事件记录
Dr. 琼斯: “大发娱乐! 我女儿10岁了，她正在发育乳房. 这是不是太快了？? 我还没准备好.“我是博士。. Kirtly Jones from obstetrics and gynecology at University of Utah Health Care and this is puberty on 范围.
播音员: Covering all aspects of women's health, this is "The Seven Domains of Women's Health" with Dr. Kirtly Jones在Scope上报道.
Dr. 琼斯: Many years ago, a dear friend of mine called me with a worried question. Her 10-year-old, flat-chested daughter had developed a small, tender bump under one nipple. “是癌症吗？”?她问. 我回答说：“哦，不. 这是更可怕的事情. 这是青春期.“但什么是青春期? 通常发生这种情况的女孩多大? 这在美国发生得更早吗?
好吧, 青春期是性腺处于睡眠状态的时期, 卵巢, and testicles of boys and girls wake up to begin the coordinated development of sexual tissues. 女孩, 它开始于乳房的发育，称为前乳, 紧随其后的是被称为阴毛的阴毛. 和 about two years after the beginning of breast development in the normal pubertal process, 第一次月经开始了, 月经初潮. This waking up of the sleeping gonads is preceded by a year or two by the maturing of the adrenal glands called adrenarche. 大发娱乐所有可爱的发展拱门, I'm waiting for an arche to name the start of the development of the mature brain.
Anyway, all of these arches, 月经初潮 is the easiest to reliably record and remember. Most women, or their mothers, don't know or recognize the 第一个 beginning of breast buds. 但 the 第一个 period is more memorable and there are many reasons why a culture may want to record the age of 月经初潮 in its girls. Not the least of which is their potential fertility and marriageability.
The average age of 月经初潮 in the early 1800s was about 17, as reported in Norwegian records. There was a steady and significant decline in the age of 月经初潮 over the past 200 years in European records. Al虽然 one researcher in the US noted about 1900 that girls with "greater culture and education" had earlier 月经初潮 by about a year, it was probably better nutrition that contributed to the earlier 月经初潮. "Cultured white girls" had earlier 月经初潮 than Irish immigrant girls or African-American girls. 和 that's probably not the culture that made a difference, but the nutrition.
Contributing to earlier 月经初潮 is early childhood nutrition and pre-pubertal nutrition. 那么，月经初潮的年龄还在下降吗? 答案是肯定的，全世界都是，但没那么快. 全国健康和营养检查调查, NHANES, found that the average age of 月经初潮 in the US dropped about one year from girls born in 1920 to women born in 1980. 非裔美国女孩的降幅最大，从13个下降到13个.6至12岁.2年. 非西班牙裔白人女孩从13个下降.3年至12年.5年. 西班牙裔女孩在中间. In Japan, Japanese girls had their change of 月经初潮 drop from 13.30岁到12岁出生的女孩中有8个.80后女孩2岁.
但, 你知道, 13, 12岁没什么大不了的, 但是换个角度想, the percent of US girls who've had their 第一个 period by age 10 was zero for girls born in the '20s and is 2% to 3% for girls born in 1980.
为什么会这样呢? 大发娱乐的水果、蔬菜和蛋白质营养好吗? 还是因为营养不良? 好吧, body weight is a contributing factor to the age of 月经初潮 and we know that kids are taller now than they were 80 years ago. The most recent changes in the past 30 years have not been so much taller kids, but fatter kids. The likelihood of reaching 月经初潮 in girls now is most likely associated and most highly associated with pre-pubertal adiposity, 或肥胖. 虽然，有些人甚至质疑这一点.
So sweet drinks in cans and boxes are associated with earlier periods. 一些独立的研究对是否是苏打水的原因进行了争论, 含咖啡因的, 糖, 或者人工加糖, 以及它们是否与月经初潮提前有关. 至于这是不是咖啡因的作用，还有一些争论, 糖, 或者人造甜味剂, but one big study suggests that sweet drinks in cans do make puberty earlier. We do know that kids that consume artificially sweetened sodas are more likely to be overweight. 但 is it the overweight kids are more likely to drink artificially sweet drinks?
或者是汽水罐上的双酚A? 好吧, BPA is a plastic with some estrogen-like activity that's been a concern for all of us. 一项研究, 虽然, looked at BPA levels in the urine of kids and recorded that the 月经初潮, 在控制种族和肥胖的情况下, BPA水平似乎并没有什么不同. 但 there is still a concern about the artificial chemicals in the environment in the lotions and potions we put on our kids that may have some effect on their puberty.
这有什么关系呢? 好吧, 第一个, 随着月经初潮年龄的下降, 10岁前月经初潮的孩子数量上升. Developing breasts at seven and periods at nine is hard for girls that we still consider as little kids. We also know that earlier exposure to estrogens is a small factor in the risk of breast cancer. 什么时候青春期提前会成为一个医学问题? 好吧, if your daughter develops breasts before the age of seven, you should talk to her pediatrician.
现在，大发娱乐能做些什么吗? 如青春期前肥胖, 肥胖, is the number one risk factor for earlier breast development and periods, we should take care with what our kids eat and drink and keep them active. We should have a say about what food is available at their schools, 比如自动售货机里的汽水、果汁和高热量零食. 大发娱乐应该尽量减少屏幕时间，增加户外活动时间. 和, 最重要的是, 因为大发娱乐无法控制一切, we need to be ready to have the talk and support our girls as girls as they make this transition. 感谢收看《大发娱乐》栏目.
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