How We Die: Reflections on Life's Final Chapter

by Sherwin B. Nuland

Like the nerve cell, the muscle cell of the heart is one of those that cannot reproduce—as it gets older, it simply wears out and dies.

After a lifetime of regenerating spare parts, the nerve and muscle cells’ capacity of rejuvenation gradually shuts down.

One after another, like my grandmother’s teeth, the cardiac muscle cells cease to live—the heart loses strength. The same process takes place in the brain and the rest of the central nervous system. Even the immune system is not immune to aging.

There is a gradual decrease in the cardiac output while at rest, and when the heart is stressed by exercise or emotion, its ability to increase is less than required by the needs of arms, lungs, and every other structure of the body. The maximal rate attainable by a perfectly healthy heart falls by one beat every year, a figure so reliable that it can be determined by subtracting age from 220.

Perhaps in an attempt to compensate, the blood pressure tends to rise somewhat. Between the ages of sixty and eighty, it increases by 20 millimeters of mercury. One-third of people over the age of sixty-five have hypertension.

Before long, every organ is getting less nourishment than it needs to do the job intended for it by nature. Total blood flow to the kidney, for example, decreases by 10 percent for every decade after the age of forty.

The bladder is essentially a thick balloon whose wall is made of flexible muscle. As it ages, the balloon loses its distensibility and can no longer hold as much urine as before. Old

When the mechanism to exchange the aging parts for new wears out, the nerve or muscle cell can no longer survive the constant destruction of components that goes on within it.

Neuroscientists may actually have discovered the source of the wisdom which we like to think we can accumulate with advancing age.

One of the most dangerous of those events is an interference with blood supply. When blood flow to some specific region of the brain is cut off (a catastrophe that usually happens suddenly), there is immediate dysfunction or death of the nerve tissue supplied by the obstructed artery. This is precisely what is meant by the term stroke.

I would have understood what was meant, but to tell me that the process I had been watching for eighteen years had ended in a named acute disease—well, it was illogical.

This is not simply a problem of semantics. The difference between CVA as a terminal event and CVA as a cause of death is the difference between a worldview that recognizes the inexorable tide of natural history and a worldview that believes it is within the province of science to wrestle against those forces that stabilize our environment and our very civilization. I am no Luddite—I glory in the magnificent benisons of modern scientific achievement. I ask only that we use our increasing knowledge with increasing wisdom.

For this to continue, mankind cannot afford to destroy the balance—the economy, if you will—by tinkering with one of its most essential elements, which is the constant renewal within individual species and the invigoration that accompanies it. For plants and animals, renewal requires that death precede it so that the weary may be replaced by the vigorous. This is what is meant by the cycles of nature.

To call a natural process by the name of a disease is the first step in the attempt to cure it and thereby thwart it.

And so, Bubbeh had to die, as you and I will one day have to die.

It takes a great deal of energy to keep the brain’s engine functioning efficiently. Almost all of that energy is derived by the tissue’s ability to break down glucose into its component parts of carbon dioxide and water, a biochemical process that requires a high level of oxygen. The brain does not have the capacity to keep any glucose in reserve; it depends on a constant immediate supply being brought to it by the coursing arterial blood. Obviously, the same is true of the oxygen. It takes only a few minutes for the ischemic brain to run out of both before it suffocates. Neurons are extremely sensitive to ischemia; irreversible destructive changes begin within fifteen to thirty minutes of the onset of the deprivation. After no more than an hour of the beginning of ischemia, infarction of significant segments of brain tissue becomes inevitable.

If one were to name the universal factor in all death, whether cellular or planetary, it would certainly be loss of oxygen.

“Death may be due to a wide variety of diseases and disorders, but in every case the underlying physiological cause is a breakdown in the body’s oxygen cycle.”

Of hundreds of known diseases and their predisposing characteristics, some 85 percent of our aging population will succumb to the complications of one of only seven major entities: atherosclerosis, hypertension, adult-onset diabetes, obesity, mental depressing states such as Alzheimer’s and other dementias, cancer, and decreased resistance to infection.