There are currently 35 million Americans over the age of 65. Of these, more than four million are over 85, and some 65,000 have attained their hundredth birthday. By 2030, the number of individuals age 65 and older will likely double, reaching 70.3 million and comprising a larger proportion of the entire population, rising from 13 percent today to 20 percent in 2030, and the number of the "oldest old" -- people age 85 and older -- is expected to grow from 4.3 million in 2000 to at least 19.4 million by 2050. (1)
As life expectancy increases, we are challenged to find ways to keep the additional years of life free of disease and disability. Today, more than half of all Americans over age 65 show evidence of osteoarthritis in at least one joint. (2) Over half of Americans older than 50 have osteoporosis or low bone mass. (3) Cardiovascular disease, cancer, and diabetes remain common among older Americans, and as many as 4.5 million Americans suffer from Alzheimer's disease (AD). (4) For many, modern medicine and new insights into lifestyle and other environmental influences are allowing people to remain healthy and socially and emotionally vital into very advanced ages; however, NIA supported research continues to address the needs of the growing number of people who will live longer.
The National Institute on Aging (NIA) leads a national scientific effort to understand the nature of aging and to extend the healthy, active years of life for all Americans. NIA achieves its mission through a robust extramural research program composed of the four research areas as described in the Budget Justification section plus a vibrant intramural research program.
NIA's research programs cover a wide range of topics critical to understanding aging and its interaction with the initiation and progression of disease and disability. For example, NIA research has identified lifestyle factors and health behaviors that directly influence physical and mental fitness and risk of disease in aging populations. NIA-supported scientists develop and refine recommendations for people of all ages regarding optimal diet, dietary supplement use, exercise, and safety to increase their likelihood of enjoying a physically and mentally healthy old age. Other researchers work to find better ways to enhance the physical, mental, and interpersonal capabilities of older people and to expand opportunities for them to achieve personal goals and contribute to society in meaningful ways. Still others explore the molecular, cellular, and genetic changes that take place in the body as we age, with the ultimate goal of developing new prevention strategies and novel therapeutic approaches to eliminate or delay the debilitating physical, cognitive, and psychological changes that can occur.
As the research on aging advances, NIA will focus more effort on the translation of basic research findings into clinical studies and trials. The institute supports large multidisciplinary programs in translational research, including:
- Edward R. Roybal Centers for Research on Applied Gerontology, designed to advance promising social and behavioral basic research findings from the laboratory and into programs, practices, and policies to improve the lives of older people and enhance the capacity of the nation to adapt to the societal shifts that come with an aging population.
- Claude D. Pepper Older American Independence Centers (OAIC), established to increase scientific knowledge for the development of innovative and cost-effective ways to maintain and restore independence.
- The Alzheimer's Disease Translational Initiative, a major effort to encourage more researchers to move from basic research on Alzheimer's disease and associated disorders into translational research and drug testing in clinical trials. Components of this initiative include program announcements on drug discovery and preclinical development and a program of toxicology services for academic and small business investigators who believe they have promising compounds for the treatment or prevention of Alzheimer's disease but lack the resources to perform the required toxicology studies.
Additional translational research efforts include:
- Recent findings which have shown that overweight, aged male mice whose high-calorie diet was supplemented with the natural compound resveratrol had better health and longer survival than their counterparts who did not receive it. NIA plans to test the effects of dietary supplementation with resveratrol in non-human primates, an important step to inform the consideration of human clinical trials.
- Several studies which suggest that physical exercise may prevent physical disability, including impaired mobility, in healthy and frail older adults. To develop definitive evidence, NIA and grantee researchers have developed the LIFE (Lifestyle Interventions and Independence in Elders) study, a clinical trial testing the effects of a physical activity program vs. a health education program among older Americans. A successful pilot study (LIFE-P) completed in 2005 showed both feasibility and positive preliminary data, permitting design and consideration of this large-scale clinical trial.
- A large body of research in animal models which indicates that substantially reducing caloric intake while maintaining optimal nutrition results in significant increase in life span. NIA-supported Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy (CALERIE) will help to determine if these beneficial effects extend to humans. Results from pilot studies demonstrated that overweight people who cut their calories by 25 percent for six months have reduced fasting insulin levels and core body temperature, two markers that may be associated with increased longevity in humans. A longer-term study will begin in January 2007.
NIA's Intramural Research Program is very active in the translation of basic research findings to clinical studies. One of its primary resources, the Advanced Studies in Translational Research on Aging (ASTRA) unit, is a state-of-the-art facility located at Baltimore's Harbor Hospital. ASTRA, opened in January 2003, is equipped with a fully functional 10-bed acute care inpatient unit, an outpatient examination and treatment unit, and other resources vital to the conduct of translational research. Recently, the Baltimore Longitudinal Study of Aging, which has been the gold-standard reference for all epidemiological studies on aging, was moved to the ASTRA unit where NIA plans to launch a number of ancillary studies that are more likely to provide information that can be directly applied to clinical medicine.
(2) See "Handout on Health: Osteoarthritis," National Institute of Arthritis and Musculoskeletal and Skin Diseases, July 2002.
(3) See America's Bone Health: The State of Osteoporosis and Low Bone Mass in Our Nation. National Osteoporosis Foundation, February 2002.
(4) Hebert LE et al.: Alzheimer disease in the U.S. population: Prevalence estimates using the 2000 Census. Arch. Neurol. 60: 1119-22, 2003.