Updated 5th June 2024

Menstruation medicine and myths, with Dr. Jen Gunter

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Today, we’re talking about periods. Jonathan and Sarah are joined by “the internet’s gynecologist,” Dr. Jen Gunter, to get a better understanding of the body's behavior during the menstrual cycle. 

Jen will rebuild your period toolkit. In this episode of ZOE Science & Nutrition, she describes the fascinating science of the monthly cycle, challenges taboos, and offers tips about navigating premenstrual syndrome (PMS).

Dr. Jen Gunter is a gynecologist and pain medicine physician at the Permanente Medical Group in Northern California.

Her books The Vagina Bible and The Menopause Manifesto were both New York Times best-sellers. Her 2024 book Blood tackles the science, medicine, and mythology of menstruation.

Want ZOE Science & Nutrition’s top 10 tips for healthier living? Download our FREE guide.

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Is there a nutrition topic you’d like us to explore? Email us at podcast@joinzoe.com, and we’ll do our best to cover it.

Episode transcripts are available here.

ZOE Science & Nutrition

Join us on a journey of scientific discovery.


[00:00:00] Jonathan Wolf: Welcome to ZOE Science & Nutrition, where world-leading scientists explain how their research can improve your health.

Today we're learning all about periods and menstruation. Now, I can't pretend I know anything about the experience of menstruation, but I've certainly heard the common questions from people who do. Why am I craving chocolate? Is PMS inevitable? Will my cycle sync with people I live with? 

Today's guest, Dr. Jen Gunter, has answers. Jen wants to bust the myths around menstruation and show why a certain superhighway to the brain might help uncover what's really going on during the menstrual cycle. Jen is a gynecologist,  a physician, and the author of two New York Times best-selling books. 

On today's episode, she shares her insights from her new book, Blood, and helps us understand what the latest science says about menstruation.

Joining me as co-host today is Dr. Sarah Berry. Sarah is a world leader in large-scale human nutritional studies that can help us learn about women's health. She's an associate professor in nutrition at King's College London, and she's chief scientist here at ZOE.

Jen, thank you for joining us today. 

[00:01:25] Jen Gunter: Oh, thank you so much for having me. 

[00:01:27] Jonathan Wolf: It's a real pleasure. Now, we have a tradition here at ZOE where we always start with a quick-fire round of questions, and we have very strict rules. You can say yes, or no, or if you have to, you can give us a one-sentence answer. 

[00:01:41] Jen Gunter: All right, I'll do my best.

[00:01:42] Jonathan Wolf: All right. Can a person have over 400 periods in a lifetime? 

[00:01:47] Jen Gunter: Yes. 

[00:01:48] Jonathan Wolf: Does your period always have to be a negative experience? 

[00:01:52] Jen Gunter: No. 

[00:01:52] Dr Sarah Berry: Is PMS inevitable? 

[00:01:54] Jen Gunter: No. 

[00:01:56] Dr Sarah Berry: Can menstrual cramps be as strong as the experience of giving birth? 

[00:01:59] Jen Gunter: Yes. 

[00:02:01] Dr Sarah Berry: Can tampon use lead to endometriosis? 

[00:02:03] Jen Gunter: No.

[00:02:04] Jonathan Wolf: Brilliant. You see, that was quite easy. Final question. And you can have a whole sentence for this. 

[00:02:11] Dr Sarah Berry: We're lucky. 

[00:02:12] Jonathan Wolf: What's the most surprising thing that you've learned about periods in writing your new book? 

[00:02:17] Jen Gunter: How impactful the culture of shame has been for centuries and centuries. So much so that even in their own personal journals, women couldn't write about their menstrual experience.

[00:02:30] Jonathan Wolf: Thank you. Well, I like to start these chats off with a bit of personal connection to the topic, but I can't sit here and pretend that I know what it's like to menstruate. 

[00:02:38] Dr Sarah Berry: But I think the thing is, even for women like myself who have menstruated or aren't menstruating anymore, I still feel I know almost nothing about menstruation. Because just like menopause, it wasn't talked about, you know, it was something that we were a bit embarrassed in our household to talk about.

It was something that then when my period first started, I really struggled. I struggled because I felt a bit unclean, I felt a bit smelly, I felt embarrassed even to talk to my own mum about it, even though she was quite an open person. And I think as a mother of a 14-year-old, I'm really hopeful that I'm going to learn some things from you that will help me do this better with my own daughter.

[00:03:15] Jen Gunter: I think that's a really common experience that just people have not talked about menstruation in an open, non-sophomoric way. You know, it's either been the butt of jokes or it's been something people have spoken about as if it's bad or disgusting or polluted. And we have centuries and centuries of history, making people feel that way.

And I think we're now starting to see a little bit of change and that's really positive. And I think the biggest step is just talking about it openly like it's no big deal. It's a body function. 

[00:03:47] Dr Sarah Berry: I would love you to educate me and our listeners on the basics because even though I have menstruated for many years, I think there's so much I don't know just because we don't talk about it. 

[00:03:58] Jen Gunter: It's one of those things that, you know, I menstruated for many years, I'm team menopause now. But people think that they know about it because they're experiencing it. But if you're not taught about the biology, then you don't actually know kind of what's going on behind the scenes as it were. 

[00:04:15] Jonathan Wolf: And Jen, can I start right at the beginning there for like, why do people menstruate?

[00:04:20] Jen Gunter: Menstruation is a byproduct of the menstrual cycle. And the menstrual cycle is the best way for us to have a pregnancy as humans. So most animals have estrus, and we have a menstrual cycle. 

The menstrual cycle has evolved five different times. Well, there's five different species that menstruate, it's evolved four different times. It's us and the great apes, there's some bats, there's the spiny mouse and the elephant shrew. So it's sort of a very eclectic group. 

[00:04:44] Jonathan Wolf: We're in a very small, I didn't realize we're in a very small group is what you're saying. 

[00:04:47] Jen Gunter: It's a very small group of menstruators. That is almost sort of like, you know, punk rock names or something, right? You know, the menstruators and here's the bass player. 

And people always say, well, what about dogs? And they have estrus, their bleeding actually is from the vagina, it's not from the uterus. 

So the menstrual cycle is a byproduct of having a very, very thick uterine lining, very thick, specialized uterine lining. And with human embryos, especially, we have the thickest lining, humans. 

Human embryos are incredibly invasive, they're basically like a cancer. They're going through the uterus, they want to get oxygen, they want to contact maternal blood vessels. That's how you grow big brains, all the things that sort of make us human.

And so you have to have basically a catcher's mitt, a backstop, to kind of handle that invasiveness. And there are situations where that goes awry and you can get placenta percreta, where actually the placenta implants on organs in the body, and that's actually a very dangerous, catastrophic situation. 

So part of it is to handle the invasiveness. Part of it is as a fitness test for the embryo. You've got to make the embryo work for it to get to the blood vessels. 

And finally, the human endometrium also acts like a biosensor for embryo quality. And so if the embryo has significant chromosomal abnormalities, significant abnormalities, it triggers this inflammatory response and out with the menstruation.

[00:06:17] Jonathan Wolf: You're explaining why you might want to have this thick uterus lining. Why doesn't it just stay there for 30 years rather than have sort of come in and out? So I'm still confused about that. 

[00:06:28] Dr Sarah Berry: That's a good question. 

[00:06:29] Jen Gunter: Yeah, that's a great question. Because you build that uterine lining up each month with exposure to successively higher and higher levels of hormones. And you need to have a fresh start each cycle to do that. 

Because the endometrium has undergone this irreversible change called decidualization, you can't now build new endometrium on top of that. And the tissue can only be decidualized and hold in that sort of perfect environment, if you will, for a very short period of time.

Because also what happens is the progesterone that produces this change, this decidualization comes from the corpus luteum, which is sort of like the eggshell left over from ovulation. And that has a time limit. It can only produce progesterone for 12, 14 days. And so when the corpus luteum basically runs out of gas and stops producing progesterone, it's the withdrawal of progesterone that triggers the bleeding.

And then the uterine lining comes out, and then you start anew, and the cycle begins again. So with humans, decidualization is triggered by ovulation. 

[00:07:33] Jonathan Wolf: I’m sorry, you said decidualization? 

[00:07:36] Jen Gunter: Yeah, decidualization. So that's the change in the uterine lining that prepares the uterus for implantation. So this thickened, specialized lining we call the decidua. And that's triggered by a progesterone release with ovulation. 

So, for humans, that specialized uterine lining is there waiting for the endometrium. But with the estrous cycle, that trigger comes with implantation. So you don't have that specialized lining waiting. So, if pregnancy doesn't happen, there's very little there and the body can reabsorb it.

[00:08:08] Jonathan Wolf: So you're saying that almost all other animals, they don't have to do this special thing, so it can just sit there all the time until you get the start of pregnancy, and then it starts to make these changes. 

And Jen, could you just talk through then the next bit actually, which is you've got this thick lining coming through to explain menstruation? What's actually going on there, over what time, and could you just again explain what's sort of going on inside the uterus to people like me who don't really understand it?

[00:08:30] Jen Gunter: So the start of the menstrual cycle actually is with the start of menstruation, because you have to time it with something that is reproducible and that you can ask people when the start of their cycle is. So we consider that day one. 

And what happens is there's follicles, which are immature eggs that have been recruited by the hormone, hormones in the brain. And there's a leading follicle that develops and the follicles produce estrogen and it's the estrogen that gets the uterine lining ready. 

And so in the first part of the menstrual cycle, we call that the follicular phase and the lining is getting thicker and thicker and kind of getting ready. And then once this dominant follicle has sort of reached a critical point, there is signaling from the brain that triggers ovulation.

You get exposure to progesterone and now that's the luteal phase, the second part of the cycle. And it's during this second part that the endometrium undergoes this irreversible change and becomes what we call the decidua. 

If pregnancy doesn't happen, the corpus luteum runs out of progesterone, and that withdrawal of progesterone triggers all kinds of chemical reactions that cause the top layer of the endometrium, the decidua, to peel off. That opens blood vessels, and now you get bleeding from the arteries and the veins. That pushes… 

[00:09:47] Jonathan Wolf: Which is what's underneath this layer right? So there's two things happening, is that right? You're saying there's this layer that comes off and then there's bleeding as it comes off.

[00:09:52] Jen Gunter: Right, and that's where the blood comes from. So the blood is just from the arteries and the uterus. It's not like special menstrual blood. It's got the same amount of hormones as in your vein. It's the same. 

And so you have the bleeding that pushes the lining out. You have release of all these inflammatory mediators to get the tissue out to push that top layer of the endometrium out.

And then what happens is you've got then a next follicle coming up and you start getting exposure to estrogen. You get new endometrium being built, and that helps to stop the bleeding, the spasms in the uterus, the contractions, which are created by prostaglandins and other chemicals, squeeze off the blood vessels so they can clot and start again.

And that's the coolest thing, I think, about menstruation, is it's the only scarless healing in the human body. But you'll get clots, the blood will clot. You shouldn't have clots that are bigger than the size of a quarter or 50-cent piece. Or if you do, that would be a time to talk. 

If you are soaking through your menstrual products onto your clothes, if you're having to change pads or tampons every one to two hours for more than just kind of once, if you have to do that, or if when you stand up you have a feeling of gushing.

So all of those things can be signs of heavy periods. Sometimes they're not, but you don't know. But those would be all the signs that would say you should probably see your doctor and be investigated. 

And the reason this is so critical is if you look at the incidence of iron deficiency, it is very high amongst women, young women. And in the United States, the study I'm referencing is from the U.S., so I don't know if the data is the same in other countries, 40% of women ages 22 and younger are iron deficient. 

[00:11:35] Dr Sarah Berry: It's similar prevalence in the U.K.  

[00:11:37] Jonathan Wolf: Forty percent under 22, do you say, are iron deficient? That's extraordinary. 

[00:11:41] Jen Gunter: It is, and it's often dismissed because people can have iron deficiency and not have anemia. And often people are told if they don't have anemia, they don't need to worry about it, but that is incorrect. And iron deficiency itself is a medical condition with consequences. 

[00:11:56] Dr Sarah Berry: So how many mls on average, as a scientist I always like data, how many mls on average would a person that's menstruating lose during a menstrual period?

[00:12:07] Jen Gunter: So it's about 80 milliliters which doesn't seem that much. 

[00:12:11] Dr Sarah Berry: Wow, it doesn't. 

[00:12:12] Jen Gunter: But there's also cervical discharge and vaginal discharge. And so the amount that comes out may actually be larger. There's also the decidua, which is kind of the lining, which isn't counted in that. So the actual blood comes from tests where they do, you know, radio-labeled stuff and to see how much blood has been lost.

So the actual blood itself is 80 milliliters, but it may seem like more than that. 

[00:12:35] Dr Sarah Berry: Okay, so you might have double the amount actually coming out, but it's mixed with other fluids and other tissue. 

[00:12:42] Jen Gunter: Yeah. So all the studies that look at the actual volume of blood, they're either weighing pads or they're actually doing these sort of radiolabeled blood samples to try and figure out like how much has been lost.

And so we say 80 milliliters, understanding that for some people that might look, it may be more than that based on the amount of discharge and other things that are going on.

[00:13:05] Jonathan Wolf: So Jen, having explained that really well, and thank you, and I've already learned a lot, and it sounds like Sarah's learned something as well already. What's the biggest misconception that you find people have about menstruation? 

[00:13:17] Jen Gunter: One is that having heavy bleeding is normal. You know, it's something that people should just suck up or suffer. And again, we have this sort of epidemic of iron deficiency amongst young people, which is really not acceptable. I think that if you have a lot of pain that that's normal and you should suck it up. 

And you know, there's sort of this dichotomy of either people saying, oh, women are able to tolerate more pain or they're complainers. Like, you know, it's sort of like, I always say being a woman is like walking on the edge of a knife. You're either too much in one or too much in the other, right? You know exactly what I mean. 

So there's that. And so people who have terribly painful periods get untreated and they don't get investigated. 

[00:13:57] Jonathan Wolf: Lots of pain is not just normal for everyone to have to experience?

[00:14:01] Jen Gunter: Well I always tell people that if the pain is interfering with your activities of daily living then it should be evaluated, you know?

I think that there are some people who have minimal cramping and don't have much, and there's other people who are the other end of the spectrum and there's people everywhere in between. 

And unfortunately pain is a byproduct of menstruation, that's how, you know, it takes uterine contractions to get the blood out. It takes uterine contractions to stop the bleeding. And so that is part of it. But for some people it can be very painful.  

[00:14:30] Jonathan Wolf: And Jen, just to understand that actually, I just want to make sure, is that what is causing the pain around the time of your period? 

[00:14:37] Jen Gunter: So yeah, so the uterine contractions are a big part of it. They can be quite intense. We sort of talked about in the rapid-fire, the intensity of the pressure can be the same as in the second stage of labor, which is when you're pushing. 

You know, you're talking 120 millimeters of mercury that it's a lot of pressure, like when you blow up a blood pressure cuff, you're blowing it up more than 120 millimeters of mercury sort of for that, you know, and that's quite uncomfortable, right? When you're getting your blood pressure checked, and then it goes down, you're like, Okay, that's better. 

[00:15:03] Jonathan Wolf: And why is your body doing this? 

[00:15:05] Jen Gunter: Well, one, to get the lining of the uterus out. So the contractions help move things along. Also to squeeze blood vessels, right? So, you know, when you're bleeding, you put pressure on something. So it's actually applying pressure. 

[00:15:18] Jonathan Wolf: So your body is both, it's a bit like you're saying there is a little bit like delivering a baby like it's squeezing things out. And then it's compress… It's doing its own sort of tourniquet on the inside to shut down the bleeding. 

[00:15:29] Jen Gunter: Yeah. And then that reduces blood flow to the uterus. So there also is probably pain related to ischemia or low blood flow. 

Prostaglandins, which are released, which are hormones that are sort of produced locally at the site of injury or inflammation, those cause pain. And so there's actually you know, other inflammatory chemicals that are also probably contributing as well.

And some people who have more pain, you know, they may have stronger contractions. They may have uncoordinated contractions, so that might be more painful. Or they may have heavier bleeding and that can be part of it, or they could have a medical condition that's contributing to pain, like endometriosis.

There are people who have very minimal cramps and like, yeah, it's a nuisance, but I can deal with it. And there's people who are really debilitated. 

[00:16:13] Dr Sarah Berry: But I think that's a really important point because I remember when I was at school, there would be a few girls that would have to take three or four days off a month because of how debilitating their cramps were.

But again, because it was a taboo subject and we didn't really talk about it, there was a kind of feeling I got from the adults in the school was, oh, they should suck it up, like we all get cramps, it's just part of the deal. 

Really important point for people to be able to acknowledge that it is worse. It's really physiologically worse. It's not just that someone's not sucking it up and other people are better at handling it. And it's because it's such a taboo topic that we don't talk in this way. 

Why do you think it is such a taboo topic? 

[00:16:54] Jen Gunter: Since the beginning of Western medicine, and in many religions, menstruation has been viewed as being toxic, being a sign of women being inferior to men. 

If you look at these sort of ancient Hellenic medicine it was a sign that, you know, men were in perfect balance and women were not. And every cell in a woman's body was overly moist, I hate that word moist, and the way they dealt with their extra moisture was menstruation. 

So if you, if your worldview is, men are perfect and women are inferior, you can make anything fit that, you know, you can find whatever physical quality, and say, oh, well, that's proof. 

And then you have religions talking about menstruation being dirty, polluting. You have cultures where women have been excluded from religious services, where they aren't allowed to prepare food in their own kitchens, where they're sent out to menstrual huts where crops failing was blamed on menstruation.

So there are many sort of patriarchal cultures where menstruation has been viewed as sort of this convenient scapegoat. 

[00:17:57] Jonathan Wolf: I'd love actually to come to some of the things you talk about in the book and particularly talk about this idea of like a super highway in the brain in the book. 

I'd love actually, if you could help us to understand why you're saying understanding this super highway could be the key to understanding what's happening in the body during menstruation and you use this word brain-brain-ovary connection, which I definitely haven't heard of before.

What is it? 

[00:18:24] Jen Gunter: Well, I made up that term, so I've been here before. So menstruation is, I think, like an orchestra. You know, there are all different aspects of your body playing a role. 

You have an area deep inside your brain called the hypothalamus, which is sending a hormonal trigger to your pituitary gland. So both of these are in your brain. So that's the brain, brain component. And then the hormones from the pituitary are then signaling your ovary. 

And it's sort of this sort of symphony between these three players that are kind of the hormonal trigger behind getting a follicle to develop, getting the ovulation to happen, getting the production of estrogen.

At the same time, all the hormones that are produced from the developing follicle, those are then being relayed back to the brain, so there can be these fine-tuned adjustments. So once you get to the right level, then another thing happens, and it's so this sort of incredible, sort of orchestrated event.

[00:19:24] Jonathan Wolf: And these are affecting some of the hormones that we often talk about, like estrogen and progesterone, these are being controlled by this sort of symphony you're describing? 

[00:19:31] Jen Gunter: Yeah. So you get pulses of a hormone called GnRH from the hypothalamus that sort of trigger the pituitary and the pituitary releases a hormone called follicle-stimulating hormone.

And what that does is there's sort of a group of follicles of eggs each month that are, or each cycle, that are capable of ovulating. Those are kind of, they've been given a VIP ticket, but they haven't got in the club yet. 

[00:19:57] Jonathan Wolf: Okay. and they're in the short queue at this point. They're in the short line. 

[00:19:59] Jen Gunter: Because it's taken about 300 days for those follicles to get ready for the VIP line. So, because there's this whole sort of incredible journey in the ovary that happens up to that point. 

So, these follicles have been given a VIP ticket and they're ready. The hormone FSH is released, and it's kind of like the bouncer, it sort of picks who gets to come in, and then a few follicles start developing, and then the estrogen that's being produced is going back and forth and communicating with the pituitary. 

Then once you get to a certain level, then the hormonal signals change and you get that hormone FSH, the trigger for ovulation. You get this surge of a hormone called luteinizing hormone. And that's where you get ovulation. And then you get the, now the egg released. So it starts its journey through the fallopian tube or oviduct that we like to call it now. And then the leftover part of the follicle, which is really the shell, that's what organizes and starts to produce the progesterone.

[00:20:54] Dr Sarah Berry: So there's this continued kind of bi-directional feedback going on involving the brain, which I, again, is, it's totally new to me. 

[00:21:01] Jen Gunter: It's this incredible symphony that's happening. And once you have a basic understanding of it, a basic understanding of, okay, well, then it's the prostaglandins that are contributing to pain.

So, for example, we know that pain with menstruation is far less likely to occur when people don't have what we call an ovulatory cycle. So you can menstruate and not have ovulation. It’s ovulation, that is what produces the prostaglandins. 

So if you know that, well, if it's prostaglandins that cause pain, then I can take medications that block prostaglandins, like ibuprofen or naproxen. You can take those, and they're very effective for many people at treating pain. 

[00:21:39] Jonathan Wolf: Jen, what role does diet play in this whole connection that you're, this symphony that you're describing? 

[00:21:45] Jen Gunter: Well, you know, we haven't really determined that there's an optimal diet for menstruation or for the menstrual cycle. And so we really say that it's the typical, the diet that's good for your heart, the diet that's good for your brain is the diet that's good for your body. 

And if you think about humans, they are incredible omnivores. And if there were a superior diet for the menstrual cycle, then we would have seen places in the world where people couldn't reproduce as much, right?

But if you think about, you know, the ancestral people in Greenland versus the ancestral people in Greece or the ancestral people in Australia, you know, they would have all had incredibly different diets. And yet they all reproduced and they all had populations that grew. 

[00:22:27] Dr Sarah Berry: And what about appetite? Because I think again, growing up, you know, I know that some people say, oh, I'm really craving this at this time of my cycle. And I think there's some evidence coming out now, you know, particularly because how you've described that the brain is so involved in this. I wonder if there's anything you can expand on related to appetite.

[00:22:44] Jen Gunter: There's a little bit more calorie requirement. And that's in the second half of the cycle. Whether that's, you know, related to sort of preparation for pregnancy, the extra tissue that's required to build, all those types of things. 

And definitely, lots of people have food cravings in the second half of their cycle, in the luteal phase. And that can be really significant for some people, can be less so for others. And sometimes that's folded into kind of the whole PMS, premenstrual syndrome, kind of complex or premenstrual symptoms. 

And definitely, there seems to be a craving for carbohydrates. That seems to be kind of a pretty universal thing. And also chocolate is a pretty universal thing too. 

Whether that's a true biological need versus, you know, chocolate makes people feel good, so it's kind of hard to know if, are people craving something because it's a time where they don't feel as well and. So chocolate makes me feel good when I have some, you know, so it's hard to know.

But yeah, so there is a slight increase in the calorie requirements and definitely people have some food cravings. And carbohydrates tend to be the ones that are listed most in that. And I'm not sure that we have a biological explanation. The hormone progesterone may be part of that, but I don't think we have a good answer.

[00:23:54] Jonathan Wolf: We had a question that came up a lot from our listeners, which is, I think, something you also touched on in the book about what role, if any, does stress play in this connection between these parts of the brain and then on. 

[00:24:07] Jen Gunter: Yeah. Well, so stress isn't good for anything. I mean, you know, that's kind of the blanket answer, but yeah, absolutely.

So people have really tried to understand this connection between stress and the menstrual cycle. And it's a hard thing to study because people often also change their eating habits when they're stressed. 

People have tried to look at it, for example, in context of war, which is incredibly stressful, but there's also often calorie restriction during that time, right? So it's very hard to tease out and people aren't keeping a food journal when they're going through an incredible stressful event. So how do you know? 

So, what we think is it probably requires a pretty significant amount of stress to have an impact. But it wouldn't necessarily have to be like a single massive stressful event. It could also be a daily chronic stress, like a bad employer, that type of thing. Or perhaps, you know, a bad home relationship. 

And for some people then, that can have an effect on the menstrual cycle and can actually stop menstruation. 

[00:25:03] Dr Sarah Berry: Okay, so it's not a myth that stress can stop you having your period, stop you menstruating.

[00:25:08] Jen Gunter: Yeah, it's not a myth but I think it's important that for a lot of women I think have sort of been dismissing, oh well you were just studying for an exam. So generally not that level of stress. It would be kind of more of a significant stressor. 

And if you think about, and many people are under significant stressors, and if you think about it from an evolutionary standpoint, if you don't have enough food, if there's a massive sort of environmental catastrophe, that's probably not the best time to reproduce, right? 

So it kind of makes sense that there's these fail-safes in there to sort of not put that massive biological investment of reproducing in a time where it may not be likely to succeed.

So you can understand that there's sort of an evolutionary basis to it. But because stress can again have impact on calories and we know calorie restriction absolutely can shut the menstrual cycle down. So we have to kind of sort all those things out. 

[00:26:06] Jonathan Wolf: I'd like to ask about PMS. We had a lot of questions around that and I think you've touched a part on this. But like could just explain a bit more like, what is it? Does it involve this brain that you're describing as well? And also sort of how prevalent is it? How does it present always in the same way to anyone who's listening to this for themselves or someone they love? 

[00:26:26] Jen Gunter: So premenstrual symptoms or premenstrual syndrome and then the more severe form premenstrual dysphoric disorder, PMDD, are sort of a collection of symptoms that are associated with exposure to progesterone.

So they can't happen in the first part of the cycle. So if people are having these symptoms before they ovulate, then it's not PMS or PMDD. It may be a different diagnosis. 

And so that's one of the reasons, one of the situations where keeping sort of a menstrual calendar for two or three cycles can be useful because sometimes people can have depression and depression can be worse with hormonal changes. And so you want to know, is it that or is it PMS, PMDD? 

And PMS is the collection of symptoms that might include bloating or fatigue or headache, irritability, food cravings. Those are very common symptoms. And if you look at the broader collection of symptoms,, it can affect 70% to 80% of women. Some people are more severely affected than others.

If you're looking at PMDD, it's much less common but it's much more severe and people can have really profound depression, really profound mental health changes during the second half of their cycle. Some people can even have suicidal tendencies. And so that obviously requires treatment. And obviously, the more severe, the more we want to offer treatment. 

But so that's kind of the spectrum. The actual cause, I think that we don't quite understand. We do know that because it has to happen after ovulation, that exposure to progesterone is clearly part of it.

But there's all kinds of other chemicals, you know, in your brain that can be affected as well. And since antidepressants can be very effective, obviously, there's involvement obviously of serotonin or norepinephrine or dopamine. But I don't think we truly understand at a brain chemistry level what's going on.

[00:28:25] Jonathan Wolf: And just for me to understand, because you talked before about some of the pain that's going to happen while you're actually having your period, but the symptoms you're talking about here are not really related to that is that right? 

[00:28:38] Jen Gunter: Yeah, that's correct. So people can have PMS and not really have menstrual cramps. So there's sort of these other collection of symptoms and people can have terrible menstrual cramps and never have any food cravings. And, and that's part of the complexities of the experience. 

And this is I think why it's again important to have the discussions because people sometimes think they're abnormal if they have the symptoms or if they don't have the symptoms. 

Many women who have PMDD, the very severe form, have been written off and been told that they're crazy or told that they're too hormonal. All these awful things have been told to them and they have a real diagnosis and a condition that has treatment and that's terrible, right?

That's part of the culture of shame of if you don't know that this is a medical condition and you've been dismissed by your providers, you could start to think, my gosh, like, am I going crazy? Like, what is going on? Everybody's telling me there's nothing wrong with me, but there actually is, you actually have a medical condition.

[00:29:36] Jonathan Wolf: And Jen, how, how long would be, you know, again, just trying to get to like the facts behind this, how long a period would like on average someone who's having these PMS symptoms experience them? Is that for like the full two weeks of the second half of the cycle or what, what sort of normal? 

[00:29:53] Jen Gunter: It can vary. So some people might just have symptoms the last few days. Some people may have it for the full two weeks. Some people might have it for seven to 10 days. 

I think that as it gets more severe, so severity can be not just the intensity of the symptoms, but the length of the time of the symptoms. 

So if you think if you have pretty disabling symptoms, but you have them five days a month or five days a cycle, you have 25 days to recover in between. If you have them for 14 days, then you might only have 14 days to recover in between, right? Or 12 days if you have a shorter cycle.

And that doesn't mean that people who have five days’ symptoms shouldn't be offered treatment. They absolutely should. But when you start to think about how then it can kind of carry over when it starts to, if you're having like basically 50% of your life affected by these symptoms, that can be pretty dramatic for people.

But some people can be really affected even just for two or three days. And so, that's again, why it's important to talk about it and to be able to offer people treatment. 

[00:30:51] Dr Sarah Berry: And for people on contraception or whether it's oral or IUD, do they still experience PMS? 

[00:30:57] Jen Gunter: The estrogen-containing birth control pill can be very effective at treating both PMS and PMDD.

It won't take away, you know, people may still have food cravings or other types of things, and obviously, it doesn't work for everybody because not all therapy is 100% effective. 

But stopping ovulation, which stops that sort of cyclic release of the progesterone and the change in hormone levels, so giving people constant hormone levels seems to be an effective treatment for many. Which tells us it's less about the levels and more about the change in levels that matter. The ups and downs can be very effective treatment. 

But with a hormonal IUD, you're still ovulating. So you're not taking away any of those triggers. So people can still have those symptoms. Absolutely. And again, I want to point out that the birth control pill may not work for everybody. So someone might say, well, I'm taking it, I still have symptoms. And yeah, I mean, not every medication works for everything. 

[00:31:50] Dr Sarah Berry: Interesting. And there's also certain diseases that I know we think about when we think about menstruation.

So one of these, again, I think that isn't talked about a lot is PCOS. So polycystic ovarian syndrome. But actually, it's really prevalent. It would be great if you could explain what it is, how prevalent it is and let us understand it a little bit better.

[00:32:10] Jen Gunter: Yeah. So polycystic ovarian syndrome affects about 10% of women. And that makes it the most common endocrine disorder among women of reproductive age. So there isn't another hormonal condition that affects, like 10% in medicine is a pretty staggering amount. 

And it's a very medically complex thing that we should suspect when people have irregular menstruation when they have irregular ovulation. And they have evidence of increased, male, what we classically call male hormones, androgens. So they may have increased acne, they have increased hair growth on their chin. They, in severe forms, they could even have some hair loss on their head. 

[00:32:57] Jonathan Wolf: What is this? What's going on? 

[00:32:59] Jen Gunter: Basically what is happening is, during the development of the follicles, so I mentioned, I alluded to this earlier, there's about a 300-day journey. 

So when you're born, you have all your follicles are dormant. They're completely asleep. And to get to the stage where they can accept the VIP ticket that we talked about, that's about a 300-day journey. And we don't, we understand very little about that. 

[00:33:24] Jonathan Wolf: There's like all this maturing that's going on that we don't even think of, this egg long before it starts the journey that I learned about in school or whatever where it sort of starts wandering down this tube. 

[00:33:32] Jen Gunter: Exactly. 

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[00:33:33] Jonathan Wolf: It's not just sitting there ready, which is sort of, I think, what I got tought.

[00:33:35] Jen Gunter: Yeah, I think people think it's like, they're asleep and then boom, they're ready for the VIP ticket. But just like going to any club, it takes you time to get ready, right? So it's a 300-day getting-ready journey. 

[00:33:45] Jonathan Wolf: I will not comment in this room on that.

[00:33:47] Dr Sarah Berry: Oh, I get ready in five minutes. I'm sure you do, Jenny, as well.

[00:33:51] Jen Gunter:  Well I think the older you get, the less time it takes to get ready. I don't think I'm going to study that though. 

So somewhere along in that development process, there is a glitch, but we don't really know, is that the trigger or is the trigger from something else?

So what we're seeing is that these follicles are not quite getting to the point where they should be able to accept ovulation, they're filling with fluid, there's hormonal imbalances in the production from the follicles.

Then we also have many people have insulin resistance as well associated with polycystic ovarian syndrome and that also contributes. And there's increased inflammation as well. 

And so it's sort of, we don't really know the chicken or the egg here. Is the disturbance of ovulation the cause or the result, right? Is the insulin resistance the cause or the result? Is the inflammation the cause or the result? Or are we actually looking at a couple of different conditions that we're lumping together because they present in the same way?

And so, in a nutshell, that's kind of polycystic ovarian syndrome and it's a really important thing to know about because not only does it cause irregular periods, which can obviously also affect fertility for people, but it is associated with an increased risk of metabolic syndrome and then also type 2 diabetes.

It's associated with an increased risk of endometrial cancer. It's associated with an increased risk of depression and suicide. And there's many other, you know, an increased incidence of fatty livers. So there's many other serious health…, increased risk of hypertension and cardiovascular disease.

So there's all these other serious health implications of polycystic ovarian syndrome. So you should really think of it as sort of like a system-wide condition, not just sort of an ovulation problem. 

[00:35:40] Dr Sarah Berry: Yeah, it's interesting. All of the factors it's associated with are very much linked with diet, you know, high blood pressure, insulin resistance, obesity, high cholesterol, et cetera, that's linked with this.

And so I guess it's a time that we have to be really, really mindful of the food that we're eating. 

[00:35:58] Jen Gunter: Obesity is not a cause of polycystic ovarian syndrome at all. What it is, is something that can make the symptoms much worse. And so, when we look at all populations, the incidence of PCOS is the same, whether someone is obese or not.

But people who are obese have worse symptoms. So when we look at study populations, they're overrepresented because who's more likely to come to a PCOS clinic, somebody who has worse symptoms? 

[00:36:26] Dr Sarah Berry: Okay, interesting. 

[00:36:27] Jen Gunter: So that's kind of has a bi-directional problem. So first of all, you know, if you tell people it's all related to your weight, then that's wrong. And their symptoms may be partially related to it, but that makes people, they feel dismissed. 

But then what happens is people who aren't obese are told they can't possibly have polycystic ovarian syndrome because they're not overweight. And so they then don't get the care that they need.

So the interaction with obesity is probably related in part to the worsening of insulin resistance. That's a component of PCOS. Worsening of the inflammation, that's part of PCOS. And so many symptoms can be improved with weight loss for some people. But it's also important for people to know that there are, there are other treatments as well.

And to understand that, many people it's very challenging, losing weight is challenging. Many people have been dismissed because of fatphobia in the doctor's office. So we have to be very, very mindful of that and, you know, offer therapies independent of that. 

[00:37:32] Jonathan Wolf: Jen, I'd love to move now for all of our listeners who've been listening to this, understanding it, switching now really to more actionable advice for them.

So, I guess maybe starting with PMS, where you described how many people, I think you said maybe 70 or 80% of women can be experiencing this, and we had a lot of questions, is there anything they can do about it? 

[00:37:58] Jen Gunter: Yeah, so first of all for many people, mood symptoms can improve with exercise.

Now, obviously, that's not the only thing we offer to people. And certainly, if I was feeling poorly, and my doctor just said, Oh, well, you just need to exercise more, I would probably like have felt like very put off. So I always like to say that that's not something that should just be offered as a standalone treatment.

But every almost every medical condition improves with exercise, and we've seen some really recent great data on the impact of exercise on mood from a beneficial standpoint. So that's one option to think about. 

Certainly, when people are really suffering with PMS, there are hormonal birth control pills that take away those hormonal fluctuations, and also antidepressants can be very effective when people are especially with the mood-based symptoms that are the worst.

And the interesting thing with the antidepressants is you can just take them for the period of time that you have your symptoms. And so that doesn't mean you have to take them the whole cycle. So if you just have bad symptoms for 10 days a month, you can take them for 10 days. 

[00:39:00] Jonathan Wolf: Okay, it's not one of these, because I think often I was under the impression this is something I have to take for like months and months before it starts to have an effect.

[00:39:07] Jen Gunter: No, not at all. So you can take them just, so, now that's not always easy for people to manage. Like it's not intuitive to say, oh, I'm going to take them for just 10 days every cycle and I've got to wait and then you think, Oh, is that my PMS? Or am I just feeling irritable because my boss was mean to me today? Like, you don't know, right? So it can be hard. 

So some people decide to take it every day because it's easier. Some people decide just to take it when they're ovulating, if they know. So then they're kind of covered the second half of the cycle. And other people decide to take it when they start when they have the start of their symptoms.

And so those are some, different strategies, depending again on the severity of symptoms. I also think it's great for people to have a, you know, a good, healthy foundational diet. But also not to beat themselves up if they feel that having chocolate for two or three days of the month makes the month much more bearable, then great. 

[00:40:03] Jonathan Wolf: Our data says that the dark chocolate is pretty good, so it's about switching the type of chocolate, potentially, rather than having to give up. 

[00:40:06] Jen Gunter: I know, I was thinking that should be like, you know, part of a government allotment that we all get our good quality chocolate every month. 

[00:40:14] Jonathan Wolf: I love that. We'll start campaigning on that. I think that's a brilliant worldwide campaign. 

[00:40:18] Jen Gunter: I think so.

[00:40:18] Dr Sarah Berry: And Jen, what about menstrual cramps? So you said some people have them as strong as if you're actually having birth contractions. What can we do to counterbalance that? 

[00:40:28] Jen Gunter: So ibuprofen, nonsteroidal anti-inflammatory drugs, naproxen, and even starting them a day before, like if you have an idea when your period is going to start, so they can be very effective at reducing menstrual cramps.

I think it's important to point out that if those don't work, it could be because you have something else going on like endometriosis. Which is a condition where tissue very similar to the lining of the uterus is growing outside in the pelvic cavity. 

But also I think it's about 10% of people that these drugs just don't work for them. So it's just, just kind of, they don't help.

Then all of the hormonal methods of birth control can be very effective. And so a hormonal IUD, the birth control pill, the Nexplanon implants, the Depo-Provera injection. Those are all very effective ways. 

And they work by one, the implant, the injection, and the pills work because they stop ovulation, but also there's a hormone in them called progestin, which is a synthetic form of progesterone. And progestin keeps the lining of the uterus very, very thin. So when there's less lining to come out, there tends to also be less cramping. 

And you can take these medications every single day, so you don't even get a period. So, that's also an advantage. 

[00:41:43] Dr Sarah Berry: Yeah, and it's interesting because the hot topics amongst many of my friends who are in their late 40s is either menopause or thinking about their children are having quite extreme symptoms, some of them. 

And something I know they would be desperate for me to ask you while you're talking about this is, is it safe from a young age, for someone who's 14, 15, 16 to go on to some of these contraceptive pills in order to alleviate these symptoms, these kind of cramps. 

[00:42:11] Jen Gunter: Yeah, so we do think it is safe. And I think that unfortunately, hormonal contraception gets a very bad rap on social media, because fear sells. 

And if you think about the risk to you, medically, of having untreated painful periods. So, people just think about, oh, well you're missing school. But we know that people who have very severe period pain are more likely to develop other pain conditions in their life. And that we think that early exposure to severe pain can prime the nervous system in a way to actually heighten the pain experience, meaning it makes you more likely to develop other pain conditions.

So could we be setting somebody up for more likely getting migraines later in life? Could we be setting them up for other medical conditions by under-treating their pain? Never mind if they have to miss two days of school a cycle, then that could affect their academic performance, which could affect getting into the university they want to go. It could affect their job performance could affect their career. 

So it's really important for people to think about this, not just as, well, it hurts, but which is important itself to treat, because people deserve to have their pain treated, but what are the ramifications of untreated pain, right?

So then you think about it from that standpoint, that the birth control pill, the IUD, the Nexplanon, they would all be a net positive. And so we think that they're very safe to be on. 

There is some conflicting data on the risk of depression related to starting hormonal contraception. And the data is very conflicting. And there are some studies that show that there could be an association for some people, and some studies that show that it isn't. If we say maybe it could be, if we err on that side of caution, then the incidence of depression associated with the pill for teenagers might be 1 in 200.

But that's not certain. It absolutely could be less than that. And I think one of the problems with the data is, so people start the birth control pill because of something. They don't just like, I'm totally fine and I don't have a new partner and I'm just going to go on the pill because. 

So teens can be in domestic violence situations, right? So starting the pill could, that could be part of that. They could be in a relationship that's having an impact. They could be starting the pill because they have PMS, which is associated with mood disturbances, and maybe they actually have depression and not PMS and it's been misdiagnosed, so they're not getting their depression treated.

Polycystic ovarian syndrome, which is a reason many people go on the pill, is associated with a higher risk of depression and suicide. 

So, it's very difficult to study, it's an active area of research, but I think that people always have to look at the reason you're going on and there is a massive impact of untreated pain.

And the idea then, so then what are we supposed to do? Like kids curl up in the corner and that's not a solution 

[00:45:14] Jonathan Wolf: Jen, we're running short on time, but I do want to pick up on this comment that you talked about earlier about the iron deficiency Because you described something like 40% of girls under 22, which sounds huge.

And I've also got Sarah as well, so both of you here. I really want to make sure we follow up what sounds like very actionable advice. What can you do about this? 

[00:45:35] Jen Gunter: Yeah, so if you are someone who menstruates and you have symptoms like fatigue, brain fog, hair loss, you just don't feel right and you get a period. So if you're somebody who hasn't had a period for five years because you've got on a hormonal IUD, then, you know, you could have iron deficiency for another reason. But most of the younger ones are related to menstrual. 

You need to not just get, a blood count to check for anemia. You need to also get a ferritin level because ferritin is a reflection of the iron stores in the body because you don't want to be brushed off. 

You can have a normal blood count and not have anemia and still have severe iron deficiency.  I diagnosed that maybe every single day in my practice because iron deficiency is associated with a lot of other symptoms. So I'm often testing people because of those other symptoms. And the number of women that I identify every week who have iron deficiency is pretty staggering, which fits with the data that we see. 

And so I think people need to get their ferritin level checked and if their ferritin level is low, they shouldn't accept that that's normal, that that's okay. It needs treatment. And if oral iron is not working, then there's intravenous iron, which is actually really very safe intravenous iron now.

And also the reason for the iron deficiency needs to be investigated. So someone needs to ask you about your periods and if you're soaking pads, if all these things, because there's treatment for heavy periods as well, and their investigations may need to happen too. 

[00:47:08] Dr Sarah Berry: You talked about oral supplements of iron and there's some fascinating research coming out now to show the benefits of if you are taking iron supplements of having them every other day.

There's a particular chemical that increases when you have an iron supplement that actually prevents you absorbing too much of the iron. Because again our body has really clever mechanisms to make sure we don't iron overload. And so actually if you can miss out a day means that you'll then have absorb it, you know, 48 hours later.

Yet if you're having it every day, this particular chemical that stops the absorption is at its peak and then blocks the absorption. 

[00:47:47] Jonathan Wolf: I'd like to try and do a quick summary, which we always do. It was quite complicated, so please correct me where I got any of this wrong. 

So we started talking about why do people menstruate at all? And I hadn't realized we're in this very small group of animals on this earth that do this. So something quite special. 

And you were explaining that we have this cycle that is really about preparing sort of the lining of our uterus in order to deal with this obviously particularly difficult human fetus compared to all the other fetuses that are out there.

And so we build this line, which I think called was a decidua. And once you do that, it's a one-way ticket. So you create this and having done it, it's like, well, if you aren't going to get pregnant, then our bodies kick off this system and says, we've got to get rid of it. It peels off.

And actually what's happening is the bleeding is when this peels off, which makes sense, like sort of ripping something off your skin. And so it's normal blood that's coming out. And there's this process that's sort of pushing this decidua and the blood out before we start the cycle again.

You then said, look, there's a lot of myths around this and things that you shouldn't accept. So if you're having heavy bleeding, that isn't normal. You should be going and seeing, your doctor. It can lead to iron deficiency, I think you said 40% of women under 22 are iron deficient in the U.S. Which is a huge number, no doubt partly affected by the diets they're all eating as well. 

You then went on and said lots of pain is also not something to just accept. And again, something you should go and speak to your doctor about because there are things that you can do. 

We then talked a bit about sort of the differences in the cycle, about how it affects how you're feeling and some of the symptoms you have and that particularly the second half of the cycle is what's associated with all of these experiences. So you can be hungrier, you know, that's true. You can have these food cravings, especially for sort of carbs and chocolate. 

Yes, stress can impact that. But you're describing like, it's not like the stress of doing an exam. It's got to be at a really high level of stress. 

Then we talked about PMS, premenstrual syndrome, and you said 70 to 80% of people who are menstruating experience this. So it's a huge number of people. Again, it's in the second cycle and the duration varies. 

What could you do about it? So you said, interestingly, you started with exercise. So that is real, it's not made up. Birth control pill can have a really big impact. And we had a conversation about whether it was safe, even for adolescents.

And I think Jen, you're saying, yes, I think it's safe. And actually in many cases, a good solution because these impacts are all very serious. An antidepressant can actually help while having symptoms and a healthy diet can also be having an impact. 

We sort of finished off talking about iron deficiency and what could you do. And, and I think Jen, you said like literally every day in clinic, you're diagnosing somebody with iron deficiency. This is not sort of a really rare occurrence. It sounds like there are a very large number of people who may be listening to this podcast with that. 

And in terms of supplementation, interestingly popping it every day is not as good as every other day. Which I think is very counter-intuitive. And then in some cases if it isn’t working you may actually have to go to having something intravenously. 

Did I manage to capture that ok?

[00:50:51] Jen Gunter: Yeah I think that's a really, a really great summary.

[00:50:53] Jonathan Wolf: Jen, thank you so much for coming in and taking us through this little summary of what came out of the book. And I know we'll have many follow-on questions, I hope we might be able to get you to come and join us again in the future. 

[00:51:05] Jen Gunter: Oh, I'd love to. I'd love to. This is great. Thank you so much for having me.

[00:51:07] Dr Sarah Berry: I have learned so much, so thank you.  

[00:51:12] Jonathan Wolf: It's a pleasure. Thank you very much. 

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