I believe there has been some research that has shown that actively enggaing one's mind (reading, research, music, creating works of art, conversation, etc.) does in deed slow the effects of Alzheimers...

Since so many of our old folk are shoved into homes, or left on their own until such becomes necessary, perhaps more contact and stimulation of a social sort might also help...in the old days, our elderly were the center of the family, of the community...