Why Men’s Fertility Is Collapsing and What It Means for Our Future | Dr. Michael L. Eisenberg

Over the last half century or so, I think there's been a rise in male infertility, and specifically, the semen quality has gone down. Dr. Michael Eisenberg is a professor of urology and obstetrics and gynecology at Stanford University School of Medicine and the director of men's health at Stanford. He is also a board-certified urologist and leading researcher in male fertility and hormones and men's health. One of the things that came up was this idea of sperm and quality and count and all that as a vital sign, as the sixth vital sign. Interestingly, you know, where their semen quality was when they were 40 predicted their death, you know, 30, 40 years later. I'm so shocked to read that the bigger a guy's belly, the worse his sperm was. I mean, if you had a fat tummy, your sperm quality and function are going to be bad. Microplastics are getting more and more attention recently that's found in most testicles of men. What is happening with all these young men who have low testosterone? If you look at data age for age, the testosterone levels have gone down. More recently, it is accelerating. It's really incredible. We are seeing increasing rates of erectile dysfunction. A study that I always quote is that if you look at men over 40, over half have some trouble with erection. Who should we be thinking about giving hormone replacement therapy to in men? Because I think that selection criteria is not clear. People think about like low testosterone is a big driver of erectile dysfunction, but it probably contributes about 5%. Don't ignore your health. And if you're a woman listening and you got a guy, go send him a gut check. Over my decades of practicing medicine, one thing has become very clear. If you want to age well, protecting your NAD levels is essential. NAD is found in every cell of your body and plays a critical role in energy production, metabolic health, detoxification, and DNA repair. 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But it really was the context of what's happening globally, which is just increasing challenges with men's health around infertility, sperm quality, sperm counts, sperm function, genetics. And we're seeing such a massive increase in challenges in men's health. You know, we see a rise in prostate cancer. We're seeing a rise in male infertility. We're seeing declining sperm counts around the world. We're seeing a lot of erectile dysfunction, and low testosterone in young guys, and we're seeing all these men's health issues. Now, women's health has been very neglected, and that needs a lot more research. But, you know, men's health in this particular aspect, and we've seen a lot of heart disease and other things, but this particular aspect around men's sexual health and sexual function has just been ignored for the most part. And you're at Stanford. You're kind of one of the leading thinkers, researchers, and advocates for rethinking how we approach men's health and take it seriously. because as I was sort of reading a lot of your work, one of the things that came up was this idea of sperm and quality and count and all that as a vital sign, as the sixth vital sign. Because that was shocking to me to read that as our sperm quality declines, and if you check men's sperm and you test it and we'll get into all that, if it's bad, your risk of death is dramatically increased, like more than smoking or getting diabetes, which I was like, wow, that's kind of crazy. So I want to kind of dive into it with you. And let's sort of sort of set the stage first to talk about infertility, because I think, you know, a lot of times women get blamed. Oh, it's the woman's fault. They go to IVF. They get all these tests. They have all these hormones. They get all these invasive procedures. And nobody actually checks the guy. Right. So talk about the rise in infertility in men. Why you think this is happening and what are the potential causes? and maybe we can get into like how do we approach this as a society because I think it's a bit challenging. Well, I think, you know, there's several factors that have led to this. I think that, you know, as you point out, infertility is really thought of to be a female problem. And so like in this country, in the United States, you know, when a couple's trying to conceive and they're having difficulty, the first thing that happens is the woman goes to your gynecologist and tests begin. And then if there's, you know, no issues or if there are issues, that sort of starts down a path often does lead to IVF. And interestingly, that's in retro fertilization, just two babies. Yeah, that's right. And, you know, maybe a quarter of a third of the time, a man has never evaluated. He's just sort of bypassed, not even a semen analysis, no evaluations done. I think there's just a lack of knowledge that man can be the problem. And if you look at couples when they're prospectively collected, when you look at couples that are trying to conceive and do analysis on both, about half the time there's a male factor. So there's some reproductive difficulty in the men. And I think there's just a lack of knowledge, you know, from the general population, also providers as well. I think people just don't realize that. And what we've found is that over the last half century or so, I think there's been a rise in male infertility and specifically, you know, semen quality has gone down. The number of sperm that we're making. And the quality of the sperm. The quality, right. The numbers, the movement, shape, all those sorts of numbers have gone down. And it's interesting because that's used to be somewhat of a controversial thought. You know, there were studies that first came out in the 70s that suggested this. Then there was a large study in the 90s that got a tremendous amount of press that was published out of Denmark. But it was still very controversial. And, you know, that group has updated it, you know, in 2017, then most recently in 2023. And really all the other studies they've added have just just increased the sort of reliability of that data. And it's really shown, you know, not just in Western countries, but Eastern countries, you know, in other countries around the world where we've seen this decline. And I think to your point, the question is why, you know, what has changed over the last 50 years? And I think there's been some discussion about some of the methodologies. But if you just look at what could affect men's reproductive health, I think we're seeing the rise. You've taught us a lot about diet, you know, other exposures. You know, these chronic diseases are certainly rising. And there is a strong link between a man's overall health and his reproductive health. And then just what we do. I was so shocked to read that the bigger a guy's belly, the worse his sperm was. I mean, if you had a fat tummy, like your sperm quality and function are going to be bad. Yeah, it's really interesting. Yeah. If you look at, you know, I always say that, you know, I do talk about fertility and sperm health as being kind of a biomarker or a vital sign. And it's interesting if you look at, you know, chronic diseases, obesity, hypertension, diabetes, and you look at those, that does give you some information about, you know, reproductive health and sperm quality. You know, a healthy man is now impacts his reproductive health. But as you're pointing out, it's also, you know, kind of a metric for the future, too. And semen quality now predicts its longevity as well. It's interesting. There was a large study done in Denmark where they had, you know, semen quality of about 50,000 men. And when that was done, they were then able to, you know, Denmark has these very sort of large longitudinal databases. Everybody's monitored. There's no health. Homogenous population. Yes, exactly. You don't have to worry about that. But interestingly, you know, where their semen quality was when they were 40 predicted their death, you know, 30, 40 years later. So it's really incredible. You know, again, everything that would happen in the intervening time, you know, this one, you know, data point at age 30 or 40, you know, can tell you what's going to happen in the future. So it's really remarkable. We're seeing some decline in sperm quality and function and fertility is going up. This is not normal. Like, something's happened in the last 50, 100 years. I don't know what, how long this has been going on for, but, you know, we're paying attention to it now. But this is not how humans were designed to have bad sperm quality. Something is going on. So what are the causes? Well, I think, you know, unfortunately, it's still relatively unknown, but I think there's lots of hypotheses. And in addition to this decline, what's really interesting is if you look over the last 20 years, the decline has been accelerating. So whatever is causing it is potentially getting worse. So I think, you know, all those things, I think, are likely contributing. I think that, you know, we're a little less healthy now. I think, you know, diet, sedentary lifestyle, all those things do contribute. That's generous, a little less healthy. We are the sickest country in the world. Yeah. So bad. Like, 93% of us have some metabolic dysfunction, 75% overweight, 6 out of 10 have chronic disease. We're in bad shape. Yeah. But we see that, you know, in Europe and other countries as well, that this decline. And again, I think that the diets may be a little bit different, but I think a lot of these exposures are the same. And again, this sort of the timeframe of this suggests that it's not a genetic cause, right? This is happening over, you know, one or two generations, which is much too quick to see any, you know, genetic causes of some of this stuff. So I think there really is some exposure that's leading to this. And so endocrine disrupting chemicals have been hypothesized. You know, microplastics are getting more and more attention recently. That's, you know, been hypothesized. it's found in most testicles of men. We look, you know, in semen as well. So it's really everywhere. It's very prevalent. That's a frightening thought. Microplastics and semen. Yeah. And then, you know, also just what we're doing, we're not walking as much as we used to. I think we spend a lot more time indoors and I think all that may also contribute to some of this. But I think it's an area that needs to be explored more. I think that, you know, as male infertility, you know, gets somewhat ignored or not, you know, not studied or not really thought about. I think one of the consequences of that is we don't look at these questions. We don't look at, you know, is sperm count going down? How quickly is it going down? Then why? Obviously, what can we do? Well, let's double click on a couple of things you said, because I think, you know, we skipped over pretty quick, this idea of endocrine disrupting chemicals. I read a book I mentioned on the podcast for like almost 25 years ago called our stolen future. Yeah. I feel Colburn. It's kind of like the silent spring of today. And the silent spring was Rachel Carson's book that outlined the problems of DDT and pesticides and the harm to animals and humans. But she wrote a book called Our Stolen Future, meaning, you know, it's affecting our reproductive health. These endocrine-disrupting chemicals are highly influential, and, you know, they're synergistic, like, and we're exposed to them everywhere. And they're basically all the plastics and pesticides and, you know, industrial chemicals that are just part of our daily life. So can you kind of dive into what those are, how we're exposed to them, what we can do about it? Because, you know, it is concerning when you see so much infertility. And also, I wonder if this affects men's hormones, too, because, you know, we're seeing higher estrogen levels in some men. We're seeing, you know, with function health, actually, which is kind of shocking. We're seeing high estrogen levels in a lot of men, which is kind of perplexing, unless you understand that when you have increased body fat and belly fat, it converts testosterone to estrogen. Yeah. So that's why. But men get feminized in this way, which is part of the problem. But I want to sort of go first on the endocrine resubbing chemicals, and let's talk about the metabolic issues, because I think that's a big one that people can do something about. Well, I think, as you point out, it's really everywhere. I think a lot of these exposures, unfortunately, are fairly ubiquitous. But I think that being a little bit more mindful of where we get exposed can help. So I think plastics are certainly a big cause. I think that plastics themselves, in theory, should be inert. But there's lots of other chemicals or plasticizers that go into that, and they leach out in water bottles, for example, and other things. So, you know, trying to cut down on exposure there. I think that kids are probably more sensitive than adults for some of these things. And certainly, you know, pregnant women and fetuses, I think, are very sensitive. So I think you want to be very mindful around that time. But trying to eliminate, you know, plastics, pesticides are certainly a big, you know, a big exposure that we have in our food. And so trying to eat organic when possible, thoroughly washing things. I think that, you know, there are some foods where just sort of notorious, very difficult to clean off some of the pesticide exposure. Strawberries. Strawberries are a big one, yeah. Of course, yeah. Just there's so many nooks and crannies. So trying to do what you can to avoid that. I think a lot of fruits, anytime you eat the outside, I think there can still be some contaminants on it. And then a lot of like the beauty products that we use, you know, like suntan lotion, you know, that, you know, oftentimes has some of those. So trying to, you know, there's sort of mineral versus organic. and trying to be a little bit more mindful of that. So I think those are some of the things. I mean, obviously, you can get overwhelmed by some of this. Yeah. And you just want to, you know, try and pick some actionable things. But I think those are some aspects that you can try and do to try and minimize exposure. I mean, there's plastic everywhere, right? I think, you know, probably most of my clothes are plastic. And so I think, you know, trying to make, I guess, more informed decisions, the department store or the clothing store, but it is difficult to try and avoid everything. But I think that, you know, again, as we get more attention around this and understand some of the downfield consequences. You know, what endocrine disruptors do is they disrupt our endocrine system. So some of them, you know, operate and they block like androgen signaling, testosterone signaling. Some of them mimic estrogen signaling. And so, you know, obviously. Lower testosterone. They can lower testosterone. I mean, some of these studies are difficult to do, and a lot of them are association studies. But, you know, certainly we have seen some studies looking at men that, you know, are exposed to more pesticides, have lower sperm count, for example. Interesting. So I think there are, again, those are things that we can talk to our patients about and hopefully, you know, over an interval can try and change things. Yeah, I mean, I think, you know, you laid out a good sort of way of thinking about how do we reduce our exposures where we can. I'm on the board of the Environmental Working Group, and they're a great organization that details what toxins are where and how to avoid them. So it's EWG.org. It's a nonprofit, and you can, there's a web-based version. There's apps like Skin Deep where you can look at skincare products, Sunblock, all this stuff. It doesn't have this stuff in it. They talk about household cleaning products that are safe, what vegetables and fruits you can eat that are non-organic that are okay, but the ones you have to eat organic. Strawberries are really bad. What kind of fish are okay? What kind of meats are okay? So it's really a very comprehensive sort of database if you're looking how to avoid it. You don't have to do everything overnight, but just slowly reduce your exposures. I mean, I don't have plastic Tupperware. I have like glass. They call it Tupperware, but it's like this glass thing to store my food in. you don't want to heat up a microwave with plastic and you know, you know, it's, it's kind of ubiquitous and everywhere. Yeah. I mean, I, I've tried to be really careful, but I recently had my plasma checked for all these toxins and I was like, God damn, you know, like I try to live a good life, but yeah. Are you able to eliminate it? You know, like everybody who's living in this toxic soup of the 21st century, we're all inundated with it. And the best you can do is sort of avoid them. Yeah. But then there's also things we can do to detoxify. So I think that's a really important thing that I've written a lot about, but there's ways to actually help your body improve your detoxification system, drinking a lot of water, making sure you're pooping, fiber. You know, there's certain supplements like N-acetylcysteine that boost glutathione. So there's ways to help, but it's important. And it's, you know, it's something you have a little bit less control over. People often ask me what I take first thing in the morning, especially on days I'm training or traveling. My answer is simple, perfect amino. It's one of the few supplements I take on an empty stomach, and it's become a non-negotiable part of my morning routine. Whole food proteins are essential. I would never replace them, but for building and repairing muscles, supporting hormones, immune cells, and neurotransmitters, your body needs all essential amino acids in the exact right ratio. That's what sets Perfect Amino apart. 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Like, it's just kind of, I'm like, I think 300, like this is like a level you see in a 90 year old. It is incredible. Like if you look at data on, you know, a cohort of men, like a group of men that were evaluated in the 80s, the 90s, 2000s, every year, like age for age, the testosterone levels have gone down. And we've looked at more recently, it's, it is accelerating. It's really incredible. You know, men born after 1970 are much different in terms of testosterone levels, you know, than their fathers. I read an editorial. Does my father have higher sperm counts than me? Probably has a higher testosterone than me, too. And I think there's a lot of things that contribute to that. I think some of these same exposures we've talked about. But I think that, you know, these other things, how our lives have changed. I think we're indoors more, we're sedentary more. I think that also contributes as well. But I really it is sort of imperative to try and figure this out because it is, you know, some of these things are really existential. right? If we can't produce sperm, I think that becomes a big deal. And, you know, the testicle is two things that makes sperm makes testosterone and we need testosterone levels to produce sperm. So, you know, it stands to reason if we're not doing that as efficiently, that may be also one of the causes that we're seeing, you know, lower reproductive health, lower semen quality. Yeah. I mean, I think big belly, lower testosterone, more estrogen. And it's all related to sugar and starch and insulin resistance. And, you know, the fact that we have such a poor metabolic health in country and like yeah 75 percent of her weight but a lot of people are skinny fat so there's a percentage of those 20 percent of people who are thin actually have have metabolic disease even though it looks skinny on the outside they're fat on the inside yeah they've lost muscle and they have belly fat and so that's like why 90 plus percent of americans have some degree of this insulin resistance phenomena and that really is what's driving a lot of the testosterone stuff And also then, obviously, secondarily to sperm stuff. So it's kind of, it's something that we just are not talking about, we're not recognizing. And I think the overall thinking of sperm as a sixth vital sign is an interesting concept because it's not something you get checked, typically. You go to the doctor, they're like, I mean, sperm. But you think it should be? I think it does. I think it could tell us a little bit more. There's an interesting observational study that I'll describe here that I think shows how much information is packed into this So you know we talked about how semen quality can predict later health right We talked about mortality And another study about 5 men showed that it predicts hospitalization. So if you have higher, you know, semen quality, you're less likely to be hospitalized, you know, in the next five or 10 years, for example. And it's interesting because if you look at that, you know, you continue to discriminate, you know, the association between sort of health and semen quality up to about 200 million sperm per milliliter. So the average is probably about 50 million. So, you know, there's a difference if your sperm is 200 versus 180 versus 160 in terms of how likely you are to be hospitalized. When we talk about fertility, that number is way down at about 15 to 20 million. So even though, you know, oh, yeah, I don't think I explained that well. So when we talk about, you know, what is normal or what is average or what is adequate at semen quality, like when I'm talking to men about a fertility evaluation, that's what they say, do I have enough sperm? Right. And so the World Health Organization has looked at semen data from fathers, you know, the last several decades. And they say that as long as you have, you know, 15 to 20 million sperm per milliliter, so this concentration, you're likely to have enough sperm. And so if you have to conceive, yeah. So if you have 30, 40, you know, there's sort of a plateau. It doesn't matter if you have more, as long as you have that number. Yeah. But when we look at health, we continue to discriminate sort of how healthy you are as we go even higher. So 50, 60, 70, 80, up to 200. Then it starts to plateau. But you continue to see that relationship. So what's like a normal sperm count? Is it 200 or? The average is probably about 50 to 100, so more in that level. Well, again, we continue to discriminate health well beyond that. So you're certainly healthier if you have above average sperm count. And, you know, again, we talked about, you know, these men with lower sperm counts are less healthy, right? They're more obese, more metabolic syndrome. So you may sort of expect that this relationship that we're saying that there exists between semen quality and health is maybe just related to healthy at our baseline, right? You know, men that are more obese have lower sperm counts, and that's why they have to be hospitalized, that's why they die, etc. But what's interesting is if you then divide men, you know, based on semen quality and obesity, let's say, you see something very different. So obviously, if a man's obese and has a low sperm count, he's going to do worse, right? That sort of makes sense based on everything we've talked about. But then if you have a man that's, so let's talk about, sorry, let's talk about the next level then. So what would be worse would be having a, being obese and having a high sperm count or having a low sperm count and being not obese. So what do you think? What do you think would be worse? I mean, I think, I don't know. I think being obese, but maybe, I think maybe you're, you're going to trick me. Yes, exactly. Yeah. So actually it's worse to have a low sperm count. The discriminator here is really sperm. So if you're obese or not obese, you're having a low sperm count puts you in a much lower category than if you have a high sperm count. So like you talked about, right, there's sort of this healthy obesity phenomenon where some men are obese, but somehow all their metabolic markers are perfect. And it may be that semen quality kind of predicts that. Some men have more reserve than others, right? And so maybe that's what it's telling us. Even when you do that same sort of trick with smoking, whether you smoke or not is not as predictive if you know that man's sperm count. So having a low sperm count and not smoking is worse than smoking and having a high sperm. That's crazy. It's crazy, right? So I think that, you know, again, I think there's lots of reasons to check a sperm. So it's not that the sperm count is secondary to obesity or to smoking. I mean, that's interesting because I would have thought that it's really directly correlated, but you're saying it's not. It's not correlated. Yeah, I mean, I think that, you know, again, all these things sort of factor together to some extent, but I think that semen quality and sperm count is really telling us something else. It's telling us sort of, again, kind of overall fitness, perhaps. But it really tells us how healthy a man is. So, I mean, I think having it checked, you know, early would be very good for reproductive reasons. But I think you'd also get a measure of health, too. And you're talking about sperm quality. You're talking about more than sperm count. So what defines sperm quality? What do you look at? And what are the kind of essential biomarkers in the sperm that you're tracking? Yeah, so there's a lot of different things we look at. So first we look at volume, you know, how much comes out. Then we also look at the sperm concentration. So how many million sperm in every milliliter. We look at motility or movement, so how many sperm are actually moving here to be alive. Are they swimming very well? Yeah, exactly. We also measure how efficiently they're swimming. Are they swimming forward? Are they swimming kind of circular? And then we look at morphology or shape, and that, again, tells us all about the efficiency of sperm production. And then in some sort of more advanced testing, we can look at the DNA integrity. Genetics. Of the sperm, yeah. So we can look to see whether there's fragmentation in the DNA, And that just predicts how efficiently the sperm is likely to fertilize the egg, which is ultimately the goal. So what we're seeing also is it's a lot older men and people having babies. And so there is some concern about the linkage between, you know, the quality of men's sperm and, you know, abnormalities in the offspring. Yeah. Whether it's neurodevelopmental issues or autism or can you talk about the data about this? You know, it's a concern for people if you're thinking about, you know, when you're 40s or 50s and you want to have a kid. what's the risk? You know, I just had a friend who was like late fifties and had a kid and it had a, you know, weird mutation, like a crass mutation. I'm like, Oh, is that because he was older? Or is that just random? Or, you know, you just don't know. Yeah. I mean, well, I always like to start by saying the oldest father ever is 96. So the biological potential, really supposedly. Yeah. So this is the good. The real Viagra. He said supposedly without, I think supposedly he had a sex, I think at least every day, you know, again, well, in his 80s. Wait, wait, he had sex every day? This is sort of legend. This is a gentleman that lived in India, and that's sort of what was told. And so he had a child in 94, and then a few years later, he had another child. And his wife was also in her 50s, which is also equally miraculous. Wow. And sadly, he did eventually die, not of old age, but in a house fire. Oh, gee. Yeah. Yeah, so a tragic ending. So he could have had a kid at 100, who knows? But, you know, again, the biologic ability does persist. But as we get older, you know, some of the functions slow down, just like as women ages, fertility goes down. The same thing can happen in men. So, you know, the semen volume declines, motility declines, concentration goes down a little the number of sperm that we're actually making. And then I think, as you're pointing out, there's also more mutations that can accumulate in the DNA as well. So, you know, the way that sperm production is made as we start with these sort of stem cells in our testicles and they regenerate themselves. And then they also divide and produce cells that go on to divide and produce spermatozoa, our mature sperm. And so this replication event, you know, begins in puberty and basically continues until we die. And so, you know, generally this replication is very efficient, but, you know, again, mutations can arise and it's usually- And they persist. And they persist. And they persist probably about two per year. So for example, like a 30-year-old will have about 20 more mutations than a 20-year-old, for example. And, you know, again, there's billions of base pairs in our genome and in all of our body. And so, you know, it's unlikely that any of those are going to be individually relevant. But again, at a population level, if we're getting older and, you know, since the 1970s to today, you know, the average age of a father has increased about three and a half years, four years. So we are seeing that on average, we're getting older and there's more fathers over 40, 45, 50. So I think that certainly is happening. and we may see more, you know, mutations come to bear. And what's equally interesting is that, you know, some of these mutations are random, but if they occur in sort of the right gene, some of these genes really proliferate in the testicle. So there are some genes that, you know, for example, where they have to do a cell division. And if you get sort of a mutation in one of those genes, that cell will then divide faster than its brothers or sisters. And so you'll get more of the sperm to harbor that particular mutation. And so you may see that more in the population. And what we've seen is that, again, there are sort of conditions that are associated with paternal age. So there's neurodevelopmental disorders, schizophrenia, autism, bipolar disorder. Wow. And if you look at sort of academic achievement, they're able to do this in some Scandinavian countries where they, again, they have these large population registries. They know exactly how old the father was. They can follow how the children do. There's, you know, higher degrees of, you know, failing grades, you know, acting up in school, lower educational attainment in some of these children as well. So a lot of neurodevelopmental, behavioral, ADD, autism. Yeah, all of those. Yeah. And then you also see the risk of miscarriage or. Yeah. So I think, you know, as fathers get older, I think it's, you know, it takes longer to get pregnant, less likely to get pregnant. We see higher risk of miscarriage, preterm birth, all those things. And so I think then we're really kind of talking about sort of the next generation. Right. Because, you know, talking about, you know, how development impacts the rest of our life. Right. this developmental origin of adult disease, you know, based on the work that David Barker did, you know, half a century ago. And so if you're born premature, you know, given there's higher risk of, you know, metabolic disorders and other disorders that may, you know, track later with life. So I think these are all things we need to be sort of aware of. And it's not just age, too. I mean, again, we're talking about health. We've seen that fathers with chronic diseases are more likely to have these same issues, more likely to have miscarriage, more likely to have preterm birth. And so really this can impact the next generation as well. It's not just getting pregnant, but obviously the ultimate goal is to have a healthy child and may put that at risk to some extent. Really paternal health does play a role in pregnancy and conception in a way that we didn't really think about before. But how does the health of the pregnancy determine by the father? Because, you know, most people just think, oh, you have sex, you donate the sperm, and then you're out. That's right. Yeah, well, I mean, we contribute half the genome, so I think we do play some role, but I certainly don't want to say that the mothers are not important. They're certainly more important given everything they do with gestation. But I think it's sort of important just to think that the father does contribute to some extent. I think that there's a lot that we do. And, you know, in addition to sort of the genetics, I think the other thing is sort of this epigenetic phenomenon. So again, all these diseases are not likely going to mutate our DNA, but they basically affect sort of the covering and the expression of some of the DNA, It's so-called epigenetics. And so, you know, that I think is sort of the most common hypothesis about how this may be transmitted. And in addition to the child, we also contribute to the placenta, right? Sort of this, you know, the component within the pregnancy that kind of nourishes the child. And again, how does it how does the male contribute to the placenta? Well, there's DNA. Some of the DNA contributes to that, too. And again, these sort of these epigenetic markers as well. And so if that's not perfect, right, you'd expect that that's also going to lead to, you know, altered pregnancy trajectory, for example. So we do see, again, miscarriage, but also, you know, even in the mother, a higher risk of preeclampsia, for example, like, you know, hypertension and pregnancy, gestational diabetes. All these things track with paternal age, but also paternal health. Well, you know, one of the things that people probably are thinking is, well, geez, what do I do to improve my sperm quality and health? Because if it's declining, what can I do? And from a lifestyle perspective, we talked about some of the environmental factors, but there's more to it than that. So can you talk about if you want to sort of advise your patients on how to stay healthy and have healthy sperm quality, what are the parameters that you really focus on teaching them so that they can have the healthiest sperm quality and the healthiest pregnancy outcomes and obviously the best healthy babies? Yeah, this is exactly how I counsel patients in clinic. Well, I think the first thing is I think that, okay, I'm like 65. I want to have a baby. Like, what do I, what do you think about? Well, I think you're living life the right way. So I'd be very optimistic. I don't know if you've ever checked a semen, you know, semen. I did. I did. I was actually, I was surprised because I wanted to see what was going on. And it was like, no genetic stuff. It was really good. And I was like, I got an A plus. I was like, you got an excellent. I was like, wow. Okay. There you go. There you go. So I think, you know, getting that knowledge is important. I think not everybody does a new semen analysis. We talked about couples in this country. Oftentimes, you know, the male fertility gets it, you know, gets bypassed. So I think that that's something that'd be important. But, you know, assuming there is or isn't a problem, I think we do counsel men about different things that they can do. So certainly taking ownership of your health, I think, is very important. You know, many times it's one of the first times a man ever comes to the doctor. Right. Usually you come to the doctor if there's a problem, like, right, if you're in pain, you broke something, you're bleeding. You know, those are really the reasons that men go to see, you know, a provider. They're half dead, right? Yeah. So this may, you know, again, allow them to sort of, you know, take a little more ownership. So when I see these patients, I do talk about these things. They don't have a primary care doctor. You can try and get them set up to get evaluated for, you know, blood pressure, cholesterol, blood sugar, all those things that we know are very important. And so then we talk about diet, talk about exercise. I think those are very important as well. Strain training really helps boost testosterone, right? All activity, I think. Hormones, really. And being outside, you said, helps low testosterone being outside. Yeah. Yeah, we just did a study looking at NHANES, the National Health and Nutrition Examination Survey. So there is an interesting correlate between sunlight exposure and testosterone levels. And it basically increased about 10 points for every additional hour you spend outside. So that can be sort of an easy thing. So when you're exercising, you know, spend time outdoors or if you're going to read or do work, if you can. The lifeguards have high testosterone. They must. They must. And then we do look at exposures that potentially are negative. So like testosterone supplementation, for example, lower sperm count, scrotal heat exposure, hot tub saunas. Those are also not. Everybody's only like saunas these days. And yeah, now there's like things you can put on your private parts. It's like trying to protect it. Yeah. Like I got cooler. Yeah. Ice pack in the sauna. Yeah. So the testicles are outside the body because they need to be cooler than the rest of the body. And that's sort of ideal for spermatogenesis for sperm production. And so if you heat it up, you know, the levels can go down. So, you know, even a short exposure to a sauna, if you're doing it, you know, once a week, once a month, you know, it takes two to three months to make a sperm. So if you have an exposure anywhere in that window, you can see effects of that. I just saw it every day. So and then, you know, like being sick, too, can do that as well. I've seen men that, you know, had normal sperm counts, got the flu. Their sperm counts went to zero. And then after they recovered, you know, from these high fevers over a few months, their sperm counts then renormalized. So that can all that can all occur as well. And then the other thing we do talk about is supplements. So there's lots of data that antioxidants. If you have to worry about laptops on your lap. Yeah, that can also affect it, too. So, you know, again. Hot tub saunas. And laptops, yes. Hot baths. So in just, interestingly, if you keep your thighs together, it can actually warm up the scrotum. But if you have a laptop, it increases the temperature even quicker. So, you know, you can actually increase the temperature of your scrotum about a degree in just 10 or 15 minutes with a laptop in your lap. And so some people tell me, well, I'm going to put a pillow. and that helps a little bit, but you still get there about 20, 25 minutes. So take breaks. I think that's something. Now they have those like, uh, those like things you can put on and block the radiation. Yeah. Is that where those work? Those little radiation exposure. I think that's also something that, you know, it's sort of theoretical. I don't know if it's EMF for the heat, but it's like, it's like a little kind of table. I'm going to put the thing on and put on your lab. I have one of those, but I don't know if it works. I mean, I think any kind of insulation, I think insulation is good, I guess, for, you know, again, radiation exposure. Again, if we think that that's going to be a role and I talk about some studies that suggest that potentially it could be. But yeah, yeah. But heat is, I think, the thing they're really talking about. So, you know, again, keeping your legs wide. That's something that's been shown about 70. If you can keep it at 70 degrees, that can beneficial. But also, you know, a table is going to be beneficial as well. So there is some risk to that as well. Wow. You know, for that, the electromagnetic field, you know, generated by phones or by laptops. There was a study where they took semen. They basically took like sort of a cup of semen and put it next to these devices. Yeah. And they saw some decrease in motility. So the movement of the sperm, some increase in DNA fragmentation as well. So no putting your phones in your pocket. Well, you know, I think it's something to be aware of. I think all of us do it. So again, that's one of those exposures that- Time for men to wear a purse with a phone in there. Or maybe a front pocket. There's other places to put it, or your back pocket. But keeping it, yeah, away from the scrotum may be beneficial. And then again, the other sort of thing that I talk to men about is supplements. So I think there's good data that antioxidants and some other supplements can help too. I partner actually with a company called Swim Club. And what we did sort of started at first principles is looked at all the data on all the different supplements and tried to get the right dosing and all the right supplements. to improve things. And the other thing that this group taught me is it's not just a supplement, it's also sort of the sourcing for all this. So they had experts in the industry as well. So I think that's also something that men can do that can be beneficial. So let's talk about the nutrients because people don't think about like women, women take prenatal vitamins. And there's a friend of mine who has a company that is called WeNatal. It is actually a multivitamin and prenatal vitamin for women, but also for men. and you're creating something like that as well, but it's really designed to sort of help with male fertility or with sperm quality or what is the goal here? All that. I think that, you know, these are all supplements that have been shown to improve male fertility as measured by semen quality. So improving, you know, the numbers of sperm, the quality of the sperm, lowering DNA fragmentation, increasing movement. And so they operate sort of on many different pathways. So, you know, there's, you know, different ingredients that target sort of mitochondrial health. Because, you know, basically sperm are, you know, motors. They're powered by mitochondria. So there's omega-3s, alpha-lipoic acid, you know, coenzyme Q. Then there's, you know, other ingredients that target, you know, cellular damage, zinc, spermidine, folate. And then, obviously, antioxidants as well because that's also sort of a powerful form of damage that can occur to sperm. Like selenium, mycopene. Exactly. And acetylcysteine. So I think all those things together help. They also help individuals that commemorate integrity and other components of the sperm. So these are, again, biologically targeted agents that can improve that. And there are also other health benefits, too. You're like a Stanford professor, and you're like, hey, these things actually have data behind them. They do. They have strong data behind them, yeah. There have been large Cochrane med analyses that you just benefit from these supplements. And you mentioned something that sounds weird, spermidine. Yeah. Talk about what is that? I mean, N-acetylcysteine, maybe people haven't heard of it, But that boosts something called glutathione, which helps detoxify your body. It's the most powerful antioxidant in the system that kind of neutralizes a lot of other antioxidant stress markers. But spermidine, I don't think people ever heard about. And it sounds weird. Yeah, it's sort of a fun name, right? Yeah, I've learned about it during this process, too. But it does help with many cellular processes, cellular health, DNA health. And so it made sense to include it as well. I actually, you know, looking at the supplement, Now, a lot of supplements out there, you know, they have the ingredients, but they're kind of window dressing. They have not really clinically effective doses. They're not often in the right forms of the nutrients. So as I'm sort of, you know, this is my gig is like understanding supplements and vitamins for 30 years. But, you know, seeing you've got, you know, things like R-alpha-lipoic acid, which is the right most bioactive form, or you've got, you know, the right forms of different nutrients and the doses. Like, you know, for example, selenium is 200 micrograms or of omega-3s, you've got 2 grams in there. You've got 200 milligrams of CoQ10. So you've got a lot of these at clinically meaningful doses. And what have you seen in people who are using this? Yeah, so we started to see some improvements. I think, you know, there have been feedback that we've gotten from some of our patients, you know, about improvements. I remember there's one man that emailed us, his sperm count doubled, his motility went up 50%. So I think clinically, you know, again, meaningful changes. And we're actually doing a study now, again, you know, one of the other things I want to just sort of highlight what this company does. And one of the reasons I wanted to work with them is they do things the right way. So they're just created this based on science, but now they're going to test it as well. And so we're recruiting patients now for studies. Hopefully we'll get that data in the next few months. It's important. You're going to be looking about, okay, this is theoretically in the literature, these different ingredients, when you put them all together, like what's the commentatorial effect on these things? So interesting. I mean, so basically take-homes are like don't eat too much chard and sugar and have a big fat belly. Yes exactly Follow Dr Hyman advice of how to eat healthy To you know reduce your environmental exposures as best you can I think the Environmental Working Group is a great site And three there are nutrients that really help improve sperm quality function production and so forth And that you can do in force to go outside. Yeah. Go outside, yeah. Sunlight. One study I read, I don't know if it actually matters long term, but like stress really has a big effect on hormones. Yeah. And it was a football study where they actually showed male testosterone levels before and after the game. If your team won, you know, your testosterone level went up. If your team lost, your testosterone level went down. That's right, yeah. I don't think the motto is, like, don't watch football or just pick the winning team. The winning team. But does stress have a meaningful impact on all this? Yeah. I mean, I do. You know, we talk about that as well. I think, you know, less stress, again, to the extent that's possible. But, you know, cortisol basically, you know, counteracts testosterone. So as cortisol and stress goes up, we see lower testicular function. So we can see sperm counts go down, testosterone levels go down. Also talk to men about sleep, right? You want to get sort of adequate amounts. And it's interesting. It's sort of a U-shaped relationship, right? It's possible to get too little, right? That makes sense. But it's also possible to get too much, interestingly. So we start to see, you know, we see declines for men that get less than six hours. But we also start to see declines for men who are getting 9, 10, 11 hours of sleep. Again, why that is, not certain, but, you know, try and keep in the sweet spot, seven to nine hours. You know, one of the things that I've seen in literature is changing in the ratio of male and female births. And that may be related to this same phenomenon of environmental chemicals that are endocrine disrupting and more estrogenic, because these are often, we call them xenoestrogens. You mentioned some of the block angiogen receptors or male hormone receptors, But there are these four molecules that seem to mimic estrogen and are actually, when you add them up, because you don't usually get them, you know, one at a time. You're exposed to a stew and soup of toxic chemicals that we live in that they actually have very significant effects on this. So I'm wondering if you could speak to that. It's very interesting. I think sex ratio is so interesting. Yeah. Because I think, as you pointed out, there certainly have been studies in the U.S., Canada, and other countries that show the sex ratio is changing. Yeah. It's sort of phenomenal. It's just, it's really incredible to think, right? That that would happen, that anything would change the ratio of male to, you know, female births. They've also found that, you know, it changes around the time of like stresses. So for example, like around the time of like a financial downturn or war, the sex ratio changes. To what? To it actually goes down a little. So there's more female. Yeah. More women. And I think you have to think about where this would happen, right? Is it at a sperm level? Is it, you know, at the fetal level? And I think that's sort of a popular belief that it has to do with sort of selective miscarriage. And it's more likely to have, you know, male miscarriages and female miscarriages. But a lot of it's sort of uncertain. But it is really a fascinating line of questioning. And people have looked at, you know, how there were some early studies. And I think the 90s, it said that, you know, diabetics were less likely to fire male births compared to female births. So, again, sort of this idea of chronic disease may see. And unfortunately for a lot of these things to see a difference in sex ratio takes millions and millions of births. So I think a lot of these things we just don't have adequate data really to look at. I want to kind of pivot a little bit to sexual health. OK. So, you know, this sperm thing is good because when you can get it checked, you can identify problems, three, you can do something about it. And that's all the good news. So you don't have to be sort of victim of it. but it's important for guys to get on this and for women listening to get their guys on it. Yeah, that's right. And think about it as not just in terms of their own fertility and having a baby, but just in terms of their general wellbeing and health. As you said, it's a highly predictive vital sign. Yeah. Or a biomarker for other things and mortality in general. So I think it's important and I think you're, you're raising this as super important. And the other thing we're seeing and we sort of touched on earlier is, is sort of increasing rates of erectile dysfunction, sexual dysfunction, libido issues, particularly even in younger men. Like I, I've got like shocked to hear, you know, how younger guys are like using Viagra. I'm like, what's going on here? Like I remember when I was younger, I certainly didn't need it. And I was like, so I, I just, just curious about, you know, what, what's happening with this sort of changed in, in sexual health around libido, sexual function performance, particularly as people getting older and like, what, what, what's, What's going on? So we are seeing, you know, increasing rates of erectile dysfunction. And, you know, a study that's actually, you know, about 20 years old now that I always quote, that if you look at men over 40, over half have some trouble with erection. So it is very, very common. I think people don't realize that. I think that, you know, in addition to being a great therapy, which Viagra is, the other thing that Viagra did is just brought a lot more awareness to it. You know, I think men now don't have to suffer in silence. I think there's, you know, a lot of great treatments that we have, and we'll talk about some of those. But even under 40, right, it's fairly common, too. You know, I usually say probably like maybe 20 percent of men under 40 also have it, too. And I think some of these same conditions can also cause because if you look at why we're getting erectile dysfunction, I think some of these same health aspects, you know, are at play. You know, we used to think that most erectile dysfunction was due to this kind of psychogenic causes. In your head. Yeah, it's in your head. But now we know that's not the case. it does contribute some, maybe about 10%, but most of it is due to metabolic derangements, cardiovascular, anything that affects blood flow anywhere in the body will affect in the penis. One of the biggest, most successful ads for stopping smoking was the Marlboro Man with the limp cigarette. Oh, yeah. I remember that. Cigarettes cause vascular injury and then the sexual dysfunction. Yeah, smoking is a big one. Exactly. Maybe that's one of the reasons that the rates have gone down so much. People think about low testosterone as a big driver of rectal dysfunction, but it probably contributes about 5%. It's actually pretty small. So I think most of it is just sort of vascular. So blood vessel flow. And the things that cause harm to your blood vessels are all the things we... Yeah, we've talked about smoking, diabetes, being overweight, hypertension, diet, all those sorts of things. Glustral issues, right? Yeah, exactly. So basically, it's almost like the first clue that you might have vascular issues, including disease of your heart and your brain, right? Because a lot of the consequences of small vessel disease is you get hardening of the arteries in not just your penis, but in your heart and your brain, which leads to heart attacks and strokes and even dementia. So I think that if you're having that, it's an important indicator, like go get checked. Go get checked for your overall health. And it's part of why I created and co-founded Function Health was for allowing people to get access to their data. We do full diagnostics, including testosterone, free testosterone. We look at FSH, LH. We look at a lot of hormones that are often ignored, prolactin levels. And we find so many interesting things that people didn't even know they had. Like high prolactin can affect, you know, sexual functions too. And we found people with like brain tumors that didn't know they had brain tumors. And it's like you just kind of go along thinking this is me, but actually it's just something wrong. Yeah. So getting checked is really important. People go to functionhealth.com and it's only a dollar a day now. We lower the price to $3.65. So, and it'll give you a really robust idea, including your metabolic health, your cardiovascular health. And if you're having a, you know, sexual dysfunction or fertility issues, it's important to really see what's going on for the guys. So don't ignore your health. And if you're a woman listening and you got a guy, go send him and get checked. You know, a lot of people don't realize how important magnesium is, especially in the winter. It's involved in over 300 processes in your body, from turning food into energy, to keeping your muscles relaxed, your nerves calm, your mood stable, and even supporting your immune system. But here's the thing. In the winter, when days are shorter, sunlight is limited, and stress tends to go up. 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You can too. so what you know besides the vascular issues there are there are other other things like neurologic things that can happen yeah there can certainly be so i think a lot of those can be a consequence of some of the surgeries that we do i mean there can be you know back injuries that some men have you know from chronic use weight lifting or injuries um but also you know some of the surgeries that we do like prostate surgery yeah colon surgery bladder surgery you know the nerves that are involved in erection are right around that area. And so sometimes they're disrupted by the surgery. Oftentimes, you know, we've gotten a lot better in terms of our anatomic knowledge. So I think we don't primarily injure them, but scar tissue forms afterwards. And so typically the nerves are stunned. And so we do see that effect too. So neurogenic causes is another one that we need to be aware of. Let's run through for guys who are listening, because it's kind of always embarrassing to talk about, but like if you have erectile dysfunction, you know, there's a lot of options now, right? There is obviously Viagra and the Salus and this spend on all these different kind of versions of the same kind of drug, which are these vasodilating, nitro oxide-inducing drugs. And they can be very helpful, but sometimes they don't work. And so there's other options. Can you talk about things like vacuum injections? There's actually a new technology out of Europe that is a kind of electrical frequency thing that they use called Vertica, which is not quite approved here in the U.S. But can you talk about some of these things and how they can be used and when they should be used? Yeah, absolutely. Yeah, so what I always like to tell men, as long as you have a penis, we can always make it hard. All right, so we can be as aggressive as you want to be. And there's lots of great options. Implants even, yeah. Yeah, that's right. So, you know, we usually start with lifestyle modifications. We start with pills. And if those don't work, we move on to other things. And in addition to, you know, lack of efficiency, some men can't tolerate, you know, the Viagra, or some of those other medications. There can be side effects, sometimes are contraindications with certain conditions or medications. So there's medications you can put in the tip of the penis, like suppositories that are kind of locally active, you know, agents like that that cause vasodilation, blood flow accumulation. Another very effective one is injections. So, you know, it's kind of similar to an insulin type syringe you can inject in the penis. Sounds scary, but it's not so bad. Well, there's certainly a psychological barrier to putting a needle in your penis, but it works very well, probably 90% of the time. There's something called a vacuum device. Are there dangers to that in terms of scarring? You're sticking a needle in your penis. Is it problems long-term? So I think that, you know, there's more scar tissue they're probably formed from not getting erections on a regular basis than getting erections. But we do want to vary where we do the injections. So we have them in very kind of location along the shaft and the side as well. But in general, you know, I think more erections are going to be better. So usually we don't see a scarring response. Again, we mitigate it through some of those things. You asked about the vacuum erection device. So it's basically a plastic cylinder you put over your penis and it sucks blood into the penis, kind of treats it like a balloon, so to speak. And then you put a band at the base to trap the blood inside so you can use that for sex. And then there are these newer therapies that are coming, kind of energy therapies. And the idea is they kind of induce sort of micro damage within the shockwave. Shockwave, yeah. Which sounds scary and terrible. Yeah. But it's not so bad. It's not so bad. I think there's not a lot of risk with it. I think we're still doing a lot of studies to see the efficacy and who the best patients are. I think that it probably helps men with mild erectile dysfunction. I think when we get into moderate or more severe erectile dysfunction, I think some of those studies are somewhat mixed. So basically it kind of shocks the penis. It shocks the penis. And then you see increase, because of the trauma, increased recruitment of repair and blood vessels and new stem cells. Exactly. Everything coming in to help more natural erections. Yeah. So I think for men that are on Viagra, a lot of times these therapies can get them off. So I think that's the benefit. And, you know, it's basically a series of obsessions where men go, you know, to their doctor, they get it done for 10, 15 minutes, and then they do it maybe five to six times. So that could be another option. It's like once a week for six weeks. Yeah. And then, you know, the final therapy is implants. So there's basically devices you can put within the penis that help you be erect when you want. And so there's some that are bendable. These are called semi-rigid. So when you don't want to have sex, you bend it down. When you're ready for sex, you bend it up. And then there's also inflatable ones. So whenever you want to have sex, you basically move fluid into the cylinders, which are in the penis. And you can use that for sex. And they work very well. You know, I always say it's a self-selected population. So we don't force men to get these. But for those that do choose this option, they're very happy. You know, 90% of men are very happy. Their partners are very happy. They recommend it to friends, sometimes family. And you have the same sensation or? Yeah. Like, yeah. They have ejaculations and all that. Yeah. So you don't need erections to have an orgasm. So, you know, again, I tell couples, too, as we're going through this, There's other ways to be intimate besides, you know, penetration. But again, the sensation is going to be unchanged with these devices. Amazing. And what about this European device? Are you familiar with it? I haven't heard about that one. I heard about it from Dr. Mohit Kara from Baylor. And he's a great guy, but they're doing some trials on it and studies. But it's available in Europe. And it basically is a device. It almost, I don't know how to describe it. It basically looks like a big wing, but inside there's like a circle. You stick your penis in and then it kind of makes all this electrical. It prevents the blood outflow, apparently. Oh, interesting. Yeah. I mean, the venous leak is certainly an issue as well, especially after like prostate surgery, for example, like scar tissue forms. And so you can imagine sort of two processes for erection, right? Blood gets into the penis and then gets trapped there. Yeah. And so when scar tissue forms, some of that trapping mechanism is lost because the elasticity of the expansion is how this occurs. Their veins are on the periphery. And so as we expand, we kind of compress those veins. And so there's not a great therapy for that other than some of the surgeries. So great to see some innovation in that space. Yeah, it's amazing. In terms of testosterone replacement therapy or people call it hormone optimization therapy, I'm kind of shocked at the number of young men who are taking it. I mean, I know the bodybuilders have been using it forever. But I'm not talking about bodybuilders. And I'm like talking to friends of mine, I'm like, what? You're in your 40 and you're taking testosterone? I'm like, what the? because I've been prescribing it for a long time, but usually to older men who have very low levels, who have, you know, loss of muscle, who have loss of motivation, energy, depression, sexual dysfunction. Yeah. There's a lot of benefits to it. Right. And historically, you know, there's sort of a negative view of testosterone therapy because we thought it caused, you know, abnormal risk for heart attacks and prostate cancer. And it does have some effects on your blood count, can cause, you know, thick blood. But, you know, can you talk about like the benefits and the risks and the age we should start? And like, how do you pick the right patient? And, you know, who should be thinking about it and who should be worried about taking it when they're younger? Because I'm like, wow, you're like, because I was, you know, Newsom was like in his 30s and was taking it. And then he couldn't have a baby like he wanted to have a baby. And they had this whole problem infertility as a result of him taking testosterone, which shuts off your sperm production. Yeah. Yeah. So I think, yeah, it's a it's a very good point. And I think that we have seen an increase in the number of testosterone prescriptions, you know, over the last several decades. So testosterone, as you point out, is very important for men's health, like energy level, sex drive, mood, sleep, concentration and sort of quality of life things. But when it gets very low, we also worry about muscle health, bone health, heart health. You know, men that have very low testosterone levels, like castrate levels, which we do for, you know, treat certain conditions. They have higher risk of metabolic disease, you know, osteoporosis, et cetera. So we do want to keep men normal. But if men are normal, we don't necessarily want to make them superhuman. You know, maybe it can help you, you know, compete athletically. But, you know, there are also some harms to testosterone as well. And so, you know, I think there used to be this fear about, you know, prostate cancer growth or heart disease. But there have been large studies now, you know, just completed the last few years that really, I think, put that to bed. But it does raise your cholesterol. It can affect, yeah. Well, it can lower your good cholesterol. It can raise, yeah, bad cholesterol. It can also thicken the blood a little bit. But even when that, it doesn't seem correlated to heart attacks or strokes. Right. Yeah, it seems independent of that. You know, hair loss, breast growth, acne can occur as well. And I think the one that we worry about the most, especially for reproductive age men, is it can lower testosterone. So the way that we work is that our brain sends signals to the testicles. Lower sperm. Oh, sorry, lower sperm. Yeah. So yeah, testosterone lowers sperm production. So the way that we work is that brain sends signals to the testicles to make sperm and testosterone. But if you're taking exogenous testosterone, you know, from gels, injections or whatever, your body senses there's enough testosterone and basically stops that signal down. And so it shuts off testosterone production, but it also shuts off sperm production as well. And actually, the testosterone levels in the testicle are much higher than they are in the rest of the body. You know, in the rest of the body, you know, normal is probably 300 to 900, somewhere in that range. But in the testicle, it's in the thousands. And so, you know, again, your serum level, if it's in the hundreds, it's not going to be in the thousands of the testicle if you're not producing it at that level. And so all that leads to these lower sperm productions. And testosterone has been tested, continues to be tested as a contraceptive. So it does lower sperm counts pretty reliably. So I think that's very important. Is it a male fertility treatment? Is it a male birth control? Well, they're working on that. So it turns out the testosterone by itself is not quite that reliable. It probably works 80% to 90% of the time. So that's not as good, you know, that's not good enough for a contraceptive. But they're working on adding other things like progestins, for example. that can get you across the threshold. So it's in trials now, and I think, you know, hopefully in the next five or ten years, there'll be some male contraceptive options. Like a pill or injection? Yeah, I think it'll be like transdermal, is all they're looking at. And there's other, again, there's also other male contraceptives that are in the pipeline as well. That'll make a lot of women happy that the men can take over the contraception. Yeah, and men too, I think. Who should we be thinking about giving hormone replacement therapy to in men? because I think that the selection criteria is not clear. And like I said, a lot of young guys are using it for bodybuilding or for I don't know what. And honestly, a lot of guys have low testosterone. We're seeing it in function health, you know, the demographics of people, and we're checking everybody for free testosterone, total testosterone. And it's like, wow, there's a younger population that's kind of got low T, we call it. Yeah. Yeah, I mean, I think that if you meet criteria, then I think it's reasonable to have this discussion with men. So you'd have to have a low serum testosterone. you know, again, it's going to vary from lab to lab, but generally probably less than 300 nanograms per deciliter. And then you do have to have some of these symptoms. And we talked about, you know, low energy, low sex drive, mood, sleep, concentration. They're somewhat vague, but those, you know, certainly can accompany low testosterone. So I think that's probably the right phenotype for who we want to have that discussion with. And then you need to, you know, understand where they are. If they're in their 30s and are thinking about having a kid in the next few years, I think you don't want to start testosterone. And there's, you know, other off-label options that we use, like clomiphene for, yeah, it's like the estrogen receptor modulators, for example, they can increase your body's own production of testosterone without, you know, the spermatogenesis effects. So I think it's, you know, again, a nuanced conversation. There some peptides now people are using for this too like desapeptin and other ones Those are yeah Any comment about that I think well it hard to get them i think in some cases um i don have experience with them in my practice yeah i know guys who use them and they're like yeah this really works you know for increasing their sexual libido function and yeah i mean i think talking to other providers that do you know that do prescribe them they do have strong belief i just you know i guess i need to see more data and have you know better uh a good source to get them from for patients so you don't think it's dangerous for younger guys, if you're not as concerned about fertility, to actually take testosterone? Well, I think, again, we want to make sure that they are truly low. So, you know, two serum testosterone before nine in the morning, because our levels do vary based on time of day. Yeah. Again, it always makes me nervous for any reproductive age man, because where a man is, you know, when he's 20 or 30, it may not be where he is. You know, he may not have met his life partner yet. So there's lots of things that can change. So, I mean, I think you can talk about sperm cryopreservation in those cases, you know, if you're worried about that. And if you come off it, does your testosterone will naturally rise again and have more sperm production, or is it a... Usually men do recover, but not always. And I think the data on men that are on it for longer term, you know, most of the data we have on recovery are in these contraceptive trials where men were on testosterone. Yeah, and stopped it. And these are a very controlled environment. It was a very short duration. So that was, you know, about a year. So if we have men on it for two years, five years, ten years, you know, we do worry about it to some extent. Because when we look at the bodybuilder population, for example, we do have a signal that it may not be recoverable. Yeah, interesting. It is a concern. They use other anabolic steroids, which are a little different. Yeah, it's a little different. The testosterone replacement therapy is interesting because what I found is when I work with guys, particularly younger guys than anybody, before I'll even think about testosterone replacement, I'm like, okay, let's look at all the things that are affecting your testosterone, your diet, exercise, sleep, stress. you know, supplements. Let's, let's see what we can do. And it's amazing when, when guys change your diet, they get off the sugar and starch, they lose the belly fat. They start lifting weights, which, you know, heavier weights and, and lower body, particularly big muscle groups, increased growth hormone and testosterone levels. Naturally, you know, getting in the sun, meditating, taking the right supplements. These things can be profoundly effective. And I've seen dramatic increases in testosterone levels when people, get healthy. So it's one thing, okay, you're unhealthy, let's just give you testosterone. But I never start there. I'm like, let's start with just see what happens when you stop living a shitty lifestyle, right? Yeah. I think that's the art of medicine, right? I think that sometimes your discussion is going to vary a little based on what you think is going on. And again, if you're a little more nervous about starting a man on testosterone, again, in his 20s or 30s versus his 50s or 60s, I think it's a very different discussion. And you talk about risks a little bit differently. And so, yeah, I mean, to your point, I think if you can find some things to correct and optimize and try and talk about, you know, some of the downsides of being on it, because once you start it, it's very hard to stop, right? You're going to be on it forever. Yeah. I mean, you know, menopause is something that gets talked about, not studied enough, obviously, but it's something that at least people know about. Yeah. Menopause happens to women, but most people don't understand this phenomenon of andropause. Yeah. Which is sort of a slower, more insidious decline. And that often results in men having low muscle mass and increased metabolic issues, lower motivation, kind of just more dwindle. I call it the dwindles. And it seems to me that for older guys, I find it so helpful. Do you think it's something that should be used more as a sort of a therapy, just like women are taking hormone replacement therapy? Yeah, I think there's a lot of barriers to testosterone therapy. And, you know, the FDA just had a hearing on this, you know, championed by Dr. Brian Christine, who's actually a sexual medicine or reproductive urologist that's now number two in HHS. So it's great that he's sort of being an advocate for himself. And so that was one of the topics that came up, who should get testosterone. And I think this hypogonadism of aging is really kind of disregarded, and it's often not covered by insurance companies. That's a big word. What does that mean, hypogonadism? Oh, it's basically where your gonads aren't working. So your low testosterone, it's also used for low sperm counts as well. But again, you know, as we age, our testosterone levels do go down. Probably starting around age 20, 25, testosterone goes down about 1% every year. So, you know, we have to reset, I guess, what's normal to some extent. But, you know, testosterone still does what it does. And so you do want kind of normal levels. And so, you know, in some ways, it'd be nice to have a baseline to understand where a man was at his peak. So when you're looking at them, you know, decades later, you can see kind of what target is. because, again, we talk about the normal range as being fairly wide, 300 to 900. So it's hard to know if 300 is normal and that's where you were always or whether you used to be at 900, now you're at 300. So it's a much different deal in terms of what your body needs for, again, energy level, sex drive, muscle mass, bone health, all those sorts of things. So I think that's one thing I think that could be done to improve prescriptions if we look a little bit more broadly at who's getting it. The other thing is that testosterone is regulated like OxyContin, for example, So it's, yeah, it's a schedule. So it's very difficult to prescribe. You have to go through a central database and, you know, make sure that men aren't getting it from other places. And so that's just a barrier. And you also, I don't find it that hard. I just said to put the prescription, I said, I put in my special secret DEA code and, you know. But it's another step. It's another step. Yeah. And then men also can't get as much. Like you can't give them, you know, like month and month, you know, like several months supply. Right. Because they really restrict how much is administered. So I think all those things I think will help with access to testosterone. And it's interesting because, you know, you have other biomarkers that are matter, like the free testosterone and the six hormone binding globulin, which regulates what levels of free hormone there are that does the work in your body. And they can be really off. So you can have a high testosterone, but also a low free testosterone. You can have a low testosterone, high free testosterone. I've seen the whole gamut. And the sex hormone binding globulin can be elevated. That can be from inflammation, other factors. So all those things play a role in trying to assess what's going on with somebody. So getting the right test is really important. Yeah, I think that's absolutely right. I think that, you know, for everybody, it may be a little different what exactly what you're looking at. You know, some men like the systolic blood pressure may be at risk, some diastolic. So I think looking, you know, very comprehensively, you know, hormone panel, I think is important, too. And, you know, also adding, you know, prolactin, like you talked about, estradiol, like you talked about. All those things, I think, are going to be really crucial. luteinizing hormone to understand a little bit more about production of testosterone and understand why levels you know aren't where they're supposed to be it's really it's really important to kind of monitor those things like most men don't get their estrogen levels checked right yeah like estrogen that's a female hormone what the the the one we check is estradiol with estrogen is there is no such thing as estrogen they're estrogens and they're different ones but estradiol is the main one and what happens is is men often who have extra belly fat or body fat will convert testosterone into estradiol. And so they'll end up having feminization features. They'll lose their body hair. They'll get soft skin. They'll get breasts. We call gynecomastia where men get breasts. And you've seen that. The classic beer belly guy. That's all from estrogenic effects. And you can measure it. And I think we're sort of shocked to see 14% of the men we're testing have relatively high estrogen levels. And I was like, wow. So all these sort of environmental things and dietary things are all affecting us. And there are things we have some measure of control over and can be empowered about. But most of us are walking around blind and have no clue. Yeah. And again, that's why I co-founded Function Health, which is to give people access to their data because the average doctor is not checking these things. You go for your checkup and they're just, if they see you, they'll check it. But you're like a Stanford professor who has been studying papers every day all night long for the last 30 years. So you're very aware. But the unfortunate thing is that people aren't getting the most sophisticated care and the answers to their questions. And they may be walking around with all sorts of issues that they don't know about. It's both their fertility issues, their hormone issues, the quality of your life. And it's such an important part of our future generations. And I'm kind of worried about us as a species. As I see, you know, you mentioned epigenetics. For those who don't really know what that is, essentially you've got, you know, 20,000 genes. But, you know, you've got to determine which genes are turned on or off or expressed. They're not all switched on. And the epigenome is sort of like the piano player above the genes that controls which songs get played in your book of life or in your whatever. Whatever. And so you kind of have to determine how to regulate those. And the epigenetics is influenced by everything we do. We call the exposome, which is our diet, exercise, sleep, stress, toxins, our thoughts, our feelings, relationships, our microbiome. Pretty much everything you can think of is influencing our epigenome, which in some ways is actually getting worse and worse. And so we now know that if you're in utero and you're exposed to toxins or stress or other things, that that has a huge impact on the development of the fetus and its later history, health history. So can you talk a little bit more about the sort of understanding of how the epigenetics is affecting reproductive health and fertility and all these other things? So I think I'm really wondering about how that plays a role. So I think that's, you know, potentially a real opportunity for us to try and improve reproductive health. So even beyond, you know, sperm counts, which we've talked about a lot, you know, there's sort of a deeper layer here. And so, for example, you know, if a man smokes or if a man's obese, that's not going to change the DNA, you know, actually the base pairs, you know, all the different molecules. But it will change the epigenetics, sort of the expression. And so our body sort of reacts to this. It says, you know, now I'm in an environment where there's smoke, so I need to get more of this particular, you know, gene and less of this gene. Or if I'm obese, you know, that means there's more food abundant, so I need to turn this on, this off. And so that then is basically hardwired into the DNA. And so the sperm that we're making, you know, have that belief about this is how the environment is. And so then the child that's conceived has those same changes. And these changes really affect everything. You know, we've seen this in, for example, mouse data, too. If you have starved mice or, you know, obese mice and then they have offspring, you see these metabolic arrangements in the children. We see this in people, too. You know, men that smoke, men that are obese. We can measure these metabolic changes in their children. So I think these are things that are, you know, very powerful and really proliferate, you know, beyond just us. You know, again, if we think, you know, I have enough sperm, everything's OK. There really could be effects. And obviously you want to, you know, give your child the best possible chance and, you know, optimize everything. I think people are talking about different ways to select the best embryo. Well, this is sort of a good way to make sure that your embryo pool is even better is if you try and maximize and optimize health as much as possible. So all these things, you know, diet we've talked about, but just making sure that you're as healthy as you can be. I think those are really powerful influence. Yeah, it's important. I mean, so, you know, you kind of kind of start thinking about all this early on. And people just don't. And most pregnancies are just sort of like not thoughtfully curated in the sense that you're not doing all the things you need to do before you actually conceive. Yeah. To make sure you have as healthy a baby as possible. Yeah. I want to end by a few rapid fire questions about is this bad for your sperm or not? We've touched on some of them, but cell phones in your pocket, yes or no? I think it's probably okay. Probably okay, but in the back pocket. Back pocket probably a little bit. What about boxers or briefs? This has been, yeah, it's a very common question. I think it's unlikely any one clothing layer is going to make a big difference. But we do want, you know, I guess as much breathability as possible. So usually I just tell patients whatever's comfortable. No, this is all sauna hot tub crazy. It is bad for guys. I mean, should we like not doing saunas or just like bringing in like an ice pack on our balls? I haven't seen good data that ice pack is going to necessarily mitigate that risk, but heat definitely is bad. So I think while you're trying to conceive, you know, again, it takes two to three months to make a sperm. So if that's something you're actively trying to do, I think it's probably best to stay away from the sauna. So stop saunas for 90 days before you want to have a baby. Yeah. Okay. How about laptops? You mentioned, yeah, you're worried about. I'm worried about those. Yeah, it's better to put it on a desk. Put it on a desk. Okay. What about time of year? Does that matter? They're interesting. There is some variation based on time of year. So turn in the cooler months, you know, winter, fall. Sperm counts can actually improve about 10 to 15%. And so we do see those changes, again, on a population level. But, you know, again, I think whenever it's never a right time to have a child. So I wouldn't tell couples to wait necessarily, but we do see changes. A lot of guys are into cycling, me included. Is it bad for your sexual health and erectile dysfunction or fertility or both? It could affect both. I mean, I always say anything that's good for your heart is going to be good for sexual function and reproductive function. Yeah. But there have been some studies that suggest there could be some issues. So I think for men that ride over five hours a week, there have been some decreases in semen quality. So, again, why that is maybe it's due to heat. You know, again, you're kind of compressed and obviously you're generating a lot of heat. You've got those tight spandex bike shorts. That's right. Yeah. They may look nice, but, yeah, they're not all good. So I usually tell men to try and stand up out of the saddle to try and, you know, get some circulation. I think that could be beneficial. And there is some data that, you know, the saddle design can actually impact blood flow to the penis. And so there are certainly men that come in to tell me about numbness, pain. It doesn't affect everybody, but maybe about 20% of men report this, and there is a higher risk of dysfunction. Because, you know, we put our weight, especially when we lean forward in a saddle, it compresses against kind of our sit bones, the ischial tuberosities. And the main nerve and artery to the penis are sit right there so they can get compressed. And usually when you, you know, kind of sit up, blood flow restores. But if you're pushing too much, it can lead to, you know, more permanent damage. So there are different, you know, saddles that can try and mitigate that risk. Again, standing up can help. I work with a company called V-Seat that has a noseless saddle design that can help with that, too. V-Seat? V-Seat. V-S-E-A-T. Oh, wow, V-Seat. I'm going to check that out. Yeah, for sure. Yeah, because I like to ride bikes. Definitely, I worry about it. How about being sedentary? Is that tech sperm quality? Yeah. So I think, you know, activity is definitely beneficial. So like there have been studies looking at like hours watching TV, hours sitting around, and it's certainly not good. So I think that, you know, being active, you know, get out of the sun and go for a run. That can be beneficial. Yeah. And alcohol. We didn't talk about that, but that's another toxin. How does that affect sperm health? So I think in moderation, it tends to be OK. I think that, you know, the one study that does support damage to sperm quality is probably about 20 drinks a week, which is a lot, you know, about three a day. So if you're at that level, I think that they're an alcoholic. There may be some other things. But interestingly, there are also probably some men that are more genetically susceptible to alcohol. So there's a condition called like flushing, like alcohol flushing. So the Asians get it. They get really red in the face. East Asians, exactly. It's the alcohol dehydrogenase gene. Exactly right. Yeah. So in some places, it's about 50 percent. In Taiwan, about 50 percent. Mainland China, it's about 30 to 40 percent. So if you have that mutation, you're more susceptible. And basically what that does is that when you're metabolizing alcohol, you know, eventually you get this accumulation of acid aldehyde, which is a toxin. And so that's why you flush. That's why sometimes people get sick with it. But it can also damage sperm quality. So we've seen significant declines in sperm motility or movement, you know, around alcohol drinking. So if you're susceptible to that, it's probably a good idea to avoid it. And we talked a little bit about sleep, but that also can affect fertility if you don't sleep enough. Exactly. So yeah, seven to nine hours, I think, is a sweet spot. And stress, we talked about. Yeah. I mean, it's easier to say less stress, but again, I think you have some good techniques to try and cut it down. Yeah, I think most people don't realize that stress comes unbidden and automatically, whereas relaxation is something you have to work at. Yeah. It's like you have to meditate or do breath work or basically, I do this thing called Yoga Nidra. Andrew Huberman calls it non-sleeve deep breaths, but essentially, it's ancient techniques of just going through a body scan and using your breath and going into a state of deep parasympathetic activation, which really, really helped with so many aspects of your health, but even sperm count. Amazing, Michael. Well, so where can people learn more about your research and your work and you? Yeah, Eisenberg Lab at Stanford. They can just look that up on the Internet. And what about this swim club? Oh, swim club. Yeah. So swimclub.co. There's a lot of information. There's a lot of testimonials. And you can learn a little bit more about the product. And is this something that all men should take? Or is this just men who are trying to conceive? Or is this just a general help for testosterone? Well, I think you know and you've taught people a lot. I think a lot of these same supplements can also help overall health, metabolic health. So I think it's not unreasonable to think about that. But right now, we're focused on reproductive men. Sorry, men that are trying to have children. Are you having a book coming out anytime soon? Not yet. Come on, you've heard a book about this. You've been very, yeah. You really inspired me, so maybe. Yeah, well, thank you so much, Michael, for your work, for being a pioneer in this field, for talking about difficult subjects, for bringing things to awareness that, you know, are honestly not talked about a lot in medicine, like our environmental toxin reload. Now that's affecting us and changes in sort of men's sexual health. So great conversation. Thanks for coming all the way to Austin and we'll see you at Stanford sometime. I appreciate it. Thank you. If you or someone you love is thinking about fertility, whether you're just starting to ask questions or navigating challenges or preparing your body for pregnancy, I want you to know you're not alone. And this year we're launching something new for our community called the Ultra Learning Series, where you can connect directly with my team at the Ultra Wellness Center for deep, practical conversations that make functional medicine simple and actionable. Now, our first workshop is Functional Fertility. It's happening Thursday, February 12th at 12 p.m. Eastern Time. Dr. Cindy Guy, who I worked with for, I don't know, 30 years now, a long time, and Lisa Drayton, my nutritionist, will walk you through what really influences fertility from hormones and inflammation to nutrition, environmental exposures, and whole body health for both partners, because, yes, it takes two. This is a compassionate and it's evidence-based conversation designed to give you clarity, confidence, and real tools, no matter where you are in your fertility journey. You're going to find the link in the show notes or just head over to Ultra Wellness Center on Instagram at Ultra Wellness Center and you'll find out everything you need to know and I really hope you'll join us. If you love this podcast, please share it with someone else you think would also enjoy it. You can find me on all social media channels at Dr. Mark Hyman. Please reach out. I'd love to hear your comments and questions. Don't forget to rate, review, and subscribe to The Dr. Hyman Show wherever you get your podcasts. And don't forget to check out my YouTube channel at Dr. Mark Hyman for video versions of this podcast and more. Thank you so much again for tuning in. We'll see you next time on The Dr. Hyman Show. This podcast is separate from my clinical practice at the Ultra Wellness Center, my work at Cleveland Clinic, and Function Health, where I am Chief Medical Officer. This podcast represents my opinions and my guests' opinions. 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