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OUR ENEMY AS WE AGE: CHRONIC DISEASE
There are two basic types of illnesses: infectious and chronic diseases. Infectious diseases are caused by microorganisms, invaders from outside the body. Examples are the flu, pneumonia, the common cold. Infectious diseases tend to come on quickly, lay us low for a few days or weeks, and usually go away without causing permanent harm. In contrast, internal breakdown is characteristic of chronic diseases. Although a few chronic illnesses are caused by known viruses, most have no identifiable outside cause. They usually involve permanent pathological changes produced by the body itself. They tend to develop slowly, get progressively worse, and have no cure. Though younger people too suffer from them, chronic diseases most often develop in middle and later life. They are related to the deterioration of the body that occurs as we age - rare in our twenties, more and more common in later years.
In 1900 the top causes of death in America were tuberculosis and pneumonia, both infectious diseases. Dramatic medical breakthroughs in the early decades of this century made these and other serious infectious illnesses less of a threat. Vaccines were developed; antibiotics became widespread. Because these diseases are relatively age blind, killing at three and eighty-three, these breakthroughs allowed most people to survive past youth. Life expectancy shot up because we now routinely live to the second half of the life span to encounter chronic diseases. By the end of World War II our major killers had changed: our nation\'s top causes of death were heart disease and cancer.
Because the chronic diseases we develop in middle and later life tend to arise from the aging process itself, they are more difficult to fight. But we are limiting their advance. Our progress shines out not by looking at life expectancy at birth but by considering the additional years we can expect to live once we reach age sixty-five. In 1960 a man turning sixty-five could expect to live to seventy-seven, a woman to eighty-one. Men and women having sixty-fifth birthdays in 1983 could expect to live about three years longer, to ages 79.5 and 84.
The chances of living to our eighties and nineties rise with each passing year. People over eighty-five are the fastest-growing part of the population. The numbers of our oldest old are increasing at an astonishing rate.
Are these gains a Faustian bargain, time tacked on to the end of our life span at the price of suffering longer with chronic diseases? A study published by gerontologist Erdman Palmore in 1986 answers a resounding no. Palmore compared surveys conducted by the National Center for Health Statistics from 1960 to 1980. In these government surveys, taken every few years, thousands of Americans are asked about their illnesses, their health problems, their physical limitations. When this Duke University researcher looked at health problems among people over sixty-five, he found less infirmity in 1980 than in 1970, less disability in 1970 than in 1960. Rather than severe physical problems multiplying as the ranks of the very old have increased, older people as a group are in better and better health.
One reason is that we now reach sixty-five healthier than ever. Many of us are physically middle-aged at the time society defines us as senior citizens (in our sixties) because we have eaten better, lived and worked in more healthful environments, and had better medical care all along. The revolution in what is happening after sixty-five has had an impact too. Within the past two decades the silver-haired marathon runner has overtaken the image of the passive older person staring into the sunset as our national old-age ideal. People in their sixties, seventies, and eighties are exhorted to stay young and vigorous. The sermons are not just wishful prayer. We now have proof that good health practices followed after middle age do dramatically extend life.
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GENERAL HEALTH
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