New study says that it may be impossible for the human life span to extend beyond to what was already reached by the oldest person on record.
The average life expectancy has risen since the 19th
century, thanks to innovations in diet, environment, public health, medicine, and more. On average, babies in the U.S. can expect to live until age 79 compared to the previous life expectancy of 47 for Americans who were born in 1900. The maximum life duration has also risen since the 1970s. According to a study published in Nature
by scientists from Albert Einstein College of Medicine, we have already reached the “upward arc” for maximum lifespan.
Jan Vijg, Ph.D., senior author, professor and chair of genetics at the Lola and Saul Kramer Chair in Molecular Genetics and professor of ophthalmology and visual sciences at Einstein, said, "Demographers as well as biologists have contended there is no reason to think that the ongoing increase in maximum lifespan will end soon. But our data strongly suggest that it has already been attained and that this happened in the 1990s.”
Dr. Vijg and his team
analyzed the data from Human Mortality Database which has mortality and population data from more than 40 countries. Since the 1900s, these countries show a late life mortality decline where “the fraction of each birth cohort who survive to old age increased with their calendar year of birth” thus pointing to a continuing increase in human average life expectancy.
However, when the scientists looked at the survival improvements since 1900 for people ages 100 and above, they found that survival gains peaked at around 100 and then rapidly declined no matter what year people were born. Dr. Vijg said, "This finding indicates diminishing gains in reducing late-life mortality and a possible limit to human lifespan.”
Dr. Vijg and his team then looked for the maximum reported age at death data where they focused on people living to 110 or older between 1968 and 2006. They found that the age of death for these people increased rapidly during the 1970s and early 1990s but then reached a plateau in 1995. The researchers noted that this plateau happened to 1997 when French Jeanne Calment died at the age of 122. Calment reached the maximum lifespan of any person in history.
The researchers then place the average maximum life span at 115. They then calculated that 125 years as the “absolute limit of human lifespan”. This would mean that seeing one person to live up to 125 would be 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."