Ask a group of people who among them wants to live to 100, and many would say they would rather die younger, with their health and their mind still intact.
But that idea of frailty, illness, and dementia extended over many painful years reflects a fundamental misunderstanding about what life is like for people who have unusually long lives, says Thomas Perls, who for 20 years has directed what is now the largest study of centenarians.
"When we started the study, the prevailing wisdom was that because things like Alzheimer's become more common with increasing age ... if you got to 100, everybody would get Alzheimer's," he says. "We quickly disproved that."
About one-fifth of the centenarians in the study had "no cognitive impairment at all," but even most of those who were ill at the very end of their lives had been "living independently, cognitively intact, until they were about 93," Perls says.
It turned out, Perls found, that the people who were living well past the average life expectancy were often doing so because of unusually good genes, which seemed to protect them — at least for most of their golden years — from many of the problems that plague others throughout their 70s and 80s.
People who live past 100 "markedly delay disability toward the end of their lives," experiencing problems only toward the very end, Perls says. "What we later found, as we enrolled many more people over the age of 105 ... is that they not only compress the time that they experience disability, but that they also compress the time that they experience diseases as well."
That finding confirms something known as the "compression of morbidity" hypothesis, first put forth by the Stanford University professor (and doctor) James Fries in 1980 and later confirmed by a 1998 study of 1,741 people. "Extension of adult vigor far into a fixed life span compresses the period of senescence near the end of life," he wrote in 1980.
In other words, people who live a long time tend to compress the bad years until the very end, giving them not only more years alive, but — what matters to most people — more good years alive.
Now, let's ask again: Would you want to live to 100?
