|One way to summarize the astounding improvements in survival at older ages is to look at the numbers of centenarians and super-centenarianspeople who live to age 110 and beyond. How many centenarians will there be in the world on Jan. 1, 2000? James Vaupel asked at a seminar earlier this month. Many wont be celebrating vigorously, of course, but there will be about 100,000 of them, said Vaupel, whose work is at the intersection of the biological and social sciences.|
The talk by Vaupel, described as a true Renaissance person whose work is at the intersection of the biological and social sciences, was co-sponsored by the Population Studies Center, part of the Institute for Social Research, and the recently formed Geriatrics and Aging Research Consortium, an interdisciplinary group convened by Jeffrey Halter, director of the Geriatrics Center.
Before 1950, there was rapid progress in reducing mortality at younger ages, said Vaupel, who is executive director of the Max Planck Institute for Demographic Research in Berlin, and heads the Institutes Laboratory of Survival and Longevity. After 1950, there has been no progress in reducing mortality at younger ages and rapid progress at older ages.
One way to summarize the astounding improvements in survival at older ages is to look at the numbers of centenarians and super-centenarianspeople who live to age 110 and beyond. How many centenarians will there be in the world on Jan. 1, 2000? asked Vaupel. Many wont be celebrating vigorously, of course, but there will be about 100,000 of them. These are people who have lived for three centuries, having been born in the 19th, living in the 20th, and living to see the start of the 21st century.
On Jan. 1, 1990, there were about 50,000 centenarians in the world, and their numbers have been doubling every decade since 1950. So, we guess that on Jan. 1, 1900, there were about 1,000 centenarians celebrating, and on Jan. 1, 1700, there were only about 20 to 30.
Then there are the super-centenarians, Vaupel noted. So far as scientists know, there were none until 1930, when a Northern Ireland woman celebrated her 110th birthday. In the 1970s there were four, in the 80s, 10, and in the 90s, there have been 24.
Citing a series of studies of twins from Denmark and other countries, Vaupel said that about 25 percent of the variability in longevity is probably related to genetic factors, with another 25 percent of the variability due to fixed, non-genetic factors before birth and during the early years of life. Fully one-half of the variability is a result of changing environmental factors and behaviors after the first years of life, including nutrition, environmental exposure to toxins, exercise and lifestyle choices.
Vaupel also discussed the age trajectory of mortality, presenting data based on hundreds of millions of observations from societies around the world. Surprisingly, the graphs show that human mortality rates may reach a peak between the ages of 100 and 110, then fall. Maybe Madame Jean Calment, who died recently in France at the age of 122 1/2, single-handedly pulled the curve down, Vaupel quipped. But in any case, the data run counter to one of the basic predictions of the biological sciencesthat there is a black hole, or stone wall of very high mortality after the reproductive ages, where death rates should rise swiftly.
Vaupel and colleagues also looked at the age trajectory of mortality in other species, from Mediterranean fruit flies to nematode worms and yeasts. The final species we examined was automobiles, he said. Toyotas and Chevrolets. That was important because it addresses the issue of the extent to which the pattern is characteristic of biological systems or of complex systems in general. And in all cases, we found some leveling off, if not a decline, at the highest ages. Its a real puzzle.
Vaupel noted that there are many interesting and important approaches to research on aging and longevity, including geriatrics, gerontology and public policy, as well as genetics, statistics and demography. The demographic approach may provide insights and methods to illuminate such questions as why there was very little progress in reducing mortality at older ages before 1950, and why such progress is accelerating so rapidly today.
About the Consortium
The goal of the U-M Geriatrics and Aging Research Consortium is to bring together the leaders of major U-M centers, institutes, and programs from across the campus with a focus on aging and geriatrics issues, explains Jeffrey Halter, to strengthen research collaborations, with a particular emphasis on genetic and societal interactions in aging. Halter directs the Claude D. Pepper Older Americans Independence Center in addition to the Geriatrics Center.
Participants in the group include Sid Gilman, professor and chair, Department of Neurology, and director, U-M Alzheimers Disease Research Center; Norman Foster, professor of neurology and clinical director, Alzheimers Disease Research Center; Richard Miller, professor of pathology and associate director for research, Geriatrics Center;
John A. Faulkner, professor of physiology and director, Nathan Shock Center for the Biology of Aging, Institute of Gerontology; Ari Gafni, professor of biological chemistry and director, Institute of Gerontology; Mark Supiano, associate professor of internal medicine and director, Geriatrics Research Education and Clinical Center, Ann Arbor Veterans Administration Medical Center; and George Kaplan, professor and chair, Department of Epidemiology.
Participants from the Institute for Social Research (ISR) include David L. Featherman, professor of sociology and of psychology and ISR director; Albert I. Hermalin, profesor emeritus of sociology; Denise Park, professor of psychology and director, Center for Applied Cognitive Research on Aging; David Lam, professor of economics and director, Exploratory Center on the Demography of Aging; Robert J. Willis, professor of economics and director, Health and Retirement Study; Lee Lillard, professor of economics and director, Michigan Retirement Research Center; and James Jackson, professor of psychology and director, African-American Mental Health Research Center.