By S. Jay Olshansky
In 2006, my colleagues and I coined the phrase “the Longevity Dividend” to describe the economic and health benefits that would accrue to individuals and societies if we extend healthy life by slowing the biological processes of aging. This idea was distinctive because we would extend healthy life by shifting our emphasis from disease management to delayed aging. We were not the first to suggest this.
Implications of Extended Life
Clive McKay and colleagues first raised the issue in the mid-50s in the Bulletin of the New York Academy of Medicine (32:2, 1956), and Bernie Strehler coined the term “gerontogeny” in 1975 in “Implications of Aging Research for Society” (from the Proceedings of the 58th Annual Meeting of the Federation of American Societies for Experimental Biology) to describe the development of interventions to extend healthy life. The first formal discussion of delayed aging among scientists appeared in Extending the Human Life Span: Social Policy and Social Ethics, published by Dr. Bernice Neugarten and colleagues in 1977 (Arlington, VA: National Science Foundation). That book was a product of a three-year project on the future of aging funded by the National Science Foundation, culminating in a conference in 1976.
Conference participants were asked to discuss these questions: should the science of biogerontology be devoted to improving older people’s quality of life? Or should it extend the lifespan of the human species? If lifespan is extended, what would be its deleterious and beneficial effects on society? How much money should be allocated to research addressed directly to extending the human lifespan? What social and ethical implications would follow from a “magic elixir” that would extend active life expectancy by 15 to 20 years?
At the conference it was noted that the longevity revolution in the 20th century brought decades of healthy life, and contributed substantially to our nation’s economic growth. But all was not rosy. Conference participants were acutely aware that extended lives came at a price—rapid increases in chronic fatal and disabling diseases. Some scientists there argued we should not pursue life extension as a national goal because the result would be an increase in the number and proportion of people requiring acute nursing care.
Gerontological Society president George Sacher expressed concern that extending life without extending health would result in a disproportionate number of years of disease and disability for the 10 percent of the population living the longest. But most conference participants agreed with James Goddard (former Commissioner of the U.S. Food and Drug Administration), who argued that healthy life extension should be a national goal requiring political support and strong vested interests.
Although the National Institute on Aging (NIA) was formed just before the Neugarten conference, the focus of modern medicine (and the majority of the NIA budgets since its beginning) has been centered on the disease model rather than the delayed-aging model. Advice from Neugarten conference participants to escalate the attack on aging, as well as to battle against major diseases, was not followed.
Re-Inventing the Argument
Four factors led my colleagues and I, in 2006, to reformulate the idea of targeting delayed aging: rapid increases in life expectancy since the late 70s; accelerated population aging; and rapid increases in chronic fatal and disabling diseases. These three occurred rapidly in developed nations, and developing nations are catching up. The fourth factor was the most important—recent advances in biogerontology suggested that it is plausible to delay aging. (For a summary of this line of reasoning, click here.)
The Neugarten conference participants had predicted the dramatic increases of chronic fatal and disabling diseases that accompanied our longer lives. Cancer, heart disease, stroke, Alzheimer’s disease, arthritis, sensory impairments and many other familiar maladies now common among older people are, in large measure, a product of the privilege of living long enough to experience them.
The question for us now is what’s next? While people are living extended lives, it is uncertain how much longer this trend can continue. As reported in a 2013 article in JAMA Internal Medicine, evidence has emerged that those now approaching retirement age are in worse health than their predecessors (doi:10.1001/jamainternmed.2013.2006) and even younger generations appear to be facing major health challenges because of the rise of obesity and other harmful lifestyles. There also is mounting evidence, reported in a 2005 article in the New England Journal of Medicine, that some populations or population subgroups are on the verge of a decline in life expectancy from the expected latent effect of the dramatic rise in childhood obesity (doi: 10.1056/NEJMsr043743), while for others (e.g., less educated white men and women in the United States) the decline in life expectancy has already begun, as noted in Health Affairs in 2013 (doi: 10.1377hlthaff.2011.0746).
Other subgroups could experience life-expectancy increases that extend beyond current official government forecasts, according to a 2009 Milbank Quarterly article (doi:10.1111/j.1468-0009.2009.00581.x). More importantly, it is uncertain whether these added years of life are going to be healthy or unhealthy, as noted in a 2013 Journals of Gerontology piece (doi: 10.1093/geronb/gbq088).
Changing the Medical Model
Complicating the portrait of health and longevity today is the current medical model that approaches chronic degenerative diseases in much the same way communicable diseases were addressed more than a century ago—one at a time, as they arise. The underlying premise is that all diseases are treated as if they are independent of each other—with their own origin and etiology, according to a 2008 BMJ article (doi: http://dx.doi.org/10.1136/bmj.a399). Scientists know this is not true. Many chronic disease behavioral risk factors relate to more than one condition, and even the physiologic mechanisms are related. Older people, in particular, often suffer from more than one condition at a time.
Underlying most of what goes wrong with our bodies as we grow older are basic biological processes of aging that advance regardless of the diseases commonly expressed throughout life. Even if deaths from most major killers today are reduced dramatically, the biological processes of aging march on, unaltered by any progress we make against specific diseases.
The Longevity Dividend is an approach to public health based on a broader strategy of fostering health for all generations by developing a new horizontal model to health promotion and disease prevention. Unlike the current vertical approach to disease that targets individual disorders as they arise, the Longevity Dividend model seeks to prevent or delay the root causes of disease and disability by attacking the one main risk factor for them all—biological aging.
Evidence in models ranging from invertebrates to mammals suggests that all living things have biochemical mechanisms influencing how quickly they age, and these mechanisms are adjustable. It is possible—by dietary intervention or genetic alteration—to extend life span and postpone aging-related diseases such as cancer, cataracts, cognitive decline and autoimmune diseases (for further reading on adjusting biochemical mechanisms, click here). Precisely which of these models will eventually be deployed as a delayed-aging intervention in humans has yet to be established, but at least delayed aging has been demonstrated as a plausible method of improving public health.
Slowing down the processes of aging—even by a moderate amount—will yield dramatic improvements in health for current and future generations. Advances in the scientific knowledge of aging may thus create new opportunities that allow us, and generations to follow, to live healthier and longer lives than our predecessors.
Bernice Neugarten and her colleagues had their finger on the right pulse decades ago—it just took 35 years for the scientific study of aging to catch up. By embracing a new model for health promotion and disease prevention in the 21st century, we have the opportunity to give the gift of extended health and economic wellbeing to current and all future generations.
S. Jay Olshansky, Ph.D., is a professor in the School of Public Health, Division of Epidemiology and Biostatistics at the University of Illinois, Chicago.
Editor’s Note: This article appears in the March/April 2013 issue of Aging Today, ASA’s bi-monthly newspaper covering issues in aging research, practice and policy nationwide. ASA members receive Aging Today as a member benefit; non-members may purchase subscriptions at our online store.
Author’s Note and Further Reading
Parts of this essay were borrowed from previous publications on this topic (doi: http://dx.doi.org/10.1136/bmj.a399; Global Population Ageing: Peril or Promise, World Economic Forum (PDF); Public Policies Intended to Influence Adult Mortality). The following co-authors on these papers deserve recognition: Dr. John Beard, Dr. Axel Börsch-Supan, Dr. Robert Butler, Dr. Leonard Hayflick, Dr. Richard Miller and Dan Perry. This essay is dedicated to the memory of Dr. Bernice Neugarten (a member of my dissertation committee) who roped me into this field to begin with, and Dr. Robert Butler—a close friend and one of the strongest proponents of the Longevity Dividend.
—S. Jay Olshansky