I once saw a documentary which studies the cause of altzheimers and in short it was the results of copper and some other things cementing up the neurons. I was quite suprised when i saw it as i was alway under the impression it was alluminum that caused it.

That said maybe if you can ensure particle size as Peter mentions with silver it may pose no problems.

If you do give it a go can you keep a diary and keep us informed on dosage an effect.
Cheers
damian