Increases in life expectancy likely to be smaller in futureBMJ 2001; 322 doi: https://doi.org/10.1136/bmj.322.7285.512 (Published 03 March 2001) Cite this as: BMJ 2001;322:512
Though life expectancy rose dramatically during the 20th century—rising by 30 years—additional increases are likely to be smaller, according to a new study.
If current trends in death rates continue, the average life expectancy will reach 85 years in 2033 in France, 2035 in Japan, and 2182 in the United States.
The life expectancy at birth for females in the United States was 79 years in 1995, the most recent data available, and the life expectancy for males was two years lower (Science 2001;291: 1491-2.)
According to S Jay Olshansky and colleagues, life expectancy in the United States will not reach 100 years until the 26th century. Their estimate assumes that age and sex specific trends in death rates observed from 1985 to 1995 will continue.
Ten years ago Dr Olshansky and his colleagues published a paper in Science in which they said that it was unlikely that life expectancy for males and females was going to exceed 85 years unless new research came up with some widely available, age-extending process.
Some people said that progress in biomedical science would permit us to achieve much more rapid increases in life expectancy than we anticipated, Dr Olshansky said.
He and his coworkers saw that as a testable hypothesis, so they waited. After 10 years, they found that although death rates were declining in Japan, France, and the United States, the decline was not enough to raise life expectancy at birth to the higher levels suggested by some other researchers.
Dr Olshansky and colleagues argue that earlier gains were based largely on saving the lives of young people by reducing infant mortality and death from infectious diseases, such as tuberculosis.
But the success of those efforts was so great that even eliminating infant mortality would not increase the average life span by much. “We have exhausted that as a source of longevity,” Dr Olshansky said.
“You can't save the young twice. If nobody ever died again before their 51st birthday, you would still add only about 3.5 years to the average life expectancy.”