials
Researchers point to a mix of structural barriers rather than a single cause. A study by Trammell found that socioeconomic factors, disproportionate exclusion from screening criteria, less access to expert care and fewer professional referrals are linked to lower participation rates among minorities, Atlanta News First reports. The same reporting notes that cognitive-decline symptoms may present differently in some communities, further delaying diagnosis in the first place.
A 2024 rapid review published in the Journal of Prevention of Alzheimer's Disease reinforces the pattern nationally, finding that racial and ethnic minoritized communities are underrepresented in Alzheimer's disease clinical trials despite higher dementia prevalence in those same communities. Across a series of six Alzheimer's disease and related dementias cooperative trials examined in the review, only 5% of participants were Hispanic and 6% were African American.
That review screened 1,915 studies and ultimately included 49 that focused on community-based recruitment approaches. It found that gaps in knowledge about the disease, its increased risk among minoritized populations, distrust, and stigma were noted as barriers to research participation, alongside practical hurdles like transportation and caregiver burden. Roughly half of the studies reviewed even specified whether they had evaluated their own recruitment methods, the journal notes, underscoring how uneven the field's efforts have been.
What Researchers Say Could Fix It
An analysis of more than 100 Alzheimer's clinical trials, cited by researchers at the Keck School of Medicine of USC, found that only 12% of participants were of any non-white race or Hispanic ethnicity. Those researchers recommend culturally sensitive and unbiased cognitive tests when evaluating potential trial participants, along with sustained collaborations between clinical trial researchers and community-based researchers who already have established partnerships and trust in the community. They also suggest that detailed diversity goals tailored to specific sites could increase site accountability going forward.
Community-based recruitment strategies commonly cited in the research include educational presentations, collaborations with faith organizations, community advisory boards, and engagement with local clinics or health professionals, according to the same rapid review in the Journal of Prevention of Alzheimer's Disease. Other efforts documented by Alzforum illustrate what sustained investment can look like: the Pathways to Healthy Aging in African Americans study spent nine years building relationships with 40 churches and 13 public or low-income housing areas in the greater Newark area before recruitment even began, eventually enrolling 500 cognitively healthy Black volunteers age 60 and older. The New IDEAS study, separately, aims to enroll 7,000 people nationwide, including 4,000 who are Black or Hispanic/Latino.
Trammell's monthly sessions engaging Black men in Atlanta reflect that same community-first approach on a local scale, aiming to build the kind of trust researchers say is necessary before people will sign up for studies at all. With Georgia's own numbers on cognitive impairment climbing among Black adults, the stakes for closing that trust gap are only growing.
