But statistics is a cruel science, and Gompertz knew it too. His data show that the risk of dying at 92 is so high that it would take an unimaginable number of people to reach 92 before he found even one person who lived to 192. It means that more than you were born. Still, Gompertz found his own datasets getting in the way. Few people were over 90, so it was difficult to know exactly what the mortality rate would be like in very old age. Do his results indicate an insurmountable limit to human lifespan, or is it just a temporary cap that can be lifted by advances in medicine?
Modern demographers have picked up where Mr. Gompertz left off, with sometimes surprising results. In 2016, his Jan Vijg and his colleagues at the Albert Einstein College of Medicine in New York concluded that after age 100, mortality begins to rise rapidly, with human lifespans reaching about 125 years. Two years later, another group of demographers, this time led by Elisabetta Balbi of the Sapienza University in Rome, came to the opposite conclusion. She argued that human mortality increases exponentially until the age of 80, slows down at age 80, and levels off after age 105. Balbi’s study, as Gompertz wondered, , posed the intriguing prospect that there is no upper limit to human lifespan at all.
If mortality really does plateau at a certain age, Robine says, extreme longevity is just a numbers game. Let’s say it hits a plateau at 50%. 5 of them She reached 111, 2 He 3 She reached 112, 1 She reached 113, Only 1 She reached 113 You can expect no one to reach the age of 114 and reach the age of 115. The number of people reaching 115 he should double to 110, etc. In other words, the upper lifespan is just a factor of how many survived the previous year. But all of these numbers depend on where the mortality plateau lies. The problem is that the data available to calculate this is not very good.
The best global dataset on death is the Human Mortality Database, but it groups everyone over the age of 110 into one group. Then there is the International Database on Longevity (IDL). This is a dataset that includes survivors and deaths over the age of 105 and was helped to launch by Robine in 2010. At IDL’s peak, we had data for 15 countries, but we’re enhancing the data. Due to privacy regulations, data coverage is inconsistent these days. Some countries have since partially withdrawn what was included.
For example, Japan has more centenarians per person than anywhere else in the world, but in 2007 the Ministry of Health, Labor and Welfare reduced the amount of publicly available data on centenarians. Those who were alive no longer produce useful information. And in countries that produce excellent data, the process of verifying and tracking birth records that can be traced back to the early 19th century remains arduous and frustrating. To verify Jeanne Calment’s age, Robin asked the supercentenarian about her childhood and compared her answers with church records, census and death certificates. Still, the IDL contains just under 19,000 records of her alive and dead in her 13 countries. But for Robin, collecting more is essential.
