Why can’t I simply die of old age, asks Dr Will Cairns

Several weeks ago the Australian Institute of Health and Welfare (AIHW) released How long can Australians live?, a discussion, or perhaps a reflection, on mortality and maximum life expectancy, and what this means for Australians.

Coincidentally, a short while before that publication, I and several colleagues had been discussing the question of whether everyone needs a pathological cause, a reason, or a disease label for their death.

And last year, when Queen Elizabeth II died, her doctor wrote “Old Age” on her death certificate (here).

Over past years I have written a number of articles for MJA InSight+ on life expectancy, the need to accept death in old age as normal, and the concept of a finite lifespan ending in death (here, here, here, here, here, here, and most recently here). You may or may not chose to read any of them, but, later in this article, I have replicated a graph from the most recent of them.

In 2015, the Commonwealth produced its 2015 Intergenerational Report: Australia in 2055 (IGR). The Executive Summary states:

“Australians will live longer and continue to have one of the longest life expectancies in the world. In 2054–55, life expectancy at birth is projected to be 95.1 years for men and 96.6 years for women, compared with 91.5 and 93.6 years today.”

This statement is founded on the assumption that health care technology will continue to deliver the gains in life expectancy that it had in the past. And this in turn seems to be based on a further unstated assumption that people in their 80s, 90s and 100s will respond to emerging technologies in the same way as their younger selves.

The Intergenerational Report 2023: Australia’s Future to 2063 released last week was more cautious:

“Life expectancies will continue to rise, but the rate of increase is projected to slow.
Life expectancies at birth are 81.3 years for men and 85.2 years for women in 2022–23 and are expected to be 87.0 years for men and 89.5 years for women by 2062–63.....

I think there is reason to doubt these more recent predictions too. As we get older, an increasing number of us enter the phase of our individual maximum biological life expectancy when our ailments are less responsive to treatment as the cause of death changes (more on this later).

The 2023 IGR opens the door to a much broader discussion about what is normal at the end of life, whether we should abandon the 20th century approach to old age as a disease to be treated, and how the appreciation of death in old age as a normal end to life lived for its maximum possible duration might change the way that we deliver health care (here).

The AIHW report discusses the reality that although increasing numbers of people are reaching their 100s, this is not translating into significantly increased numbers of people who achieve 110 — the number of people who die over the age of 110 remains vanishingly small.

Improved disease prevention and treatment when young means that more people are living long enough to get chronologically old and approach their biological maximum lifespan (which itself has a normal distribution of ages). However, despite enabling more people to die as centenarians, better health care does not protect them from dying from the natural ageing that ends the lives of virtually everyone before they reach 110.

This should not be a surprise. Almost no-one has a biological maximum life expectancy of over about 110 years. Irrespective of the increased median life expectancy due to better health and health care, there is no reason to expect an impact on the numbers of people who live beyond 110 — doubling from one handful to two handfuls might be statistically significant but not socially meaningful.

As individuals we do not exist to live on forever. Indeed, that reality is the key to the success, the continuity, of life through evolution by natural selection in response to a changing world — that individual’s lives are finite allows their species to evolve and eventually become new species.

“Death is very likely the single best invention of Life. It is Life's change agent. It clears out the old to make way for the new. Right now the new is you, but someday not too long from now, you will gradually become the old and be cleared away.”

Steve Jobs, CEO of Apple Computer and Pixar Animation Studios, Stanford University Commencement address, 12 June 2005 (here)

Evolution shapes the duration of individual lives within animal species to be as long as is necessary to support sufficient reproduction for species persistence. Our evolutionary success is not threatened by the fact that much of our body is not amenable to repair, or that many of our cells and cell lines have limited lifespans. Indeed, excessive longevity might become a liability for socially complex organisms.

There are many perspectives from which to understand our individual lives. One is to consider ourselves as a dynamic and ever-changing community of cells. Their collaboration produces the emergent phenomenon of “me” that undertakes the range of activities necessary to fulfil their/my biological goals, including engaging in the social behaviours at the next level of community necessary to achieve them. But each of those aggregations operating as “you” or “me” can only function for a period of time, and not the same amount of time for every individual of our species. Eventually, we wear out because every cell and all of our cell lines can only persist for so long — that is the way we are. And when our ageing community of cells can no longer muster the quorum necessary to sustain any one of the essential components of the complex entity that is “me” or “you” (the reader), it disbands.

How might this understanding change our approach to health care?

Perhaps we could start by integrating the reality that if we live long enough, we will all die of old age.

Most probably I will, like most people, develop a disease that can be held at bay for a time by modern technology, but eventually causes my death.

Or I may develop a number of concurrent conditions that together cause me to die. If they all contribute, then my doctor can choose the worst, or perhaps draw straws, to complete my death certificate.

But if I don’t die of something else first, the aged me will be so frail that I will eventually die from the first minor dysfunction that tips the balance of my viability, like the straw that breaks the camel’s back. I may well be comfortable, and everyone will know that I will die soon. They should be able to agree that I be left in peace, unburdened by a pointless search for a reason to die secondary to the global cause of my agedness — just as numerous of my palliative care patients had their deaths attributed to lung cancer, irrespective of whether the immediate cause was pneumonia, brain metastases, SIADH (syndrome of inappropriate antidiuretic hormone secretion), or any of the numerous other complications of that disease.

Strangely, however, if I do struggle on to attain my personal biological maximum life expectancy and just fade out, the Australian Bureau of Statistics (ABS) will not permit my doctor to write the underlying cause of “old age” or “frailty of old age” (here). So now, if because I have reached my maximum life expectancy I stop eating and drinking and peacefully go to sleep, and soon my heart stops and I stop breathing one night (or the other way round), the ABS tells my doctor that they must attribute a disease as the reason I died. We shouldn’t blame the straw. My cause of death could be celebrated because I had lived my life to its maximum biological potential.

We could ask the ABS to allow that people do die of old age or the frailty of old age. Doing so will promote a considered and individualised shift in the medical paradigm of health care in the very old from death caused by disease to death as the consequence of natural life-ending biological ageing. The focus of health care for biologically younger people can remain on disease cure and/or control, while the management of the symptoms that ail people consequent from their inevitable biological ageing can shift to the goal of comfort and quality of life.

I do not think it is ageist to observe that death in those old people who live long enough can be a consequence of the natural processes of their biological old age, and that there is no need to impose a pathological explanation.

If it was good enough for Queen Elizabeth II, surely the rest of us can be also allowed to die peacefully without suffering a disease, or its treatment?

Dr Will Cairns has retired from clinical practice as a palliative medicine specialist.