We have have heard about excess aluminium in alzheimers patients yet most of us eat aluminum every day in the use of popular baking powder.  Non-aluminum baking powder is available but is seldom if ever used in commercial baked goods and mixes.  I have read many times over concern using aluminum cooking utensils but never about baking powder.  If you want to avoid ingesting aluminum you not only have to cook all your own cakes, quick breads, pancakes, etc. and check you have bought non-aluminum baking powder, which I have found is not even available in some stores.  It is much like reading of the lead dangers warnings on plastic water faucets,and leaded crystal but no mention of the tons    of lead pumped in molecular form in the atmosphere from the old leaded gasoline.   Since lead is so heavy it does not wash away easily, so every time the street sweeper goes down the street it throws molecular lead back into the air.  I guess if we are told to watch out for plastic faucets,  leaded crystal, and aluminium pans we are supposed to ignore the main sources of hazardous metal consumption.