I hate quoting other people to make my point here, but . . . coincidentally, I was going through Reader's Digest looking at the jokes only during this past week. On page 10 of the March 2012 issue under Alzheimer's Advice, I quote: "I am concerned that 'Protect Yourself from Alzheimer's Disease' gives the mistake impression that Alzheimer's, like some forms of cancer, can actually be beat. I developed Alzheimer's at age 50 and was engaged in all the activities that Dr. Small believes help protect people from Alzheimer's. I was physically active, intellectually engaged college instructor when I first developed symptoms. SHOULD THE IMPRESSION BE GIVEN THAT THIS TERRIBLE DISEASE CAN BE PREVENTED? BASED ON PERSONAL EXPERIENCE, I DON'T THINK SO."
I know Reader's Digest isn't the final say in science, but it champions honesty and common sense. So, the above quoted person is absolutely correct. It cannot be prevented (though I believe herbology the way I practice it can contribute greatly toward a healing after the fact.)