Eternal life

 作者:孙慨吏     |      日期:2019-03-07 07:03:02
By Emma Young, San Francisco From the annual meeting of the American Association for the Advancement of Science in San Francisco Predictions that the average life expectancy of humans will soon hit 100 or even higher are wildly optimistic, according to new research. In fact, an analysis of trends in death rates between 1985 and 1995 suggests that even 80 years into the future, the average life expectancy at birth in the US will be 85. “Everyone alive today will be long dead before life expectancy at birth of 100 is achieved – if it ever is,” says Jay Olshansky of the University of Illinois in Chicago, one of the researchers. “No technologies exist today that would permit us to increase life expectancy to 100 or even 120, as has been claimed.” Leonard Hayflick, an ageing expert at the University of California San Francisco, says: “I agree that the outrageous claims made by uninformed people in this field for superlongevity in the future are simply not possible. “If you eliminated all causes of death on death certificates today, you would increase life expectation by 15 years,” he says. “Virtually all the research in ageing is research on the diseases of old age, the resolution of which will not provide immortality.” However, the maximum human lifespan is still increasing, say Danish researchers. Kaare Christensen of the University of Southern Denmark has led a team studying Scandinavian data. “Our key finding is that the death rate for people aged 80 and older has been halved from 50 years ago and there is no evidence it is slowing down,” he says. He found that the longest lifespan in any year for the past 150 years has been steadily increasing. “The key question is how long this is going to continue. No one knows – but we’re not pushing the limit now.” If the normal process of human ageing is truly to be slowed, much more research is needed on understanding why older cells are more vulnerable to attack, says Hayflick: