No One Lives Forever

A physician friend of mine recently posed a question: What would happen, he asked, if all our efforts to stamp out heart disease and cancer were finally successful?  Following our current trajectory (or, at least, the direction in which we hope we’re heading), what would happen if we were able to finally do away with the two most common maladies that we face and from which most of us ultimately die?

I gather from the tone of his question that he implies that eliminating cancer and heart disease, while noble and seemingly worthwhile, may lead to untoward consequences that we don’t fully appreciate.  Will people start living forever?  Will we create a society so overloaded with geriatric social service consumers that the relatively small class of young workers will no longer be able to support the older generations?  How can we possibly pay for the healthcare of a planet overpopulated with prune-juice swigging centenarians?  Will we need to start purposefully culling our population—a la the movie Logan’s Run—so as to not burden the earth with billions upon billions of great-great-grandparents?  Can Detroit produce enough Buicks to keep up with the exploding demand?

When he first posed the question I thought it was a relatively silly exercise in rhetorical thinking—we’re not even close to curing either disease and therefore don’t need to waste time pondering the concept.  As I chewed the idea over a little more, however, I realized that it’s not really so outlandish and that a precedent already exists for this type of wholesale shift in medical epidemiology.

To see what I mean let’s go back in time about a hundred years.  In the year 1900 the life expectancy for a man in the Unites States was only 46.3 years and for a woman it was 48.3 years.  The top ten causes of death at the dawn of the 20th century are listed here:

1. Pneumonia and influenza
2. Tuberculosis
3. Diarrhea, enteritis, and ulceration of the intestines
4. Diseases of the heart
5. Intracranial lesions of vascular origin
6. Nephritis
7. Accidents
8. Cancer and other malignant tumors
9. Senility
10. Diphtheria

As you look over this list you’ll note that many of the common maladies in 1900 are almost unheard of today.  When’s the last time one of your healthy relatives dropped over dead from tuberculosis or diarrhea?  Death from diphtheria is so rare that you’d hear about it on the nightly news.

A combination of factors has virtually eliminated many of the diseases that were daily hazards a hundred years ago.  Advances in public health and sanitation did away with many diarrheal illness, malaria, yellow fever, tuberculosis (mostly), and has had a major impact on the risk of death from influenza.  The broad availability of antibiotics has reduced the mortality from pneumonia and other infectious diseases.  Workplace safety reforms have dramatically cut the risk of death due to occupational accidents.

Within a hundred short years we’ve weeded out these now-uncommon maladies and have increased the average life-span by three decades.  I imagine that it would have seemed fantastical to a doctor in the year 1900 to ponder the possibility of a future without rampant tuberculosis or diphtheria.  What would our lives be like, he would wonder, if we could suddenly cure the most common causes of death?  How could we support a society overloaded with hoary geezers who have aged into their 6th, 7th and 8th decades?

Needless to say that our society has not crashed under the weight of an aging population (although anyone who pays attention to our current healthcare and economic crisis may argue otherwise) and we haven’t yet initiated forced euthanasia to get rid of our nursing home patients (Sarah Palin’s infamous claims aside).

Now, getting back to my central theme, if we were to again wipe out several diseases on the top ten list where would that get us?  To start, let’s look at the list from 2009 (newer data is not yet available):

1. Heart disease
2. Cancer
3. Stroke
4. Chronic lower respiratory diseases
5. Accidents
6. Alzheimer's disease
7. Diabetes
8. Influenza and pneumonia
9. Nephritis, nephrotic syndrome, and nephrosis
10. Septicemia

Currently the top three causes of death relate to either cancer or vascular disease (heart disease and stroke) and together account for 76% of the deaths on the list.  In other words, three times as many people die from the cancer and vascular disease than from all other causes combined.  What would happen if we suddenly found a cure for numbers 1 through 3?

Well, we’d probably add another 20 or 30 years to our life expectancy, upping the average to around a hundred years, giving each of us about 35 years of retirement to enjoy before we pass on.  While that seems like a good thing we should keep in mind that curing heart disease and cancer is not synonymous with finding the fountain of youth.  We’d all continue to be beset with the infirmities that accompany old age: degenerating joints, muscle weakness, slowly advancing dementia, hip fractures, urinary infections, prostate enlargement, hearing and vision decay, and shingles (to name a few).  Living to be 110 just means that you get 30 more years of being really, really old.

My friend’s implicit argument is that we put too big an emphasis on extending our lives.  By choosing to view death as the enemy—rather than as a natural part of living—we have created a society where we expect heroic efforts to extend our years even in the face of age-related debilities that degrade our quality of life.  By continuing to remove natural forms of death (such as cancer and heart disease) we are inviting deaths that are slower, more drawn out, and perhaps more miserable (note number 6 on the list above).

To an extent I agree with his viewpoint.  We’ve reached a spot (now that we’ve improved life expectancy into the 8th decade) where we need to focus more on quality of life than on duration.  There’s little point curing heart disease and cancer among the elderly if we can’t also cure Alzheimer’s and osteoporosis.

As a doctor I feel it’s my job to keep to rooting for cures.  But as a person who’ll eventually be walking around on bad knees, sporting a grapefruit-sized prostate and vanishing memory, my real interest is in seeing research dedicated to improving quality of life.  I’m thinking my 120th birthday party is going to be quite the rousing bash and I’d like to be spry enough to enjoy it.