什么?生孩子会使女性的细胞衰老11年?
中国生物技术网 · 2018/03/03
生孩子会不可避免地给女性的身心带来重大的变化,但是成为母亲所造成的终身影响可能远远超过我们的想象。


图片来源:网络

本文转载自“中国生物技术网”。

美国一项对大约2000名处于育龄女性的DNA进行的分析表明,那些已经生育的女性的遗传标记出现了改变的迹象,这表明她们细胞衰老的速度在加快。该研究已发表在《Human Reproduction》上。

美国乔治梅森大学的流行病学家Anna Pollack说:“发现这样的结果令我们非常惊讶,生孩子相当于使细胞加速衰老了11年。”


Pollack和她的团队分析了美国国家健康与营养检查调查机构(NHANES)的数据。当他们对1999–2002年期间的数据进行分析时,NHANES调查包括了对端粒的遗传标记测量。他们从中发现了某些不寻常的事情。

端粒是一个分子区域,它是扣在染色体终端的“帽”,能够保护细胞中的遗传信息不会随着时间推移被破坏,有人猜测,端粒还能够防止染色体接触到对健康有害的东西。

在这种情况下,端粒长度被认为是人在细胞水平上的实际年龄标志,端粒越长,代表健康状况越好,因为较短的端粒可能与癌症、心脏病和认知衰退等疾病相关。

现在,我们发现,生孩子也会导致端粒变短。

在研究中,他们发现,在调整了年龄、种族、教育和吸烟等因素之后,生过至少一个孩子的女性的染色体端粒平均比没有生育过的女性短4.2%。

调整后的平均差异意味着,生育过的女性缺少116个碱基对,研究人员解释称,这相当于细胞加速衰老了大约11年。

令人惊讶的是,与生育相关的端粒变短程度甚至比在过去研究观察到的更高,那项研究测试了吸烟(相当于细胞衰老4.6年)和肥胖(相当于细胞衰老年8.8年)与端粒变短的关系。

此外,在研究中,端粒变短的程度似乎与女性生育孩子数量相关。

Pollack说:“我们发现,生育5个孩子以上的女性的端粒相比于没有生育过的女性要短得更多,比那些生育小于5个孩子的女性也更短。”

值得注意的是,这只是一项观察性研究,我们并没有得出任何因果性的结论,而只是一种相关性。

至少有一项研究得出了相反的结论,2016年一项在危地马拉Kaqchikel Mayan农村地区的研究发现,在那里,拥有越多存活下来的孩子的女性端粒越长,这表明生孩子可以防止女性的细胞衰老。


过去还有研究利用细胞衰老将碱基对端粒缩短的程度进行了量化,研究人员认为生孩子仅导致4.5年的提前衰老。至少有一位没有参与此项研究的研究人员认为,生孩子至多导致3年的生物学衰老。

至于样本中端粒缩短的原因到底是什么,研究人员推测,可能是由于照顾孩子的压力,但是考虑到在该领域几乎没有什么研究,所以他们建议大家审慎对待此结果。

Pollack说:“我们的研究并不是告诉大家不要生孩子。”科学家们正在研究这到底是什么原因,我们需要理性的建议。

所有文章仅代表作者观点,不代表本站立场。如若转载请联系原作者。
查看更多
  • Parity associated with telomere length among US reproductive age women

    STUDY QUESTION Is telomere length related to parity among a nationally representative sample of US reproductive age women? SUMMARY ANSWER History of live birth was associated with shorter telomere length. WHAT IS KNOWN ALREADY Shorter telomeres have been linked with a range of chronic health conditions and mortality and parity has been associated with health indicators. However, there is a lack of research on how parity relates to telomere length. STUDY DESIGN, SIZE, DURATION This nationally representative, cross-sectional study included 1954 women from the National Health and Nutrition Examination Survey, 1999–2002, the only survey period which includes measurement of telomere length. PARTICIPANTS/MATERIALS, SETTING, METHODS Women aged 20–44 were included. Parity, defined as number of previous live births, was ascertained by questionnaire. Leukocyte telomere length was measured by polymerase chain reaction and reported as a ratio in relation to standard reference DNA (T/S ratio). The relationship between leukocyte T/S ratio and parity was examined using survey weighted linear regression. Models were adjusted for race/ethnicity, age, BMI, income-to-poverty ratio, education, early age at menarche and smoking status. MAIN RESULTS AND THE ROLE OF CHANCE Among reproductive age women in the US, the adjusted mean leukocyte T/S ratio was 4.2% (95% CI: 0.9, 7.3) shorter in parous compared with nulliparous women. Parity was associated with 116 fewer base pairs (95% CI: 26, 204) on average, using estimated coefficients from the adjusted linear regression models and mean covariate values. LIMITATIONS REASONS FOR CAUTION This study was cross-sectional and therefore was unable to establish temporality. The dataset lacked information on social factors, stress and fertility status, which may help explain these findings. Only two previous studies have examined this question and our findings should be interpreted with caution. WIDER IMPLICATIONS OF THE FINDINGS These findings in a nationally representative sample of US reproductive age women suggest that history of live birth may be associated with accelerated cellular aging. The magnitude of the observed association was greater than that of the impact of smoking or obesity on telomere length, suggesting that parity may have an independent influence on cellular aging and warrant further study.

    展开 收起
发表评论 我在frontend\modules\comment\widgets\views\文件夹下面 test