Black and Latinx adults with cognitive impairment are less likely than other groups to show the amyloid buildup that defines Alzheimer's disease, according to a nationwide study published in the journal Alzheimer's and Dementia. The finding comes from the New IDEAS study, which examined differences in amyloid positron emission tomography (PET) positivity across ethnoracial groups and in relation to social determinants of health.
The result sits awkwardly alongside a well-documented pattern: Black and Latinx populations carry higher rates of dementia overall. If fewer of those cases involve amyloid pathology, then a meaningful share of cognitive impairment in these groups may stem from other causes, which has direct consequences for how patients are evaluated and which treatments they qualify for.
That question of access is not academic. The newest anti-amyloid drugs are prescribed only to people whose scans or biomarkers confirm amyloid pathology, so a lower rate of amyloid positivity means fewer people eligible for those therapies - and a greater need for diagnostic pathways that look beyond amyloid alone. The study's attention to social determinants of health signals that researchers are treating these gaps as something more than biology.
Context matters here. Dementia cases are climbing worldwide, with more than 10 million new diagnoses each year, and roughly 60 percent of people living with dementia now reside in developing countries, a figure projected to reach 70 percent by 2050. Research that maps how Alzheimer's pathology varies across populations is a prerequisite for care systems that work for all of them.