Scientists calculate maximum human lifespan

Scientists at the Albert Einstein College of Medicine have recently published evidence that suggests that the human lifespan may not be lengthened beyond the ages on record. The paper, titled “Evidence for a Limit to Human Lifespan,” was published in Nature and the researchers stated that the “upward arc for maximum lifespan has a ceiling — and we’ve already touched it.”

The average life expectancy has been on the rise since the early 19th century, especially in developed countries. Improvements in public health, medicine, diet and the environment have led the average life expectancy of Americans to rise from 47 in 1900 to 79 in 2016.

“Demographers as well as biologists have contended there is no reason to think that the ongoing increase in maximum lifespan will end soon,” Jan Vijg, senior author of the paper and professor of ophthalmology and visual sciences at Einstein, said in a press release. “But our data strongly suggest that it has already been attained and that this happened in the 1990s.”

Using data from the Human Mortality Database, the researchers found that the fraction of each birth cohort, or the people born in a particular year, who live longer than 70 years increased each year. The data included mortality and population information from more than 40 countries. However, when focusing on people who survived 100 years or more, the researchers found that there was no correlation with the year the people were born.

“This finding indicates diminishing gains in reducing late-life mortality and a possible limit to human lifespan,” Vijg said.

The researchers also utilized the International Database on Longevity to analyze the “maximum reported age of death” data. Looking specifically at people in the U.S., France, Japan and the U.K. who lived past the age of 110 between 1968 and 2006, they found that the age at death plateaued around 1995. There was an increase in age of death for this population between the early 1970s and early 1990s, however.

Using the analysis of the data, the researchers calculated that the average maximum human lifespan is 115 years. There are outliers, however. For example, in 1997, a French woman, Jeanne Calment, lived to 122 years old, the maximum documented lifespan in history.

The researchers further concluded that the odds that a person lives to 125 years old is less than 1 in 10,000. The co-lead authors of the paper include Einstein researchers Xiao Dong and Brandon Milholland. The research was funded by the National Institutes of Health (NIH).

“Further progress against infectious and chronic diseases may continue boosting average life expectancy, but not maximum lifespan,” Vijg said. “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.”