People in their nineties are called nonagenarians. My mind always processes the word to mean “non-aging,” and to a certain extent, that is true. After 93, people seem to stop aging. In fact, when people are in their late nineties, they are no more likely to die than someone in their early nineties. I just checked an actuarial table, and it seems as if everyone in their nineties has a life expectancy of about two years, and that expectancy of two years is a fairly constant number. On each birthday in your mid to late nineties, your life expectancy is approximately the same as it was the previous birthday, so you basically aren’t aging much at all. In fact, research seems to show that whatever health issues a person had at 93 remain, but new health issues generally aren’t accumulating. Nor are nonagenarians dying from dangerous pursuits such as sky diving or motorcycling. Since many people of that age seldom leave the house, their chances of getting in a car accident are slim, as is their chance of catching a serious illness from being in crowds.
Michael Rose, a professor of evolutionary biology at the University of California says: We still don’t have a full explanation of the underlying genetics of the cessation of aging. One possibility is that there are genes that are advantageous early on but damaging to health later in life — an effect called “antagonistic pleiotropy.” And these are the genes that cease to be. We now understand that aging is not a cumulative process of progressive chemical damage, like rust. It is a pattern of declining function produced by evolution. Aristotle was wrong (Aristotle thought of aging as a remorseless process of falling apart, until death finally puts us out of our misery), and so are all the present-day biologists who try to explain aging in terms of biochemistry or cell biology alone.
In other words (at least according to my understanding), nonagenarians outlive the process of aging.
There is a chance that my 97-year-old father will live two more years despite his being on hospice, and maybe even because of it. The problems he has have been with him since his early nineties — congestive heart failure, COPD, and prostate cancer with such a low PSA number that his only symptom is occasional bleeding. What usually precipitates a serious decline in his health is a visit to the hospital. (They always seem to admit him when he is feeling his strongest, so whatever it is that bothered the doctor wasn’t bothering him.) Because the doctors take the opportunity to give him a thorough check-up (heart function, breathing problems, removing water build-up in the pleural cavity), he always returns home weeks later much worse off than when he went in. Now, with his being on hospice, he is not at the mercy of doctors who are determined to keep him alive at all costs, so he could remain at the stage he is in for a long time. (Of course, he could just as easily die tomorrow or next month, but statistically, chances are he won’t.)
I truly did not think he would recuperate from this last hospitalization — he wouldn’t get out of bed when he was there, claiming he was asserting his patient’s rights to refuse any treatment, so he ended up with pneumonia and an extended convalescent stay. When he finally got home, he was bedridden, but that robust constitution of his that outlasted a majority of his generation kicked in, and now he is up and about again, fully capable of being left alone. Apparently, he has outlived everything that could have killed him, and now he is drifting in his nonagenarianism.
Despite this cessation of aging in the elderly, they do die, so I know my father won’t be here forever, but still, it’s interesting to see firsthand the principles Michael Rose postulated.
Rose’s idea doesn’t change my mind about my own longevity, though — I’ve never wanted to live into my nineties, and for sure I don’t want to do so knowing that I could linger there for many years in some sort of pre-death limbo. I know we don’t have a choice in such matters, but luckily I take after my mother, so I probably won’t have to deal with either nonagenarianism or non-aging.
Pat Bertram is the author of the suspense novels Light Bringer, More Deaths Than One, A Spark of Heavenly Fire, and Daughter Am I. Bertram is also the author of Grief: The Great Yearning, “an exquisite book, wrenching to read, and at the same time full of profound truths.” Connect with Pat on Google+. Like Pat on Facebook.