女孩男孩过早的青春期发育,祸从何来?

In the late 1980s, when Marcia Herman-Giddens was working in a paediatric clinic at Duke University Medical Centre in North Carolina she noticed a puzzling phenomenon. More and more girls aged eight or nine who visited the clinic had started to sprout breasts. At the time, medical orthodoxy held that the average age of puberty for girls in the west was over 11. The numbers of under-10s that Herman-Giddens was seeing did not fit with this scenario. She began collecting data that eventually produced a study with the American Academy of Pediatrics that studied 17,000 girls and found that the average age of breast-budding among white girls was 9.9 years while for black girls it was 8.8.

20世纪80年代末，马西娅•赫尔曼-吉登斯在卡罗莱纳州北部的杜克大学医学中心的儿科诊所工作时，她发现了一个令人费解的现象。越来越多来诊所的八九岁女孩已开始出现乳房。当时，医学正统界认为西部女孩的青春期平均年龄在11岁以上。赫尔曼-吉登斯看到的众多十岁以下的女孩并不符合这种情况。她开始收集数据，在研究17000名女孩之后最终与美国儿科学会得出了结论，发现白人女孩胸部发育的平均年龄为9.9岁，而黑人女孩为8.8岁。

The discovery was hugely controversial. Many doctors refused to accept the fact that more and more girls had begun to mature sexually before they had reached the age of 10. "The Lolita syndrome [the prurient fascination with the sexuality of young girls] created a lot of emotional interest," recalls Herman-Giddens, now at the University of North Carolina. "As a feminist, I wish it didn't."

该发现引发了巨大的争议。许多医生拒绝接受这样的事实，即越来越多的女孩在她们到达10岁之前就开始性成熟。“洛丽塔情结（对小女孩的单纯性迷恋）产生了很多情感兴趣，目前在北卡罗莱纳大学的赫尔曼-吉登斯回忆说。“作为一个女权主义者，我希望事实并非如此。”

Today most doctors accept that the age of onset of puberty is dropping steadily. Many studies have showed this to be the case for girls, and new research carried out by Herman-Giddens, and published by the American Academy of Pediatrics, has found the same for boys. The age of onset of biological adulthood continues to plunge. Consider the statistics provided by German researchers. They found that in 1860, the average age of the onset of puberty in girls was 16.6 years. In 1920, it was 14.6; in 1950, 13.1; 1980, 12.5; and in 2010, it had dropped to 10.5. Similar sets of figures have been reported for boys, albeit with a delay of around a year.

今天，大多数医生接受青春期开始的年龄在逐渐下降。许多研究都表明这正应对女孩的情况，由赫尔曼-吉登斯开展以及美国儿科学会公布的新研究已发现这同样适用于男孩。生理上的成年期开始的年龄继续大幅下挫。考虑到德国研究人员提供的统计数据。他们发现，在1860年，女孩进入青春期的平均年龄为16.6岁。1920年为14.6岁，在1950年为13.1岁，1980年,为12.5岁，并在2010年已经降到10.5岁。男孩也报告了一组类似的数字，虽然有一年左右的延迟。

What factors lie behind this trend? Why are our children reaching biological adulthood at earlier and earlier ages? And what are the medical implications of this? Answers to these questions are still debated, although most scientists and health experts believe that the initial decline in the age in puberty was linked to general improvements in health in the west that began in the late 19th century. The trouble is that this drop, which was expected to stop, has simply continued at the same rate: a decline in four to five months in age of onset for each passing decade.

这一趋势背后的因素是什么？为什么我们的孩子达到生理成熟的年龄越来越早？这一现象的医学暗示是什么？对这些问题的答案仍存在争议，尽管大多数科学家和健康专家认为，在青春期年龄的初始下降与西方19世纪后期开始的健康条件的普遍改善有关。问题在于预计将停止的这个下降，只是还在以同样的速度继续：每10年发育年龄会下降4到5个月。

This relentless slide has begun to worry doctors who have proposed a host of causes to explain it. Increasing obesity is often quoted. In the young it is thought to increase blood levels of oestrogens that promote breast development and early studies seemed to confirm this by linking puberty to higher body mass index. However, a Danish study released last year in the journal Paediatrics found puberty occurring earlier in children regardless of body mass index at age seven.

这种无情的下滑已经开始使那些提出了很多原因来解释它的医生担心。不断增加的肥胖经常被作为原因。它被认为是增加了年轻人血液中的雌激素从而促进了乳房发育，早期的研究通过把青春期和较高的身体质量指数相联系似乎证实了这一点。然而，去年发表在儿科杂志上的丹麦研究发现，不论身体质量指数如何，儿童的青春期七岁时就更早地发育了。

Other factors that may be involved include a diet that is increasingly high in sugar and fat and declining physical activity. The cause could also be environmental, say other researchers – in particular, exposure to endocrine disrupters, chemicals in the environment that act on hormones.

其他可能涉及到的因素包括饮食中越来越高的糖和脂肪以及身体锻炼的减少。也可能是环境的原因，其他研究人员说——尤其是暴露在环境中的内分泌干扰物以及化学物质影响到了荷尔蒙。

Widespread industrial and pharmaceutical pollutants have already been shown to harm the normal sexual development of fish and animals. By extension, they may also contribute to earlier or disrupted puberty in children, these scientists contend.

大范围的工业和制药业污染已被证明伤害了鱼和动物的正常性发育。推而广之，他们也可能导致孩子的青春期提前或中断，这些科学声称。

As to the likelihood that precocious puberty poses perils for young people, this is still debated – though many parents worry that early sexual development puts strain on children who are being robbed of years of innocent childhood.

由于性早熟的可能性给年轻人带来了危险，这仍然存在争议——尽管许多家长担心性早熟给孩子们造成压力，他们正被剥夺掉天真无邪的童年。