A review of epidemiologic studies on aluminum and silica in relation to Alzheimer's disease and associated disorders.

Although the neurotoxicity of aluminum is well established, the association between the metal and dementia or associated disorders remains a subject of debate. In this article, we present a review of articles published on epidemiologic studies of this subject. Different sources of exposure are considered (occupational exposure, aluminum-containing products), with emphasis on drinking water. We separate the various health effects of aluminum into three categories: neurological disorders (other than cognitive decline or AD); cognitive decline; and dementia or Alzheimer's disease. Furthermore, we present the results obtained on silicon in drinking water, a chemical constituent that interacts with aluminum. We conclude that not enough epidemiological evidence supports a link between aluminum in drinking water and AD. The role of silica in drinking water has been less studied, and clear results have not yet emerged.