Inconvenient Truths About Human Longevity.

The rise in human longevity is one of humanity's crowning achievements. Although advances in public health beginning in the 19th century initiated the rise in life expectancy, recent gains have been achieved by reducing death rates at middle and older ages. A debate about the future course of life expectancy has been ongoing for the last quarter century.

Cardiovascular effects of fission neutron or Co γ exposure in the B6CF mouse.

In this study, the B6CF mice from the JANUS program at the Argonne National Laboratory were analyzed for increased cardiovascular disease (CVD) mortality from Co γ ray or fission neutron exposures administered in either a single dose or protracted weekly doses. The data used for this study represent the last studies conducted at Argonne and have been archived for at least 15 years. CVD mortality increased in a dose-dependent manner from γ rays as well as from neutron exposures.

Primary Prevention with a Capital .

The survival of large segments of human populations to advanced ages is a crowning achievement of improvements in public health and medicine, but in the 21st century, our continued desire to extend life brings forth a unique dilemma. The risk of death from chronic fatal diseases has declined, but even if it continues to do so in the future, the resulting longevity benefits are likely to diminish. It is even possible that unhealthy life expectancy could rise in the future as major fatal diseases wane.

Can Any Biomarker Predict the Temporal Behavior of Aging?

Journals are filled with articles describing the creation of physiological biomarkers whose temporal behavior is attributed to aging. This paper explores whether it is even possible to create a biomarker capable of describing the temporal mortality dynamics of aging. Just as Medawar referred to aging as an unsolved problem in biology in his classic 1951 lecture, this article suggests that aging remains an unresolved problem in gerontology.

Genetic variation in the raptor gene is associated with overweight but not hypertension in American men of Japanese ancestry.

Background: The mechanistic target of rapamycin (mTOR) pathway is pivotal for cell growth. Regulatory associated protein of mTOR complex I (Raptor) is a unique component of this pro-growth complex. The present study tested whether variation across the raptor gene (RPTOR) is associated with overweight and hypertension.

Impact of climate change on elder health.

Demographers predict human life expectancy will continue to increase over the coming century. These forecasts are based on two critical assumptions: advances in medical technology will continue apace and the environment that sustains us will remain unchanged. The consensus of the scientific community is that human activity contributes to global climate change.

How long must humans live?

Species are defined by biological criteria. This characterization, however, misses the most unique aspect of our species; namely, an ability to invent technologies that reduce mortality risks. Old animals are rare in nature, but survival to old age has become commonplace in humans.

Science fact versus SENS foreseeable.

Scientists in the various fields of aging share a common goal--the extension of healthy life. However, claiming that the only way to accomplish this is to treat the complications of aging rather than its causes requires more than declarations made by proponents of SENS--it requires empirical research based on the scientific method. As this paper illustrates, it will be difficult to prove that SENS interventions work because the primary result of interest, negligible senescence, is not an outcome variable in empirical tests of SENS.

Zeno's Paradox of Immortality.

Scientists who speculate on the future of human longevity have a broad range of views ranging from the promise of immortality, to radical life extension, to declines in life expectancy. Among those who contend that radical life extension is already here, or on the horizon, or immortality is forthcoming, elements of their reasoning appear surprisingly close, if not identical, to a famous mathematical paradox posed by the ancient Greek mathematician known as Zeno. Here we examine the underlying assumptions behind the views that much longer life expectancies are forthcoming or have already arrived, and place their line of reasoning within the context of a new Zeno paradox described here as The Paradox of Immortality.

Differences in life expectancy due to race and educational differences are widening, and many may not catch up.

It has long been known that despite well-documented improvements in longevity for most Americans, alarming disparities persist among racial groups and between the well-educated and those with less education. In this article we update estimates of the impact of race and education on past and present life expectancy, examine trends in disparities from 1990 through 2008, and place observed disparities in the context of a rapidly aging society that is emerging at a time of optimism about the next revolution in longevity. We found that in 2008 US adult men and women with fewer than twelve years of education had life expectancies not much better than those of all adults in the 1950s and 1960s.

The delayed impact of parental age on offspring mortality in mice.

The certitude of death makes reproduction the foundation upon which all life-history strategies are based. Plasticity in the reproductive biology of organisms is an essential adaptive response to the capricious and hazardous environments of earth. In this article, we use data from a breeding colony for laboratory mice to examine the mortality risks of offspring born at the outer boundaries of their Dam's reproductive plasticity.

What is lifespan regulation and why does it exist?

The development of a unified conceptual framework for the field of biogerontology has been impeded by confusing and misleading terminology. Thus, distinctions and definitions are provided for key terms (and their concepts) used in the paper: senescence, lifespan, potential lifespan, essential lifespan, and lifespan regulation. An organismal perspective is then used to examine the relationships between reproduction, lifespan regulation and senescence.

Does senescence give rise to disease?

The distinctions between senescence and disease are blurred in the literature of evolutionary biology, biodemography, biogerontology and medicine. Theories of senescence that have emerged over the past several decades are based on the concepts that organisms are a byproduct of imperfect structural designs built with imperfect materials and maintained by imperfect processes. Senescence is a complex mixture of processes rather than a monolithic process.

New model of health promotion and disease prevention for the 21st century.

Our susceptibility to disease increases as we grow older. argue that interventions to slow down ageing could therefore have much greater benefit than those targeted at individual disease

Senescence viewed through the lens of comparative biology.

Although mortality and longevity are inherently biological phenomena, their study has historically been the purview of demography and the actuarial sciences. An infusion of biological thinking into these disciplines transforms demography into biodemography and provides expectations and coherency to observations on age-determined mortality that would not be explainable otherwise. Comparative biology teaches us that reproduction is life's solution to the inevitability of death in the hostile environments of Earth.

Mortality partitions and their relevance to research on senescence.

The reasons for classifying causes of death into aggregate groups are discussed and the impact of mortality partitions on analyses of mortality is described. Special emphasis is given to a mortality partition that distinguishes between intrinsic causes of death that arise primarily from the failure of biological processes that originate within an organism, and extrinsic causes of death that are primarily imposed on the organism by outside forces. Examples involving mortality data for mice, dogs, and humans are used to illustrate how this mortality partition infuses biological reasoning into mathematical models used to analyze and predict senescent-determined mortality, enhances the information content of the mortality schedules generated from these models, improves mortality comparisons between populations within species separated by time or geographic location, and provides a logical pathology endpoint for making interspecies comparisons of mortality.

Health promotion in older adults. Promoting successful aging in primary care settings.

The ultimate objective of the successful aging paradigm is to improve the quality of life among the elderly. Although the aging process is currently immutable, primary care providers can modify the pathology and mitigate the expression of disease through prevention and treatment. Avoiding disease and disability, maintaining mental function and maintaining physical function are cornerstones of this approach.

Science fact and the SENS agenda. What can we reasonably expect from ageing research?

What can we reasonably expect from ageing research?

Biodemographic perspectives for epidemiologists.

A new scientific discipline arose in the late 20th century known as biodemography. When applied to aging, biodemography is the scientific study of common age patterns and causes of death observed among humans and other sexually reproducing species and the biological forces that contribute to them. Biodemography is interdisciplinary, involving a combination of the population sciences and such fields as molecular and evolutionary biology.

Misdirection on the road to Shangri-La.

Will life expectancy in the United States rise or fall in this century? The implications of either scenario are far reaching. We contend that the rise of childhood obesity in the United States in the past three decades has been so dramatic that it will soon lead to higher than expected death rates at middle ages and a possible decline in life expectancy by midcentury. The most detrimental health and longevity effects will not be seen for decades--a phenomenon that cannot be detected by current methods used to forecast life expectancy or estimate the number of deaths currently attributable to obesity.

Misdirection on the road to Shangri-La.

Will life expectancy in the United States rise or fall in this century? The implications of either scenario are far reaching. We contend that the rise of childhood obesity in the United States in the past three decades has been so dramatic that it will soon lead to higher than expected death rates at middle ages and a possible decline in life expectancy by midcentury. The most detrimental health and longevity effects will not be seen for decades--a phenomenon that cannot be detected by current methods used to forecast life expectancy or estimate the number of deaths currently attributable to obesity.

Peering into the future of American longevity.

Extract: The trend in the life expectancy of humans during the past thousand years has been generally characterized by a slow, steady increase -- though this pattern is frequently punctuated by volatility in death rates caused by epidemic and pandemic infectious diseases, famines, and war. This volatility was dramatically curtailed in the mid-19th century as infectious agents swiftly succumbed to improved living conditions, advances in public health, and medical interventions. During the past 30 years in the United States, the rise in life expectancy at birth has decelerated relative to this historic pattern, and gains in life expectancy at older ages are now much smaller than they were in previous decades.

A potential decline in life expectancy in the United States in the 21st century.

Forecasts of life expectancy are an important component of public policy that influence age-based entitlement programs such as Social Security and Medicare. Although the Social Security Administration recently raised its estimates of how long Americans are going to live in the 21st century, current trends in obesity in the United States suggest that these estimates may not be accurate. From our analysis of the effect of obesity on longevity, we conclude that the steady rise in life expectancy during the past two centuries may soon come to an end.