My darling groom often jokes that, with Alzheimer's, he comes home to a new woman every day. Truth is, he may be losing a bit of his mental capacity, I believe largely due to work-related stress and exhaustion, among other issues, but, fortunately, he does not have Alzheimer's. Unfortunately, it does run in his family and he has recently lost a favorite uncle to the disease.
Our daughter's godmother's mother died several years ago from complications of Alzheimer's. Because she lived in the neighborhood and we saw her often, it was distressing to see her deteriorate.
I've read that keeping one's mind and body as active as possible could delay the onset of Alzheimer's. I play little mind games with my mom to try to keep her little gray cells healthy. My grandfather believed this kept him going. Fortunately, neither suffered from the disease.
Here's another link that you may find helpful, to the Alzheimer's Research Foundation, where people can find information for patients, family members and caregivers: