Study reveals racial differences in early Alzheimer's brain changes

A team of researchers at the USC Mark and Mary Stevens Neuroimaging and Informatics Institute (Stevens INI) at the Keck School of Medicine of USC has identified important differences in how early Alzheimer's disease-related brain changes appear across racial and ethnic groups, underscoring the need for more inclusive approaches to studying and diagnosing the disease. Their findings are now available in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.

In a large, racially and ethnically diverse study of older adults without dementia, researchers found that Black and Hispanic participants showed higher levels of tau, a protein linked to Alzheimer's, in key memory-related regions of the brain compared to non-Hispanic white participants, even before the buildup of amyloid plaques typically associated with Alzheimer's disease. However, the relationship between these brain proteins and memory performance varied across groups, suggesting that Alzheimer's biomarkers may not tell the full story for everyone.

The findings come from the Health and Aging Brain Study–Health Disparities (HABS-HD), one of the largest and most diverse brain-imaging studies of aging in the US and were made possible by advanced PET brain scans that can detect abnormal protein buildup years before symptoms appear.

Most Alzheimer's research has been based on non-Hispanic white participants, and our results show that we can't assume those patterns apply equally to everyone. If we want to advance precision medicine efforts for all communities, we need to understand how these brain markers behave across diverse populations."