By LOUISE GREENSPAN and JULIANNA DEARDORFFFEB. 5, 2015
RECORD numbers of girls not yet old enough for middle school are starting puberty. Almost by definition, puberty arrives at an awkward age, but these are grade-school girls, thrown into a developmental gantlet before they are ready for the change.
As mothers of young girls, we see this phenomenon and fret over the implications. Early puberty can lead to eating disorders, depression, substance abuse, early sexual activity and, later in life, breast cancer. But as doctors, we wince at misleading stories that blame substances that are not likely to bear the primary responsibility — hormones in our meat or soy in our diets, for instance. The real culprits include two problems that are often overlooked: obesity and family stress.
Chemical exposures may also disrupt girls’ puberty, but less is known in this area. To better understand the early puberty phenomenon, we, together with colleagues, are conducting a continuing study of more than 1,200 girls tracked since 2005. Puberty used to begin at age 10 or 11. In our study, we found that by the age of 7, 23 percent of black girls, 15 percent of Hispanic girls and 10 percent of white girls had started to develop breasts. It is clear from the data that overweight girls are more susceptible to early puberty. Body fat secretes estrogen, a hormone that is normally released from the ovaries during puberty and is responsible for breast development. Excess body fat serves as an additional source of estrogen, and the result is earlier breasts.
Sugary drinks contribute to today’s kids’ being more overweight than in previous generations. In fact, according to one study, at least 20 percent of the weight gained by the population from 1977 to 2007 can be attributed to sweetened beverages. The role of sweeteners is intriguing. New research announced last week by the Harvard School of Public Health suggested that girls who drank more sodas were also more likely to reach puberty early, regardless of whether they were overweight.
More surprising, strong evidence reveals that emotional stress in a girl’s family can jump-start puberty earlier. Growing up in unpredictable households with high levels of conflict leads to early maturation. So does early sexual abuse. A girl who grows up without her biological father is twice as likely to get her period before age 12 compared with a girl reared with her father in the home. The effects of fathers may or may not be linked to stress, but a father’s presence in the home does seem to matter when it comes to puberty.
Endocrine-disrupting chemicals are also a concern because they can mimic hormones, like estrogen, that are the key players in a girl’s body during puberty. Many chemicals, including those in fire retardants and plastics, disrupt reproductive development in animals; however, more research is needed on humans. And research hasn’t identified a single smoking gun.
While each individual chemical may not have a direct effect on puberty, we have no idea how the hundreds of chemicals that a girl is exposed to daily might cause multiplicative effects in her growing body. It may be a combination of exposures that do real damage, as well as the developmental timing of those exposures. And going “all natural” may not be the solution because some naturally occurring substances — for example, lavender and tea tree oils — are pervasive in personal care products and might act as estrogens in the body.
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So what’s a parent, and society at large, to do?
There are ways to protect against early puberty. Breast-feeding early in life appears to help. What’s more, when a mother maintains a healthy weight before and during pregnancy, her daughter is less likely to get her period early. Work by our team also shows that consuming soy foods may delay puberty, which is contrary to the widely held belief that all soy-based products accelerate it. Providing a warm emotional environment at home can not only help prevent early puberty, but also mitigate the psychological effects if it occurs. To buffer against toxic stress, parents should prioritize setting aside time to engage with their daughters and bond emotionally.
We also need to continue to improve our daily menus and enhance the quality of school lunch programs. Opting for alternatives to sweet drinks and candy as the ubiquitous rewards for school achievement, good behavior and celebrations is a start. And adults need to demonstrate healthy habits that support our own ideal weights and reduce stress levels.
Puberty is a complex biological phenomenon that is unlikely to be triggered by a single factor. Rather than be overwhelmed by the multitude of targets to tackle, perhaps we can begin with a focus on obesity and stress, the two culprits that research shows have direct and detrimental effects. It also makes sense to take a cautious approach toward chemicals in our households and in our foods. As mothers and researchers, we advocate for more research and also support the precautionary principle when it comes to making policy: If we don’t know whether something is safe, then we shouldn’t be exposing our children to it.
I don't know. I have a lot of anecdotal feels about this. I feel like historically (on average), at least in America, girls had MUCH more stressful lives, way fewer protections, and way less security than they do now. And children born in the 60's-90's before all the pro-BF stuff were often formula fed, right? When did the early puberty thing start?
Post by fortnightlily on Feb 5, 2015 8:37:35 GMT -5
Yeah, I kind of have the same questions as summer. I know anecdotes aren't data, but the one girl I know who seems to be hitting puberty early (10!) is neither obese (diet notwithstanding...) nor living in an especially stressful environment.
It's hard to quantify stress because it's all about the perception of the individual dealing with it. A psychologist buddy of mine claims that a girl fretting over grades and mean girls in middle school would perceive that in the same way her great-grandmother perceived economic insecurity, racial or ethnic discrimination or abuse. I find this hard to wrap my mind around, but she's the expert.
What constitutes "breastfeeding". While 3/4 of new moms breastfeed in the hospital (2013), just under half are breastfeeding at 6 months and even fewer are exclusively breastfeeding at 3 months. Is that level enough to confer the benefits of breastfeeding for this purpose?
It feels to me like your dates may be off but it's hard to know. Commercial formulas weren't available until the 1920s and then primarily in urban areas. Of course, some mother fed homemade formulas made from evaporated cows milk or some other mammalian milk. Breastfeeding was actually pretty common, especially among rural women and those with limited resources. Breastfeeding was often the closest thing a woman had to a method of family planning which may have added to its popularity as a feeding choice.
I'm older. I know I was not breast fed- I got goat's milk for some reason. My sister who was born in the very early 1960s got a homemade evaporated milk and corn syrup brew common of the era. Grace Kelly and LLL started to have a small impact of public perception in the late 1950s.
My mother and her siblings were all breastfed for 6-9 months. I suspect my dad wasn't. It seemed a lot of the women I knew who had children in the 1970s at least did some breastfeeding- I babysat a couple of my mom's teacher friends whose kids were breastfed. Of my nieces and nephews born in the 1980s, only the two nieces of my one SIL were not breastfed my sister and my 2 other SILs breastfed for some time. Of my mom friends who had their kids in the 1990s- everyone tried to breastfeed- only one failed because of reduction surgery so far as I know. It's really hard to find older information around this.
I have the anecdotal feels, too. I'm suspicious of milk, in particular. It contains growth hormone, for Pete's sake! At least it won't hurt anything to give the kiddos organic, non-hormonal milk.
I definitely, definitely think that estrogenic chemicals in our food and our environment are playing a role, here. I don't totally buy the increased stress hypothesis because I'm pretty sure that our current levels of stress are not significantly higher than in the past. I mean, are we saying that girls today face more abuse and upheaval than in the past? I don't think so.
Obesity plays a huge role, yes, but there is a chicken and egg argument to be made here about growth hormones and estrogenic chemicals which may be playing a role in obesity as well.
I think so too.
There was a Terri Gross about this a while back where the researchers discussed all this along with the BPA/other chemicals playing a the biggest role. And it's not simple enough to just avoid plastic since there are in basically everything.
So what's actually really interesting is that puberty is also tied to when you get your teeth as an infant (for both boys and girls). If you're an early teether, you're going to hit puberty earlier. I was BF and didn't hit puberty until I was 14. My first friend was 10, we were in 5th grade and it sucked for her I thought there had been studies that showed that hormones in milk and meat were connected to earlier puberty?
I don't know. I have a lot of anecdotal feels about this. I feel like historically (on average), at least in America, girls had MUCH more stressful lives, way fewer protections, and way less security than they do now. And children born in the 60's-90's before all the pro-BF stuff were often formula fed, right? When did the early puberty thing start?
I should go looking for this, but several studies did find a link to obesity (where the insulin does something to your hormone production) and a larger amount of hormones (used in commonly in livestock to boost their production/size) with significant correlations to early puberty. I was thinking that was in the later early 90's or late 80's when the changes jumped a lot. I'll have to go find the study I read. I feel like it was linked from here maybe 3 or so years ago.
I was thinking the same thing! I got my period in 6th grade and was one of the first girls to get it.
If you look around for historical data, it looks like anywhere between 13 and 17 was the average for industrialized nations. Hunter-gatherers are closer to 16-17. The move from 13 to less than 13 is post 1950's US.
So from pre-industrial populations to 1950's there's quite a large shift from 16-17 to 13.
This is particularly interesting if you consider the shift in life span as well.
Ditto I thought it was the hormones in cows' milk.
My mom had menarche at age 9, in 1950, which was SUPER early. But she also had received a shitload of steroids in treatment due to a severe case of rheumatic fever for which she was hospitalized for a few months. The difference between her 4th grade and 5th grade class photos are striking; she grew like 5 inches and gained 30 pounds.
Whereas I didn't have menarche until I was 13 1/2, in 1985. All my friends got it between 11-13.
And if it's the chemicals altering hormones, then what about boys? Are they entering puberty later due to estrogen-like influencers? I wouldn't be surprised if all of our exposure to plastics and stuff plays a role in this but I don't think it's the whole story.
I was going to ask about this also. I'm very interested in the use of soy to stave-off early puberty in girls and also to use to help women transition into menopause with fewer symptoms.
I also wonder what does this do to our boys? I avoid feeding much soy to my boys (because it does act like estrogen) and I worry that will cause some hormone imbalance. Plus one doctor told me to try the milk-based formulas first and if my kid did okay, to use those since she was "wary" of soy-based formulas for long-term hormonal issues for boys. Is that a thing? We only used formula for about a month so I didn't worry about it. Conversely the testosterone used in meat production might spur boys into early puberty or cause hormone disruption for both boys and girls (isn't that part of PCOS - too much testosterone production?). I'm very curious, but also know that I think a lot of these things have been studied and continue to be studied in the public health sciences.
I'm having actual emotional feels about this because DD2 is 10 and she's getting boobs already. I really hope her period holds off a little longer. She is SO immature for her age, I don't know what that would do to her. Anecdotally, she was a very early teether and she's always been thin and tall. My oldest was 12, nearly 13. I was 12.
That said, I think it's all about the food. It'll be interesting to see if DD3 does any differently, since we definitely made some food/milk changes before she came around.
Yeah I feel about this the same way I feel about large birth weights. We don't have enough history to really talk about it and what we do have was tainted by a lot of bad health and bad lifestyles. And apparently girls who start puberty early often have family who did as well, so that's another nature vs. environment layer.
So what's actually really interesting is that puberty is also tied to when you get your teeth as an infant (for both boys and girls). If you're an early teether, you're going to hit puberty earlier. I was BF and didn't hit puberty until I was 14. My first friend was 10, we were in 5th grade and it sucked for her I thought there had been studies that showed that hormones in milk and meat were connected to earlier puberty?
Both of my kids are scripted to hit puberty early, then. Just like I did. I got mine in 5th grade and was one of the first girls to do so. It sucked. Hardcore. I also had big boobs and was chubby. Just thinking about it makes me want to cry when I think of my kids.
I grew up in the dairy state, FWIW. A whole lot of meat and milk happened in my house. I also drank a metric ton of soda starting from a very early age (I remember as early as 6) and ate processed foods like they were going out of style.
So what's actually really interesting is that puberty is also tied to when you get your teeth as an infant (for both boys and girls). If you're an early teether, you're going to hit puberty earlier. I was BF and didn't hit puberty until I was 14. My first friend was 10, we were in 5th grade and it sucked for her I thought there had been studies that showed that hormones in milk and meat were connected to earlier puberty?
I had no idea about the teething thing. BBT was a very late teether (she only had two teeth by her first birthday) - it will be interesting to see if she's also late to puberty.
I got my period when I was 13, and I feel like that was pretty average for my friends and classmates at the time.
So what's actually really interesting is that puberty is also tied to when you get your teeth as an infant (for both boys and girls). If you're an early teether, you're going to hit puberty earlier. I was BF and didn't hit puberty until I was 14. My first friend was 10, we were in 5th grade and it sucked for her I thought there had been studies that showed that hormones in milk and meat were connected to earlier puberty?
I had no idea about the teething thing. BBT was a very late teether (she only had two teeth by her first birthday) - it will be interesting to see if she's also late to puberty.
I got my period when I was 13, and I feel like that was pretty average for my friends and classmates at the time.
It's what our ped told us. Neither of my kids had teeth by their first bday and both my brother and I were really late to puberty (as was my dad) but no one can remember when we got our teeth. It sucks for guys for sure, but I wouldn't mind if the girls were late to puberty (though it will probably bother them).
Post by Scout'sHonor on Feb 5, 2015 13:29:54 GMT -5
My younger sister got hers a whole year before me, so when she was 11 and I didn't get mine til 13, so I felt like I was late. I have no idea about the teeth though.
I thought when you started puberty was genetic. My mom started around 9 and I got my period the week before my 10th birthday. I had always heard if was common to start around the same age as your mother.
I thought when you started puberty was genetic. My mom started around 9 and I got my period the week before my 10th birthday. I had always heard if was common to start around the same age as your mother.
I've heard this as well. If I recall correctly, both my mom and sister started at the same age as I did (5th grade). But, then there is my niece (my sister's daughter) who will be 13 this year and still hasn't gotten her period. She is extremely active, though, so that might play a part.
I remember being one of the last in my class. I was the youngest too, but I was 13 and in 8th grade when I got my first period. It seemed like we had one girl around 9/10 in 4th and then the rest were mostly 5/6/7 at the 10-13 range.
I had it early. Started deoderant in 2nd grade, bad acne and starter bras in 4th grade, full height and D cup bra in 6th grade (age 10), got my period the summer between 6 and 7th (younger side of age 11). Looking back, it was one of the positive aspects of being a grade ahead because while I was early, there were a few other girls along with me. I think most girls seemed to deal with getting their period between grades 7-9. If I had actually been in my 'real' grade, it would have been so much harder. I was a normal weight until I hit puberty (overweight by age 14), and while my parents didn't have a great relationship, I didn't really pick up on that and actively stress over it until I was 10-11yrs old.
Post by anastasia517 on Feb 5, 2015 14:22:17 GMT -5
Well, I was a late teether and had a very low body fat and I started my period a couple months after turning 12. I didn't even really need a bra for a couple years after getting my period, wore 00 pants, and was maybe 80lbs despite being 5'3" ish when I started.
My little sister started when she was a year younger than me. Our mother started at 12 though, so we were both in the same range as her. We were born in the early 90s and she had us in her early 30s, for the record.
I thought when you started puberty was genetic. My mom started around 9 and I got my period the week before my 10th birthday. I had always heard if was common to start around the same age as your mother.
as far as hormones and fertility go I am much more like my father's family than I am my mom's.