Why the preeminent risk factor in sporadic Alzheimer's disease cannot be genetic

Abstract 

If genetic risk factors are preeminent in the etiology of sporadic Alzheimer's disease, three corollaries follow: age-adjusted death rates from it should be fairly spatially uniform, should not vary significantly over time and should not alter markedly with migration. Globally, none of these corollaries hold true. The APO E₄ allele and other genetic aberrations that promote sporadic Alzheimer's disease do so most effectively in low alkalinity-high aluminum environments, especially if these are experiencing acid rain.