Americans today may be more concerned with living longer than at any point in their history. But the science of aging is by no means young. As molecular biologists begin to understand the mechanisms behind the aging process (see “The Fountain of Health”), they address questions raised in the pages of this magazine 65 years ago. In the June 1941 issue of Technology Review, Edward J. Stieglitz urged the scientific community to pursue gerontology. Noting the dramatic increase in life expectancy over the first part of the 20th century, he wrote,
…in 1900 only 17 per cent of the total population of the United States were forty-five years old or more. In 1940, 26.5 per cent were over forty-five, and conservative projection results in the estimate that in 1980 – only forty years hence – more than 40 per cent of our population will be over forty-five years of age.
Figures from the 1940 census reveal that the median age of the population of this country increased from 26.4 years in 1930 to 28.9 years in 1940. This is an increase of two and a half years of median age within a decade. The median age of the population will probably be forty-four years in another half century….. Such figures speak for themselves. Because of them, gerontology, the science of aging, is no longer merely academically interesting but has become an urgent matter in the minds of those who can see the handwriting on the wall.
As it turns out, those conservative estimates were wrong. In 1980, only 31.1 percent of the population was 45 or older, and in 1990, the median age merely reached 32.3 years, an increase of 3.4 years – not the predicted 15.1 – over 50 years. We can’t fault Stieglitz for his exuberance. As he looked back at the dramatic historic increases in average life expectancy – from 23 years in ancient Rome to 40 years for a New Englander in 1850, and up to 63 years for his contemporaries almost a century later – Stieglitz expected to see continued robust improvements in longevity. Not only did Stieglitz presciently argue for advancements in gerontology, he raised questions about the biology of aging that precisely – and amazingly – echo those posed by scientists today.
(1) The biology of senescence as a process. Here our ignorance is profound. Unanswered as yet are such fundamental questions as: Just what happens to a cell with aging? Why does aging occur? What accelerates or retards it? What mechanisms are involved? Why? The elucidation of these basic questions may solve many riddles – among them the riddle of cancer and perhaps that of arteriosclerosis. Scientifically, the cancer problem is but a subdivision of the bigger question of aging.
(2) The clinical problems of senescence in man. These questions are clearly divisible into those relating to normal senescence and those relating to abnormality due to disorders associated with advancing years….. Chronologic age, as measured in years and months, is not identical with biologic age. Physiologic age varies with each individual. The greater the duration of life, the greater the variation. Furthermore, no individual ages uniformly throughout, for different structures and systems age at different rates at various times in the life span…..
(3) Socio-economic problems. The sociologic problems introduced by increased longevity, greater life expectancy, and the rising median age of the population are immense and extremely complex. Industry is just awakening to the implications of the fact that the average age of employees is increasing at a surprising rate. Problems of placement and retirement, utilization and conservation of the health of older men in positions of greater responsibility, the complexities of workmen’s compensation laws in relation to occupational exacerbation of pre-existent disease, and many more questions are becoming increasingly urgent.