The Straight Dope: Does exposure to aluminum cause Alzheimer's disease?

The Straight Dope: Does exposure to aluminum cause Alzheimer's disease? :

The question is whether chronic exposure to small amounts can affect you. Despite lots of research, we still don't know. . . Even more insidious, aluminum is added to many municipal water supplies to help remove floating debris. Aluminum is also found in household baking powder, self-rising flour, cake mix, pancake batter, and frozen dough (as sodium aluminum phosphate, a leavening agent); in nondairy creamers, table salt, and other powdered foods (as an anticaking ingredient); in processed cheese (as an emulsifier); and in hemorrhoid preparations (up to 50 percent aluminum hydroxide).