The industrialized world has gained over 25 years of life, and this achievement is nearly equal to the life expectancy attained during the preceding 5000 years of human history. Soon, baby boomers will reach 65. The United States is not unique. Longevity is a function of social and economic progress, better public health and nutrition, and the application of important medical concepts, such as the germ theory of disease. Furthermore, in this century we have enjoyed steady success in meeting the challenges posed by the increasing number and proportion of older persons in many nations, through such advances as social security, health insurance, and biomedical research.
All major changes have unpredictable ramifications.
For instance, the Industrial Revolution, which drastically transformed societies in positive ways, also contributed to adverse environmental changes, such as global warming. Similarly, along with the positive aspects of the longevity revolution we have acquired a significant minority of severely disabled and impaired people, devastated by Alzheimer's and vascular dementias, frailty, and problems with mobility. The new longevity has resulted in considerable cultural, political and economic uncertainty, as nations consider rising public pension and health care costs. However daunting the challenges of population aging appear, we must not be swayed by gloom and doom prognosticators. The odds are in favor of the growth of a vital, active, experienced, engaged and useful older population.