Curing Key Diseases Would Add Little to Life Spans, Study Finds

University of Chicago researchers have concluded in a new study that even curing leading killers such as cancer, heart disease and diabetes would add no more than a handful of years to the average American’s life.

The study takes direct aim at the promise that medical science can continue to significantly extend life expectancy and suggests that the United States should dramatically shift its priorities from prolonging life to improving the quality of life.

The upper limit of average life expectancy, according to the researchers, is about 85 years. In the United States, the average life expectancy now is 79 years for women and 74 for men.

Even if all cancers were cured tomorrow, the average American’s life span would increase by only three years, according to the new analysis of death rates, which appears in today’s issue of the journal Science.

“Once you go beyond the age of 85, people die from multiple-organ failure. They stop breathing. Basically, they die of old age. And there’s no cure for that,” said S. Jay Olshansky of the University of Chicago and Argonne National Laboratory, the study’s principal author. “Barring a reversal of human aging on a molecular level, the rapid increases in life expectancy are over.”

“We’ve accomplished the first step. We’re living longer. Now we should concentrate on diseases that give aging a bad name,” said Jacob Brody, dean of the School of Public Health at the University of Illinois in Chicago.

Olshansky and his colleagues, Christine Cassel of Chicago and Bruce A. Carnes of Argonne, warned that further gains in longevity would lead to a dramatic rise in the aged population. While Americans might live longer, the researchers questioned whether they would live better.

Frailty, and disabling but not life-threatening illnesses of old age, could condemn a growing population to aching joints, blindness, deafness, incontinence and dementia, they said.

But the limits on life span proposed by Olshansky and his colleagues were challenged Thursday by rival researchers who offered a rosier vision of the future.

By reducing major risk factors--such as reducing blood pressure, obesity and smoking, for example--some demographers said they believe the average life expectancy could reach 98 or 99 years.