evidence: Advances in public health and medicine during the twentieth century increased human life expectancy to about three years per decade. But Olshansky and others have long argued that this rate of improvement is not sustainable, despite more-optimistic forecasts that predict most children born in the twenty-first century would live for a 100 years or more2. But this is difficult to confirm, because the only way to be sure is to wait for enough people to die, or not. [...] It’s clear that further extension of the average lifespan is difficult because that would require researchers to find treatments for illnesses that affect older people, says Dmitri Jdanov, a demographer at the Max Planck Institute for Demographic Research in Rostock, Germany. Jdanov wrote, together with his colleague Domantas Jasilionis, an accompanying commentary on the paper. Both articles are published in Nature Aging today. [...] National Heart, Lung, and Blood Institute, NIH