A study published online today in Nature by Albert Einstein College of Medicine scientists suggests that it may not be possible to extend the human life span beyond the ages already attained by the oldest people on record.
Since the 19th century, average life expectancy has risen almost continuously thanks to improvements in public health, diet, the environment and other areas. On average, for example, U.S. babies born today can expect to live nearly until age 79 compared with an average life expectancy of only 47 for Americans born in 1900. Since the 1970s, the maximum duration of life—the age to which the oldest people live—has also risen. But according to the Einstein researchers, this upward arc for maximal lifespan has a ceiling—and we’ve already touched it.
“Demographers as well as biologists have contended there is no reason to think that the ongoing increase in maximum lifespan will end soon,” said senior author Jan Vijg, Ph.D., professor and chair of genetics, the Lola and Saul Kramer Chair in Molecular Genetics, and professor of ophthalmology & visual sciences at Einstein. “But our data strongly suggest that it has already been attained and that this happened in the 1990s.”
Dr. Vijg and his colleagues analyzed data from the Human Mortality Database, which compiles mortality and population data from more than 40 countries. Since 1900, those countries generally show a decline in late-life mortality: The fraction of each birth cohort (i.e., people born in a particular year) who survive to old age (defined as 70 and up) increased with their calendar year of birth, pointing toward a continuing increase in average life expectancy.
But when the researchers looked at survival improvements since 1900 for people aged 100 and above, they found that gains in survival peaked at around 100 and then declined rapidly, regardless of the year people were born. “This finding indicates diminishing gains in reducing late-life mortality and a possible limit to human lifespan,” said Dr. Vijg.
He and his colleagues then looked at “maximum reported age at death” data from the International Database on Longevity. They focused on people verified as living to age 110 or older between 1968 and 2006 in the four countries (the U.S., France, Japan and the U.K.) with the largest number of long-lived individuals. Age at death for these supercentenarians increased rapidly between the 1970s and early 1990s but reached a plateau around 1995—further evidence for a lifespan limit. This plateau, the researchers note, occurred close to 1997—the year of death of 122-year-old French woman Jeanne Calment, who achieved the maximum documented lifespan of any person in history.
Using maximum-reported-age-at-death data, the Einstein researchers put the average maximum human life span at 115 years—a calculation allowing for record-oldest individuals occasionally living longer or shorter than 115 years. (Jeanne Calment, they concluded, was a statistical outlier.) Finally, the researchers calculated that the probability in a given year of seeing one person live to 125 anywhere in the world is less than 1 in 10,000.
“Further progress against infectious and chronic diseases may continue boosting average life expectancy, but not maximum lifespan,” said Dr. Vijg. “While it’s conceivable that therapeutic breakthroughs might extend human longevity beyond the limits we’ve calculated, such advances would need to overwhelm the many genetic variants that appear to collectively determine the human lifespan. Perhaps resources now being spent to increase lifespan should instead go to lengthening healthspan—the duration of old age spent in good health.”
The Nature paper is titled “Evidence for a Limit to Human Lifespan.” The co-lead authors of the paper are Xiao Dong, Ph.D., and Brandon Milholland, Ph.D., both at Einstein. The study was supported by National Institutes of Health grants AG017242 and AG047200, the Albert Einstein College of Medicine Institute for Aging Research/Nathan Shock Center and the Paul F. Glenn Center for the Biology of Human Aging at Albert Einstein College of Medicine.
Non-natural humans, like Kurtzweil, may live longer. Tech Hybrid stuff.
This article is not really worth reading, baliwick aside….lol…
(Aging is my bailiwick, and I blog regularly for this web site.)
It’s silly to speculate that something is impossible based on theory in the biosciences. Theory never works very well in the biosciences, and our technology is changing rapidly, in directions we never would have suspected even a decade ago.
Even worse, the theory on which this article is based has made many predictions in the past that have turned out to be wrong. By reasonable scientific standards, this theory has been falsified long ago.
The whole idea that there is such a thing as a “maximum lifespan” for a species is a problematic theoretical construct. And, while it’s fair enough to say that we have no documented proof of anyone living past the age of 122, it is specious to say that this is equivalent to having proof that no one indeed has lived past 122. There are many, many such claims, and we should not be surprised if some of them turn out to be true.
“When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.” — Arthur C. Clarke