人类寿命将无限延长？
There’s no limit to longevity, says study that revives human lifespan debate
一份来自《科学》杂志上的研究称人类寿命没有极限，该研究再次引发了关于人类寿命的终极讨论。
Death rates in later life flatten out and suggest there may be no fixed limit on human longevity, countering some previous work.
这项研究指出，人的死亡率随着年纪的增大而变得越来越平缓，人类的寿命可能没有上限。该研究的结论和以前的研究结论截然相反。
There might be no natural limit to how long humans can live — at least not one yet in sight — contrary to the claims of some demographers and biologists.
人们的寿命可能没有自然限制，至少现在没人知道，这和人口统计学家和生物学家之前的结论完全相反。
That’s according to a statistical analysis published Thursday in Science 1on the survival probabilities of nearly 4,000 ‘super-elderly’ people in Italy, all aged 105 and older.
6月28日刊登在美国《科学》杂志上的数据分析显示，意大利4000名超级长寿老年人的年龄都在105岁以上。
A team led by Sapienza University demographer Elisabetta Barbi and University of Roma Tre statistician Francesco Lagona, both based in Rome, found that the risk of death — which, throughout most of life, seems to increase as people age — levels off after age 105, creating a ‘mortality plateau’. At that point, the researchers say, the odds of someone dying from one birthday to the next are roughly 50:50 (see ‘Longevity unlimited’).
罗马大学人口统计学家伊丽莎白.巴尔比（Elisabetta Barbi）及罗马第三大学的统计学家弗朗西斯哥.拉格纳（Francesco Lagona）带领的研究团队发现，在人一生的绝大部分时间里，死亡的风险与年纪成正比，但是到了105岁时，死亡率趋于平缓，研究人员称，当人们到了这个阶段，人的死亡率大约为50:50（参考“长寿无上限”）。
“If there is a mortality plateau, then there is no limit to human longevity,” says Jean-Marie Robine, a demographer at the French Institute of Health and Medical Research in Montpellier, who was not involved in the study.
“如果死亡率呈现了平缓的趋势，那么人类的寿命就没有上限了，” 蒙彼利埃法国卫生医学研究所人口统计学家约翰.玛利亚-罗比纳（Jean-Marie Robine）说道。约翰.玛利亚-罗比纳没有参与这项研究。
That would mean that someone like , the Japanese great-great-great-grandmother who, at 117, is the world’s oldest known person, could live for years to come — or even forever, at least hypothetically.
这可能意味着像Chiyo Miyako这样的跨四代的日本长寿老人可能活得更长，或者她可以永远的活下去，至少我们猜测如此。Chiyo Miyako今年117岁，是目前世界上最长寿的老人。
Researchers have long debated whether humans have an upper age limit. The consensus holds that the risk of death steadily increases in adulthood, up to about age 80 or so. But there’s vehement disagreement about what happens as people enter their 90s and 100s.
研究人员针对寿命是否有上限进行了长时间的讨论。他们得到这样的共识：成年期的死亡风险呈稳步增长趋势，这样的趋势将一直持续到80岁左右。但是当人们到了90或100岁的时候，人们对死亡风险的分析完全不同。
Some scientists have examined demographic data and concluded that there is a fixed, natural ‘shelf-life’ for our species and that mortality rates keep increasing. Others have looked at the same data and concluded that the death risk flattens out in one’s ultra-golden years, and therefore that human lifespan does not have an upper threshold.
部分研究人员核实了人口统计数据，得出了这样的结论：人类有一个固定、自然的“储存期”，在这个阶段中，死亡率是递增的。其他人看到相同的数据，得出了这样的结论：当人们到了期颐之年，人们的寿命就没有了上限。
Age rage
关于寿命的激烈讨论
In 2016, geneticist Jan Vijg and his colleagues at Albert Einstein College of Medicine in New York City rekindled the debate when they analysed the reported ages at death for the world’s oldest individuals over a half-century. They estimated that human longevity hit a ceiling at about 115 years — 125 tops.
2016年，当遗传学家简.维吉和纽约爱因斯坦医学院同事分析了报告中半个世纪中世界上最大年纪的人群的死亡率时，他们重新激起了人们对此类问题的讨论。他们估计，人类寿命将达115-125岁。
Vijg and his team argued 2 that with few, if any, gains in maximum lifespan since the mid-1990s, human ageing had reached its natural limit. The longest known lifespan belongs to Jeanne Calment, a French super-centenarian who died in 1997 at age 122.
维吉和他的团队称，自1990年代中期以来，人类寿命上限的延长是相当罕见的现象，因为人类衰老已达到了自然极限。世界上寿命最长的人是来自法国的雅娜·卡尔芒，她于1997年去世的，去世时已经是122岁的高龄。
Experts challenged the statistical methods in the 2016 study, setting off a firestorm into which now step Barbi and Lagona. Working with colleagues at the Italian National Institute of Statistics, the researchers collected records on every Italian aged 105 years and older between 2009 and 2015 — gathering certificates of death, birth and survival in an effort to minimize the chances of ‘age exaggeration’, a common problem among the oldest old.
专家质疑了2016年研究中的统计方法，与此同时，巴尔比及拉格纳研究引发了医学界的研究热潮。在2009至2015年期间，这些研究学家和意大利统计局的同事们一起收集了每个105岁以上（包括105岁）的意大利人的记录--他们收集了这些老人的死亡证明、出生证明和幸存证明，从而缩小了年龄增长扩大化的几率，这是一种常用的研究最年长老人的方法。
They also tracked individual survival trajectories from one year to the next, rather than lump people into age intervals as previous studies that combine data sets have done. And by focusing just on Italy, which has one of the highest rates of centenarians per capita in the world, they avoided the issue of variation in data collection among different jurisdictions.
他们还跟踪了每个人逐年的生存轨迹，之前的研究是将全部的人分成几个年龄阶段，并结合以上受访者的数据来完成。该研究只在意大利展开，这样他们就避免了因为每个地方数据收集方法不同而带来问题。意大利是世界上百岁老人最多的国家之一。
As such, says Kenneth Howse, a health-policy researcher at the Oxford Institute of Population Ageing in the United Kingdom, “these data provide the best evidence to date of extreme-age mortality plateaus in humans”.
英国牛津大学人口老龄化研究所健康政策研究人员肯尼斯.豪斯（Kenneth Howse）称：“这些数据提供了人类极限年龄稳定时间段的最佳证据”。
Ken Wachter, a mathematical demographer at the University of California, Berkeley, and an author of the latest study, suspects that prior disputes over the patterns of late-life mortality have largely stemmed from bad records and statistics. “We have the advantage of better data,” he says. “If we can get data of this quality for other countries, I expect we’re going to see much the same pattern.”
加州大学伯克利分校的数理人口统计学、这个最新研究的作者肯.瓦切尔(Ken Wachter)猜测，之前关于晚年死亡模式的争论，从很大程度上来说，是源于记录和统计的失误。“我们现在有更加完善的数据，如果我们能得到质量相等的他国数据，我想我们将不会得出之前的结果。”他说道。
Robine is not so sure. He says that unpublished data from France, Japan and Canada suggest that evidence for a mortality plateau is “not as clear cut”. A global analysis is still needed to determine whether the findings from Italy reflect a universal feature of human ageing, he says.
罗比纳不是十分确定，他说，法国、日本和加拿大未公开的数据指出，105岁以后的死亡率更加稳定的说法不太可信。意大利百岁老人的结论是否反应了人类寿命的普遍现象，还需要结合全球的分析来做出最终判断。
Off limits
寿命没有上限
The world is home to around 500,000 people aged 100 and up — a number that’s predicted to nearly double with each coming decade. Even if the risk of late-life mortality remains constant at 50:50, the swelling global membership in the 100-plus club should translate into a creep upwards in the oldest person alive by about one year per decade, says Joop de Beer, a longevity researcher at the Netherlands Interdisciplinary Demographic Institute in The Hague.
海牙荷兰多学科人口研究所长寿研究学家约普.德.比尔(Joop de Beer)说，世界上有50万名100以上（包括100岁）的老人，预计这个数字在每十年将翻一倍。即使晚年死亡率依然是50:50，百岁老人数量将在全球范围将慢慢的增多，最年长的老人的寿命将呈现出每十年增加一岁特点。
Many researchers say they hope to better understand what’s behind the levelling off of mortality rates in later life. Siegfried Hekimi, a geneticist at McGill University in Montreal, Canada, speculates that the body’s cells eventually reach a point where repair mechanisms can offset further damage to keep mortality rates level.
很多研究人员称，他们希望能更好的了解105岁以后死亡率变缓的的原因。加拿大蒙特利尔麦吉尔大学遗传学佳海克米, 赫基米推测，人体的细胞将逐渐接近一个状态，这个状态下的修复机制能抵御细胞的进一步损伤，致使死亡率趋于平缓。
“Why this plateaus out and what it means about the process of ageing — I don’t think we have any idea,” Hekimi says.
赫基米称：“我们无从得知死亡率放缓的原因，以及它对衰老的过程意味着什么。”
For James Kirkland, a geriatrician at the Mayo Clinic in Rochester, Minnesota, the strong evidence for a mortality plateau points to the possibility of forestalling death at any age. Some experts think that the very frail are beyond repair. But if the odds of dying don’t increase over time, he says, interventions that slow ageing are likely to make a difference, even in the extremely old.
对于明尼苏达罗彻斯特梅约诊所老年医学专家詹姆斯.柯兰克（James Kirkland）来说，死亡率放缓乃至任何年龄阶段的死亡人数的减少，是最强大的证据。一些专家认为，老人是没有自行修复能力的。但是如果死亡的几率不会进一步增加，这将使人为干预衰老成为可能，甚至将逆转年龄极大的老年人的衰老过程。。
Not everyone buys that argument — or the conclusions of the latest paper.
然而，不是所有人都同意这个观点或最新论文的结论。
Brandon Milholland, a co-author of the 2016 Nature paper, says that the evidence for a mortality plateau is “marginal”, as the study included fewer than 100 people who lived to 110 or beyond. Leonid Gavrilov, a longevity researcher at the University of Chicago in Illinois, notes that even small inaccuracies in the Italian longevity records could lead to a spurious conclusion.
2016年《自然》上一篇论文的作者布兰登.密霍蓝德(Brandon Milholland)称，死亡率下降的证据非常少，该研究里面记载了少于100个活到110岁以上的老人。芝加哥大学伊利诺伊分校长寿研究中心列昂尼德.加夫里洛夫称，即使是特别小的误差也能让意大利长寿记录的结论站不住脚。
Others say the conclusions of the study are biologically implausible. “You run into basic limitations imposed by body design,” says Jay Olshansky, a bio-demographer at the University of Illinois at Chicago, noting that cells that do not replicate, such as neurons, will continue to wither and die as a person ages, placing upper boundaries on humans' natural lifespan.
其他人说，从生物学方面来说，这个研究的结论是不真实的。伊利诺伊大学生物人口统计学家杰伊.奥利尚斯基表示，当你身体受到基本条件的限制时，神经元等细胞不可能再生，当人们进入衰老过程时，这些细胞将继续萎缩或死亡，人类自然寿命将受到限制。
This study is thus unlikely to be the last word on the age-limit dispute, says Haim Cohen, a molecular biologist at Bar-Ilan University in Ramat-Gan, Israel. “I’m sure that the debate is going to continue.”
以色列拉马特甘巴伊兰大学分子生物学家哈伊姆.科恩(Haim Cohen)表示，因此，这个研究不太可能可能成为年龄限制的最终结论，他认为这个这场关于寿命的争论将继续下去。
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