Carl Zimmer in The New York Times:
Since 1900, average life expectancy around the globe has more than doubled, thanks to better public health, sanitation and food supplies. But a new study of long-lived Italians indicates that we have yet to reach the upper bound of human longevity. “If there’s a fixed biological limit, we are not close to it,” said Elisabetta Barbi, a demographer at the University of Rome. Dr. Barbi and her colleagues published their research Thursday in the journal Science. The current record for the longest human life span was set 21 years ago, when Jeanne Calment, a Frenchwoman, died at the age of 122. No one has grown older since — as far as scientists know. In 2016, a team of scientists at Albert Einstein College of Medicine in the Bronx made the bold claim that Ms. Calment was even more of an outlier than she seemed. They argued that humans have reached a fixed life span limit, which they estimated to be about 115 years. A number of critics lambasted that research. “The data set was very poor, and the statistics were profoundly flawed,” said Siegfried Hekimi, a biologist at McGill University. Anyone who studies the limits of longevity faces two major statistical challenges. There aren’t very many people who live to advanced ages, and people that old often lose track of how long they’ve actually lived. “At these ages, the problem is to make sure the age is real,” said Dr. Barbi.
…But that’s not what Dr. Barbi and her colleagues found. Among extremely old Italians, they discovered, the death rate stops rising — the curve abruptly flattens into a plateau. The researchers also found that people who were born in later years have a slightly lower mortality rate when they reach 105.