為什么女人比男人長壽？

科學(xué)家也許已經(jīng)找到了為什么女人比男人長壽的原因

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.

一項(xiàng)新的研究表明，科學(xué)家可能已經(jīng)找到了為什么女性比男性長壽的原因——這可能與擁有兩條X染色體有關(guān)，而這兩條X染色體可以防止衰老。

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.

根據(jù)周三發(fā)表在《生物學(xué)快報(bào)》上的一篇報(bào)道，多出來的X染色體提供了一個(gè)堅(jiān)固的細(xì)胞結(jié)構(gòu)，可以防止基因突變和疾病。

“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.”

研究人員寫道:“這些發(fā)現(xiàn)是揭示影響壽命的潛在機(jī)制的關(guān)鍵一步，它可能為延長壽命指明道路。”“我們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.

在這項(xiàng)研究中，新南威爾士大學(xué)的科學(xué)家們收集了229種昆蟲、魚類和哺乳動(dòng)物的性染色體和壽命數(shù)據(jù)。他們發(fā)現(xiàn)，有兩條相同性別染色體的動(dòng)物——比如有兩條“Z”染色體的鳥類——壽命延長了近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.

他們的研究是建立在一種被稱為“無保護(hù)的X假說”的理論基礎(chǔ)上的，該理論指出X可以作為抵御疾病的緩沖器。

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.

按照這個(gè)理論，每個(gè)女性細(xì)胞中只有一個(gè)X被激活，所以一個(gè)細(xì)胞中的有害突變不太可能影響所有細(xì)胞。

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

科學(xué)家稱，這使得突變相關(guān)的疾病在女性身上更容易被“掩蓋”。

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類型的突變，因?yàn)樗麄兊腦Y染色體只有一個(gè)孤獨(dú)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.

總的來說，根據(jù)這項(xiàng)研究，在雄性有兩條同性染色體的物種中，雄性的平均壽命比雌性長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.

當(dāng)染色體模式相反時(shí)——就像人類的情況一樣——女性的平均壽命比男性長21%。

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

但科學(xué)家們表示，可能還有其他因素與壽命有關(guān)，比如戰(zhàn)斗和冒險(xiǎn)。