Endocrine Disruptors - Common Chemicals That Severely Alter Your Hormones - Dr. Shanna Swan

[Music] I'm Shanna Swan I'm a reproductive epidemiologist  and I'm really concerned about how fast sperm   counts are declining I've been studying this for  a long time and I and my colleagues published   a paper in 2017 which went viral when we  concluded that sperm counts had declined   over the past 50 years at the rate of one  percent per year basically been cut in half   and following that we decided because of the great  interest in it that we should expand that paper   bring it up to date and so just a few weeks ago  we did that we published the update of that paper   and so now we have more studies  a longer time period and some new   results that I think we'll talk about so let me let me so we added seven years of data and  that doesn't sound very much when you have   almost 50 years but it's important because  it's now and people are most concerned about   what's happening now and we found two things  that are really important in this new analysis   the first has to do with geography  and the other has to do with rate   of decline so let me break those  down in our original paper in 2017   we searched the entire literature and got every  paper that met our eligibility criteria regardless   of the location but there were very few papers in  South America Asia and Africa and so that meant   that even though we did publish those we were  not able to say anything conclusive there was   nothing that was statistically significant about  the declines in those areas because there were so   few papers so that was a real important question  for us on our re-analysis has that changed and the   answer is yes since we published that paper and  since we and since the studies that were included   in that paper that first one there have been  quite a few studies published in South America   Africa and Asia so many that now we can conclude  yes among men who didn't know what their fertility   was we call those unselected men among unselected  men who are by the way most representative of the   general population there was a significant decline  you in Asia Africa and South America so now we can   say that our finding of a significant decline  in sperm concentration and count is worldwide   so that was a big change from the 2017 paper the  other change from the 2017 paper was actually how   fast are they declining so we concluded in 2017  that the rate was a little over one percent per   year decline now when we look in recent years  particularly since the turn of the century   the rate is 2.64 per year that's more than double  1.16 which was the prior finding more than double   the rate of decline that is very fast and very  unusual given that this is only in the last it   was 18 years from twenty two thousand to 2018  minus 2.64 per year extremely rapid decline   so the causes of this decline of course  is the question on everybody's mind   um what's causing it and can we do anything  about it so when we think about causes   we think first of all could it be genetic and the  answer is no and that's because it's too fast so   genetic changes take many generations and we're  looking at a little over two generations now human   generations and um so if it's not genetic then  what is it well the sort of the two baskets are   Gene environment right so that leaves us with  environment so what is environment is it just   chemicals in the world well that's certainly an  important part of it but also environment if you   think of the environment for an unborn child for  example what is that environment that environment   is affected by many things that are going on  in the mother's environment in the father's   environment and those are things like smoking  did the father smoke right before he conceived   the pregnancy that matters if the mother smoked  when she was pregnant that definitely matters   um did he drink a lot did she drink a lot that  matters how stressed were they how obese are they   how much exercise do they get what kind of food  do they eat all of these things affect sperm count   and that's been published I've published that  other people publish that it's well known   so those are lifestyle factors put those aside  and then there are if you will the involuntary   environmental factors many of them chemical  but not all chemical by the way so heat matters   the temperature actually matters noise matters  although not for sperm count I don't think but um   and then you have the chemicals so the chemicals  are all over the place right and there are   chemicals in the products we bring into our house  they're also chemicals in our dust in our air in   our water so they're things that we can actually  control to some extent by our purchases and you   know what we allow into our house and some things  we can't control we really can't control the   chemicals in our air right in our air pollution  that's made up of chemicals and and and what's in   our water um well we can do something about that  perhaps by filtering and Distilling and so on but   it's hard to keep track of them because they're  just coming at us from all directions all the time   and among all those exposures there's a class  that's particularly important for sperm decline   so sperm are part of our reproductive system  there are germ cells that are produced by the   reproductive system eggs also in the woman so  those germ cells are Productions the production   of those germ cells is governed by hormones it's  tougher governed by genetic programming and then   played out via the hormones the body's hormones  natural hormones so that could be testosterone   it could be progesterone it could be estrogen  and so on and those sex hormones if you will   are altered by many of these chemicals so here  are these hormones that are critical for the   production of healthy sperm and eggs and they're  being interfered with all the time by these   chemicals coming into our bodies through our food  our water our breathing our skin every way you can   think of they come into our body and all the time  they change our body's hormones what chemicals are   those those are chemicals in Plastics but not only  in Plastics but Plastics are big players because   the products in them like phthalates and bisphenol  others are essential to the structure of the   plastic right so if you look at a soft water  bottle and a hard water bottle could contrast   so the soft water bottle is soft because it  has certain phthalates in it that's a hard   nasty word but um there it is and um it's those  are chemicals that lower our body's testosterone   I mean that's big isn't it men don't want to have  their testosterone lowered if they can help it   and yet they're drinking from these soft water  bottles and they're putting things on their face   and on their skin that contain these phthalates  and this does measurably lower their testosterone   and when the mother is carrying a fetus and  she's drinking from that soft water bottle or   putting Cosmetics on her face or perhaps getting  these through scents perfumes wall fresheners   air fresheners have plugged into the wall she's  lowering her testosterone and that might not   matter so much for her but it matters a lot  for her unborn child particularly her unborn   son and so back to the man with a soft water  bottle if he chooses the hard water bottle   then he's going to expose himself to bisphenols  that's BPA people know that as BPA or it's   bad cousins BPF and BPS  which have been substituted   so the manufacturers can say this bottle doesn't  contain BPA and it turns out that in a factory in   China that studied men making bisphenol a there  were more complaints of erectile dysfunction   so in a way this is a hard choice  you know the hard water bottle or the erectile dysfunction um so those are  just two examples pesticides have been known   and shown oh for just a long time now  uh to reduce sperm count even to zero   that's in adult men and the good news is that if  the man stops using that pesticide his sperm count   in about three months will recover on the other  hand if the mother is exposed to these chemicals   that alter her hormones when she's pregnant  and the Sun is affected he will not recover   so they're quite different impacts of what the  mother experiences and passes on to her son the   father experiences and passes on to his son or  daughter by the way because women are affected   as well um and what you do as an adult so you  have some control over what you do in adult and   so when people ask me what can I do I can only  tell them things that will change their adult   exposure I can't of course tell them how to  change their prenatal exposure but if they're   pregnant or thinking of getting pregnant they can  think about changing their offspring's exposure so   it's something we should worry about for ourselves  and also for our Offspring and by the way also for   our grandchildren because it is past so perhaps  the area that's most sensitive to these stalarts   when the fetus is in utero is a small area  which is really amazing because it tells us   what the mother was exposed to and what the fetus  was exposed to In Utero and that's a black box   there's no way to know what's going on in the  womb by direct measurement but this indirect   signal tells us how much testosterone that that  little guy experienced when he was in utero   and the amazing thing is that it also tells us how  he'll function as an adult how can that be well it   turns out that the distance from the anus to the  genitals which is called the ano General distance   is much smaller in females than males I  should say genetic females and males and   um about 50 to 100 percent bigger in a genetic  male than a genetic female and that makes sense   if you think about what it actually measures  it's a distance that goes has to include all the   paraphernalia between the anus and the top of the  genitals or the scrotum so there's a lot in there   for male much more than for a female because in  the female the organs are internal but for a male   they're external and that's why they take up so  much more space right okay so in every mammal   almost there are some exceptions but in every  mammal we have this phenomenon that male   distance called in a general distance or  the taint or the gooch or the grundle on   the street and I'll just call it AGD so  the AGG um is a marker like I said of how   much testosterone there was in utero the  more testosterone the bigger the distance   if there isn't enough testosterone or it comes  at the wrong time because your whole growth and   development is timed and programmed genetically so  if the signal is the cue comes okay testosterone   start doing your job at this time in development  if it's in the wings and not getting the cue   it's not going to happen and then that genetic  mail will have an AGD Which is less than it   should be he'll be more feminized so there are  consequences and it turns out that if a young man   has a shorter than expected EGD for his size for  his body size then he'll have a lower sperm count   and he'll be more likely to be infertile so this  is undoubtedly part of the picture of declining   sperm count and declining fertility by the way  which has declined at the same rate as sperm count   about one percent per year so what can  do that the chemicals we talked about   particularly the phthalates so here's the  whole picture there's the fetus male fetus   developing around the first couple weeks of  the first trimester the genetic signal is for   the testicles to develop and start making  testosterone and here comes this Foreigner   this foreign influence from phthalates telling  the body well you don't need to make as much   testosterone we got it covered they occupy  the spaces The receptors that the testosterone   um the Androgen receptors the testosterone  receptors they sit there and they say okay   we're good here you don't need to make any  more okay so then the body says okay okay   won't make any more then the AGD can will stop  growing and the boy will be under masculinized   and that also affects the germ  cells that will go on to become   sperm when he's a young man and so they are  impaired by this as well and so when he goes   on to be you know be in his 20s or whatever  trying to have a child 30s um he won't do   as well his sperm count will be lower and he he  won't be able to do the job so that's the story   so if we continue exposing ourselves to  chemicals and we continue on this path   that we're currently on where does this all  lead boy there's so many consequences mark in terms of reproductive development going to be harder to conceive a child and  we know that's going on now because more   couples are going to a clinic and saying  we're not getting pregnant can you help us   and there's various ways that medicine can help  fortunately that field is developing rapidly and   and and there's a lot of very good things that  can be done consequences I want to point out   um one study not not very new actually I think  it was 2008 showed that boys born to couples   that had gone through assisted reproduction  actually themselves have lower sperm count   so it doesn't doesn't reboot totally it  doesn't reset the system totally but it does   allow you to have a child so so that's great  there are also consequences to the brain and   we can talk about that if you want there are also  um yeah I would say those are well there are also   consequences to overall health because men with  low sperm count die younger so that's kind of   dramatic so sperm count tells us something  not just about ability to conceive but it   also tells us something about longevity which is  pretty important and another consequence is that we are having fewer children in the world that's  what it means for the fertility rate to go down   and in some ways that's good some people  say that's good and we can talk about that   um but um the predictions by  good demographers are that   population will increase continue to  increase as it's increasing till perhaps   and the years vary with a demographer 24 to 2050  and it will go down and it will never come back   the consequences of that are that will have many  fewer young people to support the older people   so the old population pyramid which was a very  strong big base of newborns and young children   supporting a very small peak of very old people  right that that pyramid was actually an actual   physical pyramid you could draw it that way but  now if you look at the population pyramids in say   Japan they're totally messed up and the bottom is  very small and the top is very big because people   are living longer Japan has I think the longest  life expectancy and one of the lowest fertility   rates so it's been inverted and what that means  is for the society is huge huge because you don't   have the people to generate the products and the  income that's needed for that Society you don't   have the people to support say Medicare in this  country you know um and you just don't have the   people to support the older people and this is a  this is a social problem that's growing and that   particularly the Asian countries are aware of and  trying to do something about but the problem is   even though they offer economic incentives to  people to have more children it's not working   why is it not working well fertility rate goes  down in countries in which women are educated   okay so as women become more educated they  enter the workforce the couples have a   larger income base and they don't want to go  back you know why do they want to go back to   very poor economic situation with lots of kids  that they have to support to being much more   comfortable having a you know jobs out in  the world where women are respected and you   know and so on and so forth so it's it's an  indication of social change and social growth   to have for fewer children and that's  the trend and people will not go back   women particularly will not go back to  staying home and taking care of five kids this was the most popular question  or comment on the last video   people said oh the population is  going to collapse this is a good thing   is there any reason why this isn't a good  thing and why we should be concerned about it there are several reasons why we should  be concerned about population decline um the first let me just say population is  made up of people and a basic human right   I feel many people feel is the ability  to reproduce and these forces external   forces chemicals and so on are limiting that  right limiting our right to choose to have   children when we want to and the way we want  to so that's one way that it's a bad thing   another thing to point out is that some people say  well this is a matter of choice people shouldn't   have kids if they don't want them that's true but  I'm saying people should be able to have kids if   they want them and if you look at other species  that have become endangered if not worse in the   environment today you see many many smaller  litters smaller population size and these   animals are not choosing this it's not because  they have contraception available it's not because   they they want to have a bigger income it's not  the it's someone is you know obvious and and so   they're exposed to the same chemicals we are so  if we want to know what's going on I would say   look at the animals because we're a part of  that the other thing is that as I have said   if you shift the population so that they're not  enough children available to take care of the   older people which is what is happening then  this is a very big social problem and a burden   economically how do you support the population how  do you maintain production if there's few people   in those middle years that will be producing  so I I would say if we want to look at where   things are most severe um probably Asia and  East Asia and in countries like South Korea   South Korea the fertility rate is below one  child per couple it's actually I think 0.89 now   um which is historically low that means that  the average couple who should produce 2.1   children to maintain the status quo right  two people two children 0.1 for loss um is now 0.89 or 0.1 as it is in my most much  of uh East Asia and it's just not sustainable   it's just not sustainable and there's um many  social phenomena that are seen in Japan right   now which are alarming that reflect that  for example the phenomena of rent a family um you can rent a family member if you for  an occasion if you don't want to go alone to   an event if you want to be seen with a child  or with a wife you can rent a family member   shocking isn't it I mean there's also a phenomenon  in Japan of women marrying themselves and this   goes hand in hand with a decline in um libido  which is associated with decline in testosterone   and we found by the way that in our studies  we asked women about their sexual satisfaction   and those who had higher levels of phthalates  in their body had less sexual satisfaction um the number of times that  couples have sex has decreased   um there's a whole literature on that now um  so the decline testosterone is an essential   for libido and declining testosterone which is  happening worldwide is has consequences not only   for population size but also for population  satisfaction both of those are going down   is that shocking that is really  shocking and I I'm wondering   is is this all by accident this all these  things that are affecting our libido and   testosterone and sperm count are all these things  just kind of a side effect of incompetence we just   didn't know or or do you think that there's any  deliberate attempt to lower the population oh I   don't think it's deliberate I don't think it's  deliberate no I think I think that uh foreign I don't know about ignorance because you  know people have been pointing this out I   think it's economic I think that people who are  manufacturing Plastics and and and pesticides   and so on flame retardens and on and on and on  they have businesses and and and people want   these products because they're seen as modern  and part of everyday life and necessary for our   survival and it's kind of an addiction um and  um and manufacturers are happy to to supply the   the drugs if you will um so I think we're we're a  society now which is you know I would say addicted   to these products these endocrine disrupting  products and that addiction is being exploited   um by the way the stock the feedstock  for these chemicals is you know Fuel   and the production of fuels coal and so  on those byproducts are what's used for   making these phthalates and bisphenols and so  on so the companies that you know around 1950   when production started taking off they  had to think about what to do with the   byproducts and they put them into our everyday  household products and that way they could kind   of capitalize on both ends make the fuels  and then make money off of the byproducts   and that's worked for a long time until people  started noticing that it wasn't good for a society   are people becoming aware and do you think  through awareness we're gonna just through   demand we're going to say hey we don't want these  anymore or do you think we need like regulation   I definitely don't think that people will  be just become aware and stop using things   I think we're creatures of habit and let's  face it these products are nice they're   useful they're we're dependent on them so it's  it's going to be we're going to have to find   safer Alternatives with which to make these  products we're not going to stop asking for   a disposable water bottle or something to liner  frying pan so it doesn't food doesn't stick we're   still going to want that right we just have to  find ways to do it more safely and that takes   a lot of work and money and regulation because  why should people stop making products that sell   very well for possibly better products that  they might be able to sell to people that's   not a good business model so unless they're  forced to do that they're not going to change so when we talk about the possible  connection between endocrine disruption and   the lgbtq Spectrum I like to start by segregating  separating the issues so there's a condition   called disorders of sexual development DSD there's  a code for that medical code and um that can be   fused labia that can be a micropenis that can  be um ovaries and testes in the same individual   those disorders are not by the way usually  considered on the Spectrum but I just want   to start there and those disorders can be  caused by endocrine disrupting chemicals   and a great example is the frogs that Tyrone  produces by exposing them to atrazine which is a   pesticide and he also finds them in the wild near  fields that were sprayed with atrazine Okay so   there's no question that those changes  can be caused okay so let's move   to the next category which is  the cat the question of choice of   sexual partner the sex of your partner partner  choice and homosexuality and that can be caused by   environmental chemicals and again the best  example is these frogs that are homosexual and Tyrone has lots of paint you know photos  of male frogs mating with other male frogs   and they're the Museum of Sex in  New York has a whole floor which is   um devoted to homosexual homosexuality in animals  non-human animals some of those will be naturally   occurring and some may be influenced by  environmental chemicals we don't know   but it's certainly a phenomenon the third  category if you will is the question of   gender Choice gender dysphoria and this is much  much more difficult because we can't look to   animal models because this is a condition of  your how you view yourself how do you feel   do you feel you're in the wrong body do you  feel that you should have been born a male   when you've been when you're a genetic female  okay so there's no way to ask an animal that   right you ask your dog do you think you would  no you can't do that right the the closest   again I talked to Tyrone Hayes about this  and I said what do you think and he said   he said I don't know but I can tell you that in  the homosexual frogs that we produced by exposing   them to atrazine some of the males prefer  to be a top and some prefer to be a bottom   that's the closest we can come to saying to  an animal expressing their preference and I   certainly wouldn't say that's the same situation  at all but I'm just saying that's the a little   hint that maybe there's something there other  than that I don't think we have any way to know   we could study this and we will study this  I'm sure I won't probably but other people   will where you can take chemical exposure in the  woman's body before she gave birth follow those   children until their teenagers or 20 or 30 years  old and ask them ask them that study has not been   done and that is an absolutely critical study  to answer this question because without asking   people you're not going to answer this question  so I have to say I just don't know but I do want   to say that the this is usually preceded by  somebody saying well do you think the increase   in gender dysphoria is due to environmental  chemicals and I would question the increase certainly there is more reported certainly there  is more medical attention to it certainly you know   it's in the political Arena and it wasn't before  but that's happened for many things and and you   know when I was growing up nobody would consider  talking about being born in the wrong body you   know being you know it was just not in the public  Consciousness individuals might have thought that   but they would not have said it and so we're sort  of hamstrung in a way we can't turn to Animal data   um we don't have a good historical record so  we're really starting our investigation now   and we'll no more in another  generation but not now that was a fantastic answer   and really thank you that was probably the most  informative I don't know I've ever gotten yeah by the way um there is a this is such a delicate  you know because the problem is that if you ask   do environmental chemicals cause homosexuality  gender dysphoria you're saying in a way those are   negatives those are illnesses those are problems  whereas people who are on the Spectrum very often   will say no it's not a problem it's fine I love  it I'm happy to be here it was a problem you know   so you have to be very careful in talking  about this not to medicalize it and not to   characterize it as a defect and and by  the way this is also the reaction of   um some Downs uh families and downs people people  with Down syndrome and also people with ASD   who would say this is how I am and I have a lot  of you know I get a lot of good things out of   this and I I don't want to say was this caused  by this problem or this problem you see that   it's it's it's very just the just the asking  of the question has political implications so be careful so I think it's always nice to end a video with um  a positive note if people do want to have kids one   day if you're talking to a group of college kids  and one day they want to have a family what would   you tell them I would tell a group of college  kids who want to have a family that they should   think about what they're  allowing into their bodies   even right now in terms of the kind of food  the kind of drink the kind of air the kind of   products they use in their house Cosmetics they  use mostly just to be aware that it all matters   and they might not want to change but  they could say okay I understand this   skin cream contained salads and those go into my  body and they might affect my testosterone level   but that's okay because I really like this skin  cream fine fine just be aware I think more people   that people can be aware of chemicals that were  totally blind to better off it'll be and then   I would say men should Bank a Siemens  Apple why not it's not difficult it's   not particularly expensive now you can do it in  your home there are companies that allow you to   do it at home and mail in a sample and I don't  think it's going to get better in the short term   although I hope it will get better in the long  term but if you want to conceive a child in the   next say 10 years why not have a sample that's  probably okay and the Same by the same measure   I would say that every man should have his  sperm tested and if it's not great quality then   you know he can think about what to do to  improve that in terms of his lifestyle in   terms of his exposures uh and so on so there are  ways to be active that way a woman cannot have   her eggs tested because they're they're hidden  they're not available so that's unfortunate but   if she's concerned she can be checked for various  conditions like you know the her Fallopian tubes   are they open and so on and so forth so  do a little homework ahead of time not the doctor and say if I want I want a pregnant  now would I be able to do limitations do you   see any barriers that I could take care  of and and then like I say be aware of   chemicals that are sneaking into our body  against our will and um try to keep them away   unfortunately reproduction is not very much talked  about or studied you know people are embarrassed   to talk about their problems having a child  women are embarrassed particularly because they   feel it's their fault they take a lot of blame on  themselves if they have a miscarriage or can't get   pregnant and if you look at research agendas all  the way up to the NIH reproduction is not there   it's just not there there's cancer there's birth  defects there's diabetes and there's neurology   but reproduction is a poor stepchild and I think  that's one reason why we know relatively little   about it and I think that the more we can  recognize this as a societal problem and put   more resources there the better off we'll be so  I've really enjoyed making this episode of after   skool I hope you did too and I hope you'll want  to learn more and you can do that by reading our   book countdown how our modern world is threatening  sperm counts altering male and female reproductive   development and imperiling the future of the  human race thank you [Music] thank you [Music]

Channel: After Skool

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Length: 40min 51sec (2451 seconds)

Published: Tue Jan 03 2023