Los Angeles (LabNews.io) – A large-scale study from the Keck School of Medicine at the University of Southern California (USC) has detected significant differences in early Alzheimer's-associated brain changes among various ethnic groups. The USC Mark and Mary Stevens Neuroimaging and Informatics Institute (Stevens INI) team found higher levels of tau in key memory regions among Black and Hispanic participants compared to non-Hispanic White participants in a study of over 1,500 cognitively normal or mildly impaired older adults – even before the deposition of typical amyloid plaques.
The findings, based on data from the Health and Aging Brain Study–Health Disparities (HABS-HD), were collected using advanced tau PET tracers. While higher tau levels were generally associated with poorer memory performance, this association was amplified by amyloid deposition in non-Hispanic Whites and Hispanics – but not in Black participants. This suggests that memory changes in Black adults may be more influenced by other factors such as vascular health, comorbidities, chronic stress, or social determinants.
The researchers emphasize that most previous Alzheimer's studies have been predominantly based on data from non-Hispanic White participants, and the observed patterns are not readily transferable to other populations. The findings underscore the need for more inclusive research approaches to accurately interpret biomarkers and improve personalized diagnostics and prevention.
Furthermore, the authors pointed out that some observed differences in tau levels could partly be due to limitations of the imaging itself, such as non-specific signals in adjacent brain regions. This necessitates careful validation of imaging techniques across diverse populations.
The study was published on March 4, 2026, in Alzheimer’s & Dementia and was funded by the National Institutes of Health. (LabNews.io)
