November/December 2001
the zen of science

What to do after you've figured out 
you're not gonna live forever

By Marc Ringel, MD

You may recall that in the last installment of "The zen of science" I discussed the Hayflick phenomenon, the ultimate barrier to the immortality of individual cells and, consequently, to whole organisms, including human ones. Thanks to cells' finite ability to reproduce, your body won't last forever no matter how well you take care of it. In this column, I'll discuss where we might refocus some of our individual and societal resources once we've accepted that there is a limit to our longevity, no matter how much we spend on healthcare.

Let me start with a parable about engineering. My friend had a car (I forget which make) that fell apart at 80,000 miles. Everything—transmission, interior, horn, water pump, suspension—quit working at once. So uncanny was this simultaneous failure, that he was convinced that all the individual parts were wired to the odometer which had been programmed to send out a self-destruct message as the numbers rolled over to 80k. My friend, a frugal guy, would have preferred for his car to last to 100 thousand, 150 thousand or more miles before he had to get rid of it. Sturdier parts would have been nice, though they would have made the vehicle more expensive. On the other hand, if the better-built car didn't all wear out at once, it might have cost more in the long run, nickel-and-diming him as he replaced one part at a time.

Engineers, whether they're designing a coffee grinder or a skyscraper, strive to make every part just good enough and not much better than the others (with a built-in margin of safety). Unless you design a coffee mill to accept inexpensive replaceable blades, for example, you don't want the blades to wear out much before the motor. If they do, you've either installed too good a motor or too poor a quality of blades. If it all gives out at once it means you've chosen right. For the heavier duty model, you'll need to match better blades with a longer-running motor. Of course, it will cost more.

The same is true for bodies, for which it's a lot harder to obtain spare parts. Ideally, everything—kidneys, heart, brains, joints, lungs—goes at once. The better the overall quality of the parts, the greater the function and longevity. When things don't all peter out at the same time—for example, when the brain stops working well because of Alzheimer's while the rest of the body lives on; the joints cripple and pain a person while their brain works just fine; or the kidneys give out and doom the person to a lifetime of dialysis—there is potential for loads of suffering and expense.

Notwithstanding surgical and medical miracles, we are born with our factory-installed equipment already chosen for us. Who gets the big engine, heavy-duty suspension or heated seats is mostly the luck of the genetic draw. But once we start living consciously, we can take steps to care for all of our systems, lavishing special attention on the ones which seem most vulnerable. By careful maintenance, we can strive to keep everything working at about the same level, even in the midst of the inevitable overall decline that comes with apoptosis (the process by which cells age and die). We ought to aim to keep all systems go as we age so we can live the fullest, healthiest life possible up until it all gives out, like my friend's car.

Careful maintenance, to be sure, will probably help us to live longer but still not much past the four- or five-score years our cells have been preprogrammed to endure. The challenge is to be as whole and functional for as long as possible. By living healthier lives—not burning out our lungs too soon with tobacco, our skin with solar rays, our arteries with fat, our joints with repetitive motion, our livers with alcohol, our brains with unhelmeted accidents, and a host of other factors, many as yet unknown—we'll really reap those rewards in old age.

When we're young, our bodies are full of redundancy. For example, young brains have lots of extra cells and connections, which is why children are in general much better able to recover from strokes than adults who lose the same proportion of brain tissue. CT and MRI images of many older folks show some loss of brain tissue, and the older they are, the more is missing. Still, they may function completely normally as the sorts of people we declare to be sharp as a tack. The missing brain cells may account for nothing more than diminished reserve, not to be missed until a situation arises that calls for those reserves.

When I say no to a cigarette or choose the salad instead of the steak for lunch I'm betting that my health-conscious actions will hold down the rate of aging of some of my cells. Taken together, thanks to thousands of such micro-decisions over a lifetime, I'm liable (though not guaranteed) to live longer: Longer but not forever. Perhaps the more important effect of wise lifestyle decisions is that I'll probably live better. More reserves means I feel and function better. It means that society functions better too. Notwithstanding the recent Philip Morris study of the Czech Republic (since apologized for by company flacks) which found that the country benefited financially from the premature death of its smokers, lifestyle reform means healthier and happier old folks who consume far fewer services.

Our goal should be for everybody to live as close to their potential, in age and function, as they can. To accomplish this laudable objective we will need to place a lot more emphasis on health and, since resources are limited, a little less on dramatic rescues from acute illness. I don't underestimate the odds against such a shift of priorities because people are much more willing to pay a lot of money on healthcare when they're desperately ill than they are to spend a little money when they're feeling just fine. Consciousness will also have to change. Imagine trying to match the success of ER with a TV series called Monounsaturated.

Of course, there's a lot more involved in being healthy than spending more money on health and shifting breakfast from Frosted Flakes with milk to bran flakes with soy milk. American society will have to give up the illusion that we can stay forever young. We will have to increase our appreciation of age, experience, wisdom, wrinkles, thinning hair and creaking knees. By taking advantage of what seniors have to offer we make them an integral part of our communal life. They stay fit by staying vital, contributing more than they consume. And we can look forward to saving money on retreads by caring better for the original parts. With as many seniors as are coming up in my generation of baby boomers, we'd all better be thinking about how to keep us humming along.