How to Safeguard Your Hormone Health & Fertility | Dr. Shanna Swan

welcome to the huberman Lab podcast where we discuss science and science-based tools for everyday [Music] life I'm Andrew huberman and I'm a professor of neurobiology and Opthalmology at Stanford School of Medicine my guest today is Dr Shauna Swan Dr Shauna Swan is a professor of environmental medicine and Public Health at the mount siai school of medicine she is a world expert in how exposure to various toxins and compounds in the food and environment impact our reproductive Health she focuses on how these compounds in our air 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 impact 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 why 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 Swan emphasizes the things that you can do every single day and 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 podcast is separate from my teaching and research roles at 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and enter the code huberman at checkout today's episode is also brought To Us by better help better help offers Professional Therapy with a licensed therapist carried out entirely online now 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 a good rapport with somebody that you can really trust and talk to about any and all issues that concern you second of all great therapy provides support in the form of emotional support but also directed Guidance the dos and the not Tod do and third expert therapy can help you arrive at useful insights that you would not have arrived at otherwise with better help they make it very easy to find an expert therapist with whom you can really resonate with and provide you with 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if so which are the ones that you think about and perhaps if you could just mentioned a few of the more Salient um maybe even shocking but Salient results that you've observed over the years like what was what was the the kind of like wo result or results that have really um steered your attention in the last a 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 our our biology messing up our health and yet you've found some so if you could just share with us uh what you've observed and what you find really compelling and important for people to know about we can dive in there that was a lot of questions I could probably talk for a long time feel free I won't speak until you're done no but I want to break it up let's break it up so I think the first question about was are there 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 uh what dose and so on and so forth but whether there are let's just say broadly things yes of course um 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 um so my um 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 hormone altering 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 an you know laying out an experiment right there right so so so focusing in on hormone disrupting chemicals I think is useful absolutely 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 quality so I'm a reproductive epidemiologist I got there in an indirect path I think probably my work on um oral contraceptives led me there most directly and oral contraceptives are endocrine disrupting chemicals that's what they're designed to do right that's what they're designed to do change your body's hormones your reproductive hormone so it's interesting you know way back when when I worked on the study at Kaiser on oral contraceptives which was the largest study of its kind in the world actually trying to figure out were they adverse effects of oral contraceptives if so you know for whom and when and how much and so on and so this was a very great study and um Coming forward in time um I you know I studied environmental chemicals not so much Pharmaceuticals um for quite a while in when I was at the California Department of Health Services and and then I had an aha moment um I was flying to Japan with my friend John Brock who's a chemist at CDC wonderful chemist and you have long flights we're talking about this and this and he says shaa you should look at thades and I'm going why should I look at thot I never heard of thades right and he said well we can now measure them at the CDC and we see they're in everybody they're in women of reproductive age Fact one fact two colleagues at the ntp have shown something they are calling the phalate syndrome and so he explained what is ntp National toxicology program sorry than for using alphabet super right National toxicology program a governmental you know Research Center and um and their job is to look at chemicals and see what is the toxicity so it could be reproductive it could be carcinogenicity it could be neurotoxicity that's what they do and um so they had signaled out these thids as being reproductively toxic and specifically to males and specifically when exposure is in utero pregnant mom is exposed to phalates and somehow the fetus is disrupted yes if you don't mind I'd like to know um is Mom ingesting phalates in the form of food is she inhaling phalates are they landing on her skin what are the modes of entry into the body of the mom that um let's just 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 thies get in there but let's come back to that let me go to the experiment at ntp so what they did at ntp National toxicology program they they fed um mother rats various doses of these various thades and um and what they found was no changes in the females or not that they found at that time they're the female Offspring female Offspring sorry but in the male offspring they found that the genitals were I summarize it by saying incompletely masculinized so I'll explain what that is so for that I have to back up and say um something you know probably know very well but I'll just explain it the genital tract initially is a ridge it's a 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 male programming window in rats its days I think 9 to 12 of gestation so very short window to orient people I think rat mouse gestation 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 um 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 right and so what they tend to have is a smaller penis um less Descent of the testin is more likely to have unended testicles um there are internal changes that we didn't get into in our human study because we can't look there but um the epidemis there are changes and so on the whole genital tract is altered and the most important measure for me as it turned out and for humans um and perhaps for 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 thallid syndrome now you're a physician and you I challenge you to think of any syndrome aside from alcohol you know they FAL alcohol syndrome of course there's a syndrome but not what syndrome is attached to a chemical class just for um technical purposes I'm a PhD not a clinician but um but but I worked on neural development for many years and and then prior to that some endocrine stuff so I'm I'm um fasile with the general terms um one that comes to mind would be for instance um the thalidomide babies right a miscarriage anti- miscarriage drug that changed limb development that's a very extreme example um I would say for um in um human de normal development what I'm most familiar with are the or early organizing effects of androgens that convert to estrogen on external phenotype which is basically nerd speak for during development the Y chromosome uh produces it leads to the production of a number of genes and eventually proteins through RNA Etc that um 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 it's a bunch of things not just testosterone the penuts Grows Right so that and lots of other right other things right so so the um the the word soup that I just uh you know put forward is basically saying that there a lot of things in development where hormones set up a uh 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 establishes a potential for the penis to grow when exposed to things later during puberty do have that right right right as far as the name goes which is the thid syndrome there is thalidomide it's not usually called theide syndrome but it could be so you're right about that but it's extremely rare and I there is no environmentally you know a chemical in the environment uh 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 phide syndrome right yeah so when well at this point it was only animals right because John was telling me about the ntp study which was in rats and so I thought wow you know I like Puzzles so my first question was is this happening in humans you might ask that you know it's a natural thing to ask great 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 thight in the mother changes in the genitals of The Offspring connect them how do we do that right so we have to start with th and the mother so 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 women's urine coincidentally if you will I thought well save it you know it's not expensive and not hard - 80° freezers doesn't take a lot of room put it in there so I had this urine save from pregnant women and then I knew from John that we could look in the urine for thite metabolites so these are products that the body forms when they're exposed to phalates and they you can measure them in urine so I thought okay I could get that urine I could look at the thite metabolites and then I'd know what the mother was 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 then I had to get the babies 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 babies's genal right how willing were parents to let you do that that seems they were okay most of them were okay with that yeah yeah well they trusted us you know they had been in a study with us and and you know we were reputable those babies were still um young but not newborn so this was a a while later the the babies that we actually got were on average I think about a month uh 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 yeah the reason I asked is there's always the potential for ongoing phade exposure to the newborn absolutely so some but I suppose in either case you're able to draw some potential link between or potentially draw a link I have to be careful with my language there um between phade exposure in utero and ex utero and these external biomarkers 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 N 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 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 of life because I knew it was unlikely to change these measures do other things but maybe but not these measures so then the question became kind of what you were asking is what do we measure what do we actually measure and if you think about a newborn r or Mouse their genitals are pretty small and there's not there's 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 a boal and and so I got a pediatrician at in Los Angeles who worked with me 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 the anus part of it was easy you go to the center of the anus so that was easy then what's the other landmark what's the the genital Landmark so it turns out there are in males two and in females there are two as well so but let's just talk about males so for males the best place to measure and actually closest to the rat measurement is the place where the tissue changes uh where the scrotum um inserts and that it goes from rugat to smooth tissue and that point is pretty clear pretty easy to measure um the other measure that was the anos scrotal distance and the other measurement we took was the anop penile distance and that was the insertion the anterior insertion of the penis the part closest to the body the closest 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 there so where exactly do you put your caliper and um we had a lot of discussion about do you press down do you what uh you know how where exactly do you make that Mark and actually the anos chronal is the measurement with the least variance because you can measure most precisely but the anop penol is is is another measurement and um 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 across Examiner and what we finally did was bring the mothers in bring the babies in um and um 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 so I just mentioned that out of honesty you know there's somebody in Mexico did this but um to my knowledge this is the first time it was used as a toxicological measure in humans right so we were um we did that study we related those measurements to what CDC had measured in the urine of our women collected while they were pregnant and we found to Sal Thal syndrome could you explain what the correlation was between phalate metabolite levels which is I believe not not by number because I don't remember it anymore but but there was a significant um let's just take the AGD the AGD of mothers who had higher levels of three the most anti-androgenic phades I'll tell you what those are in a minute had significantly shorter aner gental distance and then I have to say that which I haven't said should have that anal distance is actually dimorphic so it tends to be 50 to 100% 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 in males between the anus and you know let's say the penis penal insertion much more than in females so it's natur that that will be longer but that that's that's an air and that I began doing some work in other looking at other species and it turns out that that's true in all Maman 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 be amused by it I think well I you know about hyenas I do I know more about hyena genitalia than I'd like to admit um and I can tell you why after you educate us but I'll make I'll keep my um explanation brief but I'm very familiar with hyena genitalia so I um I have I know Steph Glickman who works with a you might know him too he works in Berkeley with he was my instructor when I was a graduate student at Cal and I used to run in Tien Park I suppose I'll tell it now and there was a colony of wild hyenas but they were behind chain link yes it's actually a favorite hike of mine up the Strawberry Canyon Trail yeah and um I did that trail a good friend of mine uh Brian pgas who's now a professor of the University of Chicago worked on the Prairie vs that were also housed at that facility and um a fun thing to do was to go see the hyenas with Steve um they're brutally dangerous animals um and Steve has tons of stories about them we we should probably resist our temptation to spiral into that may maybe sometime I'll do a little um like evening chat podast cast where I I tell Steve Glickman stories he's a delightful person and um yeah those uh let's just say this the female hyenas have clitorises larger than some of the male hyena penises and those females give birth through those clitorises yes as we both know so you will not be surprised to know that the female HD is longer than the male right because they're heavily androgenized exactly as I recall by andersin Dion as actually I don't know that it became popular during the era uh of steroids in professional baseball because andin diione was being used pretty uh um frequently in baseball at that time anyway we have to be we could go down the spiral of of of uh but also in terms of behavior the female is the alpha right right they eat first yes they're physically and um hierarchically dominant in in hyen so yeah it's really interesting isn't it that they would have a long longer more masculine eneral distance elephants we won't go into now but they're kind of Midway in many things so including they're they're about equal interrenal distance in males and females other than that humans and other species male anal distance is 50 to 100% longer however so three thades DL hexal Thal DP dbal Thal DBP and butal benzil phid bbcp are the most anti-androgenic testosterone lowering phades and those are the ones that were associated with a shorter indal distance in males in human males human males and animal so we 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 um and that study is still going on the children are still being followed I think we started in um 2012 um the paper first paper on en General distance came out in 2005 had a pretty big impact and um so so these are are studies where you're looking at the anogenital distance in um relatively newborn humans then tracking that distance no that's a different tracking is another study okay this is just two studies on demonstrating the Thal 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 um and whether what it does to their reproductive function we don't know the kids are only 12 years old now so so we we would like to know that and we will know that okay but I have another answer to 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 um by the way these are both in four cities in the United States um and um there we did it right so we got the urine in the first you know early urine because we knew that could be important we didn't have that option in the first one remember those urine samples accidental we got them when we could right and we got repeated urines one in each trimester to look at the effects in different trimesters and then We examined the baby at birth which is what the rats so we came much closer to replicating the the rodent study and we saw it again I'd like to take a quick break and thank our sponsor ag1 ag1 is an all-in-one vitamin mineral probiotic drink with adaptogens I've been taking ag1 daily since 2012 so I'm delighted that they're sponsoring this podcast the reason I started taking ag1 and the reason I still take ag1 once and often twice a day is because it is the highest 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travel packs and a year supply of vitamin D3 K2 with your order omega-3 fatty acids are critical for brain health mood cognition and much more again go to drink a1.com huberman to claim this special offer more thall exposure equates to Shorter uh anogenital distance in males it it um was approaching the distribution in females um it sounds like that that the distributions moved more closely together yes yes right yes although it wasn't the females that moved sorry the male distribution became more like the female became more uh right femin could say feminized but more female like in it and they but these boys also had smaller penises less Descent of the testes um smaller scrotums so they were smaller you know everything was in their genital area are all the secondary sex characteristics of puberty in males Adams Apple facial growth um thickening of the vocal cords therefore lowering the voice Etc are those all later activating effects of hormones or are there precursors to those that are present in in um in males because in mice as I recall like like I couldn't I couldn't tell you like we call it in the laboratory people always chuckle at this but it's like sexing the animals when you you know look to determine if it's a male or female 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 um as they get older it gets easier but when the mice are um uh you know feet down back up you know you can't really you can't really tell you can't really tell right the as the mice get older their testicles become visible in the males from even from above but you know as far as I know there aren't really external markers so you may have found the one truly external biomarker of maless of maless and and so I I I do want to say one thing about females because then that'll lead me to my conclusion about the role of this measure um 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 genital dist is that the case yes so it's a bidirectional effect can we also presume that if the mother either secretes or is exposed to more Androgen then the males can become hyper male no we' never I don't know what that would be we never saw anything that would be hyper male um so the the yes I said to you was the result of a study uh where we looked at the girls born to women with PCOS so women with cosos is you know have excess testosterone polycystic sorry polycystic ovari that's good we've talked about it a little bit before in the podcast it's a um It's associated with my understanding is It's associated with um elevated levels of androgens that's right and these women often have facial hair and you know they not just the moms but the the people the women with PC yes have elevated androgens yes not just we're not talking about pregnant moms anymore right um 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 interal distance what what age group were you looking at in the INF in the infants oh the PC was at was at diag at pregnancy at the time they were pregnant so presumably people between their like somewhere in their 20s out to their 40s yeah yeah so adult human females who have PCOS tend to we know they have higher levels of androgens but they also have more maleik anogenital distance they do not their daughters do their daughters do thank you for that clarification they're 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 uh and so this is very early first trimester you can't even get you know flu 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 in to female Offspring or um let's just say reduction in functional Androgen exposure to male offspring the reason I'm using this uh you know loop-to-loop language as as you probably know but for the audience not trying to complicate things here but a lot of the mascul izing effects of hormones in fetal development is actually testosterone that's converted into estrogen so it can get pretty tricky right and um 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 right it's just that people form such strong associations falsely that you know testosterone is male mess that's not true and and and estrogen is femaleness and they both and it just gets really murky but for for the time being um 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 anog gal distance well I can tell you there are many boys that are probably worried about it right now right they probably got the ruler and the calipers out right now just you know um 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 in the animals my colleague Earl Gray who did these studies said his name is Earl Gray yeah that's cool yeah um he said a GD is forever anogenital distance is forever now what that means is it's not like your anogenital distance today is what it was when you were born of course you're a bigger person but that means adjusted for body size right so if you assume that AGD is forever if you're born with a short for your size AG 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 anogenital distance we're getting a reflection of what it was when they were Bor 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 them $75 and one of the guys said for 75 bucks you can do anything and so what we did was we met measure their anal distance and then we got them to give us seamen sample and complete a questionnaire and things you do in a study we'll link to that study but I have a couple questions about the controls in that study just for sake of people understanding how a study like this would be done I don't expect you recall all the all the details but um 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 um in other what you're trying to do is backtrack to what it likely was at at um no we didn't actually try to go back what we let me just tell you what the results were in this group of men if they had a longer anogenital distance they had a higher sperm count got it so you were correlating 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 AGD and sperm count so it's easy to say AGD is related to sperm count because we measured that we saw that a correlation that's published okay if we want to say their early AGD 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 AG were there conditions of being a participant in the study such as uh refraining from alcohol cannabis Etc in the 90 days prior 90 days being the the duration of spermatogenesis yeah I don't remember that these are college students so presumably some of them are drink okay so but in the end it it was a robust um a robust link and then U Mike Eisenberg who you might know my colleague at Stanford he's been on this podcast good good so he's a colleague of mine too and um he uh looked at um men in infertility clinic and those who had born children and those who had not born children and the men who had born children had a longer in gental distance than men who had never born a child never born but were trying yes right these were not people who opted out these were exactly these were people who were who are who were having challenges with fertility versus success with with uh by the way you know the question of how you measure AG in an adult man is a different question question then how you measure it in a newborn and we did a lot of work on that and Michael helped with that too so it sounds like um oh and may I ask were the sperm counts that were on the let's just say the lower um like the lower cortile 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 spolski with Mike Eisenberg and now I'm asking you you when we hear that sperm counts are going down down are they going down to the point where fertility is is impacted that's really the the one of the I think functional questions so I'm going to let's lay aside the question of AGD right that's an really interesting but let's talk about sperm count okay so um if you there's a a beautiful study um among pregnancy planners out of Denmark um quite a long time ago um 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 in relation to and what they showed is a really interesting curve which has never been correct it to my knowledge it's it's it's what I use and what I think people use which is that if you I wish I could draw it here wish I had a BL you should have a board a white board the problem is a lot of people are listening but maybe we you know we can talk people through it sorry so so just think about um a curve where you go all the way down to zero that would be no sperm um 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 um and um 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 Mill uh so just pure concentration not number of motile sperm this is just how many sperm we're not talking about quality we're Talk number a number and and when you have 45 to 50 million per Mill and below it matters a lot what your sperm count is you know people say it 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 it starts to level off and then after that after certainly after 100 probably 75 it doesn't matter at all so 100 million sperm per milliliter yes of semen yes okay so can you see this okay so it so when people say does sperm count matter for fertility yes it matters a lot if it's low and no it doesn't matter at all if it's high so you just we just have too many sperm I mean I don't but humans you know and there's so nature runs a probability game overproduced sperm right some of those will be high quality some will be low quality depending on their age when they were that is when they were generated or their conditions you know or their conditions how much heat exposure Etc so nature runs a probability game that's right hoping that the the the best quality sperm will fertilize the egg right um so below 45,000 uh excuse me below 45 million milon per milliliter 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 Mill of sperm then it's all good to you're good to go right and sperm counts uh range anywhere from you know it could be low 8 n 10 million per Miller in the very low situation it could be zero in some people right all the way up to 400 yeah 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 thied exposure yeah I'd like to take a quick break and thank one of our sponsors function I recently became a function member after searching for the most comprehensive approach to lab testing while I've long been a fan of blood testing I really wanted to find a more in-depth program for analyzing blood urine and saliva to get a full picture of my heart health my hormone status my immune system regulation my metabolic function my vitamin and mineral status and other critical areas of my overall health and vitality function not only provides testing of over 100 biomarkers key to physical and mental health but it also analy IES these results and provides insights from to doctors on your results for example in one of my first tests with function I learned that I had two high levels of mercury in my blood this was totally surprising to me I had no idea prior to taking the test function not only helped me detect this but offered medical doctor informed insights on how to best reduce those mercury 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fact that sperm counts are dropping there's a relationship to anogenital distance and there's a relationship between anogenital distance and Thal exposure yeah and then I asked 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 um and then of course we have the socio uh the sociobiology uh piece where people are opting out um or it's also economics in some cases um opting out of having kids right um 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 phalates was not through sperm count right it was through this question of my colleague ask me you know you should look at this and 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 um 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 hormonally 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 H 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 a 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 that's that's a big claim for a little little paper you know um but I'll look at it because it's important and so what I did then was to think about all the fact factors that we epidemiologists call confounders things that might have caused that decline if it wasn't real biologically right and so we could think of some of them together um 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 um but it turned out that wasn't the case cuz they actually had all used the same method um and maybe the men had changed so maybe there's a you can't get a sperm count at random you have to get somebody to volunteer right so who were these men were they very different you know in the early part of the study and the late part of the study in a way that maybe in the late part of the study there were men with lower sperm gut and they were more concerned you know maybe they were more obese that's pretty plausible obesity is related to se sperm Camp fertility um and maybe they smoked more and maybe and so on and so forth 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 explained anything and I was like oh my God this looks like it might be real and and for those listening what Dr Swan 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 uh this is really important um to 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 populations that are out there living you know some of these men probably you know smoke some cannabis I'm not saying that reduces sperm count it might reduce sperm amount mot motility however we covered that in the podcast now that all the Cannabis folks go well uh you know so and so got so and so pregnant when they were doing swing a lot of weed and I always say okay well there are a number of other factors right you know but alcohol there's um frequency of ejaculation right the the requirement to abstain for 48 to 72 to hours to up to five days prior you know Etc all 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 so all the different things right right this is so very different than looking at for instance um ovarian reserve like the the number of eggs where you use ultrasound and you use amh levels and um sure things can impact that but it's a little different than when taking uh sperm counts so thank you for doing the the studies so carefully and for repeating them so many times I mean many of the studies that you've done are are um you you've done followup 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 there was an update I noticed online so you are extremely thorough you and and it probably reflects your um early training in math and statistics and probability Theory you're not somebody to just kind of go in and go oh 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 um if today's discussion feels like we're really um we're Laing through this um that's intentional um and it's important for people to hear these these kinds of um claims are not the sort of thing that you could people make them all over all over the board but work like this needs to be done um with an extremely meticulous eye and consideration of all the variables well good scientific method yeah yeah yeah and I would say especially with human epidemiological work because of the number of potential confounding variables right right so so when I saw that and actually did another study to select my own studies and not accept her 61 studies that had been published that Elizabeth Carlson had published uh so new studies came up to more recent times went back further um 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 I turned to the why okay because up and down now we hadn't said anything about why we 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 talked to people and ruled out genetics because it was too fast it's two generations it's too fast 50 years two generations so if it's not genetics then it's environment and so what is it about the environment that could do 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 designed next which was another study and by the way this preceded the AGD so it just so we had four cities in the United States that we picked with different environments and then we got men to come in and we used the same equipment at each place we used the same method of selection them selecting the man the tech technicians were trained centrally at UC Davis we had very good quality control so samples were sent 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 um and that's how I had those urine samples 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 to give me a SE 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 Care almost all and if their Partners will give a seaman 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 um and of course they'll have slightly higher SE quality because they got their partner pregnant but um and so we had their urine we had their blood and um we looked at their semen quality and then we decided to look at pesti pdes and the reason we look at pesticides um was because there was a lot of gradation across our for centers in 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 um those men had half as many moving sperms as men in Minneapolis whoa whoa huge right and then we went one step further and within 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 app 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 okay I don't remember so so plant and fruit crops presum was yeah whatever whatever they were growing in Columbia Missouri at that time and and just to make sure I understand that it's not that the men 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 is it is it still called dust crop yeah we didn't go into how they got these we just looked in their urine and there were the metabolized the metabolists don't get in their urine unless they were exposed exposed through the air or exposed by eating corn and soybeans we don't know we don't know okay we don't know um but this was not a particularly you know we didn't we didn't sample Farmers Only or anything like that so 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 in our study they're the male you know urine M's urine was measured for for these pesticides I'm sure a number of people including myself are wondering in what other products are these five pesticides present um are these commonly used pesticides or is it something about they were they're called the the iine pesticides atrazine is was the most widely used and it's a huge use around the world I mean it's highly you know one of the most the largest commercial pesticides um so these were very big players in the pesticide field a relevant um theme there would be uh maybe we could take a moment and talk about atraid and its effect on uh male sexual behavior in amphibia and we'll come um come back to the the the sperm cies because um 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 Aden there are multiple Deans on campuses Tyrone Hayes is a wonderful researcher um who established a link through his research between atrazine exposure and um male sexual behavior of amphibia yes could you elaborate on that result yeah so Tyrone first caught frogs in the wild uh in environments that were more or less exposed to atrazine and showed effects on development and sexual behavior then he in his lab he actually exposed them so he knew exactly who was exposed and how much and he showed that the and 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 they CL they mounted them he has photos of the male males mounting males and so presumably this is a neural change that occurred neuroendocrine change but ultimately neural since mounting behavior is controlled by actually we now know the the um 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 um uh working on on this specific issue of what the what the the circuitry um is um that's a remarkable result it's been kind of um you know used and misused out there in the in the in the media and in popular culture um but if nothing else it suggests that the organization of the neural circuits and neuroendocrine Pathways that control um sexual I don't want to say part like because his mating thing this the frogs aren't monogamous but um uh sexual preference are um significantly impacted by this by this atrazine yes and and it suggests that that there other environmental chemicals can as well and we I don't know how if we'll have time to go there but I did work on neurodevelopmental outcomes in relation to prenatal phid exposure and so I think the overarching idea here is that the brain like the genitals is 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 the work of Frank Beach and the psychology department at UC Berkeley I know um showed this in beagles it's been it's been shown in pretty much every species tell but it's not a better worse I think this is what people need to hear like dimorphic does not mean better worse it means different right right and that there and there are for example advantages to spatial um reasoning in a male that which are related to testosterone you right you know that so I mean I think there 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 meteor preoptic area of the hypothalamus is known to be sexually dimorphic dependent on testosterone converted into estrogen during development etc etc and there's just so much evidence of this um how it links to behaviors is can I think can be reasonably placed into um ethologically relevant um uh evolutionarily logical um arguments when talking about rodents or beagles or even reesus macak monkeys I think where people get um a bit inflamed is when people try and take the sexual dimorphisms have been observed in animal brains or in even in human brains and Tack those to specific abilities or or or lesser 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 uh almost at no man's land a no person's land of of of comp of confounding variables right but I really appreciate that you raised this and also that you said it and I didn't because I I feel safer that way but look there is a a very simple outdated questionnaire and it's play Behavior it's called the psai it's been used for years have you I don't if Rough and Tumble play yes yeah yes and there are 24 questions on there and they are sexually goric I guess you could say that there you know my child likes to play with dolls my child likes to play dress up my child likes to play rough and tumble uh Etc and we gave that questionnaire to our population um and looked at the answers uh that the mothers gave both in our population by the way and a Swedish population of a colleague there uh Carl borag and Gustav borag and and um what we found higher thite levels these anti-androgenic phics were Expos you know associated with less masculine male typical play in our male boys so this is thid exposure to the to the mom baby is born in the young human child four four yeah four year I think it was four years of age four years of age less Rough and Tumble type play that's right among the boys whose mothers were exposed to Mor phalates during a critical period of development now you can see that's a politically loaded issue now I mean you know yeah well I think we're I mean let's let's let's have some fun with this in in in the scientific sense the the notion of dimorphism is you know okay male and female brains are different right which and male female defined in those almost all those studies as presence of a y chromosome and then people say well there's some there's x y y and then there's XX y okay but most of the time you're talking about XX chromosome or X why 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 uh you know two hills of data separated by a valley these are overlapping distributions right right so you get males with a quote unquote female likee distribution you get females with a quote unquote maleik distribution and I think as long as we acknowledge that then we're just talking statistics right we're not we're not placing any cultural or um any value on it really whatsoever right but but if you you could make the analog to the inter gental distance it's kind of similar you know you have the same exposure salid exposure you have something changed statistically we don't see huge differences in the boys genitals uh and and we don't see huge I don't we know these kids have not been scan so we don't know how their brains look but based on their answers we don't see huge differences we see tenant we see they are more likely if they had been exposed to these stots 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 um if a young boy has a sibling that's a sister there's more lik be dressed as right she's if he has two older brothers there might be more Rough and Tumble play happening in the house and I have some friends that are women who have older brothers and those women are uh 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 and fight right you know so so I think that um none of this is deterministic right as we know I but but let me just add we did control for the sex of The Sibling older sibling and we also asked about the parents attitude just toward 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 did your child play with dolls well what what if there were no dolls this is super interesting to me I I don't want to reveal too much but I um just because it's not it's just an N of one but I grew up in a household where I have a sister but then after a certain age I received very strong messages about what sorts of um play were um were gender appropriate um and I think I also just naturally defaulted to there were a bunch of boys that lived in my neighborhood they had older sisters so all the sisters hung out together it's kind of interesting and all the the younger brothers pretty much hung out together and the the guys that weren't didn't have siblings or had Brothers for siblings so there was a really strong Divergence but I grew up in the SE that was in the 70s and early ' 80s when things were let's just say culture was more dimorphic then clearly right I mean there were television 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 I mean nowadays people will 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 phalates that um we have agency over that we can take control over right so let me ju correct you it's not that sources of phalates necessarily pesticides there are phalates in pesticides um but that's not the worst player in um the in the story if you look at the different classes of exposures that are hormonally active right pesticides are phalates are bisphenols like bisphenol a BPA BPA certain metals are there's a posos chemicals there's all these different classes right and if we want to go excuse me into what in our daily life exposes us to these things that's another story that um we we can talk about but they're going to be different depending on the class right so let's um 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 um some people will be pregnant as they listen to it but um would you say it's you know drinking out of plastic bottles is it laundry detergent um is it you know rubber tires that are cascading down on us through the air and we're in ing them I mean presumably all of the above but what are which ones that we have agency over do you think are the most let's just say concerning where people could make better choices um I would say foodborn exposures exposures in the food in the food packaging in the food storage in the food in the cooking of utensils um we can go through the various things but um we're doing that all the time you know we're eating all the time we're getting food into into us and these are bringing in in a very you know in a way that we have some control over some agency over uh you know we can make changes in our Foods um very close to that is drink you know food and beverage um 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 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 um then a company that I work with a million marker out of Berkeley has a trained staff that interviews them not only them but anyone who signs into to this company interviews them and ask them what they use what do they use for their faal facial care what do they use for their shampoo what do they use for their cleaning products and their laundry detergent and their what do they store their food in and on and on and on so this's this long inventory that they take of all products that people are aware of using okay and um 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 um then in the film and in this little It's actually an experiment that I designed and we're 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 Thad any product any fragrance product if fragrance is no perfume no lotions soap with fragrance right even essential oil fragrances like essal oil is a tricky right it's a mix it's a mix yeah so I I'm I'm going to that's guarded but but anything you know spray deodorants roll on deodorant laundry detergent yep in shamp and any if you can smell it it's probably affecting your hormones I'm so happy about this answer not because I have any steak in any company related to fragrance free stuff but I I I've a very strong sense of smell and I um either love or hate smells and I hate synthetic smells like going through the dutyfree especially in a European airport where with all the perfumes and I'm just I was going to hold my breath it it feels like I'm breathing poison I know um uh well well you are actually yeah yeah yeah in some sense most soaps right yeah um super interesting so that's your primary intervention is to tell them get rid of anything with fragrances no it's only one thing we get rid of so then we we talk about how the Plastics that they use to store their food food storage containers try to get them to get rid of those if they're made of plastic we try to get them to get rid of their um non-stick pans because of the posos chemicals that are in those and and so on and so forth so we go through all steps of their life and try to tell them how to make changes that will reduce their exposure but presumably also um changes like if if uh the man is obese for instance you might have him walking a bit more no you don't touch any of that well you see Andrew if we did that we would be mixing up two interventions we would be mixing up an obesity intervention I see this is a study I I'm sorry I thought that this group is uh is missioned with um helping couples get pregnant no no this is how this is a study to look at what happens if you make these product related changes great just product related changes exactly exactly we would love to do and probably will do another study separate one on Obesity and you know a lot of these chemicals just to let you know are obesogens they increase obesity there's a book out called obesogens you can read about them and so you know it'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 obesogens 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 say with a big box and in this box are these alternative products and um so you know straws and and and bamboo 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 you know I'm not a I'm I'm pretty careful in what I so I 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 uh 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 six of the 3 months they and hopefully in six months they will they are still making these changes in their lives did um 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 can't talk about until the babies are born just kidding um um and and we did get their sperm count at the beginning and the end and and had some very interesting data on that which too early to report to too too early let me ask you this then and um I appreciate that the not wanting to share specific uh results until this the all the data are in and it's published um if somebody listening uh were having trouble conceiving um for 12 months or more um are the sorts of replacement intervention product interventions that you're talking about here things that you would um at least feel comfortable saying um would might be a good place to start or to explore absolutely absolutely there's no harm you know we we're not none of the changes are putting people at risk or doing anything that could be harmful them I'm sure of that very careful and some are are going to be cost-saving um I think that's where like drinking out of uh plastic bottles far less if at all like I um just for reasons related to wanting to reduce waste I I use a mason jar or use these or ceramic although you'll probably tell me that the lining on the ceramic mug might have endocrine disruptors no I okay great okay well then I'll keep drinking um but it's very reassuring to me that there are things that we can do in terms of cost-saving elimination or replacement of of consumables buying in bulk that can improve endocrine status maybe fertility buy in bulk um 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 MH um one of the things I did with the couples was go shop with them 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 lettuce heads of lettuce or wrapped up in plastic Bunches of lettuce and I said let's compare the price I actually didn't know until we did it but the freestanding unwrapped lettuce was cheaper and I think that's you know because that 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 PA exposure and some of these forever chemicals um that you mentioned um seems like reducing uh fluid intake from plastic vessels is going to be number one the primary source of BPA is in the lining of cans so any drink or soup or anything that comes in a can is going to be um any can all can any 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 um such as BPS and BPF and and maybe you're be interested in this story so when it came out that BPA was um estrogenic which is what it is um and by the way it's kind of the evil twin of phalates because phalates are anti-androgenic and B is estrogenic and phalates 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 um the manufacturer started selling things that say BPA free I'm sure you've seen that the trick is that instead of BPA they use BPS sneaky rat and BPF and these are chemicals these are lookalikes they're analoges and they're just as harmful sneaky sneaky sneaky so 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 um 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 it's like it's not it's 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 like infinitely complicated um maybe you can do that but I'm far less optimistic and now that I'm 49 years old I can say things like now that I'm 49 I feel like um but what you're saying is really important if I look at a can it says BPA free doesn't mean anything it could have bps's or other uh endocrine disruptors right so drinking out of glass vessels um drinking out of um ceramic vessels um metal metal but not cans not metal cans not aluminum cans right not cans no good but okay you know you can get a a metal water bottle that's not lined with BPA steel steel yeah steel yeah and um is it true that microwave safe means it just means that the plastic won't melt in the microwave but it's do never never put plastic in a microwave so here's the story The BPA phids 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 chemical 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 it warms up the bottle and then the stuff goes into your water you don't want to mix these chemical and your food but if you do the worst thing is to do it in a heated environment I think about all the the food that was consumed in college in the in the 90s and 2000s like uh the cup of noodles with the styrofoam the um 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 finish 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 um strawberries at the farmers market blueberries at the farmers market which is what I try to do but sometimes I buy strawberries at the market and they have those plastic flip top things and of course I 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 we have to do that experiment I don't know yeah so I guess so it sounds to me like um not drinking out of cans not drinking 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 phalates are actually added to pesticides and they're 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 um so the same property of phalates that makes them good for pesticides also makes them good for our hand cream just mentioning absorption absorption anything that's absorbed in the body is going to have phades in it and it also holds scent and color so it's added to those scents and it's also added to your lipstick and to your colored you know whatever you put on face and so on anything that holds scent and color that's going to be th um sorry I've been accused on line and uh of being a sunscreen truther I'm not a sunscreen truther I'm going to keep repeating this as many times as I can I I understand that UV damage to the skin can cause certain cancers I get that um I agree with that um the data are pretty clear to me based on having researched this pretty extensively and talked to many many people including Derm oncologists 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 in Europe there's tons of evidence that the chemical based sunscreens are safe okay fine you use them I'm not going to the point being that UV damage is bad there are ways to prect protect ourselves from the Sun including physical barriers like clothing hats Etc um 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 what do we do do we have to hunt really carefully for the right sunscreen uh yeah I I think that's a good idea um are you familiar with environmental working group uh is another one out of the Bay Area no oh okay I don't know actually where they are they're pretty big sounds sounds familiar but I'm not I can't say I'm familiar with they have Consumer Guides and in those consumer so environmental working group I'm not part of them I'm you know but I like their work and in these Consumer Guides you can put in the product and they have categories you can put 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 in independent of any like funding of that question will probably come up for you too um uh people will say where did she get her funding you know people people get very suspicious about this I can tell you yeah that would be great yeah so I uh am a a tenure professor at Mount Si get some salary there because I'm only part-time and I have a funer one funer who funds found funded my um sperm decline uh second 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 philanthropy yeah and it's actually not a lot of money so no And so there's no reason to think that anything that you're telling us is um 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 um but I think nowadays people have just been taught to you know 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 F food pyramid for instance people were under the impression that somehow that was biased by 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 um all I know is that um 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 thing and it's woven in with a lot of um psychological and emotional issues yeah yeah okay um what are a few things that you do Andor 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 uh for any age but it's it's really remarkable I I feel comtable sharing this because someone else published it online recently you are soon to enjoy your what birthday 89th 89th birthday amazing and um 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 disruptors um and she has a wonderfully rich life of curiosity and other things um but yeah what are some other things that you do uh and and avoid in light of what you know for which there may or may not be a control old study but I think we're all just curious we'll frame this as what you do so water our water I worry about the water I studied water for a long time in my past life so we actually distill our water so we have a tabletop distiller um my husband Steven cleans it out there's a lot of gunk in it by the way even though it's San Francisco that has clean water at the end of the day after you've distilled the water there's a lot of gun so you distill the water so this is not reverse osmosis distilling okay yeah so it's steamed 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 was just over and and he said this tastes like melted snow I thought it was lovely and you use that for drinking for coffee for tea for cooking too if you make rice you're using distill actually no no but for ice cubes and you know whenever I can think about it we can't use too much cuz you be too busy always but he does it once a day that it's just the two of us so water is important um we try to leave our shoes at the door tell me about that one well dust that you bring in um contains a lot of the particularly the posos chemicals and uh so that's actually um I'm not 100% good on that but we try try to do that um 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 um and I go to the farmers market I always buy organic always buy organic um but I know that's a cost issue for some people um and an availability issue for some people but I in San Francisco you can do that um some areas where I don't do more of what I should I think I'm starting to be aware of the um chemicals and clothing we haven't talked about that but um 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 you're sweaty you're hot and you're bringing these chemicals into your body and that may be one of the interventions that we do uh get a bunch of athletes to use um safe clothing and and traditional clothing and see what their body burden is that's how you know so um airing toward cotton as AO as opposed to synthetic material right right and the dyes are important so you you don't want you want maybe plant-based dyes 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 um I'm just saying that's another area that I think people will soon be paying attention to um there's also the area that is much more difficult which is what's in building materials and Furniture but um a lot of these posos and the tens 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 um 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 I'm thinking about the opener of The Simpsons and doing the exact opposite where like in the opener of the The Simpsons there's like a three-eyed fish and there's the the chemical plant and I'm just thinking you just look at the opener of The Simpsons you do the inverse of everything that's there the inverse of everything that's there including alcohol intake um uh you know which is um robust on The Simpsons um yeah right but it interesting so and when it comes to food sourcing like of 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 I mean you can if you go to a farmers's market but this stuff can get pretty tricky pretty expensive and most people listening are not not going to be you know living in somoma where they might have a a neighbor that has chickens or something yeah um it's it's 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 um but um I know that's not the case everywhere so um I think being aware honestly is a really big step if you're 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 dyes in uh children's toys in particular toys um from overseas right remember kids are not you know babies are always gnawing on stuff and teeing and and and there was a lot of attention like hey like what's in these sippy cups and my understanding is uh toys and sippy cups and my understanding is that bpas were banned from sippy cups thit excuse me based on my work based on your work thank you so much thank you for the clarification truly and and for and for the work that led to that um we we have this um innate thankfully uh innate reflex to protect our young as does every most every species um thank goodness and we know that baby skin is more absorbent than older skin we know and so there there are literally laws in place and restrictions in place to make sure that some this 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 it depends on your budget where you go and so we we can't rely on governing bodies to to do this um but I think it's a useful conversation especially given your relationship to um 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 lotion Etc that you're aware of that are prominent here in the US maybe that's a good filter to 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 thide connection it was 10 years two studies 10 years $10 million by the way so if you're going to wait for that I don't know what you know given the number of chemicals out there 80,000 or more um forget it you know so so I think the reach policy of testing before something's 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 are those are those animal tests um or animal and human tests that they're doing over there whatever defin safety it depends on the chemical it depends on you know what the product is I I can't answer that in general but so that be a good Avenue for changing legislature here right to to install something similar to reach absolutely but it's not going to 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 I'll give you one example um so you know that you might not know but should know that thids are very prevalent in the hospital setting there're if you think of a tube you know to to dialysis to chemotherapy to IV that's all PL that's all phids right and that's going into your body and there was a recently um a bill passed in California that DP could not be in IV bags it's fantastic success in the actual bag yes the bags could not contain these endocrine disruptors yes DP specifically dehp diyl hexalite the most anti-androgenic Thal so so that was a great step for for 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 bbrw which makes Hospital products and they are very forward-thinking and they set up a a factory in Florida to make alternative IV bags out of another product um poly oan and and the problem is that we're not sure about the safety of polyphant so it's a it gets really difficult you know you can say remove dhp 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 dissolution you and your your listen you know that's a that's a huge challenge that we're up against we know it's safer we know it's safer and we know what the Bad actors are and we know 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 yeah I I'm thinking about this a former um president of Stamford who was also happen to be a family friend years ago um he since passed Don Kennedy when he retired as president Stanford went in my understanding is that he went and directed the FDA and I was just thinking to myself like um when did thisen happen um because I know he was super into Health he was like an avid Runner he was very fit well into his 70s yeah hit replacement kept running or maybe it was knee replacement I don't know the guy was obsessed with health and so I don't think that um there's there's a lack of interest in health at the level of things like the FDA and um 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 like when we go to a restaurant it's challenging to know like what they're doing in the kitchen and and and at some point it becomes neurotic to you 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 um but maybe uh they they're more significant issues who knows um the seed oil crowd is pretty pretty intense um and I like olive oil anyway so I air to that but I think if people are interested Ed 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 counts is we can't control what happened to us during pregnancy right 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 um 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 cannot change things further and make things worse but here here's a here's a fact if a male's mother smokes when he's in the womb then he has a this is a Danish study by the way 50% reduction in sperm count if his mother smoke while he was in the womb how much smoking are we talking I don't know I don't remember 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 the sperm count he can stop and his sperm will be res restored he can get a sperm Health back but whatever happened in the womb stays in the womb if you will it's developmental it's not going to you know it's going to be be there for life and that's true of the brain as well so um I think anybody who's thinking of conceiving a pregnancy or pregnant 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 this germ cells for your grandchild are going to be carried in within your child so germ cell are um not germs as in infectious germs it's the cells that will produce the egg and sperm that germinate hence hence the word germ right so it's a huge responsibility and I think people should take it very seriously um that they have you know they're going to be affecting the health of subsequent gener some Labs say it's seven generations I don't know if that's true but certainly three generations um are affected and um so I should mention my book can I mention please I'll mention yeah I believe I mentioned it in my introduction but yeah please so in in uh countdown uh two words by the way because if you say countdown one word you won't find it but countdown um we have two chapters on things you can do you very practical things you can do and also websites you can go to and links you can go to now this came out in um 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 um in the sorts of things you're talking about like is there a whole field of this of of excellent people are you are you a small team of of of people that are against the grain I I mean I confess I don't know many people doing the sorts of work that you're doing but I you know you're the the most public facing and prominent and um I I 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 and it's International and there is now um a global um Plastics treaty under negotiation by the way tell us about the Plastics treaty people are trying to create get ped by various countries um an international Plastics treaty I can't I don't want to talk a lot about it I'm not involved in that process but in the process you they you could see if you looked into there hundreds of scientists and concerned citizens and activists and you know people in legislation who are working to specifically on the chemicals and plastic now plastic is really a bad actor I 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 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 um though you asked about scientists in this area yes there's huge amount of science going on for this in this there's um and it's funded by NIH and it's funded by um the EU and um primarily I think those are the two 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 red ction and smoking um and control of Infectious Disease and Control of infectious diseases um but lifespan is definitely increasing um whereas the use of plastics has clearly increased um and so uh I guess one could argue that we're living longer but we are less robust than we were less um reproductively competent is that uh the people that are reflected in that longer 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 then there was no you know um and there were other things of course but it not as they are today so um 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 industry is 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 I'm I'm 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 birth rats are way down and and so this is a an enormous problem for societies because the people in that small support group at the bottom can't drive the society to support the L the large growth on top you see what saying is this true 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 we're facing now because um it's everywhere it's very acute and there's only limited things we can do to to to counter it um there's a wonderful website called it's 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 you and see what the f fertility rate in each country in the world each year and you can see that and what you see is that um a decline about the same rate as sperm decline by the way about 50% in 50 years and um the critical point for fertility is two so what's that mean that's called replacement and that's two people replace themselves with a total fertility rate of two 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 and there are many countries in the world that are below that including the United States and for example the worst I've seen is actually South Korea which is at 0.78 wow Japan is at one wow so large parts of the world are just not replacing themselves and why that is is maybe another discussion but or we can talk about it I don't know if you want to go go into that but um it's not just sperm count for sure yeah along those lines let's talk about egg count and quality uh you mentioned the PCOS results earlier um before we were on Mike uh you mentioned an interesting study that you did about the use of electric blankets um and assessing whether or not the use of electric blankets had impacted um egg number or quality in women and the answer was it actually what we looked at in women I'm sorry to correct you but was their the outcome of their pregnancy their fertility and and what if they got pregnant how how did that turn out excuse me so thank you for that clarification but but um I'm sure there' be a lot of other studies that have looked at that you know I 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 cell phones or um 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 looked at my understanding of the cell phone data uh for sperm uh count and motility AKA quality um is I discussed amended analysis uh covering this 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 I want to be careful here impact um sperm count and and motility uh quality but um Direct effects of of emfs on sperm there's no evidence that it is disrupting sperm at least to my knowledge I honestly I have to say just going to say I don't know but I do know that um heat is related to fertility and sperm count right and um you can look at the birth rates as a function of the month of conception and you can see that for example in war months in war climates uh there's less yeah so there he he does play a role but how much that's tied to cell phone use I I think that's something that's now under investigation by a lot of groups and um we'll see what they find yeah the data on sitting more than a few hours a day on um having legs that are very large as a consequence of obesity or even just legs that are large uh heating the the scrotom and th those data are fairly um I would say solid in terms of the relationship to reducing sperm count um heat is not good for sperm which is why the scrotum has its um the features that it does to move the the testicles further or um closer to the body um getting back to egg um egg count and quality there's some evidence that um girls are entering puberty earlier um but that uh women are also undergoing perimenopause menopause earlier earlier um do we do we know what that is the consequence of there are several new papers 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 um I think that's right I think there is growing evidence that earlier you know fewer it's also called premature ovarian failure um so that women are just not producing the eggs as long as they used to yeah but um [Music] um the I just want to say something about the fertility can we go back to fertility please um so when this comes up and there I'm sure you've seen the literature there's a lot of literature on this that say fertility is going down you know fewer children are being born a people say well that's a good thing because it's less of a load on the planet which is an another discussion and then they say well this is due to choice that people are choosing to have fewer children and they're choosing to um delay childbearing till they're no longer as fertile uh 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 um I just need to point out whenever I hear this that it's not just human fertility that's declining um the number of species that are becoming extinct is increasing rapidly and there is there have been for at least 40 years evidence that those pesticides that affect us are affecting animals as well and um so the decline in fertility in non-human species cannot be attributed to delayed childbearing or use of contraception right right and it's interesting because um 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 is about to go distinct um like the Florida panther right or you know we we hear that you know there the species of like there's a very small subset of them left uh the blackf footed ferrets in Montana I think one feret his name is um Scarface SED something like 300 lit that then led to the EV they started out outbreeding because if you do too much inbreeding obviously it's not good and but then they were able to at least partially recover maybe fully recover the those populations and people forget the the domino effect of these ecosystems when one species is compromised like when the black-footed ferrets I know it might sound kind of silly but um were 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 on bugs and you know and I'm not an expert in this but one doesn't have to be an expert to understand like you you move one pin here and and the whole web moves and um and so or you move one node and the and the whole web uh reconfigures and um and that's what Nature has been doing for millions of years right but um 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 that's not like a an outrageous sci-fi movie like right like at some point humans might be added to the endangered species with the exception that we have we're very clever and so we found a lot of ways to do medically assisted you know conception right ixie the the the literally you Gentle grabbing of one sperm and forcing it to con to uh to um fertilize the egg um is something we've covered on this podcast in our fertility episode with Natalie Crawford in a Solo episode that I did um there are questions that people have reasonable questions about whether or not the um The Offspring of those types of scenarios are the same as the right the the genetic um probability experiment as you mentioned before of having you know 200 million sperm and then letting Nature Select the one that is most um robust in that environment yeah and and you know the number of Technologies is increasing we're very clever species and and um for example I don't know if you've heard of gam Genesis so it is now possible to create um an embryo from a a sperm cell from a skin cell skin cell can produce um uh a sperm cell and an egg cell and you give it the right transcription factors and you can you can um so this is kind of interesting exciting and scary right this is like the the um what is it I think the vulture vultures the females uh there's some way in which two female vultures or maybe a single female vulture can um create Offspring in the absence of a male there's also a three-party IVF I don't know if you're aware of this where this was um developed where there's a mitochondrial disease you can take the uh two eggs one from the intended mother you take the nucleus so you get the DNA you put it into an egg of somebody that um where the DNA has been removed but where the spindles which are rich with mitochondria are from a typically a much younger host and then he use a sperm so it's actually three parents it's the spindle of one mom 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 um and in theory legal issues must be yeah but and but in theory this would allow women of any age provided they can they still have eggs um to have their DNA propagated forward because they could the DNA can be put into a younger egg that is um has the spindle quality that allows for um you know the production of more cells I mean this is this Canon has been done in humans yeah yeah so we're 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 CH you know to meet the challenge of declining fertility by ordinary conception 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 um conception and and and then the question is going to be and it'll take time to know this is whether there are effects in The Offspring adverse effects in The Offspring um it's it's a little tricky because for example if you use the sperm of an infertile couple and you see let's say say the sun is is subfertile that's born that way um but you do it you know in a test tube or whatever and then you can say well maybe um that's because the father was infertile and he's got inheritance from his father from that you know you know what I'm saying so you can't know whether the if you see an adverse effect in in an offspring you have to be very careful 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 y yeah um super challenging fascinating problem so in anticipation of this sitdown together uh I put a question out on X formerly known as Twitter um I let people know that I was hosting an expert in endocrine disruptors in phalates and pesticides rep productive uh 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 um 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 re mineral remineralization excuse me difficult word to say can also be effective Etc um there were a lot of questions about um cosmetics and laundry Det detergents um I don't know if we discussed laundry detergents what do you use in terms of laundry detergent um or that is presumably one can find I don't even remember okay don't go by my product okay for one thing I'm not going to be pregnant anytime soon no um the uh I I believe there are some solutions um related to the uh like instead of bleach people can use um hydrogen peroxide can't speak about specific products actually um you know I can tell you who can you might like to talk to her so you remember I mentioned million marker the company that did the inventory not the comp well they are a company but um so they look at million marker I think you'd be interested okay yeah and and and the person who runs at Genoa is a Chinese American um who uh and a friend of mine and we're going to be writing a grant together um and she participated in the film so our participants send their so what if you go to million marker you log on and if you agree to pay whatever it is $199 I think you send your urine in they give you a kit you send your urine in 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 so blah BL you can see the different levels of 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 so um right and we won't um expect you to give product names and um I'll follow your recommendation that you just gave um somebody asked about food dyes just generally the dieses in Foods I saw 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 I saw you can see the organs saw that it's wild it's so scary I sent it to Rogan and he uh I won't he was like whoa his his version of wo um I was like I also said wo he probably said holy right um no he no no I'm not going to say what it said but it was he didn't curse there were a number of questions about household items again not looking for specific products but for instance soaps body wash cleaning sprays floor cleaners laundry related cleaners do any or all of these contain endocrine disruptors unless one is careful to to find the ones that don't okay um receipts how serious is it should we be concerned about the bpas and other end endocrine disruptors on receipts yes so and my suggestion is just ask for an electronic receipt MH and then you don't have to deal with it yeah but they're definitely absorbed you know into your body any impact of um endocrine disruptors of the sort we've talked about today on the thyroid system yes presumably in the in the bad Direction not yeah I mean this is an interesting point let me just say another word about it so um the there was a ongoing study in the Pharaoh Islands off Denmark and they studied posos chemicals and showed that um people who fished there there were Fisher people and they they ate the fish and they were getting high levels of posos in their body and had um this is published um effects on their um immune response so my concern and I don't know if anyone's looked at this is given everyone's vaccination like our 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 there is a whole field of the effect of these chemicals on the thyroid system and there's a lot of evidence that it's adverse can these endocrine disruptors be detoxed from the body is there anything that we can do what's the quickest ways um things like sweating um 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 photes and the bisphenols leave the 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 um posos chemicals pesticides are and though but so it has to do with how they're handled by the body are they put into the you know if they're water soluble you pee them out if they're fat Sol soluble they're going to be around for a long time so it just depends on the chemical structure of the chemic of the the compound there was a question about non-stick pans you covered that earlier if someone had to pick between non-stick coated pans versus seasoned iron pans no question iron there's no risk associated with SE seasoned iron panss a number of other questions such as why does Europe have such more stringent laws Etc um lots of questions about atrazine questions about ointments and fragrances you've covered and I I must say that um as I scroll through these hundreds of questions if not more um you've done an amazing job at um 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 right um and well you know there 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 sure it's a huge field so you know maybe with some you know ask the question of chat gpg yeah we we'll be certain to um ask chat GPT and we will be certain to ask um uh other experts in in these areas but um 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 um that you mentioned um that you stored the urine of those pregnant women that you analyzed it and that you've gone down this path of of exploring you know things that are really disruptive to our health and potentially to the existence of our species as um you know as we talked about earlier there is the possibility that we go extinct um not because of a meteor but because we fail to replace ourselves um and that we fail to replace ourselves because we destroy our biological ability to replace ourselves I think it's hard for people to um internalize that very real possibility because we feel ourselves sitting in traffic with thousands of other people and go there's too many people right this kind of thing but um 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 um 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 been ingesting and exposed to um especially in terms of consumables that they've spent their hard-earned money on have been um harming them harming them and their offspring and generations to follow that there's something that really lands deep in in that way but you you've also offered us a lot of um possibility and a sense of agency over these these things and I love um that you weave your math and statistics and probability uh Theory background into all of this because what comes through is um 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 discussion with Dr shaa 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 note captions also I should mention that if you're interested in learning more about microplastics and endocrine disruptors I did a solo episode of The huberman Lab podcast on that topic and that is also linked in the show note captions if you're learning from and or enjoying this podcast please subscribe to our YouTube channel that's a terrific zeroc cost way to support us in addition please follow the podcast on both Spotify and apple by clicking follow on Spotify and apple and on both Spotify and apple you can leave us up to a fstar review please also check out the sponsors mentioned at the beginning and throughout today's episode that's the best way to support this podcast also if you have any questions for me or comments about the podcast or guest or topics that you'd like me to consider for the hubman Lab podcast please put those in the comment section on YouTube I do read all the comments for those of you that haven't heard I have a new book coming out it's my very first book it's entitled protocols an operating manual for the human body this is a book that I've been working on for more than 5 years and that's based on more than 30 years of research and experience and it covers protocols for everything from sleep to exercise to Stress Control protocols related to focus and motivation and of course I provide the scientific substantiation for the protocols that 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