From what I understand, the medicine available is fairly successful at staving off further disease progression but the normal late stage diagnosis often means it’s far too late. This might make outcomes significantly better if it works as well as reported.

The article states there are medications that can slow or reverse the disease, if the disease is diagnosed early enough.

"An early diagnosis is critical for those with dementia. New drug technology can slow, or even reverse the progress of Alzheimer’s, but only if the disease is detected early enough. The drug lecanemab is one of two new treatments for the disease."

Probably diet and exercise. Would be interesting to see an interventional study based on this.