April 21st, 2002

bswing

In search of Methuselah: estimating the upper limits to human

Olshansky SJ ; Carnes BA ; Cassel C

In search of Methuselah: estimating the upper limits to human
longevity.

Abstract: Estimates of the upper limits to human longevity have
important policy implications that directly affect forecasts of
life expectancy, active life expectancy, population aging, and
social and medical programs tied to the size and health status of
the elderly population. In the past, investigators have based
speculations about the upper limits of human longevity on
observations of past trends in mortality. Here the estimate of
the upper bound is based on hypothesized reductions in current
mortality rates necessary to achieve a life expectancy at birth
from 80 to 120 years and an expectation of life at age 50 from 30
to 70 years. With the use of conditional probabilities of death
from complete life tables for the United States, reductions in
mortality required to achieve extreme longevity (that is, 80 to
120 years) were compared with those resulting from hypothetical
cures for all cardiovascular diseases, ischemic heart disease,
diabetes, and cancer. Results indicate that in order for life
expectancy at birth to increase from present levels to what has
been referred to as the average biological limit to life (age
85), mortality rates from all causes of death would need to
decline at all ages by 55%, and at ages 50 and over by 60%. Given
that hypothetical cures for major degenerative diseases would
reduce overall mortality by 75%, it seems highly unlikely that
life expectancy at birth will exceed the age of 85.
Science 1990 Nov 2;250(4981):634-40