While women have for centuries been labelled as the weaker sex, new research suggests the truth is quite the opposite。
According to a study, the fairer sex is genetically programmed to better resist infections and cancer, and also have a back-up system for fighting disease。
The discovery sheds light on why members of the so-called stronger sex succumb to "man-flu"。
The reason why women are more robust appears to be microRNAs - short strands of RNA encoded on the chromosome, scientists believe. RNA is a genetic cousin of DNA and can have important biological effects。
The microRNAs have the effect of "silencing" immunity genes on X-chromosome, according to the new research. This leaves men at a disadvantage since they only have one X chromosome. Women have two, so that even when immunity genes are silenced on one the other can compensate. So man's immune systems are no match for those of wives and girlfriends
Study leader Dr Claude Libert, from Ghent University in Belgium, said: "Statistics show that in humans, as with other mammals, females live longer than males and are more able to fight off shock episodes from sepsis, infection or trauma. We believe this is due to the X chromosome. "
From a biological point of view, the difference has probably evolved because women are more likely to ensure the survival of the species. They need to be able to resist infection when pregnant and when nuturing a child。
The research is published today in the journal BioEssays。
据英国《每日电讯报》9月28日报道，几世纪以来，女性都被打上弱势性别的标签，但一项新研究表明，事实可能正好相反。
根据该研究，女性基因更能有效抵抗传染病和癌症，同时其基因还具备一套抵御疾病的支持体系。
这一发现解释了所谓的强势性别——男人总易患流感的原因。
科学家认为，女性更健康的原因可能在于微RNA(核糖核酸)，它是染色体上RNA编码的短片段。而RNA是DNA(脱氧核糖核酸)的基因表亲，具有重要的生物学效应。
根据这项新研究，微RNA具有“屏蔽”X染色上的免疫基因的效果。这使只有一条X染色体的男性处于不利地位，而女性拥有两条，所以即使一条上的免疫基因不能发挥作用，另一条上的也能起到弥补作用。所以，男性的免疫系统无法与他们妻子和女朋友的匹敌。
来自比利时根特大学的研究领导者克劳德·力博特博士说：“数据表明，在人类和其他哺乳动物中，女性寿命更长，更能抵御因败血症发作引起的休克、感染病和创伤。我们认为这可以归因于X染色体。”
从生物学角度来说，这种差异的演化可能是出于女性更有可能确保种族生存。她们需要在怀孕和养育子女的时具备抵御传染的能力。
该研究发表在今日(28日)的《生物》杂志上。
