Figures from the article may help us think about this issue more clearly. "Alzheimer’s disease is practically unheard of in adults younger than 40, and very rare (one in 2,500) for those under 60. It affects 1 percent of 65-year-olds, 2 percent of 68-year-olds, 3 percent of 70-year-olds. After that, the odds start multiplying. The likelihood of your developing Alzheimer’s more or less doubles every five years past 65. Should you make it to 85, you will have, roughly, a fifty-fifty shot at remaining sane."

When we are talking about a disease with base incidence of only 3 percent even for seventy-year-olds, we are so far talking about a disease that has been a low-priority disease. It's only in recent decades, as life expectancy has increase at all ages from 40 on up to 80,[1] that a lot of people have outlived heart disease, cancer, and the infectious diseases that used to cut life short at younger ages. As more people who are otherwise healthy age into ages at which their risk for Alzheimer disease increases, there will be increasing research and study of treatments related to Alzheimer disease. The fact that there are still people who can live past age 100 without getting severe signs of any kind of senile dementia suggests that we have something to discover about individual differences to find out what protects some people from Alzheimer disease decade after decade after decade. There is no need to give up hope. Incremental improvement--a little change in treatment here, a little change in lifestyle there, and a better understanding of prevention overall--is most of what has improved healthy lifespan in relation to other diseases, and there is no reason to think that Alzheimer disease is any different.

My own maternal grandmother, born in the 1800s, lived to the age of ninety-nine. Near the end of her life, she plainly had some kind of dementia, and presumably that was Alzheimer disease, and I think that was her cause of death. But she had a lot of interaction with her eleven children and thirty-eight grandchildren and various great-grandchildren for a long time after she was widowed, and I don't think anyone in the family looks back on her life and thinks that her death needed to be hastened. Some people retain memories of childhood in extreme old age even after they no longer form new memories of current events. For my grandmother, this was shown by one visit I had with her in her mid-nineties, when she no longer was sure who I was, but still remembered and was able to sing along me a song she had learned in childhood. (The song was in German, her native language, so I know she had not heard it for many years by the time I sang it with her. I had learned the song only when I studied German in university studies.) So don't give up on communicating with your aged relatives. Try to reach back in time to the best memories they have of their childhoods. They may surprise you with their understanding for a long time. And by a long time from now, when all of us reading this are old, Alzheimer disease may be largely a thing of the past.

The lengthy second-person-viewpoint account of caring for an aged parent with Alzheimer disease in the article is disturbing and moving. It reminded me deeply of caring for my late dad during the last six years of his life, when his thinking was completely intact but his mobility was destroyed by a spinal cord injury. There are a lot of devastating forms of disability that human beings can face, and, no, Medicare in the United States does not take care of patients with long-term disability of any kind. I did feel a lot of futility when talking to my dad (who had difficulty talking not because his brain wasn't working, but because he was paralyzed from his second spinal vertebra down, and couldn't even clear his throat or swallow on his own). He wanted to walk again--or at least to be able to scratch his own nose again--but he never did after his injury. Taking care of a helpless relative is rough--any time, for any reason--but we didn't give in to the idea that he should die early just to make our lives more convenient. He died only when a lot of other health problems (many of them aggravated, surely, by six years of immobility) piled up just after his seventy-eighth birthday. There a lot of memories I have of my dad (and my children have almost ALL of their memories of their grandfather) after the day on which his spinal cord was injured. I was willing to interrupt a career transition and diminish my "free" time to almost nothing to be with him in his old age. That wasn't easy, but that's what we did.

[1] http://www.nature.com/scientificamerican/journal/v307/n3/box...