Older Americans are generally better off—healthier and wealthier—than ever before.1 Average life expectancy in the United States has at least doubled over the past century, and a baby born today is expected to live almost 30 years longer than one born in the year 1900. These improvements in life expectancy, from an average of 49 years in 1900 to age 76 at the turn of the 21st century, plus the advent of such programs as Medicare and Social Security have helped to improve both the physical and fiscal well-being of the Nation's older population. The added years of life have allowed the vast majority of older Americans to enjoy a healthy and active retirement. A majority of people 65 and older rate their health as good or excellent.
But good health is far from a universal reality for older Americans. The latest national surveys indicate that about one-fifth of people age 65 and older, more than 7 million people, report some disability.2
Chronic disease, memory impairment, and depressive symptoms affect large numbers of older people and the risk of such problems significantly rises with age. Nearly half of those age 85 and older suffer from Alzheimer's disease.3These millions of less fortunate older people struggle with daily activities as simple as bathing and dressing, with families and friends taking on the difficult and often costly role of caregiver.
Understanding the difference between advanced years that are active and independent and those that are characterized by frailty and dependence is at the heart of the NIA's research program. Since the Institute's founding in 1974, research has shed considerable light on aging and health.It is now known that aging itself is not the cause of disease, disability, and frailty associated with advancing age. Indeed, the converse is true: It is disease and disabling processes, influenced by age-related changes in the body and by unhealthy choices and sedentary lifestyles, that are the most important factors in compromising the quality of life for older people. This fundamental shift in thinking was reinforced most recently with insights from the National Long Term Care Survey (NLTCS) and other such longitudinal analyses. According to the NLTCS, the rate of disability among older Americans dramatically declined from the 1980s through the mid 1990s, even among people age 85 and older, who are most vulnerable to disabling conditions. These findings, along with evidence from a number of clinical trials and studies testing specific interventions, suggest more strongly than ever that disease and disability can be addressed and are not inevitable consequences of aging.
The challenge now is to maintain and even accelerate the trend in declining disability and to reduce rates of disease amid a steep rise in the number and proportion of older people. The task is urgent. Demographic projections show that the U.S. population is beginning to age at a rapid pace, with the first baby boomers turning 65 in 2011. Between now and the year 2030, the number of individuals age 65 and older likely will double, reaching 70.3 million and comprising a larger proportion of the entire population, up from 13% today to 20% in 2030.4 Of great interest is the explosive growth anticipated among those most at risk of disease and disability, people aged 85 and older. Their ranks are expected to grow from 4.3 million (1.6%) in 2000, to at least 19.4 million (4.8%) in 2050.3 The racial and ethnic makeup of the older population will change dramatically as well, bringing with it possibly even greater racial and ethnic disparities in health among a more diverse population of older Americans. These demographic factors threaten to combine to increase the burden of age-related diseases and conditions on individuals, families, and society. Unless new understandings and interventions are developed and implemented to reduce disease and disability before the population ages so intensively, the costs, in both human and financial terms, could be extraordinary.
In the 20th century, health research and public health practices did much to extend life and improve health. At the start of this new millennium, the NIA's research portfolio is aimed primarily at increasing "healthspan," or years of healthy active life expectancy. Aging research is at the threshold of discovery,poised to build upon the work of recent years to make a difference in the lives of older Americans and their families. Toward that end, NIA's overall program is wide-ranging and includes research on: the biochemical, genetic, and physiological mechanisms of aging in humans and animal models; the structure and function of the aging nervous system; social and behavioral aspects of aging processes and the place of older people in society; and the pathophysiology, diagnosis, treatment, and prevention of age-related diseases, degenerative conditions, and disabilities. The NIA is the lead federal agency for Alzheimer's disease research.
In close collaboration with the National Advisory Council on Aging and other public and private organizations, the NIA has developed a strategic plan for aging research, to identify goals for the next 5 years. These goals address scientific areas that hold the greatest promise for advancing knowledge, many outlined in this narrative. The NIA also recently completed a strategic plan on disparities in health status of older Americans of different racial and ethnic backgrounds. In this narrative, the Institute focuses on recent progress and future directions for research in four key areas: Section I.) Alzheimer's disease and the neuroscience of aging; Section II.) reducing chronic disease and disability; Section III.) the biology of aging; and Section IV.) the behavioral and social aspects of growing older. In each of these efforts and more broadly, the Institute is paying special attention to reducing health disparities among different groups of Americans (Section V.). Interspersed within the narrative, in two sections, are "Stories of Discovery," which follow the history and the drama of unfolding scientific knowledge in a specific area of interest.
- 1.Federal Interagency Forum on Aging Related Statistics. Older Americans 2000: Key Indicators of Well-Being. 2000.
- Manton KG, Corder LS, Stallard E. Chronic disability trends in elderly United States populations: 1982-1994. Proc Nat Acad Sci USA 94: 2593-2598, 1997.
- Evans DA, Funkenstein HH, Albert MS, et al. Prevalence of Alzheimer's disease in a community population of older persons; higher than previously reported. JAMA 262: 2551-2556, 1989.
- Federal Interagency Forum on Aging Related Statistics. Older Americans 2000: Key Indicators of Well-Being. 2000.