CHICAGO -- If medicine could miraculously wipe out cancer, heart disease, stroke and other major killers, the average American still wouldn't live much beyond the age of 85, a team of researchers from the University of Chicago and Argonne National Laboratory reported yesterday.
Americans already are approaching their maximum life expectancy, bringing to an end the spectacular extension of the human life span that increased from 47 years in 1900 to 75 years in 1988, the research team reported in the journal Science.
"Barring major advances in the development and use of life-extending technologies or the alteration of human aging at the molecular level, the period of rapid increases in life expectancy in developed nations has come to an end," said Dr. S. Jay Olshansky, assistant professor of medicine at the University of Chicago and an Argonne demographer.
The findings, which are based on U.S. life tables, refute the generally held belief that the average life span would continue to increase to about 100 years or more, he said.
"Even if we found a cure for most fatal diseases, such as heart disease and cancer, the natural degeneration of the body puts a cap of about 85 years on the average age of death," Dr. Olshansky said.
Major killer diseases occur later in life, and curing them would not add many years to the average life span, he said.
Eliminating all forms of cancer, for instance, would increase life expectancy at birth by only three years, Dr. Olshansky said.
The findings underscore two growing problems that the federal government and health planners have so far neglected, he said.
The first is that, as more people approach the age of 85, the size of the elderly population will dramatically increase, Dr. Olshansky said. Currently more than 3 million Americans are 85 or older, and they make up 1 percent of the population. But this group is expected to increase to 16 million by 2050, constituting 5 percent of the country's population.
The second problem is that as the elderly population increases, more people probably will suffer from such long-term degenerative diseases as blindness, arthritis, Alzheimer's disease, sensory impairment, osteoporosis and other disorders, Dr. Olshansky said.
The time has come for a major shift in medical research to look for treatments and cures for these degenerative disorders that now threaten to make a person's later years ones of frailty and dependence, said Dr. Cristine Cassel, a team member and University of Chicago professor.