Welcome to the huberman Lab podcast where we discuss science and science based tools for everyday life. I'm Andrew huberman. And I'm a professor of neurobiology and opthamology at Stanford School of Medicine. My guest today is dr. Shawna Swan dr. Shawna Swan is a professor of environmental medicine and Public Health. At the Mount Sinai school of medicine. She is a world expert in how exposure to various toxins and compounds in the food.
Food and environment impact, our reproductive Health, she focuses on how these compounds in our are in our food supply, in our water supply in cosmetics, even in household items, impact, the developing fetus children, and adults at the level of their reproductive biology. So, things like testosterone and estrogen, and the pathways within the brain and body that are impacted by testosterone and estrogen but also how, all of those things in our environment and that we put into our body.
Packed our health on a daily basis and our long-term health. So, during today's discussion, you will learn why fertility rates are indeed dramatically dropping from year to year and have been for quite some time now. You'll also learn why testosterone levels are dropping y, sperm counts, are dropping why things like polycystic, ovarian syndrome are increasing in women and what we can do about it, in fact, during much of today's discussion dr. Swann emphasizes the things that you can do every single day and that
That in fact, turn out to be very simple. They involve certain things to do and certain things to avoid in order to limit your exposure, to these environmental toxins and their impact. So, by the end of today's episode, you will be highly informed by the world expert on endocrine disruptors and environmental toxins. And you will also be highly informed in terms of how you can have agency, how you can take control of your health, in relation to these various compounds before we begin, I'd like to emphasize that this
Cast is separate from my teaching and research roles at Stanford. It is however, a part of my desire and effort to bring zero cost to Consumer information about science and science related tools to the general public in keeping with that theme. I'd like to thank the sponsors of today's podcast. Our first sponsor is element element is an electrolyte drink, that has everything you need and nothing you don't. That means the electrolytes sodium magnesium and potassium in the correct ratios, but no sugar, we should all know that proper. Hydration is critical for optimal brain and
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Again that's our okay a.com and enter the code huberman at check out. Today's episode is also brought To Us by better help better. Help offers Professional Therapy with a licensed therapist carried out entirely online no I've been doing weekly therapy for well over 30 years. In fact I consider doing regular therapy just as important as getting regular exercise including cardiovascular exercise and resistance training exercise which of course I also do every week now, there are essentially three things that great therapy provides first. It provides
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I've seen some of your appearances on other podcasts and I got to see you speak while we were both in Copenhagen. I was in the audience. You didn't know I was there but incredible stuff that you've been doing it as a researcher as a public educator. As a writer. Let's kick off by just asking the basic question.
Are there things in our environment, including our food that are diminishing, our reproductive and overall health. And if so which are the ones that you think about, and perhaps if you could just mention a few of the more Salient, maybe even shocking but Salient results that you've observed over the years. Like what was what was the that kind of like, whoa, result of results that have really
Steered your attention in the last couple of decades and I'll just say what we were talking about before we were on the microphone, which is that you are a skeptic, you are not somebody who walks out into the world and looks for things, that could be messing up. Ours, our biology messing up our health and yet you've found some. So, if you could just share with us, what you've observed, and what you find really compelling and important for people to know about, we can dive
in with a lot of questions. I could probably talk for a long
time. I feel free. I won't speak until your
Done know, what I want to break it up, let's break it up. So I think the first question about was, are their forces chemicals agents in the environment that can affect our reproductive Health. Yes. Okay, so my answer to that is yes, I think there's no question about that. The question comes down to when and in whom and what dose and so on and so forth. But whether there are
Let's just say, broadly things. Yes, of course the category that I focus on are man-made primarily man-made chemicals. Although I do also include the influence of
Other factors factors of choice. For example, sleep exercise. That kind of thing we can talk about that, but let's just focus here on the on the chemicals because I think that's what led me to do. A lot of my research and to write the book that I wrote. And so my thesis is that chemicals in the environment.
That's a very broad class. So we'll have to say some chemicals in the environment at the right time to the right organism affect fertility. Okay? So, and let me just say fertility is one area that I focused on. But actually this class of chemicals that I'm primarily interested in are those that affect the body's hormones. So those are known as hormone disrupting chemicals or endocrine disrupting chemicals.
Um, hormone, altering, chemicals, whatever. You know, there's a lot of names, but that helps you focus on where to look for the effects because if it's hormonal during you can now have something to really ask, okay, here's a chemical, does it affect a hormone? Which hormone, when how and then you start? That's almost a, you know, laying out an experiment right there, right? So, so focusing in on hormone disrupting chemicals I think is
useful.
Solutely. Yeah, and I think much of what we'll talk about today, probably centers on the estrogen and testosterone Pathways as they relate to masculinization or feminization right of the brain and body, right? And sperm and egg. Right koala. So
I'm a reproductive epidemiologist, I got there in an indirect path. I think probably my work on
Oral contraceptives led me there most directly and oral contraceptives are endocrine disrupting chemicals. It's hard to do right. That's for what they're designed to do. Change your body's hormones, your reproductive hormones. So it's interesting you know way back when when I work on the study at Kaiser on oral contraceptives which was the largest study of its kind in the world actually trying to figure out where their adverse effects of oral.
Receptive. So, you know, for whom and when and how much insulin as others are very great study and coming forward in time
I you know, I studied environmental chemicals. Not so much Pharmaceuticals for quite a while in when I was at the California Department of Health Services. And and then I had an aha moment. I was flying to Japan with my friend, John Brock, who was a chemist at CDC, wonderful chemist, and you have long
Lights were talking about this. And that's when he says Shauna, you should look at valleys and I'm going. Why should I look at Sally's? I never heard of phthalates, right? And he said well we can now measure them at the CDC and we see there in everybody. There are women of reproductive age. Fact one fact, two colleagues of the ntp have shown something. They are calling the phthalates syndrome and so he explained
What is ntp National toxicology
program? Sorry, thank you for using
alphabet soup or
national toxicology program. A governmental you know Research Center and and their job is to look at chemicals and see what is the toxicity? So it could be reproductive, it could be Carson, do this today, it could be neurotoxicity. That's what they do. And so they had signaled out these salads as
Being reproductively toxic and specifically to males and specifically when exposure is in
utero pregnant. Mom is exposed to phthalates and somehow the fetus is disrupted. Yes, if you don't mind, I'd like to know is Mom ingesting phthalates in the form of food? Is she inhaling phthalates? Are they landing on her skin? What are the modes of entry into the body of the mom? That was
Assume it goes through the placental barrier into the fetus and is impacting, fetal development,
right? So in those experiments, it was through food, but we are exposed in all those ways. You mentioned every way, that something can get into our body Sally's, get in there. But let's come back to that. Let me go to the experiment at ntp. So what if they did at ntp National toxicology program, they fed mother rats various doses of these various phthalates and
And what they found was, no changes in the females are not at, they found at that time. There, the female Offspring, female Offspring, sorry. But in the male offspring, they found that the genitals were I summarize it by saying in completely masculinized. So I'll explain what that is. So for that I have to back up and say something, you know, probably know very well but I'll just explain it the genital tract initially.
A ridge. So single Ridge. It's the same in males and females it's not sexually dimorphic at the beginning. And then under the influence of testosterone in a very specific window called the mail programming window in rats is days. I think 11:51 of gestations, a very short
window to orient people. I think rat mouse just station is about 21 days or so. Yeah. Okay, so
so so it's for us it'll be early first trimester, okay, but that comes later.
So, so at that time, if they feed their mother, that chemical in her food, then her male offspring are born with changes in his genitals or more likely to write. And so what they tend to have is a smaller penis, less Descent of the testes more likely to have understand the testicles. There are internal changes that we didn't get into
In our human study because we can't look there. But the epididymis there are changes and so on there, the whole genital tract is altered. And the most important measure for me is it turned out and for humans and perhaps our animals is something that the scientists animal scientists had studied for a long time for actually 90-plus years but had never been studied in humans and that is the
distance from the anus to the genitals this collection of changes in the male, genitals was given the name the phthalates syndrome. Now you're a physician and you I challenge you to think of any syndrome aside from alcohol. You know, they're feel alcohol syndrome. Of course there's a syndrome but know what syndrome is attached to a chemical class
just
Technical purposes. I'm a PhD. Not a clinician, but okay but but I worked on neural development for many years and then prior to that time endocrine stuff. So I'm facile with the general terms
One that comes to mind would be, for instance, the thalidomide babies, right? Ed miscarriage. Anti miscarriage drug, that changed, limb development. That's a very extreme example. I would say for in human normal development. What I'm most familiar with are the early organizing effects of androgens that convert to estrogen on external phenotype which is basically nerd speak for during
Development the Y, chromosome produces at least to the production of a number of genes and eventually proteins through RNA Etc that are including testosterone and dihydrotestosterone that in the brain organizes the brain male and causes the growth of the penis or organizes meaning it is. It sets up the penis to then during puberty when the penis is exposed to testosterone and estrogen and DHT to bunch of things. Not just this dosterone, the peanuts grows
So that right, lots of other things, right? So so the the word soup that I just, you know, put forward is basically saying that there are a lot of things in development where hormones set up a a potential to respond to other hormones later. It's not that testosterone grows the penis during development, it does that, but more so it's stablish has a potential for the penis to grow when exposed to things like.
Later during puberty. So I have that
right. As far as the name goes, which is the salad syndrome. There is so little my dad, it's not usually called thalidomide, so nobody could be, you say, you're right about that, but it's extremely rare. And I know there's no environmentally, you know, chemical in the environment as opposed to a pharmaceutical that is given a syndrome. So this is very, very unique and and so I thought
wow.
John's telling me this on the plane, right?
Something in the environment that is basically having an endocrine and body disruptive effect at least on par with alcohol. Fetal alcohol syndrome. And so let him I'd syndrome,
right? Yeah, so when well this point it was only animals, right? Because John was telling you about the ntp study which was in rats and so I thought wow you know, I like Puzzles. So my first question was
This happening in humans, you might ask that, you know, as a natural thing to ask a question and then, I thought, how would we find out?
And answering that question took me 10 years, okay? And so if you think about okay, phthalates in the mother,
Changes in the genitals of The Offspring, connect them. How do we do that? Alright, so we have to start with satellites in the mother. How do we know that? Well, fortunately or not, I had stored a lot of urine from pregnant women, from a study that I was doing on sperm count. I just got the woman's urine. Coincidentally, if you will, I thought well save it, you know, it's not expensive.
Civ and not hard minus eighty-degree. Freezers doesn't take a lot of room, put it in there. So I had this urine safe from pregnant women.
And then I knew from John that we could look in the urine for salad metabolites. So these are products that the body forms when they're exposed to salads and they you can measure them in urine. So I thought, okay, I could get that urine. I could look at the satellite metabolites and then I'd know what the mother is exposed to
And based on the animal data, we have good evidence that it actually makes its way to the fetus.
So then I thought, okay, then maybe there's a change in the babies so that I had to get the baby. So, fortunately, I had done this study on pregnant, couples pregnant, women, and their partners. And I was able to call them and say, would you come in and let us measure your baby's channels? Right,
how willing we're parents to let you do that? That seems.
Okay, most of them were they without. Yeah, yeah, well they trusted us, you know?
Oh, they had been in a study with us and, you know, we were
reputable. Those babies were still
young but not newborns. So this was a while later the babies that we actually got were on average. I think about a month 12 months old, so not ideal. Maybe because the rats had been measured at Birth. The rat genitals have been but that's what we could do at that time.
The other reason I asked is there's always the potential for ongoing phthalate exposure to our new boss.
Absolutely. So some but I suppose, in either case, you're able to draw some potential link between or potentially draw a link have to be careful with my language there. Between phthalate exposure in utero, and X utero, and these external
Benchmark. I mean, given that the critical window is quite short and quite early, by the way, let me just say, when the rats they did, a lot of work on this critical window, and when the rat moms were exposed before day 9, it did nothing. And when they were
Exposed after day 12, it did nothing. So it was only the exposure during that critical window is very delicate and it's, by the way, true of the brain as well. So there are you teasing out, what is the critical window? Is one of the challenges that we have when we work with these chemicals. So I wasn't so much worried about exposure in the delivery room and, you know, in their feed as in the first year of life because I knew it was unlikely to change.
Change these measures, do other things but maybe but not these measures. So then the question became kind of what you're asking. Is what do we measure?
What do we actually measure? And if you think about a newborn rat or Mouse, their genitals are pretty small and there's not there's an it's very difficult to know exactly how that corresponds to the human genital system and what you see at Birth you know, when you spread avoids legs and right and and so I got us a pediatrician at in Los Angeles who worked with me on.
On how to make that translation and how to do do this exam. And that took us quite a while because we really wanted to come as close as we could. What was clear, was that the anus part of it was easy? You go to the center of the universe. So that was easy. Then what's the other landmark, what's the general and myrrh? So it turns out there are in males to and in females there are two as well. So, but let's just talk about meals. So, for males, the best place to measure and actually
Ali closest to the rat measurement. Is the place where the tissue changes where the scrotum inserts and that it goes from Rue Gator too smooth.
Tissue and that point is, pretty clear, pretty easy to measure the other measure. And that was the inner Squirtle distance and the other measurement we took was the a no penile distance. And that was the insertion, the anterior insertion of the penis,
the part closest to the body,
the close to the Head.
Yeah. Closest to the Head.
Yeah. And and that was not so obvious because you don't have a change in tissue or there. So where exactly do you put your caliber and
We had a lot of discussion about, do you press down? Do you want to, you know, how where exactly do you make that Mark? And actually, the anus kernel is the measurement with the least variance because you can measure most precisely, but they know, penal is another measurement. And, and then in you can do something similar in females and we did that, but that's, we maybe don't have to go into that now. So we designed this,
Exam and we did a lot of work to make sure it was repeatable cross-examiners. And what we finally did was bring the mothers and bring the babies in and got three measurements. And then on every 10th baby, we got an independent examiner to get three measurements. So we could look at within and between examiner variation, you understand? This is the first time this had done been done this way in humans. There was
A Mexican study that tried to do this. And I never learned very much about it and I was excited that they had done this, but I'm not sure how it relates to this. I've just mentioned that out of honesty, you know, there's somebody in Mexico did this but to my knowledge, this is the first time it was used as a toxicological measure in humans, right? So we were, we did that study, we related those measurements to what CDC had
gerd in the urine of our women collected while they were pregnant.
And we found a salad Valley syndrome.
Could you explain what the correlation was between phthalates metabolite levels? Which is,
I believe not by number because I don't remember it anymore. But but there was a significant let's just take the AGD, the AGG of mothers who had higher levels of three the most Anti androgenic phthalates. I'll tell you what, those are in a minute, had significantly shorter.
Her inner Channel distance. And then I have to say that which I haven't said, I should have that energy General distances, sexually dimorphic. So it tends to be 50 to 100 percent longer in males than females that makes sense. If you think about what's going in that space,
There's a lot of real estate in males between the anus and, you know, they say the penis penal insertion much more than in females. So it's natural that that will be longer. But that's that's an area that I began doing some work in other looking at other species and it turns out that that's true in all mammalian species except two and one is the hyena, all right? And one is the elephant. So, in the hyena,
I'm just saying this because you would be amused by
it. Well, II - I do, I know more about hyena genitalia than I'd like to admit and I can tell you why after you educate us, but I'll make, I'll keep my explanation brief, but I'm very familiar with hyena
genitalia. So I know Stephen, Glickman, who works with a, you might know him to his Works in Berkeley
where he was my instructor when I was a graduate student at cow.
And I used to run in Tilden Park. I suppose I'll tell it now and there was a colony of wild hyenas but they were behind chain-link. It's actually a favorite hike of mine up, the Strawberry Canyon Trail and I did that trail. A good friend of mine, Brian Prendergast. Who's now a professor at the University of Chicago worked on the Prairie voles that were also housed at that facility. And a fun thing to do was to go see the hyenas with Steve, their brutally, dangerous animals.
And Steve has tons of stories about them. We should probably resist our temptation to go inside our lands that maybe sometime I'll do a little like evening chat pod cast where I tell. Steve Glickman stories. He's a delightful person and you had those let's just say this, the female hyenas have clitoris is larger than some of the male hyena, penises and those females give birth through those clitorises. Yes, as we both
know you will not be surprised to know that the female
Male HD is longer than the male,
right? Because they're heavily Androgen eyes. Exactly. As I recall by androstenedione as actually I don't you know that it became popular during the era of steroids and professional baseball because understand I owned was being used pretty frequently in baseball, at that time. Anyway, we have to be we could go down the spiral of. But also in
terms of behavior, the female is the alpha, right? Right.
Eat first? Yes, they're physically and hierarchically dominant in hiding.
So it's really interesting. Isn't it? That they would have a longer more masculine and your channel distance the elephants we won't go into now. But they are kind of Midway in many things. So, including they're about equal inner gel distance and males and females. Other than that humans and other species mail and
General distance is 50 to 100 percent longer. However, so three, phthalates diethyl, hexyl. Fowler dehp dibutyl phthalate, DBP and butyl benzyl foul. I'd be bzp are the most Anti androgenic look testosterone, lowering salads, and those are the ones that were associated with a shorter, initial distance,
In males in human males,
human males and animal. So we replicated that animal study in humans and then because you know this is how it is in science. I had to do it all again, right?
So I started a whole new study and that study is still going on. The children are still being followed. I think we started in 2012. The paper first paper on Energon, General distance came out in 2005, had a pretty big impact. And
so these are our studies where you're looking at the Inno General distance in relatively new,
when humans than tracking that distance.
No, that's a different tracking, is another study. Okay. This is just two studies on demonstrating the salary syndrome in human males, okay? So the first one, I described the second one, the replication and the second one is the one that's going on still. So and whether what it does to their reproductive function, we don't know. The kids are only 12 years old. So, so we, we would like to know that and we will know that, okay, but I have another answer,
Tea for you about that. So, so we started the second study and the second study, which is called Tides, which is the infant development environment study, by the way, these are both in four cities in the United States and there we did it, right? So we got the urine in the first, you know, earlier, Vern, because we knew that could be important. We didn't have that option in the first one. Remember those urine samples were accidental, we got them, when we
Good. Right. And we got repeated yourens one in each trimester to look at the effects in different trimesters and then we examine the babies at Birth which is what the rats. So we came much closer to replicating their the rodent study and we saw it
again.
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And to claim this special offer more phthalate, exposure equates to Shorter in a general distance in males. It was approaching the distribution in females. It sounds like the distributions moved more closely together. Yes, right.
Yes, although it wasn't the females that move,
sorry, the mail distribution became more became more right, there is a feminized but my female like in
it and they put these boys also had smaller penises
Less Descent of the testes smaller scrotums though so they were smaller. You know everything was in their genital
area are all the secondary sex characteristics of puberty and males. Adam's Apple facial or growth thickening of the vocal cords. Therefore, lowering the voice etcetera. Are those all later activating effects of hormones, or are their precursors to those that are present in, in in males because, in mice, as I recall
I like like I couldn't I couldn't tell you like we call it in the laboratory people. I was chocolate this, but it's like sex in the animals. When you, you know, look to determine if it's a male or female at when they're when they're really young, you have to like look carefully at first, right? And then you get pretty good at it. As I get older, it gets easier but when the mice are you know, feet down back up, you know, you can't really you can't really tell, you know, you can't really tell
Right? The as the mice, get all their, their testicles become visible, in the males, from, even from above. But, you know, as far as I know, there aren't really external marker. So, you may have found the one truly external biomarker of, maleness
of maleness. And and so, I do want to say one thing about females because then that'll leave me to my conclusion about the role of this measure. So if the mother
Is exposed to more testosterone than expected.
You might expect that, her female offspring would have a more male in a general
distance. Is that the case? Yes. So it's a bi-directional. Yes. Can we also presume that if the mother either secretes or is exposed to more Androgen than the males can become hyper
male know? We'd never. I don't know what that would be. We never saw anything. That would be hyper mail. So the the yes I said to you was the result of a
Study where we looked at the girls born to women with PCOS. So women with PCOS as you know have excess testosterone
polycystic
cystic. Oh sorry
polycystic ovarian syndrome. That's what we've talked about a little bit before in the podcast it's a its associated with my understanding is its associated with elevated levels of
androgens, huh? That's right. These women often have facial hair and you know, the
not just the moms but the
The women with PCOS. Yes. Have elevated androgens. Yes, not just we're not talking about pregnant moms. Exactly.
And so, in our study population, we did a search for women who had diagnosis of PCOS and took that as a marker of higher testosterone, exposure and then looked at the girls and yes, those girls had a longer quote more masculine in a general
distance. What age group were you looking at
the PCOS? Was that
Was that diagnosed at pregnancy at the time they were
pregnant. So are you moving people between their, like, somewhere in their 20s out to their 40s? Yeah. So
Adult human females who have PCOS tend to we know they have higher levels of androgens but they also have more male, like, you know, genital
distance, they do not their
daughters, do their daughters do. Thank you for that
clarification, their daughters. And so put this together, this measure is
A look inside the womb at the Androgen level that the fetus is exposed to at that time, which is amazing because you can't go in there without disturbing. You know you can't. And so this is very early first trimester you can t get you know, fluid and so on. So this tells you this is like a readout of what was in.
You know, in the fluid at the time. So then, your next question was, what does this mean for later, fertility? Yes.
Yeah. What? What is the impact of this early Androgen exposure to female Offspring? Or let's, just say reduction in functional Androgen exposure to male offspring. The reason I'm using these in a loop
Dilute languages as you probably know but for the audience, not trying to complicate things here, but a lot of the masculinizing effects of hormones in fetal, development is actually testosterone. That's converted into estrogen. So it can get pretty tricky. And but maybe for sake of Simplicity today, we'll just stick with Androgen effects on masculinization with the understanding that some of those effects are the consequence of testosterone being converted into estrogen.
It's just that people form such strong, associations falsely that testosterone is a male what maleness in it. That's not true. And and an estrogen is femaleness and they both and it just gets really murky. But for the time being you identified, an external biomarker of fetal, Androgen AKA masculinization.
Via the mother. That's right. Got it.
Okay, so
Then we asked the question, you've asked, and many people asked, who cares? What, what, why would we worry about a boy having a slightly smaller and a
gentle distance? Well, I can tell you there, many boys that are probably worried about it right now. All right, I probably got the ruler in the calipers out right now just, you know,
but I'm going to answer that question, right?
So I told you that our kids are too young. They're not producing sperm right now, right? So we had to go to an adult population, right? And so we went to a population of college students in Rochester, New York,
And what we did, there was make an assumption.
Which is based on animal data. It's true in animals. We've been following the animal path here all along. So the in the animals, my colleague, Earl Grey, who did these studies? That
Name is Earl Grey. Yeah, that's cool.
You said a GD is forever.
He's a general distance is
forever. Now, what that means is it's not like your engine will Justin's. Today is what it was when you were born. Of course, you're a bigger person but that means adjusted for body size.
Sighs, right? So if you assume that HUD is forever, if you're born with a short for your size AGD, then when you're 20 you'll have a short for your size AGD, okay? Can we assume that? Okay, so if we assume that then if we get these college students to come in and we can measure their a new general distance, we're getting a reflection of what it was when they were born, okay? And then we can get their sperm count.
And then we can see if they're related and that's what we did. So we got this population of volunteers, paid him $75 and one of the guys said for 75 bucks, you can do anything. And so what we did was we measure their inner General distance and then we got them to give us a semen sample and complete a questionnaire and things. You do in a study,
will link to that study, but I have a couple questions about the controls in that study. Just
Or sake of people understanding how a study like this. Yeah, would be done. I don't expect you recall all the all the details, but you're adjusting for body size and body weight. Yeah, height weight. What are the factors that would scale here? That would allow you to normalize? In other words, what you're trying to do is backtrack to what it likely was that? No one should
actually try to go back. What we? Let me just tell you what the results were in this group of, man.
If they had a longer and a general distance, they had a higher sperm count, got it. So, you were correlate, those two measures, right? And then, if we wanted to say something about, we didn't try to say anything about how it was when they were born. We just said, okay, we'll take that assumption. That this reflects their early AGD. If we want to say something about early age, UD and sperm count. So, it's easy to say a GD is relator sperm count because we
I heard that we saw that a correlation that's published. Okay, if we want to say their early age you at Birth and their sperm count,
That's a leap of faith in some sense because we don't have their early for these guys in Rochester. We didn't measure their
agent Burke, so we're there any conditions of being a participant in the study such as refraining from alcohol, cannabis Etc, in the 90 days, prior 90 days being the, the, you know, that thing's duration of spermatogenesis. Yeah, I don't remember. These are college students. And presumably some of them are drink, okay. So but in the end it was a robust robust link
and then my
Like Eisenberg, who you might
know. Yeah, probably get Sanford. He's been on this podcast. Yeah. Good. Good.
Yeah. So he's a colleague of mine too and he looked at men in an infertility clinic and those who had warned children and those who had not borne children and the men who had borne children, had a longer in a general distance than men who had never borne a
child never born, but we're trying. Yes, right? Yes, we're not people who opted out, that's where exactly, these were people who are whores were having challenges with
Tilly versus success with, with, by the way.
You know, the question of how you measure a GD in an adult man is a different question than how you measure it in a newborn, and we did a lot of work on that and Michael help with that too. So it
sounds like oh and may I ask where the sperm counts that were on the, let's just say the lower like the lower
Quartile where the quote unquote, lower sperm counts like functionally lower because I always wonder about this like it's come up in a number of discussions. Like with Robert sapolsky with Mike Eisenberg. And now I'm asking you when we hear that sperm counts are going down, are they going down to? The point where fertility is is impacted. That's really the. One of the, I think functional questions.
So I'm going to let us lay aside the question of a GD, right? That's a really interesting but let's talk about sperm count.
Okay. Okay, okay, so if you there's a beautiful study among pregnancy planners out of Denmark, quite a long time ago, and in that study, what they did was take couples that were trying to conceive that had never or not. Recently, I can't remember used oral contraceptives and then they saw
What the sperm count was and how long it took them to conceive, right? Time to pregnancy and relationships. And what they showed is a really interesting curve which has never been corrected to my knowledge. It's what I use. And what I think people use which is that if you I wish I could draw it here where a tablet. You should have a board and
white party from is a lot of people are listening, but maybe we, you know, we, we can talk people through it yet. Sorry.
So, just think about a curve where you go all the way down to
Zero, that would be no sperm and then as the probability of conceiving is zero, so you're looking at sperm count along, you know, is the x-axis and months to conception, and what you see is that if you have no sperm, you don't have no conception. If you go up to around 40 45, there's a steep increase. So, the more sperm you
have 40, 45
million million per milliliter,
And this is million per milliard just so, just pure concentration, not number of motile sperm. This is just how many sperm we're not talking about quality, we
survived number. And when you have 45 to 50 million per milliliter and below, it matters a lot. What your sperm count is, you know, people say doesn't matter. Yeah, if you get in this range where the probability of conception is dropping off really rapidly, it matters a lot and then they're around 45 to 50 starts to level off.
Off. And then after that, after certainly after 100 sir, probably 75, it doesn't matter. At
all, huh? So, 100 million sperm per milliliter. Yes, of semen. Yes.
So, can you see this? Okay, so it, so when people say does sperm count matter for fertility? Yes, it's matters. A lot if it's low and no, it doesn't matter at all. If it's high. So you did. We just have too many sperm? I mean, I don't
Humans, you know, and
there's is nature. Runs a probability game over produce sperm, right? Some of those will be high qualities and will be low quality. Depending on their age when they were jet, that is when they were generated or their conditions, or their conditions, how much heat exposure, Etc. So, nature, runs a probability game. That's right. Hoping that the best quality sperm will fertilize the egg. All right, so below 45,000, excuse me, Beefalo.
85 million later below, 45 million, sperm per milliliter of semen, the sperm count really matters. It drops off precipitously. That's right. Once you get up to 75 100 million per milliliter of sperm, then good cook. You're good to go right and sperm counts range anywhere from you know, it could be low. Eight nine ten million per milliliter in the very low situation row. What could be 0? And some people write all the way up to 400.
Million. There's a huge range. That's right. And that's a function of age, it's a function of genetics. It's a function of presumably phthalate exposure.
Yeah,
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In a general distance and there's a relationship between a no General distance and phthalate exposure. And then I ask the question, you know, okay we're hearing about sperm counts dropping. But is it functionally relevant are is that one of the reasons why fertility is dropping? And we've also got the female side where we've got women with elevated androgens. So we can talk about that a little bit later, but and then of course, we have the socio the sociobiology piece where people are.
Opting out, or it's also economics, in some cases opting out of having kids, right?
So, let's go back to sperm count because we haven't really talked about that. It's a kind of a different path and my introduction into salads was not through sperm count, right? It was through this question of my colleague asking me, whether you should look at this and the challenged, and I looked at it and that was really, really interesting Journey that I went on. Okay, so that but there was a separate
For a while Journey that I was on and that started in the late 1990s when I was asked to join a committee of the National Academy of Sciences and that committee was assembled to look at the question of whether hormone only active. Chemicals, endocrine disrupting chemicals in the environment, posed, a threat to human health.
Because at that time, it was like, well yeah we hear about this but should we care, right? And so that committee wanted to consider a study that had come out of Denmark a few years earlier, which claimed that sperm count had dropped, 50% in 50 years.
Wow, that's a huge drop. That's
what we're seeing worse than that, by the way, now. So okay,
They said to me, I was the only statistician on the panel. Would you look at this and see if we need to consider this in our deliberations? And, as I mentioned, I'm skeptical. And I looked at it and I thought, yeah, I don't think so. That was my initial reaction and that was because
First of all, I didn't know who had written this. I just saw it in that journal and and it was not very big and not very many figures not very much data and I thought of it and I thought oh that's that's a big claim for a little little paper but I'll look at it because it's important and so what I did then was to think about all the factors that we have a de Mille just call confounders.
Things that might have caused that decline if it wasn't real biologically, all right? And so we could think of some of them together, you know, maybe the method of counting sperm had changed. So that later methods counted fewer sperm in the same sample. That's certainly possible, Right? But it turned out that wasn't the case because they actually had all used the same method and maybe the men had changed. So maybe there's
You can't get a sperm count at random, you have to get somebody to volunteer, right? So, who were these, men are where they very different, you know, in the early part of the study in the late part of the study, in a way that maybe in the late part of the study, there were men with lower sperm count and they were more concerned, you know,
maybe they were more obese. That's pretty plausible. Obesity is related to see my sperm count fertility, and maybe they smoke more and maybe and so on and so forth. All right, so what I did was to get the 61 studies go through them and try to extract information on all the factors that could explain the decline.
so, I created a multivariable model and ran that model
And to my astonishment.
when I was done,
The slope of the decline was exactly the same to the first decimal place.
It had not explain anything. I was like, oh my God, this looks like it might be
real.
And for those listening what dr. Swann is describing is being the excellent scientist that she is. She went and looked for all the things that could impact the result that were not related to what the main conclusion seemed to be, which is that sperm counts were going down over time, right? Right? And this is really important too, because I think what we're talking about here in parallel to the main conversation is how to do really great science especially in human.
Nations that are out there living, you know, some of these men probably, you know, smoke some cannabis. I'm not saying that produces sperm count. Might reduce / Mount Motel motility. However, we covered that in the podcast. I'll now that all the Cannabis, folks, go. Well, you know, so-and-so got so-and-so pregnant when they were doing some, your lot of weed. And I always say, okay, well there are number of other factors, right? You know, but alcohol, there's frequency of ejaculation, right? The, the requirement to abstain, for 48, to 72 hours to up to
Five days prior. You know, it's that are all these these factors that men may or may not Faithfully report but you assume that if some are telling the truth and some aren't that, there's an equal distribution of that's all the different things, right? Right. This is so very different than looking at for instance ovarian reserve like the number of eggs where you use ultrasound and use amh levels and sure things can impact that. But it's a little different than when taking
Sperm counts. So thank you for doing the study so carefully and for repeating them so many times. I mean many of the studies that you've done are our you've done follow up on these sperm count studies across multiple years. You know, as you said, the first study was in 1992, then you did one in 2017. Then there was one again and there was an update, I noticed online. So you are extremely thorough you and and it probably reflects your early training in math and statistics and probability Theory. You're not somebody to
Is kind of go in and go. Yeah. Like in these people that eat a few too much of this, then there's a little bit less of that. So I just wanted if today's discussion feels like we're really we're leaving through this, that's intentional. And it's important for people to hear these kinds of claims are not, the sort of thing that you could people make them all over the all over the board. But work like this needs to be done with an extremely meticulous. I and consideration of all the variables. Good scientific method. Yeah.
Yeah, yeah and I would say especially with human epidemiological work, right? Because of the number of potential confounding variables, right?
So so when I saw that and actually did another study to select my own studies and not accept her 61 studies that have been published that Elizabeth Carlson had published some new studies came up to more recent times went back. Further, did it again. Found. Exactly the same thing. Okay, so there were three, you know,
Three looks at that and I thought, okay, I'm going to accept this now, this is sperm. Count is declining.
And why do I turn to the Y? Okay, because up and down. Now we hadn't said anything about why? It just said, is it doing that? Yes. Okay, if it now we believe it is declining why? And so then I thought quite a lot and talk to people and ruled out genetics because it was too fast. Is two generations is too fast 50 years to generation, so if it's not genetics then its environment. And so what is it about the environment that could do this?
This. So I asked, okay, in the environment.
There could be things that are making sperm decline. So if you think about how you might look at that, you might design the study that I design next, which is another study. And by the way, this preceded, the AGD. So just so we had four cities in the United States that we picked with different environments. And then, we got man to come in and we used the same equipment at each place. We used the same method of selection. Then selecting the man,
And the technicians were trained centrally at UC Davis, we had very good quality control. So samples were centered around every quarter to make sure that everybody was measuring things. The same way we didn't want drift, right? And then we got their urine and that's how I had those urine sample. So, if you wanted to do this study and you wanted to get a representative sample of men,
Where would you go because you can't. I can't ask a guy in the street. You give me a semen sample, right? I mean, it's not, it's not something you get very, you know. So I thought, how can I get a representative sample and, which would teach me something about a larger population called the parent population? So here's a sample, it should represent the parent. So how do I ensure that? And what I decided was to sample partners of pregnant women because pregnant women all come to Medical
Elk are almost all and if their Partners will give us a man sample, then we have a representative sample and when we know what we're looking at. So that's what we did. So this is a the Seaman study is the study of Partners of pregnant women and and of course they'll have slightly higher semen quality because they got their partner pregnant. But and so we had their urine, we had their blood and we
Looked at their semen quality and then we decided to look at pesticides and the reason we look at pesticides was because there was a lot of gradation across our four centers and pesticide use. And what we found was really extraordinary that men who were living in Central Missouri where I was living at the time who were in the middle of a agricultural belt, where there was spraying all the time for soybeans and so on.
Those man had half as many moving sperm as men in
Minneapolis.
Whoa,
whoa.
Huge, right? And then we went one step further. And with, in Missouri, we looked at a sample of men who had very high sperm parameters, and very low sperm parameters and showed that five pesticides were significantly higher in the men with the low sperm parameters that include motility. Morphology, you know,
all of them. So these are pesticides that are being sprayed in the air on crops. You mentioned soybeans? What other what other types of crops?
I don't know because I don't
remember so. So planting fruit crops problem
was yeah whatever. Whatever they were growing in Columbia Missouri
and and just to make sure I understand that it's not that so many corn and soybeans corn and soybeans but we're not talking about eating corn and soybeans. We're talking about living in an area where pesticides are being used by. This is still called dust
crop. Yeah we didn't go into how they got these. We just looked in their urine.
And and there were the metabolites. The metabolites don't get in their urine unless they
were exposed exposed through the are exposed by eating corn and soybeans. We don't know, we don't know. Okay, we don't know.
But this was not a particularly waiting. Wouldn't sample Farmers Only or anything like that. So, it was whoever came into the, remember how we got these men? Their wives were pregnant. They were having prenatal care at the University of Missouri. So, that's where we got them. Whoever happened to come in to the prenatal clinic and agree to be a nurse.
Study there, the mail you know, urine, males urine was measured for for these pesticides.
I'm sure number of people including myself or wondering
In what other products are these five? Pesticides present? Are these commonly used pesticides? Or is it something
about they were there called? Triazine, pesticides. Atrazine is was the most widely used, and it's a huge use around the world. I mean, is highly, you know, one of the most, the largest commercial pesticides. So, these were very big players in the pesticide field
a relevant theme, there would be
Maybe we could take a moment and talk about at reside and its effect on male sexual behavior in amphibia and will come come back to the, the sperm says, because when I was a graduate student at UC Berkeley, I had the wonderful experience of taking a course from the now, I think you mentioned, he's a dean, there are multiple genes on campuses. Tyrone, Hayes is a wonderful researcher who established a link through his research between atrazine exposure.
And male sexual behavior of amphibia? Yes. Could you elaborate on that result?
Yeah. So, Tyrone first caught frogs in the wild and environments that were more or less exposed to atrazine and showed effects on development and sexual behavior. Then he in his lab, he actually expose them. So, he knew exactly who was exposed and how much and he showed that
That I can't tell you what percent or what, you know, but a significant number of frogs exposed to this pesticide, atrazine chose to mate, with other male
frogs tried to mate with other male frogs, presumably unsuccessfully.
Well, like they mounted them. He has photos of them male meals mounting males
and so presumably, this is a neural change, that occurred neuroendocrine change, but ultimately neural since mounting.
ER is controlled by. Actually we now know the the hypothalamic nuclei that control this David Anderson, who's been on this podcast has people in his laboratory that including a former graduate student of mine working on on this specific issue of what the what the circuitry is.
That's a remarkable result. It's been kind of
You know, used and misused out there in the in the in the media and in popular culture. But if nothing else, it suggests that the organization of the neural circuits and neuroendocrine Pathways that control sexual. I don't want a partner because his mating thing, this is frogs aren't monogamous but sexual preference are significantly impacted by this, by this atrazine.
Yes, and, and it suggests that
that there are other environmental chemicals can as well, and I don't know how we'll have time to go there, but I did work on neuro developmental outcomes in relation to prenatal, phthalate exposure. And so I think the overarching idea here is that the brain like the genitals sexually dimorphic,
And there's many people by the way who will take offense at that. Really. Yeah. I
think there's, I mean, going back to the work of Frank beach in the psychology department at UC Berkeley showed this. In beagles, it's been, it's been shown in pretty much every species, but it's not a better worse. I think this is what people need to hear like dimorphic does not mean better worse. I means
different, right? And that's there. And there are, for example, advantages to spatial
Reasoning in a male that which are related to testosterone. Right. You know that said
station, I think they're. Yeah. I mean my understanding of this literature and I'm not an expert in this particular aspect, which is the behavioral phenotypes. But you know, like the medial preoptic area, the hypothalamus is known to be sexually dimorphic dependent on testosterone converted to estrogen during development, etc, etc. And there's just so much evidence of this. How it links to behaviors is, can
I think can be reasonably placed into mythologically relevant evolutionarily, logical arguments, when talking about rodents or beagles or even rhesus, macaque, monkeys. I think where people get a bit inflamed is when people try and take the sexual dimorphism, 's that have been observed in animal brains or in even in human brains and Tack those two specific abilities, or or or less.
Sir abilities. I think that's when people sort of go, wait a second like I have much better sense of direction than my husband and you go. Well, yeah. Like, you know and then you go well does that mean that she has higher testosterone than him? And then, maybe and then and pretty soon. You're, you're in almost a No Man's Land. I know person's land of conflict of confounding variables, right? But I really appreciate that. You raise this and also that you said it and I didn't because I feel safer that
way. There is a very simple
Outdated questionnaire and it's play Behavior. It's called the PS a--. I he's been used for years. Have you heard her if she's
hurt them? Tumble play? Yes. Yeah,
yes. And there are 24 questions on there and they are sexually dimorphic. I guess you could say that they're, you know, my child likes to play with dolls. My child likes to play, dress-up my child likes to play rough and tumble Etc, and we gave that questionnaire
To our population and looked at the answers that the mothers gave both in our population, by the way, and a Swedish population of the colleague there. Carl born a hug and Gustav Warner hug and and what we found.
Higher phthalates levels, these anti-angiogenic Malik's were exposed you know are associated with less masculine male. Typical Play In Our Mail, boys. So
this is just a lead exposure to the drought to the mom. Baby is born in the young human child
or for ya, for your. I think it's
four years of age or years of age, less Rough and Tumble type play. That's right. Among the boys, whose mothers were exposed.
Phalates during a critical period of
development. Now you can see that's a politically loaded issue. No. I mean you know
I yeah well I think we're I mean, let's let's let's have some fun with this and in the scientific sense.
The notion of dimorphism is you know, okay male and female brains are different right? Which out and male-female defined and those almost all those studies as presence of a y chromosome and then people say well there's some there's xyy and then there is xxy, okay? But most of the time you're talking about XX chromosome or exit, Y chromosomes, at Birth, forget everything else for the moment.
These are always distributions. This is what I think people need to know. We're not talking about, these are not, this is not you know to Hills of data separated by a valley these are overlapping distribution because right, right. So you get males with a quote, unquote, female like distribution. You get females with the quote-unquote male like distribution and I think as long as we acknowledge that, and we're just talking statistics, right? We're not, we're not placing any cultural or any value on it.
Whatsoever. Right?
What is it? But if you could make the analog to the inner Channel distance, it's kind of similar, you know, you have the same exposure Sal exposure, you have something changed to historically, we don't see huge differences in the boy's genitals and and we don't see huge. I don't we know these kids had not been scanned, so we don't know how their brains look. But based on their answers, we don't see huge differences. We see tenancies, we see they are more likely.
If they had been exposed to these salads, to want to play dress up and have tea parties, more likely doesn't mean that they're all going to, but that's the direction and so on. So I think we have to just think about more likely not absolute.
Yeah and of course there are also the the sociobiological variables such as if young boy has a sibling that's sister there's more likely to be dresses around, right? She's going to yeah they've if he has to
Older brothers. There might be more Rough and Tumble play happening house. And I have some friends that are women who have older brothers, and those women are, you know, some of them roll Jiu-Jitsu or do you know? And I know some women who are only children, who do martial arts and and fight, right? You know. So so I think that none of this is deterministic, right? As we know, but let me just add, we did control for the sex of The Sibling older sibling. And we also asked about the parents attitude
Towards same-sex play. So what would, how would you feel if your child your male child played with dolls? Would you be discouraging? Would you encourage because it has a lot to do with what's in the house? You know, if you say does your child play with dolls? Well, what if there were no
dogs is super interesting to me. I don't want to reveal too much but I just because it's not it's just an N of 1 but I grew up in a household where I have a sister but then after a certain age I received very strong messages about
About what sorts of play were, were gender appropriate, and I think I also just naturally defaulted to him. There were a bunch of boys that lived in my neighborhood. They had older sisters to all the sisters hung out together is kind of interesting, all the younger brothers, pretty much hung out together and the, the guys that weren't didn't have siblings, or at Brothers, four siblings. So, there was a really strong Divergence, but I grew up in the set that was in the 70s and early 80's, when things were, let's just say culture was more dimorphic. Then clearly, I mean they were telling
In shows like All in the Family which the entire basis of the show was the wife going back to work and the husband being confused about and nowadays people would go like what that's wild I have to ask because I know people are wondering and I'm wondering what are some non pesticide sources of phthalates that we have agency over that we can take control
over, right? So let me correct you. It's not that sources of salads necessarily pesticides. There are
Are phthalates in pesticides, but that's not the worst player in the in the story. If you look at the different classes of
Exposures that are home only active, right? Pesticides are. Phthalates are bisphenol. 'S like this phenol. A BPA BPA certain metals are there's a pfos chemicals. There's all these different classes, right? And if we want to going, excuse me into what in our daily life, exposes us to these things. That's another story that we
We can talk about but they're going to be different depending on the class, right?
So let's throw our arms around all of those for the moment and I'll just ask you given that. You're an expert in this area.
What are the top three to five sources of endocrine disruptors?
That we have agency over and let's forget about pregnancy for the moment since we're all out of the womb. If we're listening to this, some people will be pregnant as they listen to it. But would you say it's, you know, drinking out of plastic bottles, is it laundry detergent, is it, you know, rubber tires that are cascading down on us through the air and we're inhaling them. I mean, presumably, all of the above, but order, which ones that we have agency over. Do you think are the most
Let's just say concerning where people could make better choices.
I would say, foodborne exposures exposures in the food in the food. Packaging in the food storage, in the food. In the cooking utensils. We can go through the various things but
We're doing that all the time. Okay, we're eating all the time we're getting food into us and these are bringing in in a very you know in a way that we have some control over some agency over you know we can make changes in our Foods very close to that as drink you know, food and beverage. So
I,
First of all, I've talked about this a lot. I've written about it in my book. I'm also as you know, involved in a movie where in the movie, that might be a good time to talk about that. What we do in the movie, the movie is about six couples that are infertile.
Okay they haven't been able to conceive in 12 months, that's the definition and then a company that I work with million marker out of Berkeley has a trained staff that interviews them, not only them but anyone who signs in 2002 due to this company, interviews them, and ask them, what their use. What do they use for their facial? Facial care. What do they use for their shampoo? What do they use for their cleaning products and their laundry detergent? And their what
Store their food in and on, and on and on. So this is long inventory that they take of all products that people are aware of using, okay? And based on that we identify likely bad players in the list. So how we do that is another, you know, we can talk about that later but then in the film and then this little is actually an experiment that I designed and
We called an intervention and we are then intervening in their exposures by changing out these things that they told us so we will tell them you know don't use any product with fragrance for example. That's a major source of exposure to phthalates any product, any fragrance products fragrance is a
perfume, no lotions soap with fragrance, right? Even essential oil
fragrances like, well, it's a tricky.
It's a mix. It's a mix. Yeah.
So I'm going to that's guarded but but anything you know,
spray deodorants, roll-on
deodorant laundry, detergent with, yep inch. And any if you can smell it, it's probably affecting your hormones.
So happy about this answer. Not because I have any stake in any company related to fragrance free stuff. But I have a very strong sense of smell and I either love or hate smells. And I hate synthetic smells like going through the duty-free
Especially in a European airport where it with all the perfumes. And I'm just who that was gonna hold my breath it. I know it feels like I'm breathing poison. I know. Well, you are actually. Yeah, you know, some sense most soaps, right? Yeah. Super interesting. So that's your primary intervention is to tell them. Get rid of anything with
fragrances know. It's only one thing we get rid of. So then we talked about how the Plastics that they used to store their food, food, storage containers, trying to get
To get rid of those, if they're made of plastic, we try to get them to get rid of their non-stick pans because of the pfos chemicals that are in those and and so on and so forth. So we go through are all steps or their life and try to tell them how to make changes that will reduce their
exposure. But presumably also changes. Like, if the man is obese, for instance, you might have him walking a bit more. No, no. You don't touch any of
that. Well, you see, Andrew, if we did that, we would be mixing up.
Up to interventions. We would be mixing up and obesity intervention.
I see, this is a study, I'm sorry. I thought that this group is is commissioned with helping couples get pregnant. No, no,
this is a study to look at what happens. If you make these product related
changes, great just product-related change. Exactly love. Exactly.
We would love to do and probably will do another study 71 on Obesity and you know, a lot of these chemicals just to let you know our obesogens, they increase obesity.
There's a book out called obesogens, you can read about them. And so, you know, we'll be it's very, you know, there is some overlap. So, by reducing some of these chemicals that are in your food storage containers, you're also reducing obesity has. So it's not a clear, you know? Yes, no. We gave them a box. Each couple, I went to their house, six, couples around the United States with a big box. And in this box are these alternative products
And so, you know, straws and bamboo shoots spoons and, you know, $500 per box. I think it was approximately, it had to do with their personal, you know, exposure and, and then they made these changes. Now, unlike another study that you reported, they are at the end. Quite happy to keep doing this. By the way, they love this. They love doing this. It was
So gratifying to see that they felt in many, many ways, their life got better. Are, you know, I'm not a pretty careful in what I. So I hesitate to say this because the data is not hard, but the impression is that they are
Happy happier, they're sleeping better. They report more energy and so on and so forth. Having made these changes, we need to follow that up with hard data. I'm not writing that I'm not, you know, but that they but I can say and I can write that, they felt very positive and are, we're going to go back and see if they did continue. We need to do that. But at the end of the sixth of the three months they and hopefully in six months they will they are still making these changes in their lives.
Did you collect data on whether or not they were able to conceive after having made these
changes? Yes, we did. But I actually can't talk about that.
Until the babies are born. Just kidding.
And and we did get their sperm count of the beginning and the end and had some very interesting data on that way to early to report
tour earlier. Let me ask you this then and I appreciate that the not wanting to share specific results until this, the all the data are in and it's published.
If somebody listening, we're having trouble conceiving for 12 months or more are the sorts of replacement interventions product interventions that you're talking about here, things that you would at least feel comfortable saying, might be a good place to start or to explore
solutely, there's no harm. You know, we're not. None of the changes are putting people at risk or doing anything that could be harmful to them.
Sure, of that, very careful.
And some are going to be cost-saving. I think that's weird. Like, drinking out of plastic bottles far less. If at all, like I just for reasons related to wanted to reduce waste. I use a mason jar or use these or ceramic, although you'll probably tell me that the lining on this ceramic mug might have endocrine disruptors. Know I do. Okay, great. Okay, well then I'll keep drinking but it's very reassuring to me that there are things that
That we can do in terms of cost saving elimination or replacement of consumables buying in bulk, that can improve endocrine status, may be fertility, awesome bulk. Bring a container to the store and fill it up a glass jar. Instead of buying something in plastic, you're winning on both ends because those bulk products are cheaper. One of the things I did with a couple's was, go shop with him. And we went around and we looked at various products. And for example, we looked at the produce and there was option to buy
Freestanding Bunches of letters, heads of lettuce or wrapped up in plastic, Bunches of letters. And I said, let's compare the price. I actually didn't know it, so it did, but that freestanding unwrap lettuce was cheaper and I think that's, you know, because the makes sense because there's a work involved in, wrapping it up and in the container and so on. And so not only are you getting something that's more toxic but it's more expensive
when it comes to reducing BPA exposure.
Exposure. And some of these forever chemicals. That you mentioned seems like reducing fluid intake from plastic vessels is going to be number one,
the primary source of BPA is in the lining of cats. So any drink or soup, or anything that comes in a can is going to be
any can all can't
can unless it's a high-end.
You know, Elite company that's made the change from BPA to an alternative lining and they'll say that so and by the way, BPA has some bad relatives such as BBS and BPF, and maybe you'd be interested in this story. So when it came out that BPA was estrogenic is what it is. And by the way, it's kind of the evil twin of phthalates because phthalates are Andy Anderson Eric and be
Is estrogenic and phthalates make plastic, soft and BPA. Makes plastic hard. You don't want either. Okay? So when this came out, that this was a bad thing, the manufacturers started selling things. That's a bpa-free. I'm sure you've seen that the trick is that instead of BPA that use BPS, sneaky rat, and BPF. And these are chemicals, these are look alikes. Their analogs and they're just as harmful
sneaky.
Be sneaky sneaky. I'm not a conspiracy theorist, but it's just so dirty. It's so dirty. It's like, it's, um, you know, right now is a really important time to be having this discussion, because there's been a lot of movement on Capitol Hill and there's been a lot of movement on social media about trying to call attention to metabolic syndromes and highly processed foods and and issues like this and it's become unfortunately, politicized. I mean, I hear this stuff and I just think to myself the only good faith,
Um, that we can really trust is our own desire to be healthier and to have our families and friends be healthier and to try and consume and not consume things on the basis of that, that my belief is that we can't trust any any larger agency to either protect or harm us that it's like it's not it's like they're going to do what they're going to do. We just have to be informed as opposed to trying to like dismantle the systems that led to this which just seems it like infinitely complicated.
And maybe you can do that, but I'm far less optimistic, and now I'm 49 years old, I can say things like now that I'm 49, I feel like. But what you're saying is really important, if I look at a can of says BPA, free doesn't mean anything because I have BPS is or other endocrine disruptors, right? So drinking out of glass vessels drinking out of ceramic vessels, metal metal but not cans, not metal cans, not aluminum
cans, right? Not cats. Now
Okay, you know, you can get a metal water bottle. That's not lined with
BP steel, steel steel. And is it true that microwave? Safe means. It just means that the plastic won't melt in the microwave, but
it's never never put plastic and a microwave. So, here's the story, The BPA salaries. Plasticizers are added to the plastic but they're not.
Chemically bound to it. Okay, so if you put anything in a container that has these chemicals in it, they will and then put it in a hot environment, they will come out of the plastic and go into the food.
So if you in a microwave or you put your bottle in the car and the Sun comes in at warms up the bottle and then the stuff goes into your water, you don't want to mix these chemicals and your food. But if you do, the worst thing is to do it in a heated environment. I think
about all the food that was consumed in college in the in the 90s and 2000's like the cup of noodles with a styrofoam the you know, things in packaging stuff like that is pretty.
Straightforward to eliminate once one understands and decides then we start getting into the more nuanced thing of like. Okay, you can buy a really nice tasting anyway, grass-fed grass-finished steak, but it's wrapped in plastic. Well or you can go to the butcher but most people don't have time to go to the butcher or you can get strawberries at the farmers market, blueberries, the farmers market, which is what I try to do. But sometimes I buy strawberries at the Mark and they have those plastic flip-top things and of course,
Recycle the plastic. How bad is it? If you know you rinse the strawberries off with good clean water that were in the plastic container. Are you
supposed to do that experiment? I don't
know. Yeah, so I guess so it sounds to me, like, not drinking out of cans, not drink out of plastic bottles, it's going to be not microwaving plastic ever. And in general, just avoiding avoiding plastic intake.
If you can afford it, buy organic.
So you're going to avoid the pesticides. And then phthalates are actually added to pesticides and their added because they increase absorption. So you know the you want your pesticides to get into the plant, right? And to kill the bad stuff and and insects and and so the same property of phthalates, that makes them good. For pesticides. Also makes them good for our hand cream just inching up absorption absorption anything.
It's absorbed in the body. It's going to have salads in it and it also holds scent and color. So is added to those sense and it's also added to your lipstick and to your color, you know, whatever you put on your face. And so on anything that holds senton color that's going to be valleys, sorry
I've been accused online and being a sunscreen truther. I'm not a sunscreen truth or I'm gonna keep repeating this as many times I can I
Stand that UV damage to the skin can cause certain cancers. I get that. I agree with that. The data are pretty clear to me based on having research to this pretty extensively. And talked to many many people including Durham oncologist that mineral-based. Sunscreens like zinc oxide and titanium dioxide but certainly zinc oxide are safer than the chemical sunscreens. A lot of people get upset when I say that and they say well and Europe. There's tons of evidence that the chemicals based on screens are in our
Okay, fine, you use them. I'm not going to the point. Being that UV damage is bad. There are ways to protect protect ourselves from the Sun, including physical barriers, like clothing hats, Etc. But pretty much all sunscreen that I'm aware of is designed to be absorbed. So, what do we do? If we want to get some UV protection, from whatever kind of sunscreen, we deem safe for ourselves, but we want to avoid
These exposures to these other things. What do we do? Do we have to hunt really carefully for the right? Sunscreen. Yeah, I think that's a good idea. Are you familiar with environmental working group is another one out of the Bay Area? No. Okay, actually, they're pretty big sound sounds familiar, but I'm not, I can't say, I'm familiar with have Consumer Guides and in those consumer and so, environmental working group. I'm not part of them on, you know, but I like their work and in these conditions
Consumer Guides, you can put in the product and they have categories. You can been sunscreen if we had time we could do it right now, but and then you can put the name of your sunscreen and it'll give you a number. And then if the number is less than 10, it'll tell you why.
Are they independent of any, like, funding funding? Yeah, of that cushion. Will probably come up for you to. People will say, where did she get her funding? You know, people people get very suspicious about this until yeah. Yeah, that'd be great. Yeah,
so I am a tenured professor Mount Sinai. Get some salary there because I'm only part-time and I have a funder. One funder who funds found funded my sperm decline.
9, s sperm, decline analysis and the publicity of my book. So he's a he's a it's a foundation. I won't says philanthropy. Yes, fun trip. Yeah and it's actually not a lot of,
I don't know. And so there's no reason to think that anything that you're telling us is linked to like the food industry or an alternative product or
anything. I'm very very careful, not to endorse any product because I don't want that complication. Yeah,
thanks for clarifying that I wasn't I wasn't suspicious but right, but I think
Nowadays, people have just been taught to appropriately. So they've been taught to say, well, wait, where does this funding come from? Because a lot of the studies about the that led to the few food pyramid, for instance, people were under the impression that somehow that was biased by companies that were funding the work. And I don't know, I haven't done the forensics on that. I don't have the time or the energy. All I know is that when it comes to what people eat, what it comes, when it comes to what people put on their body, it becomes a very personal.
Personal thing and it's woven in with a lot of psychological and emotional issues. Yeah. Okay. What are a few things that you do?
and or avoid,
In light of what, you know, about these endocrine disruptors. And by the way, it goes without saying that you're in spectacular, cognitive and physical shape, for any age, but it's really remarkable. I feel comfortable sharing this because someone else published it online. Recently, you are soon to enjoy your what birthday 89th 89th birthday, amazing. And with all the talk about longevity, cognitive and physical longevity. Everyone's thinking including me like what does she do? Well, she avoids. All these endocrine.
And she has a wonderfully rich life of curiosity and other things but yeah. What are some other things that you do enter and avoid in light of what you know for which there may or may not be a controlled study, but I think we're all just curious will frame this as what you do.
So water, our water. And I worry about the water are studying water for a long time and my past life. So we actually distiller water. So we have a tabletop to
Stiller, my husband Stephen cleans it out. Is a lot of gunk in it, by the way, even though it's an Francisco that has clean water at the end of the day, after you've distilled the water, there's
a lot of guns, you distill the water. So this is not reverse osmosis just chilling. Okay.
Yeah. So it's steam distilled and then it condenses in a glass container and then we put that in glass containers in the fridge and so, and it tastes really good by the way, really, really somebody did was just over and he said this tastes like melted.
Snow, that was lovely and use that for drinking for
coffee 44, cooking to, if you make rice, you're using distilled.
Actually no no no. But for ice cubes and you know, whenever you think about it, we can't use too much because you'll be too. Busy always is dead, but he doesn't want today, and it's just the two of us. So, water is important. We try to leave our shoes at the door, well dust that you bring in contains a lot of
of the pretty good. Be the pfos chemicals and so that's actually I'm not 100% good on that but we tried to do that and I'm careful with the products I put on my face. I check them out the way I suggested, you know, environmental working group and I go to the farmers market. I always buy organic. Always, buy organic, but I know that's a cost issue for some people and
and an availability issue for some people, but I in San Francisco, you can do that.
Some areas where I don't do more of what I should. I think I'm starting to be aware of the chemicals and clothing. We haven't talked about that but there's a turns out there's a lot of particularly in, it's a problem for workout wear, because you're absorbing so much your sweater, you're hot, and you're bringing these chemicals into your body and that may be one of the interventions that we do, get a bunch of athletes to use safe clothing and
And traditional clothing and see what their body burden is. That's how you
know, so airing toward cotton as a put as opposed to synthetic materials,
right? And the dyes are important. So you don't want you want, maybe plant-based dies. It's not my area of expertise. I have a colleague who I work with on this and I'll go with her advice, but but I'm just saying that's another area that I think people will soon be paying attention to. There's also the area that
It is much more difficult which is what's in building materials and Furniture. But a lot of these pfos and the flame retardants are in our furniture and in our building materials and trying to think about how to build. I was asked about safety in a new Village that's being built in California by the way. And it's really challenging to think about if you were going to do this, right? And you were going to build a town that was toxic free. How would you do that?
I'm thinking about that. Hmm,
I'm thinking about the opener of The Simpsons and doing the exact opposite. We're like in the opener of The Simpsons, there's like a three-eyed fish and there's the chemical plant and I'm just thinking, you just look at the opening of The Simpsons, you do the inverse of everything, that's there, the inverse of everything that's there, including alcohol intake, you know, which is robust on The Simpsons. Yeah, for but interesting. So, and when it comes to
Food sourcing like a but non-fruit non vegetable food sourcing. Is there anything we can do? I mean, it's so hard for people to get eggs from farms. He's, I mean, you can, if you go to a farmers market but this stuff can get pretty tricky. Pretty expensive. And most people listening aren't not going to be, you know, living in Sonoma, where they might have a neighbor that has chickens or something. Yeah, it's a hard problem.
It is a hard problem, and, and I think maybe people,
Asking for it more would help. I don't know. I mean, in San Francisco. I'm lucky because I can just get, you know, just on the phone fresh direct order the and I know it's okay, but I know that's not the case everywhere. So, I think being aware honestly, it's a really big step. If you are aware that this is something you want to change, you will find ways to change it. It's interesting because a few years back, there was a lot of discussion about
Dies in children's toys, in particular toys from overseas. Remember kids are not young babies, always gnawing on stuff and teething. And and there was a lot of attention like hey like what's in the sippy cups? And my understanding is toys and sippy cups in my understanding is that bpa's were banned from sippy cups. Alright that's a late, scuse me so my work based on your work. Thank you so much. Thank you for the clarification truly. And and for end for the work that led to that, we have this
Innate. Thankfully innate reflex to protect our young as does. Every most, every species, thank goodness. And we know that baby skin is more absorbent than older skin. We know. And so, there are, there are literally laws in place and restrictions in place to make sure that some of the stuff is minimized in young kids. But then we sort of after age 12, we're kind of like, okay, well, it's a free for all depends on your budget where you go. And so we can't rely on governing bodies to do
This but I think it's a useful conversation especially given your relationship to Scandinavia, which is a fun one to elaborate on to illustrate some of the discrepancy between the US and Europe.
What sorts of chemicals are banned in Europe? In food in lotions, Etc, that you're aware of that are prominent here in the US. Maybe that's a good filter to place. Some of this Choice making
through Europe, has a has had a policy called reach and under reach, you have to show that a chemical is safe. Before it's put into the marketplace. Not
So what the way our system is here is put in the marketplace and then if somebody gets worried about it they might do a study they might find harm. Remember how long it took me to find that valid connection. It was ten years to studies 10 years, 10 million dollars by the way. So if you're going to wait for that, I don't know what you know, the given the number of chemicals out there eighty thousand or more forget it, you know. So so I think their reach
Policy of testing before something is put in the market is making a big difference in Europe. And that's I think that's one reason why they're much better
off. Those those animal tests or animal and human tests that they're
doing over there, whatever to find safety, it depends on the chemical. It depends on, you know what the product is. I can't answer that in
general, but so that might be a good Avenue for changing legislature here, right to to install something similar to
reach. Absolutely. But it's not gonna happen.
I don't think no, no, because there's too many forces against that. It's very, very hard for manufacturers to make changes. I'll give you one example. So you know that that you might not know, but should know that salads are very prevalent in the hospital setting there, if you think of a tube, you know, to dialysis, to chemotherapy to Ivy, it's all plastic that's all phthalates, right. And that's going into your body and there was
Recently a bill passed in California that dehp could not be an IV bags. It's fantastic.
Success in the actual bag. Yes. The bags could not contain these endocrine disruptors. Yes. Dhp specifically HP,
diethyl hexif a light the most Anti intergenic valid. So so that was a great step forward but that's like one chemical, right? In one product and that was a battle. So you see how
Hard. It is to do this extremely hard. There's a company be Braun, which makes Hospital products and they are very forward-thinking and they set up a factory in Florida to make alternative IV bags out of another product polyolefin. And the problem is that we're not sure about the safety of polyolefin. So it's a it gets really difficult, you know, you can say
They removed ehp. But now we scientists have to say, what does it mean for a chemical to be safe? And we don't know that.
I don't mean to disillusion you and your friend. No,
that's okay. I mean,
I think that's a huge challenge that we're up against. We know it's safer. We know it's safer and we know what are the Bad actors are and we know the things we don't want to be exposed to, but we have to be careful when we think about what do we want to put in instead?
Is that yeah, I am thinking about this at a former president of Stanford who was also happen to be a family friend years ago, he's since passed.
Don Kennedy, when he retired as president Stanford. When and my understanding is that he went in directed the FDA. And I was just thinking to myself, like when did this happen? Because I know he was super into Health. He was like an avid Runner he was very fit well into his 70s. Yeah, hip replacement kept running or maybe was need replacing. I don't know. The guy was obsessed with health and so I don't think that there's there's a lack of interest in health at the level of
The FDA and but there's clearly a problem. And I'm just trying to think of solutions and it seems to all boil down to what we can take control of in our home. They can we go to a restaurant, it's challenging to know what they're doing in the kitchen, and at some point, it becomes neurotic to your. I know, although I know people that won't go to restaurants where they use seed oils. There's this whole new thing, cropping up about avoiding seed oils, but maybe
They're more significant issues. Who knows the seed oil crowd is pretty pretty intense. And I like olive oil anyway. So I are to that but I think if people are interested in limiting their exposure to these endocrine disruptors, one of the key questions that's going to come up again and again especially in light of PCOS and sperm count is
We can't control what happened to us during pregnancy. But once we have some sense of agency over what, we put into our body and how we put it into our body.
Do you think that there's a that there's plasticity and resilience to this system? So, you know, God forbid, if somebody was exposed to a lot of these things early on, can they, you know, by making changes can they can they rescue themselves to any degree? No. So it's really just dependent on what your parents
did. Yes. That's not to say that your own exposure to cannot change things further and make things worse. But here's a, here's a fact. If a male's mother,
He smokes when he's in the womb, then he has a, this is a Danish study, by the way, 50 percent reduction, in sperm
count if his mother smoked while he was in the womb. How much smoking are we talking? I don't know. Okay,
but the, the, the reason I bring this up is because there's nothing he can do to change that.
Okay. If he smokes as an adult, he has I think a similar reduction is sperm count. He can stop and his sperm will be restored. He can get his sperm Health back, but, whatever happened in the wombs days in the womb. If you also whatever its developmental, it's not going to, you know, it's going to be there for life, and that's true of the brain as well. So I think anybody who's thinking of conceiving a pregnancy or
Has a responsibility to really learn how to reduce their exposure because these things are, by the way passed on for several Generations. It's your child and your child's child because the germ cells for your grandchild are going to be carried in within your
child. So germ cells are not germs as an infectious drums. It's the cells that were produced, the egg and sperm, right? That germinate, yeah, hence, hence the word germ.
So it's a huge
Each responsibility. And I think people should take it very seriously, that they have, you know, they're going to be affecting the health of subsequent. Jen, some Labs say, seven generations. I don't know if that's true, but certainly three generations are affected and so I should mention my book kind of.
Yeah, please I'll mention. I yeah, I believe I mentioned in my introduction. Yeah, yeah.
So in in countdown to words, by the way, because if you say,
Countdown one word, you won't find it. But countdown, we have two chapters on things. You can do it very practical, things you can do and also websites, you can go to and links, you can go to. Now this came out in a while ago, so 21 so there are many more things now but I think it's a good start.
How lonely are you in this expedition of identifying endocrine disruptors in food in pesticides, in
The sorts of things you're talking about late, is there a whole field of this of excellent people or you, or you, a small team of people that are against the grain? I mean, I confess, I don't know many people doing the sorts of work that you're doing but, you know, you're the the most public facing in prominent and I guess my question is like, is the NIH funding a lot of this sort of thing? Absolutely. It's we're an army and it's not in his International and there is
now, a global Plastics treaty under negotiation, by the way, it was just the Plastics treating people are trying to
Create get passed by various countries and international Plastics treaty. I can't, I don't want to talk a lot about it. I'm not involved in that process but I'm in the process. You then you could see if you looked into their hundreds of scientists and concerned citizens and activists and, you know, people in legislation who are working to specifically on the chemicals in plastic now plastic.
Is really a bad actor. I but it is not the only bad actor. So I want to just mention that plastic is really important. But, you know, pesticides are not plastic and, and so on. So there are many other classes that you have to worry about but certainly controlling our exposure to plastic is huge. And the you asked about scientists in this area. Yes, there's
Huge amount of science going on for this in this. There's and it's funded by NIH and it's funded by the EU and primarily I think those are the two funders of Scandinavia has funding within you know in Scandinavian countries. So there's a lot of work and a lot of very good people working really hard but it's a huge problem and it's been here since
Well, plastic started to rise in popularity in 1950. So we have like 75 years to battle against and it's not going down. Anytime
soon lifespan is increasing pretty significantly. Presumably in large part because of the reduction in smoking Montreal of Infectious Disease Control of infectious diseases. But lifespan is definitely increasing whereas the use of plastics.
Has clearly increased. And so I guess one could argue that we're living longer but where you are less robust than we were less reproductively competent. Is that the people that are reflected in that long or lifespan were not necessarily exposed early in life? Which is when it's most critical. So, you know, I was born in 1936, there was no plastic that there was a not you know,
There were other things, of course, but not as they are today. So I don't think that you can make the inference that because we're living longer plastic growth. You know, the growth of the Plastics Industries somehow driving that longevity. Absolutely, not absolutely not. I think what it's driving is decrease in fertility and what's happening is that the shift in populations is pretty dramatic. We're getting, you know, the pyramid used to be like this.
Making a triangle with my arms showing very few people on top and a lot of people on the bottom. But what's happening is that that's getting inverted. So we're getting more and more people on top and fewer and fewer people on the bottom birth rates are way
down first weights are
redone. And and so, this is a enormous problem for societies because the people in that small support group at the bottom can't drive the society to support the large growth.
On top. You see the same in other countries as well? Yes, absolutely. Absolutely. It's all over the world and and the decline in fertility. In my mind is probably well, one of the biggest challenges were facing now because it's everywhere, it's very cute. And there's only limited things we can do to try to counter it. There's a wonderful website called
By the World Bank, put out by the World Bank, it's called fertility data. And if you go in there you can see what is the fertility rate every year but you can put in, you know, plug in a country or a year or in and see what the frell fertility rate and each country in the world each year and you can see that. And what you see is that a decline about the same rate as sperm declined, by the way, about 50% in 50 years and the
Critical point for fertility is too, so what's that mean that's called replacement and that's two people replace themselves with a total fertility rate of to actually 2.1 because you have a little bit of loss but 2.1, you're good to go society. When you fall below that, you're shrinking. Then there are many countries in the world better below that including the United States. And for example, the worst I've seen as actually South
Korea, which is at 0.78. Wow, Japan. Is that one. Well, so large parts of the world are just not replacing themselves and why that is is maybe another discussion or we can talk about it. I don't know if you want to go into that but it's not just sperm count for sure.
Along those lines, let's talk about egg count and quality. You mentioned the PCOS results earlier before we were on Mike.
You mentioned an interesting study that you did about the use of electric blankets and assessing. Whether or not the use of electric blankets had impacted egg number or quality and women and the answer was
actually what we looked at in women. I'm sorry to correct you but it was there the outcome of their pregnancy, their fertility, and, and wits, I got pregnant to how did that turn out. Thanks me. So thank you for that clarification, but I'm sure they're being lot of other studies that have looked at that, you know,
Oh, I just have been away from that field for a long time but so far, I don't see convincing evidence that the use of cellphones or you know, other exposures to electromagnetic radiation are affecting our pregnancies and our fertility. That's not to say, it's not happening but I have not looked at it and I don't like to make statements about things. I haven't you'll get my understanding of the cell phone data for sperm count and motility AKA
Quality is discussed a meta-analysis covering this. It on the podcast previously is that there are some heat effects of cell phone use and keeping the phone in the pocket that may that may want to be careful here, impact sperm count, and, and motility quality, but Direct effects of EMF, son, sperm, there's no evidence that it is disrupting sperm as at least to my knowledge,
honestly, have to say just going
To say, I don't know. But I do know that heat is related to fertility and sperm count, right? And you can look at the birth rates, as a function of the month of conception. And you can see that, for example, in the warm months in warm climates, there's less. Yeah. So, there he does play a role but how much that's tied to cell phone use. I think that's something that's now under investigation by a lot of groups and
We'll see what they find. Yeah, the data on sitting more than a few hours a day on having legs that are very large as the consequence of obesity, or even just legs that are large heating, the scrotum and those data are fairly, I would say, solid in terms of the relationship to reducing sperm count, heat is not good for sperm, which is why the scrotum has. Its the features that it does move the, the testicles further or closer to the body game back to egg.
Big accounting quality. There's some evidence that girls are entering puberty earlier, but that women are also undergoing perimenopause menopause early earlier. Do we do we know what that is? The consequence of
there are several newspapers actually on the menopausal age showing relation to a number of chemicals, but I can't quote them to you right now. I don't remember which class it was that they looked at, but I think
Think that's right. I think there is growing evidence that earlier, you know, fewer. It's also called premature, ovarian failure. So that women are just not producing the eggs as long as they used to. Yeah. But
The, I just want to say something about their fertility, can we go back to fertility, please? So when this comes up and there, I'm sure you've seen the literature, there's a lot of literature on this. That's a fertility is going down. You know, fewer children, being born a people say, well that's a good thing because it's less of a load on the planet, which is a another discussion. And then they say, well, this is due to choice that people are choosing to have fewer children.
Darren and they're choosing to delay childbearing till they're no longer as fertile, they're using more contraception. Women are more educated, they're entering the workforce. All of these social factors are given as the reason for decline in fertility, and I just need to point out whenever I hear this, that it's not just human fertility. That's declining.
The number of species that are becoming extinct is increasing rapidly. And there is there been for at least 40 years evidence that those pesticides that affect us are affecting animals as well. And so, the decline in fertility and non-human species. Cannot be attributed to delay childbearing, how our use of contraception
and rent prices, right? Right. And
And it's interesting because we hear, we usually hear first about species that are about to go extinct that are badly endangered, I don't know what the proper language is. But it was about to go distinct, like the Florida panther or, you know, we hear that. You know, they're the species of the like, there's a very small subset of them. Left the black-footed ferrets in Montana. I think one ferret, his name is Scarface, sired, something like 300, litters that then led to the eventually. They started out outbreeding because
You do too much in Reading. Obviously, it's not good, and but then they were able to, at least partially recover, may be fully recover, the, those populations and people forget the domino effect of these ecosystems. When one species is compromised, like when the black-footed ferrets, I know might sound kind of silly, but we're compromised in terms of their populations. The prairie dog population went up, the grasses were getting eaten far more and then there's all these Downstream consequences you know, on bugs and you know and I'm not an expert in this.
Us. But one doesn't have to be an expert to understand like, you move one pin here and, and the whole web moves. And, and so, or you move one node and the whole web reconfigures. And that's what Nature has been doing for millions of years, right? But at some point it is conceivable, no pun intended. That we are going to be the species on the endangered, species list, right? I mean, that's not like a, like, an outrageous sci-fi movie.
They was right. Like at some point humans might be added to the endangered
species list exception that we have were very clever. And so we found a lot of ways to do medically, assisted, you know, conception
right XE. The literally gentle grabbing of one sperm. And forcing it to connect to to fertilize the egg. Something we've covered on this podcast. In our fertility episode with Natalie Crawford and a solo episode that I did.
There are questions that people have reasonable questions about whether or not the The Offspring of those types of scenarios are the same as the right. The the genetic probability experiment, as you mentioned before, of having, you know, 200 million sperm. And then letting Nature, Select the one that is most robust in that
environment. Yeah. And and, you know, the number of Technologies is increasing. We're very clever species and, and
Example, I don't know if you've heard of gametogenesis so it is now possible to create an embryo from a sperm cell from a skin cell skin cell can produce a sperm cell and an egg cell.
So you give it you give it the right transcription factors and you can, you can.
So this is kind of interesting exciting wild
areas like the, the what is it? I think the vulture vultures the females
There's some way in which two female vultures or maybe a single female vulture can create Offspring in the absence of a male. There's also three party IVF, I don't know if you're aware of this, where this was developed, where there's a mitochondrial disease, you can take the 2 eggs, 1 from the intended mother, you take the nucleus, so you get the DNA, you put it into an egg of somebody that where the DNA has been removed but where the spindles which are rich with mitochondria,
Our from a typically a much younger post, and then he used a sperm. So it's actually three parents as the spindle of one on the DNA of another mom and a sperm. They do this in the UK for mitochondrial disease, it's still illegal in the United States, as far as I understand, and it's done in other countries and in
theory legal issues must
be. Yeah. But anybody in theory this would allow women of any age provided they can they still have eggs to have their
DNA propagated forward because they could, the DNA can be put into a younger egg. That is has the spindle quality that allows for, you know, the production more cells. I mean, this is, this Canon has been done in humans.
Yeah. So where I mean, you and I won't think of all the things that will be developed, you know, in the next 10, 20 years to chat, you know, to meet the challenge of declining, fertility, by ordinary,
Ian, I mean I think that's that's how we're going to solve this problem for us. We're going to just be smarter and smarter about how to do a medically assisted conception and and and then the question is going to be an, it'll take time to know. This is whether there are effects in The Offspring, adverse effects in The Offspring,
It's a little tricky because, for example, if you use the sperm of an infertile couple and you see lots, I say the sun has subfertile that's born that way, but you do it in a test tube or whatever and then you can say, well maybe that's because the father was infertile and he's got inheritance from his father from that, you know, you know I'm saying. So you can't know whether the if you see an adverse effect on her, if an intern Offspring, you have to be very
Awful that it's not something that they've gotten because of problems that led the couple to seek. Assisted reproduction, you see you follow me. Yep.
Yeah super challenging fascinating problem. So in anticipation of this sit down together I put a question out on X formerly known as Twitter I let people know that I was hosting an expert in endocrine.
Ders in phthalates and pesticides reproductive implications Etc. And I asked for questions and they came up with a huge number of excellent questions. Many of which you've already answered things, like is tap water safe. What can we do to our tap water? You mentioned you distill water my understanding is that reverse osmosis provided, There's real mineral remineralization, excuse me, difficult word to say can also be effective at cetera. There were a
Lot of questions about cosmetics and laundry detergents. I don't know if we discussed laundry detergents it what do you use in terms of laundry? Detergent, or that is presumably one can
find, I don't even remember. Okay, don't go buy my products. It's okay for one thing. I'm not going to be pregnant anytime soon.
No, the I believe there are some solutions related to the like instead of bleach.
People can use hydrogen
peroxide speak about specific products actually, okay. You know, I can tell you, who can, maybe you might like, to talk to her. So you remember I mentioned million marker, a company that did the inventory. Not the come, you know, they are company, but so they look at million marker, I think you'd be interested. OK. Yeah. And and, and the person who runs at Genoa is a chinese-american who and a friend of mine and we're
to be writing a grant together and she participated in the film. So our participants Center. So what if you go to million marker you log on and if you agree to pay whatever it is 101 99 I think the you send your urine in that give you a kit, you said your urine and and they test it for all these things in your urine. So you know what's in your body, you might want to think about it might be interesting and and then if you pay another 100, I think you get these this counseling and some blah blah. This even see the different
Also, but she knows all about products. I don't know about product because it's a moving Target, I don't. And also, I don't like to talk about product names because it sounds like I'm endorsing
them, Yo, right? And we won't expect you to give product names and I'll follow your recommendation that you just gave. Somebody asked about food. Dyes just generally the dies in Foods. I saw heard an incredible study recently that Science magazine covered. So Science magazine, very reputable, of course, yellow. Number five,
I forget what the precise name is, but the thing that makes Cheetos really bright, they put it on the bellies of adult mice and it literally makes them translucent. Oh yeah. So you can see the organs is wild. It's so scary. I sent it to Rogen and he his I won't. He was like, whoa, his version of, whoa, I was like, I also said whoa, he
probably said, holy shit, right?
I'm not gonna say what it said, but it wasn't he
Didn't curse. There were a number of questions about household items. Again, we're not looking for specific products, but for instance, soaps body, wash cleaning sprays for floor cleaners laundry, related cleaners.
Do any or all of these contain endocrine disruptors? Unless one is careful to to find the ones that count. Okay. Receipts, how serious is it? Should we be concerned about the bpa's? Another indicator endocrine disruptors on
receipts. Yes. So in my suggestion is just ask for an electronic receipt and then you don't have to deal with it. Yeah. But they're definitely absorbed, you know, into your body,
any impact of endocrine disruptors of this.
What we've talked about today on the thyroid system? Yes, presumably in the bad direction.
That, I mean, this is an interesting point. Let me just say another word about it. I'm so the there was a ongoing study in the Faroe Islands off Denmark, and they studied pfos chemicals, and showed that people who fish there, there were special people and they ate the fish and they were getting high.
Those of pfos in their body and had this is published on effects, on their immune response. So my concern and I don't know if anyone's looked at this is given everyone's vaccinations to like our is our response to vaccination now altered by these chemicals. I don't know but I think it's a really interesting question but there is a whole field of the effect of these chemicals on the thyroid system and there's a lot of evidence.
Since that its adverse
can these endocrine disruptors, be detoxed from the body. Is there anything that we can do? What's the quickest ways? Things like sweating? Are there ways to improve liver clearance of these endocrine disruptors
that the answer to that depends on the class of chemicals. So the chemicals that are water soluble.
In particular, the phthalates and bisphenol has leaves a body in a matter of hours. You don't have to do anything. You just have to stop taking them in.
Right. The forever chemicals, the people use chemicals, pesticides are and though, so it has to do with the how they're handled by the body, are they put into the, you know, if they're water soluble up' them out if they're fast Hollow soluble they're going to be around for a long time. So it just depends on the chemical structure of the chemical of the compound.
There was a question about nonstick pans, you covered that earlier if someone had to pick between nonstick coated.
Ann's versus seasoned iron pans,
no question iron. There's no risk associated with seen season earned as
a number of other questions such as why does Europe have such more stringent laws, Etc. Lots of questions about atrazine questions, about weight, mints and fragrances you've covered. And I must say that as I scroll through these hundreds of questions. If not more, you've done an amazing.
Zing job at clarifying for us. What's known? What is not known and essentially where it's a probably should avoid definitely avoid and look, we just, we just don't know.
And, you know, there's, I have to distinguish between, we don't just don't know and I just don't know, it's not. I mean, there are many things that I don't know, huge field. So, you know, maybe with some, you know, ask the
Question of chat gbg?
Yeah. Well, it will be certain to ask G PT and we will be certain to ask other experts in these areas, but I just want to make very clear.
I and everyone listening and watching, truly appreciate the work that you've been doing in this area for a number of years. We're so grateful that you took that Airline flight with your, this chemist, that you mentioned, that you stored the urine of those pregnant women that you analyzed it, and that you've gone down this path of exploring things that are really disruptive to our health, and potentially to the existence of our species, as
You know, as we talked about earlier, there is the possibility that we go extinct, not because of a meteor, but because we fail to replace ourselves and that, we fail to replace ourselves because we destroy our biological ability to replace ourselves. I think it's hard for people to internalize that very real possibility because we feel ourselves sitting in traffic with thousands of other people know, there's a too many people write this kind of thing, but I want to thank you for the work that you've been doing.
And continue to do for your willingness to write books and to educate the public on podcasts like this and others. Because these are topics that are pretty emotionally loaded for people. I don't think anything gets people quite as inflamed as the idea that what they've been ingesting and exposed to, especially in terms of consumables that they've spent their hard-earned money on have been harming them, harming them, and their offspring and generations to follow that. There's something that really
Lance deep in that way, but you've also offered us a lot of possibility and a sense of agency over these these things. And I love that you weave your math and statistics and probability Theory background into all of this because what comes through is intense curiosity, intense rigor, and a real desire to do good. So, thank you so much for joining us and please come back again. As you make more discoveries,
it's been really fun.
Thank you for joining me for today's.
Day's discussion with dr. Shawna Swan to learn more about her work and to find a link to her excellent books on these topics, please see the links in the show notes captions. Also, I should mention that if you're interested in learning more about micro Plastics and endocrine disruptors, I did a solo episode, The huberman Lab podcast on that topic, and that is also linked in the show. No captions. If you're learning from and, or enjoying this podcast, please subscribe to our YouTube channel. That's a terrific, zero cost way to support us. In addition, please follow the podcast on both.
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