Berkeley - The oldest age at death for humans has been rising for more than a century and shows no signs of leveling off, according to a demographer at the University of California, Berkeley.
This new finding, based on Swedish national death records for each year since 1861, calls into question the belief by many scientists that the human life span has a set end-point of 120 years.
In research published today in Science, the nation's premier science journal, UC Berkeley associate professor of demography John Wilmoth and his colleagues in Sweden and the United States show that, in the1860s in Sweden, the oldest ages at death for men and women centered around 101. That average maximum age moved up slowly throughout the century to about 105 in the 1960s and then accelerated to 108 in the 1990s.
"We have shown that the maximum life span is changing. It is not a biological constant. Whether or not this can go on indefinitely is difficult to say. There is no hint yet that the upward trend is slowing down," said Wilmoth.
Wilmoth said that Swedish demographic statistics - considered the world's best records on birth and death - are a good indication of patterns in other industrialized nations, where it has become commonplace to survive to a very old age.
But until now, there has been no evidence that the maximum age at death was being pushed back, leading to a lengthening of the human life span, said Wilmoth.
"Human progress is real, somehow," he said. "We are changing the limits of the human life span over time."
For individuals alive now, the current life span makes it rare to live past 110 years, said Wilmoth. "But future generations could have a higher range."
Such statements run counter to recent predictions by other experts in the field who theorize that the human life span is biologically limited to 115 or 120 years.
"Those numbers are out of thin air," said Wilmoth. "There is no scientific basis on which to estimate a
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Contact: Patricia McBroom
pmb@pa.urel.berkeley.edu
510-643-7944
University of California - Berkeley
27-Sep-2000