Human Life Expectancy May Be Limited to Age 85, Researchers SayPAUL RECER , Associated Press
Nov. 2, 1990 12:30 AM ET
WASHINGTON (AP) _ An average life span of 85 years is the best that humans can hope for, even if medical science defeats all of the major killer diseases, researchers say in a study published today.
University of Chicago researcher S. Jay Olshansky said the upper limit of human life expectancy is set because uncontrollable effects of aging set in, causing a slow decline that slides irreversibly into death.
Medicine now stands helpless before this apparent design of nature, he said.
In a study published today in the journal Science, Olshansky and two co- authors wrote that even if cures were found for most of the fatal diseases, ''the natural degeneration of the body puts a cap of about 85 years on the average age of death.''
The conclusion differs from many other studies and some experts on human aging disagree strongly.
''If we keep making progress as we have made in the past, then a baby born today can expect to live 100 years,'' said James Vaupel of the University of Minnesota. ''There may well be some biological barriers, but we are spending a lot of money on biomedical research and the sciences are poised to make some really significant breakthroughs.''
Olshansky said most of the major advances in life expectancy have already been achieved through improvements in public health, nutrition, immunization and advanced medical care. The average life span in the United States went from 47 years in 1900 to 75 years today.
''This trend is not likely to continue,'' Olshansky said. ''The easy advances have already been made.''
Death rates for the young and those under age 50 are now so low that even if all dying in that age group were eliminated, the life expectancy at birth would increase by only 3.5 years, said Olshansky. The major killers - heart disease, cancer, stroke and diabetes - usually strike after the age of 50.
''In order to increase the average life expectancy of the population to just 85 years, we would have to achieve the equivalent of the elimination of all deaths from heart disease and cancer,'' Olshansky said. ''There are very few people around who argue that is realistically possible.''
But even controlling the major killer diseases would have little statistical effect on the average life span, he said.
''Just because we eliminate major fatal disease does not mean that we will not grow older and die. It just means that we will grow older and die of other diseases,'' he said.
''Once you go beyond the age of 85, people die from multiple organ failure. Old age, basically. And there is no cure for that,'' Olshansky said. ''We don't know why we age. But it happens. It affects everyone. No matter what you do in terms of eliminating these diseases it's still going to happen.''
Vaupel said he believes the Olshansky study is too pessimistic.
''We are beginning to gain a fundamental understanding of aging and we eventually may be able to slow down that process,'' he said in a telephone interview. ''I don't see any evidence at all that there is a cap at 85.''
Vaupel said women in some populations already are approaching life expectancies of 85. In Okinawa, the average life span of women now is 83, and the life expectancy of women in some Mormon groups is almost 85 now, he said. This was accomplished without major medical intervention, he said.
Another researcher, Ken Manton of Duke University, said the Olshansky study is ''seriously flawed'' because it fails to take into account recent research that could push life expectancy rates upward.
Manton said, for example, that medicine is now identifying specific disorders of aging, such as Alzheimer's disease, and is beginning to search for cures. Such work is almost certain to enable people to live longer, he said.
Most experts agree that research should emphasize not just extending life, but how to make later years more free of disease.
''The prospect now is that those added years will be crippling years,'' Olshansky said. ''It is possible to alter that course of life by going after those crippling diseases. That's what we should be doing.''
Olshansky said about 2 million Americans are over age 85, most of whom require close attendance and care. If U.S. life expectancy rises to an average of 85, he said, then there will be about 16 million people over that age.
Olshansky's co-authors were Bruce A. Carnes of the Argonne National Laboratory in Illinois and Christine Cassel of the University of Chicago.