APOE and Mental deterioration: In this study, we investigate the association of brain copper (assessed using ICP-MS in four regions -inferior temporal, mid-frontal, anterior cingulate, and cerebellum) and dietary copper with cognitive decline and AD pathology burden (a quantitative summary of neurofibrillary tangles, diffuse and neuritic plaques in multiple brain regions) at autopsy examination among deceased participants [N = 657; age of death: 90.2(±6.2) years, 70% women, 25% APOE-ɛ4 carriers] in the Rush Memory and Aging Project.