In this podcast episode, EWG President and co-Founder Ken Cook spotlights the chemical compounds known as endocrine disruptors and how they can interfere with hormones. The health harms that can result, and how to prevent them, are gaining increasing attention.
The podcast revives Cook’s interview from 2010 with Dr. Louise Greenspan and Juliana Deardorf, Ph.D. about their book, “The New Puberty,” to discuss how exposure to endocrine-disrupting chemicals can lead to early-onset puberty and related issues.
Cook later in the episode speaks present day with Dr. Natalie Shaw, a pediatric endocrinologist and clinical investigator, to discuss her team’s new study showing that chemical exposure to young brains impacts their hormones, which can result in early-onset puberty.
Disclaimer: This transcript was compiled using software and may include typographical errors.
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Ken: In recent decades, pediatricians have discovered a disconcerting phenomena in their practice when they were examining young girls. Many of them appeared to be entering puberty years earlier than they had in previous generations. To give you a bit more context for what you just heard, this is an interview from the EWG archives that I did in 2010.
For those of you listening to the audio version of the podcast, you missed out on a really great necktie I was wearing. A necktie, by the way, was a long, slender piece of fabric that was knotted around the neck for ceremonial purposes. I'm Ken Cook, and I'm having another one of my episodes. And just to remind you, at EWG, we're driven by facts, not emotion.
But sometimes, the facts really piss us off. The facts we'll consider today, girls are entering puberty at younger and younger ages. Why? And what role might environmental chemicals be playing? My organization, EWG, has been tracking this disturbing phenomenon for many years. So the question is, what are we doing to our girls? And why?
Now let's go back to that archival interview from 2010 while I go and try and find that necktie.
It began as a scientific mystery. And then became a scientific debate. But now we know that in fact there is a new puberty. It has profound implications for parents and most importantly for our girls. A new book by Juliana Deardorff and Louise Greenspan called The New Puberty is a must read for anyone who wants to understand what might be happening to our girls.
Louise Greenspan, MD: A large study that came out in 1997 that was done on a large group of girls where they were examined once. And some of the techniques that were used in that were criticized by people in my own field, pediatric endocrinologists. And there was some, there was a huge debate within the community, the scientific community, about whether the study was done correctly and whether the results were right.
So, in 2001, we entered into looking at this. So, the results came out showing that at age 7, 23 percent of African American girls had signs of breast development. And for the Hispanic girls it was about 15 percent and the, uh, Caucasian girls it was about 10%. Prior to that, people in my field and pediatricians had said any development at age 8 is a medical situation.
And now we're talking about almost a quarter of African American girls having this. And that was 2010, and I think at that point people realized, no, this is a real phenomenon, and this is not, based on a faulty study, and that the study in 97 was actually a good study.
Julianna Deardorff, PhD: I also think it's really important to mention that we have seen puberty accelerate or start earlier across all ethnic groups in this country.
So there are both short term and long term problems that have been associated with early puberty. In adolescence, girls who mature earlier than their same age peers are more likely to initiate alcohol and drug use earlier, um, to be sexually active at earlier ages. They're also at higher risk for depression, anxiety, eating disorders.
It's a host of kind of alarming outcomes. In the long term, uh, in adulthood, girls who have their period, first period, or experience menarche early, it's been linked to breast cancer risk, also cardiovascular risk.
Louise Greenspan, MD: The main reason we wrote this book is because we wanted to help the girls that we don't see in our office.
We really wrote this as a guide, not just to prevent early puberty, but if it does happen, how to build the emotional closeness to prevent those sort of scary things from happening, as well as the practical things that would prevent the health outcomes.
Ken: So, as you describe in the book, it's not like we're evolving so rapidly as a species.
There's a combination effect here between what we bring to the party genetically, And something we're exposed to, maybe several things we're exposed to in the environment, that in combination might be resulting in this phenomenon that you call the new puberty.
Julianna Deardorff, PhD: We come to the table with, uh, not just a genetic makeup, but an ability to determine what genes to turn on and off based on the environmental messages that we're getting.
Louise Greenspan, MD: So the other question that I think is of great relevance to EWG's work is, we used to say that it was two to three years between breasts and first period. Now we're saying, well if you do the math, if it starts at 8 and it ends at 12, it's a 4 year window. We think of that time as a great window of susceptibility to any exposure, any environmental exposure. Because the breasts are developing and changing and the body is growing rapidly as Julie said.
So one of the concerns we have when we think about the environment is any exposure that you have at that time, the effect is probably magnified because of the rapidly growing cells.
So exposure to toxins might be magnified, and the effects might be worse if you have a longer window of susceptibility, if puberty is longer.
I think we have to take a step back and, and wonder why are girls being so exposed? And it's because there's a huge marketing apparatus that tells them that they need to be using this stuff at a very, very, very young age.
So I think you can start to rail against that and, as a mirror, I mean, I, I, just not using things you don't need to use. One example that I like to pick on is deodorant. Girls often get stinky armpits, body odor, is a technical word for that, but I won't use it, um, well before any other signs of puberty, and that can start happening age 7, very, very young.
And some people just want to throw deodorant on it, and I think that's concerning because the reason you have smell under your arms is because they're sweaty and there's bacteria. And if you teach your daughter to wash under her arms every day, or your son, either way, they take care of that and they don't need the deodorant.
So you should wash. Wash, use soap and water. Preferably a soap without triclosan. Um, just soap and water. And you can shower, you can do the little armpit bath. Then you don't need deodorant.
Ken: So simplify it. Simplify it.
Louise Greenspan, MD: And I also like that discussion because it then opens up, listen, I'm talking to you about stinky armpits. I'm showing you what I do. And that actually paves the way for starting that conversation about the changes in deodorant.
Ken: That was 2010. Let's snap back to today. One of the themes of my episodes is exploring the frontier of new science, linking the environment to our health. And it doesn't get newer than endocrine disruption or hormone disruption.
Now, concern about chemicals messing with our hormones isn't just on the minds of people like me or the odd scientist here or there. This idea has been formally embraced by the Endocrine Society. The Endocrine Society is an organization of about 20,000 endocrinologists who are either researchers, medical practitioners or like our guest today, both.
These are the people you go to if you have an endocrine related health issue. Now that could be anything from cancer to an immune system problem. And what they say about endocrine disrupting chemicals is pretty alarming. Many of the sources of endocrine disrupting chemicals are the ones we talk about all the time on this show.
Household cleaners, fabrics treated with flame retardants, cosmetics, lotions, products with fragrances, pesticides in food, I could go on and on. Medical professionals who treat people for endocrine problems are worried about these chemicals. Let me say that again, the leading professional organization, the endocrine society, their leadership, and their rank and file members are officially worried on the record, that all manner of synthetic industrial chemicals you're exposed to in the environment are messing with our hormones, your hormones.
And if they're worried, shouldn't you be worried too? And new reasons for concern pop up every day in the scientific literature. My colleagues bring these stories to me constantly.
Today, for example, in the lead story for Environmental Health News, which by the way, you should consider subscribing to, it's amazing and it's free, goes like this. A recent study in Environment International examined concentrations of endocrine disrupting chemicals in the breast milk of new moms from 20 Chinese cities.
And again, Environmental Health News says, in short, in 19 cities, newborns ingestion of these endocrine disrupting chemicals through breast milk exceeded safe exposure levels. Five of these chemicals, including multiple parabens, bisphenol A, or BPA, and triclosan were detected in over 50 percent of the breast milk samples tested.
And I'll just say those are very common chemicals and products that we are associated with in daily life constantly. The authors note that the results also point to additional sources of exposure beyond breast milk and highlight that many lifestyle factors can expose new moms and infants to harmful chemicals.
Now, it's worth noting that breastfeeding has a lot of proven benefits and the study findings reported here are only one of the factors worth considering when mothers decide to breastfeed their children. Right, mothers shouldn't face a trade off when feeding their babies because our stupid fucking chemical industry has contaminated it, whether it's breast milk or formula.
Which brings us to today's episode. About a week ago, I read a new study from Dr. Natalie Shaw and fellow researchers that put a fresh twist on our understanding of the potential threat posed by endocrine disrupting chemicals. Dr. Shaw is a clinical investigator in pediatric medicine and endocrinology at NIEHS.
That's the National Institute of Environmental Health Sciences. You've heard of the U. S. National Institutes of Health. Well, NIEHS is one of the institutes. Natalie's study is very compelling. Her team exposed neuropeptides in brain cells which are thought to mediate the activation of puberty. To something in the ballpark of 10,000 different chemicals and what they observed was…
To tell us more about this study is Dr. Natalie Shaw herself. So welcome Natalie Shaw. Congratulations. We all thought this was such a cool, elegant study. I want you to tell me all about how you did it, but starting off, tell me a little bit about your background. Tell everyone what a pediatric endocrinologist is. I happen to know because it's been relevant to our family.
But welcome to Ken Cook is having another episode and you caused this one. This one's entirely on you.
Dr. Shaw: Okay, great. Thanks so much for having me. So a pediatric endocrinologist is basically a hormone doctor for kids. We treat things like growth problems, thyroid conditions, diabetes, and puberty, so early puberty or delayed puberty, and that's really been my focus.
I work at one of the branches of the National Institutes of Health that's called the National Institute of Environmental Health Sciences, and we're based in Research Triangle Park, North Carolina. And the goal of our branch is to understand how the environment influences human health. And my focus is how the environment affects pubertal timing and pubertal development.
Ken: Yeah, thank you for that. And so, does your day begin seeing a patient, or does it begin putting on a lab coat and going into some apparatus that's going to help you conduct your research? Which way does it go?
Dr. Shaw: Um, it depends on the day. So, I have an adjunct appointment at UNC Chapel Hill, so I see patients in their pediatric endocrinology clinic.
And then we have a clinical research unit on our campus where I see research patients. And then I also have a wet lab where we do some cell based studies, but this particular study was a collaboration with another NIH institute called NCATS, or National Center for Advancing Translational Sciences, and they're the ones that performed the screen of the 10,000 compounds.
Ken: We'll get into that. I've been to NIEHS a number of times, so have many of my colleagues at EWG. We actually did a symposium there on mixtures and cancer some years ago. We jointly sponsored it. This was when Linda Birnbaum was running NIEHS. Yeah, dear friend. So tell us a little bit about The endocrine system, what is it?
An endocrinologist, I know, studies hormones and all its many applications, but it hasn't been all that long, maybe 30 years, something like that, maybe 35 years, to my knowledge, that we've been concerned about chemicals messing with our hormone system. I was around at the release of Theo Colborn and Pete Meyers and Diane Dumanowski's book, Our Stolen Future, which sort of brought the notion of endocrine disrupting chemicals to the public eye.
In fact, we helped launch it in the mid nineties, but lots of sources of hormones in our body, right? A lot of organs secrete hormones. Tell me why you picked, the hormone location that you picked and how we know when an endocrine function or system is disrupted. How do we study that?
Dr. Shaw: Yeah, so puberty in boys and girls, it starts in the brain.
So there's a part of the brain called the hypothalamus. We kind of know that there are these different hormones. We call them neuropeptides. They're proteins released by the brain. And one of those is called Kisspeptin. And another one is called gonadotropin releasing hormone or GNRH. And those hormones then stimulate the pituitary gland to release two other hormones, LH and FSH.
And those stimulate the testes and ovaries.
Ken: And have we known this for a long time?
Dr. Shaw: GnRH much longer. Kispeptin maybe about 10-20 years.
Ken: Yeah, so I say that because all of environmental law and regulation is premised on science that's much older and focused on fairly major identifiable health endpoints like cancer and neurotoxic damage of various kinds.
Endocrine disruption is newer on the scene and also a very actively evolving area and you're, if I may say, you're at the forefront of it.
Dr. Shaw: Yeah, definitely. I'm not an expert in EDCs. I came to NIEHS about 10 years ago, so I'm sort of building that into my portfolio. So I'm not an expert in, you know, phthalates or PFAS, although those are things that we're studying.
I think that most of the studies looking at environmental compounds and relationship to puberty have focused on receptors outside the brain. So like the estrogen receptor or androgen receptor or effects on body fat. And I just felt like there was this, why are we looking down there and not in the brain if puberty starts in the brain?
Ken: Yeah, that struck all of us at EWG when we read the study for those exact reasons. And good on you for, for doing that. So, as you formulated this idea, how did you figure out which chemicals to expose these and you're exposing brain cells, right? Do I have that right?
Dr. Shaw: Yeah. Initially we used a human cell line that's commercially available and we overexpressed those specific receptors.
Ken: Now what does overexpressed mean?
Dr. Shaw: Oh, we made those cells put a lot of those receptors on the cell surface. So you do that using genetic tools. When those receptors get activated, calcium gets released in the cell and there are different ways you can measure that calcium signal using this robotics platform that NCATS has.
So we kind of were looking downstream of the receptor to see signs that it was being activated.
Ken: And so when it's activated, what does that translate into in terms of the phenomenon of, of puberty?
Dr. Shaw: So the Kisspeptin receptor is one level above the GnRH hormone. So if the Kisspeptin receptor is activated, then GnRH would be released.
And then down one level, if the GnRH receptor is activated, then LH and FSH would be released. In that initial screen, we were just looking for candidates and then that's when we did validation studies in the human brain cells and also in zebrafish.
Ken: Zebrafish as well. Yeah, that was interesting to me that you, uh, this is a common animal used in, in these kinds of toxicity studies.
What did the zebrafish tell you? You can't interview them.
Dr. Shaw: Not yet. Yeah. Um, no,
Ken: not yet. If we keep messing with their hormones, who knows, you know, they may have a podcast before long. Right.
Dr. Shaw: Yeah. So we collaborated with another colleague of mine, Dr. Erica Davis at Northwestern. And she exposed zebrafish embryos to one of the compounds called musk ambrette.
In these zebrafish, again using these genetic tools, you can link a hormone to this fluorescent reporter. And so you could actually see the change in the number of GnRH neurons in the zebrafish in response to this exposure.
Ken: So these are sensitive systems, right, that I'm always struck by the fact that of all the realms of science that look at the interface between chemicals and biological effect that endocrinology is commonly a science that operates in the parts per trillion level, right?
These systems are so exquisitely attuned. I guess the basic thesis is that these. External chemicals, these environmental chemicals. And in this case, you were looking at a whole bunch of chemicals that are in personal care products that they are causing this to happen at extremely low doses. Now, how did you figure out how much of the chemical to expose the cells to?
Dr. Shaw: I might have to call in the NCATS experts on that. I think that's pretty standardized, I would say, for when they do these screens.
Ken: But they're trying to mimic real world exposures, I guess.
Dr. Shaw: Everything in their library is based on the likelihood that these compounds are in our environment. So yeah, they're trying to mimic kind of what the exposure level would be, although, you know, again, what we found, we still need to do studies in humans and figure out, well, what sort of exposure would be necessary?
Is short term enough? Is long term required to activate these receptors?
Ken: Right. That's an interesting question, isn't it? Because with personal care products, there's the prospect that it wouldn't necessarily have to be a short term.
Dr. Shaw: hmm.
Ken: Phenomenon, since people tend to use these things every day.
Say a little bit about what the consequences are of early onset puberty. You must see it in your practice. And, um, how do you have those conversations, Natalie?
Dr. Shaw: Yeah. Usually patients are coming to see me when it's extremely early. Precocious puberty is defined as breast development before age eight and girls or are signs of puberty before nine and boys.
Ken: Can we just stop a minute, so this is happening to these little kids.
Dr. Shaw: I mean, parents are almost always very worried about it. And mostly, you know, what is my daughter going to do when she gets her period? But usually that's, you know, from the time of breast development to the first period is usually about two years. So there is some time there.
I guess the good thing is that we do have ways to treat it. So there are medications called GNRH agonists. And those are given either as shots or as an implant and they basically suppress the system like they break.
Ken: They pump the brakes.
Dr. Shaw: Yep.
Ken: Yeah.
Dr. Shaw: When you stop those medications, everything just restarts back up.
Ken: This is what we're making kids do to deal with a problem that's been caused, you know, by these exposures. And, um, so you hate, you, you hate the risk of a side effect, but sometimes you have to do that too.
Dr. Shaw: So these drugs, you know, have been around, I think since the 1980s. So they do have a very good safety record.
And we know that in girls who are treated with these drugs, they go on to have regular menstrual cycles, have no problems with fertility. So we know of no long lasting effects. Most of the side effects are just, you know, you could have an abscess or infection at the site of the injection or related to the implant.
And in very, very rare cases, girls can have like hot flashes like a menopausal woman would because you're dropping their hormones down. But I have not seen that in my practice, but theoretically.
Ken: That's possible. And, and so just two immediate questions. Um, I, I touched on it earlier. Why did it take so long to figure out that early onset puberty was a real thing when there was a debate?
I know in the nineties, I remember that people questioned, is that just, um, part of the distribution of children on the continuum and there's no elevated occurrence of this phenomenon at an early age, but then people concluded otherwise. Can you say a little bit, a bit about that scientific revelation?
And I always thought it was because it was probably men doing the studies in the nineties, but that's just me.
Dr. Shaw: Yeah. Well, I think there were some initial doubts because in those early studies, breast development was assessed by just inspection. So just looking at the child without touching, without palpating.
And so there was some thought that fatty tissue could have been misinterpreted as being breast tissue. And I should just say, so the age at breast development has declined, but the age at menarche has not changed all that much. We're talking months. I mean, it's still earlier, but it's not years and years earlier.
But the breast development is interesting and that does seem to be happening earlier in the general population.
Ken: And there are all kinds of questions about that. Uh, I don't think anyone's saying it's all chemicals, but I think it's not evolution. Nothing, uh, sped up evolution in the early nineties or whatever it was.
So it is something that having to do with lifestyle, um, which, you know, is kind of a confusing term to me because that can mean a lifestyle can be, yeah, I use personal care products all the time, but it's actually the chemicals in the products, not your habit of using them. And then what do we know about the long term consequences if you don't treat?
Why do we worry about this phenomenon taking place, other than some of the obvious things about, you know, the parental alarm and the appearance of breasts and pubic hair that would be, you know, seen as maybe socially embarrassing or, you know, ostracizing. I know these have all been factors that have come to light.
But what are the deeper associations with health impacts later in life, Natalie.
Dr. Shaw: Well, definitely there have been a lot of epidemiological studies, mostly looking at agent menarche, because that's just an easier data point to collect. But that that's associated with higher rates of cardiovascular disease, diabetes, breast cancer, obesity, depression, anxiety, earlier, uh, sexual debut, sexual abuse.
Yeah, I mean, it hits all systems. And then in the girls with truly precocious, very early puberty, we worry about short stature because initially estrogen will cause a growth spurt, but then it'll cause the growth plates to close.
Ken: Oh, okay. I hadn't heard of that association.
Dr. Shaw: And so if you don't treat, you're talking about if, especially if the girl has short parents, not being able to reach the pedals in the car. That's kind of the extreme, but that also does come into the conversations.
Ken: Yeah, of course, well, not an outcome that we want if we can avoid it and let's talk about avoiding it. So what chemicals did you select? In the article, it talked mostly about, I think the ones, well, it talked about all of them, but mostly the ones that caused the positive effect where the, you know, where that was the big finding.
And those were things like musk ambrette, uh, which is, we don't find it in our extensive database of personal care products online Skin Deep, but it's hidden in probably in some fragrances because fragrance is a catch all term that can include, in many cases, we know from experience working with companies, it can mean hundreds of chemicals that are blended together to create a fragrance that might be hiding a bad smell or creating a good smell or both.
And musk ambrette is something that is used in some, you know, detergents and perfumes, oftentimes sort of the cheaper ones, it seems like. It's banned for some applications in the EU, but what, what was the range of chemicals that you looked at? What kinds of things were they?
Dr. Shaw: Yeah, it was things like you mentioned, things that could be found in personal care products, dietary supplements.
You know, chemicals, drugs. There are, you know, like you said, this is a compound that's prohibited and regulated, but these days you can buy what you want off the internet, right? And I mean, I just think I don't want to overstate what the exposure to this could be, but I just would say, you know, pay attention to what you're putting on your kids bodies.
Ken: Yeah. And go with a reputable company. Don't get that bargain fragrance because a little known or unknown brand that's much more, more likely to be a risk. And for anyone out there who's wondering if this is sort of a one off or if this is just the concern of Natalie Shaw and a few of her colleagues, I invite you to go to the Endocrine Society's website.
Dr. Shaw: Yeah. Well, I'm a member. Yeah.
Ken: Yeah. It's a scientific association of some 18 or 20,000. Practitioners, uh, sometimes they're scientists, sometimes they're medical professionals, or in your case, both. And you really have to read what the Endocrine Society says about these endocrine disrupting chemicals to appreciate the extent to which the people who work in this field day in and day out are looking at these minute doses, looking at these health impacts, to appreciate how concerned the Endocrine Society is and about these chemicals coming into our bodies and fooling our bodies into thinking there's a hormone that's supposed to be there, but it, it's not, it's a chemical that you've put on your skin, you've been exposed to when you've cleaned your house, something that might come out of an exhaust pipe or whatever it might be.
There's lots of different sources. And we've only really recently begun to look at relatively recently begun to look at how they might In subtle ways affect our hormone system.
Every time I read the site, I think, man, I have to catch up. I have to be more concerned. So as you did your study, what was it like when you started to see the findings come in? What was the reaction? On the research team. I mean, I assume your hypothesis was That some of these chemicals were going to trigger these chemical signals that you'd, and you'd be able to detect them.
But we have the same kind of thing at EWG. We might test food for toxic chemicals. And it's like, yeah, we found it. And then we think, oh yeah, we found it. Right? Like, why are we, I mean, there's an excitement about the discovery, but there's also then this sort of, uh,
Dr. Shaw: Right. I mean, we didn't really know what we would find because we're looking at these very specific receptors in the brain.
But yeah, I mean, I think it was kind of exciting as a proof of concept, like this sort of design can help us identify things in the environment. We can use this, what I call like an unbiased approach. We're not cherry picking things that we think might be important. And so it was, It's exciting for sure to find something and, and then, you know, this isn't an all encompassing library so there's a lot more work to do and to see, okay, now we have a structure of this one compound, so what else is in that family that, that might not be in the library but could also similarly affect the receptors.
Ken: It's a pretty good sized team, it looked like. Will you keep the band together and do follow ons, or is everybody going off in their own directions? What, what's next?
Dr. Shaw: So we're going to do another screen looking at another gene that's expressed in the same population of cells in the brain. We want to do maybe some work using a mouse model to look at, you know, what sort of exposure is necessary to activate these brain cells.
And then maybe move to human subjects and try and get a sense in kids, you know, how often are kids exposed to these products.
Ken: That's exciting to think about that you're going to follow up on that. And I guess one question is, could exposure like early, early on to these cells, these cells must develop fairly early in developmental biology.
So that'll be a question. Can exposure of the parent?
Dr. Shaw: Right. Right.
Ken: We don't know, right? So it's moms and dads, be careful too, don't just worry, right? Well that, it sort of gets me to, at the personal level, Doc, and you see, you see these girls and you see their parents. And so if someone you cared about had young ones coming along or was pregnant and thinking about maybe for the first time environmental exposures in a way that a lot of people don't think about until they are in that stage of their life.
What do you tell them because you know, we see online a fair amount people saying well you know, this is just there's no real evidence that there's harm here. Um, this is overblown. This is you know activists trying to raise money or whatever, whatever arguments come out. I always send people, if it's endocrine disruption, straight to the endocrine society and say, Hey, don't take it up with me.
Talk to the people who do this for a living. But you personally, how, how do you think about this? I mean, you know, I know my journey has been complicated by the learning I've been exposed to from my colleagues. What would you say to your best friend? What do you tell them?
Dr. Shaw: It's a hard question because even the study that we did, you know, we haven't proven causation and you just really can't do that.
We're not going to expose kids to this and see what happens, you know.
Ken: It's illegal, immoral, and everything else that's ill, yeah. Yeah,
Dr. Shaw: But I think, you know, like what we touched on before, keep it simple and you know, pay attention to ingredients and like, unless your kid has a skin condition, like, why do you really need to be putting this stuff on their skin?
Like, what's wrong with soap and water?
Ken: Very much like the advice we give people. We try and make it very clear that we don't. often have causation, but, but where there's concern from studies like yours and many others that have come out, we say, look, we've probably haven't gone about this just right. As a society, we have introduced things into the world that we didn't fully understand the impacts of.
And because that's the case, so often the case, you're not crazy to take, you know, steps to simplify your life, remove exposures. In some cases we may never know, right? There, there's not enough money to know there's enough money to get it on the market. There's not enough money to understand the impact of it is what it comes down to.
And so that's not the same as saying, hey, nothing to worry about. They're just growing up a little earlier.
Well, Dr. Shaw, thank you so much. This has been great. I look forward to following your work and congratulations on this paper to you and, and all your colleagues. We'll put it up on the screen. So they're all, they're all shown, but we, we very much appreciate that you've pulled away from your patients and your laboratory, uh, to spend some time with us today.
Dr. Shaw: Thanks for having me.
Ken: You bet.
Thank you, Dr. Natalie Shaw, for coming on the show and for all the work that you and your colleagues are doing. I'd also like to thank Dr. Louise Greenspan and Dr. Juliana Deardorff for speaking with me in 2010, teaching me so much, and for writing The New Puberty, an amazing book.
Thank you to my necktie. Lastly, I want to thank you out there for listening. If you'd like to learn more, be sure to check out our show notes for additional links for a deeper dive into today's topic. Make sure to follow our show on Instagram at KenCooksPodcast and if you're interested in learning more about EWG, head over to EWG.org or check out the EWG Instagram account.
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My ask is that you send it to that person or as many people as you see fit. Today's episode was produced by the amazing Beth Rowe and Mary Kelly, and our show's theme music is by Moby. Thank you, Moby. And thanks again for listening.