A caustic debate over whether there’s a limit to how long people can live erupted again this week, with scientists writing in Nature that we’re close to hitting a wall. It has been almost 20 years since the death of the world’s oldest person, 122-year-old French woman Jeanne Calment (above). The new study adds fuel to the fire: Jan Vijg, the senior author and chair of the genetics department at Albert Einstein College of Medicine in New York City, and his colleagues used a large database to argue that historic gains in human longevity are slowing to a crawl, perhaps because of inherent life span limits buried in our genome.
Vijg and his colleagues dove into the Human Mortality Database to examine whether the oldest of the old from four countries—France, Japan, the United Kingdom, and the United States—were getting even more ancient with each passing year; they later broadened their analysis to an additional three dozen countries. Around 1980, they concluded, that maximum age seemed to plateau, with the chance of surviving past 100 no longer increasing notably. In an accompanying commentary, demographer S. Jay Olshansky at the University of Illinois, Chicago, whose work has long backed this view, agrees that life expectancy can’t keep going up without dramatic medical breakthroughs. Olshansky even wondered whether those would be enough, or whether we’re “running up against a formidable barrier.”
This is unlikely to be the last word on the topic. James Vaupel, a demographer at the Max Planck Institute for Demographic Research in Rostock, Germany, who has been in a long-running dispute with Olshansky, released a statement calling the paper a “travesty.” That’s because, Vaupel says, although the findings seem plausible, they add “nothing to scientific knowledge about how long we will live.” Vaupel cites gains among average citizens in Japan, where the life expectancy at birth has been climbing and is now more than 83 years old. (Average life expectancy is a broader measure than maximum reported age at death, which the study authors used.) Furthermore, Vaupel notes, for years scientists have suggested that both life expectancy and maximum life span were on the cusp of plateauing—only to see them continue to inch up.