Until I Can Do No More

An older friend of mine died recently. I shall not give his name, since death does not extinguish a man’s claim to privacy, and the circumstances of his last illness are of no public interest. He had lived sensibly, remained active and entered his eighties in what appeared to be excellent condition. Then came a small difficulty, followed by another, and within a surprisingly short time he was gone.

At seventy-three, one no longer treats such news as an interruption in the ordinary course of life. The death of a contemporary may still be received as a shock. The death of an older friend is more like the arrival of a formal notice whose contents one already knew. It is addressed to someone else, but the postman has made plain that he is working his way along the street.

What puzzles many of us is the speed with which an active person in his eighties can fall apart. We see a man walking to the shops, tending his garden and speaking with complete possession of his faculties. A few months later he is in hospital, bewildered by weakness and unable to recover from an ailment that a younger man would have thrown off in a fortnight. There appears to have been no single catastrophe sufficient to explain the change.

Bryan Mercadente has offered an explanation that interests me. According to him, the collapse is not truly sudden. What disappears is the biological reserve that had previously concealed the long process of decline. In youth, the organs work well below their full capacity during an ordinary day. If pneumonia or some other serious infection appears, the heart and lungs can increase their effort while the kidneys and immune system meet the additional demand. The young body possesses a large margin between what it ordinarily does and what it can do in an emergency.

That margin contracts with age. By the ninth decade, even a person who has exercised throughout life may be using much of his available capacity merely to remain upright and apparently well. A minor fall or an infection may then impose a demand for which no reserve remains. One part of the system fails to compensate, this places additional strain elsewhere, and the decline gathers speed.

There is something almost legal in the distinction. A company may appear solvent because it continues to pay its bills, though its reserves have been consumed and one unexpected liability will finish it. The day of insolvency seems dramatic only to those who have not examined the accounts. The decisive loss occurred by degrees and out of sight.

Young Bryan takes the explanation down to the level of the cell. Telomeres, the protective ends of chromosomes, shorten as cells divide. Cells eventually lose their ability to continue dividing normally. Some become senescent: they remain in the tissues, but cease performing their former work and contribute to chronic inflammation. Meanwhile, the body’s ability to repair damage and replace worn tissue diminishes. No single mechanism appears to explain the whole of human ageing, and I would be cautious of any account that claims otherwise. Yet the general proposition is persuasive. Ageing is not merely the acquisition of a list of diseases. It is also the progressive loss of the power to recover from them.

A further explanation is evolutionary. Natural selection has been successful at producing creatures able to survive long enough to reproduce and raise their offspring. It has had much less reason to perfect the maintenance of those creatures far beyond that stage. We have built a civilisation in which many of us can outlive the period for which our bodies most urgently evolved, but civilisation cannot repeal the terms of the original settlement. Mortality therefore rises sharply with age. The Gompertz-Makeham description of mortality expresses the matter mathematically: after adulthood, the underlying risk of death increases approximately exponentially. The precise rate varies between populations and circumstances, but it is often summarised by saying that adult mortality risk doubles about every eight years. Exercise and good food may improve one’s position among people of the same age. They do not abolish the curve.

There is comfort in this, though perhaps not the kind advertised by the health industry. My friend did not fall apart because he had secretly failed some moral examination. His sensible habits probably gave him more good years and allowed him to enjoy them with greater independence. They could not obtain an injunction against mortality.

I have been reading Bryan’s advice about health and fitness with considerable interest. It is both sensible and supported by more evidence than the dietary enthusiasms that come and go with the regularity of trouser fashions. I suspect, however, that much of it has arrived too late for me. I have never taken exercise. I have walked when a destination required it, but have always regarded motion without purpose as one of the stranger practices of the modern world. The sight of elderly gentlemen paying to pedal machines that go nowhere has never tempted me to join them. If I had been intended for athletic distinction, Providence would surely have supplied some early indication of it. My diet is rich in carbohydrate and processed food. I smoke, and I drink. I do not advance these habits as a rival programme for longevity, nor do I propose the idiotic argument that because some smoker reaches ninety, tobacco is harmless. I have behaved badly by the standards of preventive medicine and have so far been lucky. That is the whole of my defence.

There is always a temptation, when danger has failed to arrive on schedule, to suppose that one has disproved it. A man who has crossed a busy road with his eyes shut may boast of the soundness of his method, but the evidence establishes only that the traffic has so far missed him. My continued existence proves nothing about the wisdom of my habits.

Would reform now make a difference? Almost certainly it would make some. The body at seventy-three has not ceased to respond altogether, and even modest movement might preserve strength or balance that I shall otherwise lose sooner. Better food might improve the years remaining to me. Giving up tobacco would not cause the lungs to revert to their youthful condition, but that is hardly an argument for continuing to injure them. Yet there is a difference between improving one’s remaining prospects and imagining that one can renegotiate the essential bargain. I have no wish to spend the rest of my life managing it as though it were an anxious medical enterprise. Life is more than the avoidance of death, especially when the avoidance can only be temporary. One may sacrifice every pleasure to longevity and discover, at the end, that the accumulated reward consists of a few additional months in which pleasures are no longer possible.

This is not an argument for deliberate self-destruction. It is an argument for proportion. I may take more notice of Bryan than my past conduct would lead anyone to expect, but I shall not pretend that seventy-three is an eccentric form of middle age. The account is already long, and a prudent man does not value an ageing concern as though all its future earnings were guaranteed.

I know what lies ahead, unless something abrupt intervenes. Strength will diminish, recovery will take longer and tasks now performed without thought will become negotiations. There may come a point at which an infection or a fall consumes the last of my reserve. What others will call a sudden collapse may then be only the public appearance of a process that has been under way for decades.

My intention is to keep busy until I can do no more. There are books to read and arguments still worth making. There is work on my desk, and I prefer its demands to the endless inspection of my own decline. Occupation cannot lengthen the telomeres or defeat the mortality tables, but it can prevent death from taking possession of life before its proper arrival.

My friend has gone where, in the ordinary course, I shall follow him. His death has reminded me neither to boast of my luck nor to despair of its approaching end. The postman is still making his way along the street. Until he reaches my door, I see no reason to sit in the hall waiting for him.