““In 1980, Stanford University internist and epidemiologist James Fries recognized that modern medicine was not extending the human lifespan, and yet survival curves were changing. More people were living vitally until eighty-five or ninety, and then dying quickly, like the wonderful one-hoss shay in Oliver Wendell Holmes’s poem, which ran perfectly for a hundred years and then fell apart all at once.2 Fries called this phenomenon “compression of morbidity.”3 In 1900, because most deaths were premature, the human survival “curve” was a diagonal line; now it is more of a rectangle—especially if you have no risk factors (Figure 7.1). In 2040 there will be ten times as many eighty-five-year-olds as there were in 1990. This is not because the normal human lifespan is any longer than it was, but because fewer people will die before eighty. After eighty the lifespan will reflect little increase. Medical advances like antibiotics, new cancer treatments, and kidney transplants all serve to decrease premature death. But they do not alter the fact that the bodies of most of us, like the one-hoss shay, have not evolved to live past one hundred.””
