科学家也许已经找到了为什么女人比男人长寿的原因

Scientists may have figured out why women live longer than men — linking it to having two X chromosomes, which defend against aging, a new study says.

一项新的研究表明，科学家可能已经找到了为什么女性比男性长寿的原因——这可能与拥有两条X染色体有关，而这两条X染色体可以防止衰老。

The extra X provides a sturdy cellular structure that protects against gene mutation and sickness, according to a report published Wednesday in the journal Biology Letters.

根据周三发表在《生物学快报》上的一篇报道，多出来的X染色体提供了一个坚固的细胞结构，可以防止基因突变和疾病。

“These findings are a crucial step in uncovering the underlying mechanisms affecting longevity, which could point to pathways for extending life,” the researchers write. “We can only hope that more answers are found in our lifetime.”

研究人员写道:“这些发现是揭示影响寿命的潜在机制的关键一步，它可能为延长寿命指明道路。”“我们希望在有生之年找到更多的答案。”

For the study, scientists from the University of New South Wales gathered data on the sex chromosomes and lifespan of 229 species, including insects, fish and mammals. They found that animals with two of the same sex chromosomes — such as birds with two “Z” chromosomes — live nearly 18 percent longer.

在这项研究中，新南威尔士大学的科学家们收集了229种昆虫、鱼类和哺乳动物的性染色体和寿命数据。他们发现，有两条相同性别染色体的动物——比如有两条“Z”染色体的鸟类——寿命延长了近18%。

Their research piggybacks on a pre-existing theory known as the “unguarded X hypothesis,” which notes that one X can serve as a buffer against disease.

他们的研究是建立在一种被称为“无保护的X假说”的理论基础上的，该理论指出X可以作为抵御疾病的缓冲器。

As the theory goes, only one X is activated in each of a woman’s cells, so a harmful mutation in one cell is less likely to effect all cells.

按照这个理论，每个女性细胞中只有一个X被激活，所以一个细胞中的有害突变不太可能影响所有细胞。

That makes mutation-related disorders “masked” more often in females, according to scientists.

科学家称，这使得突变相关的疾病在女性身上更容易被“掩盖”。

By contrast, guys are more likely to be exposed to the same types of mutations because their XY chromosomes only have a lone X.

相比之下，男性更可能暴露于相同类型的突变，因为他们的XY染色体只有一个孤独的X。

Overall, males live an average of 7 percent longer than females in species where males have two of the same sex chromosomes, according to the study.

总的来说，根据这项研究，在雄性有两条同性染色体的物种中，雄性的平均寿命比雌性长7%。

When the chromosome pattern is the other way around — as in the case of humans — women live an average of nearly 21 percent longer than guys.

当染色体模式相反时——就像人类的情况一样——女性的平均寿命比男性长21%。

But there may be other factors tied to longevity, such as fighting and risk-taking, the scientists said.

但科学家们表示，可能还有其他因素与寿命有关，比如战斗和冒险。