Black and Latinx Americans may be at a higher risk of dementia due to a higher prevalence of diabetes and cardiovascular conditions. But research also indicates they are 22% and 28% less likely to test positive for beta-amyloid plaques on PET scans. Experts aren’t sure why, but they hypothesize their cognitive impairment might be driven by a combination of other conditions, that may make the brain vulnerable to symptoms of Alzheimer’s at a lower level of beta-amyloid.