E94: The Physical Domain of Friendships

Kirtly: Welcome to the "7 Domains of Women's Health." Over the past many years of this podcast, we've talked about women's health from the medical lens, and the social lens, and the environmental lens. We've talked about healthy habits and healthy environments and healthy genes. And today, we're going to start the seven-part series on the aspect of being human and being women that may be the most important for our health: friends, good neighbors, meaningful relationships, and social groups.

I'm Dr. Kirtly Jones from Obstetrics and Gynecology at the University of Utah Health. I'm a reproductive endocrinologist. I'm an OB/GYN who specializes in women's hormones and family planning and infertility and menopause. And with me is my dear friend, Dr. Katie Ward, a friend for over 30 years. Katie's a specialist in women's health, a professor in the School of Nursing, and a PhD in anthropology.

Together, we are going to talk about friends, and we're going to start with the physical domain today, how good friendships help make life longer and more healthy and worth living.

So Katie, what do you do when a friend walks in the door or when you see a friend?

Katie: There's a saying about friends, that some come in for a reason, and some for a season, and some for a lifetime. And my life has seen a lot of changes. I've moved, so geographical changes, social mobility changes, career changes. So I've had a lot of seasonal friends, I think, but I noticed that I'm much more open to making friends when I'm in a new space and open to experiences. And I think it's maybe one of the reasons I enjoy travel so much.

So I just came back from a trip where I made a lot of new friends. How do I know they're a friend? There's just something about . . . you connect. I connect visually. There was a young man that was sitting alone in a restaurant. I smiled at him, he smiled back at me. We spent the next few days walking together. We didn't speak the same language, but we had had a lot of fun.

It was a connection across a room, but it was also being in a space where I was open to that greeting and getting to know somebody new.

I tend to diss on social media a bit, but making friends around the world and being able to maintain that little bit of connection to them, even if it's just that somebody likes my post or stays connected. So I do see why the social media works a little bit, because it does maintain a relationship that otherwise would be impossible with people I've met around the world.

Kirtly: Yeah. Well, for me, when a friend walks in the door or into my sight, I smile, and I feel warm inside. So that's how I know it's a friend. And that's goofy, perhaps, but I have an instant firing of the motor neurons that create a real smile all the way up to my eyes.

Fake smiles, unless one is practiced, make your mouth turn up, but they don't crinkle your eyes. A fake smile doesn't release a charge of beta-endorphins and dopamine and oxytocin bonding hormones. That's where the warmth in my chest comes from.

So I can't help but smile, and my eyes crinkle, and the part of my brain that says, "Friend. Yay, friend." I have this surge of hormones that make my heart feel warm. So that's how it goes.

Well, there are many studies that say if you eat this or you don't drink that or you do drink that, you will live longer. But it may depend on what you're doing when you're doing some of these things.

One of the most commonly quoted studies about men's health, of course, with a bunch of TED Talks about it, is the Harvard Study of Adult Development. Now, of course, it's all about guys, because when it started, there were only men at Harvard.

They followed 268 Harvard sophomores through their teens, starting in the late '30s, to see if there were clues that would tell us about a healthy and happy life. And they followed these guys to when they died, and then they followed their children, who are now in their 50s. Lo and behold, the biggest predictor of a healthy and happy life were their relationships.

The director of this study, Dr. Robert Waldinger, said in a TED talk, and I'm quoting here, "We gathered together everything we know about them at age 50. So it wasn't their middle-age cholesterol levels that predicted how they were going to grow old. It was satisfied with how satisfied they were with their relationships. The people who were the most satisfied in their relationships at age 50 were the healthiest at age 80."

And a recent publication from the first 25 years of the Northwestern University SuperAging Program revealed the same thing. They studied what they called superagers, people in their 80s that were healthy and had the cognitive firepower of people in their 50s. They didn't all follow the Mediterranean diet. Some smoked, some drank alcohol, some didn't, some exercised, some didn't, but almost all of them were social. They had good friends and good social relationships.

And of course, it's hard to know if the relationships keep them healthy or the people who are healthy have good relationships. But their neuroimaging studies were interesting, and I'm going to get to that in a bit.

So, Katie, maybe we can have pizza and beer as long as we do it with friends and a laugh. Maybe it's what you're doing when you drink alcohol and eat pizza.

Katie: It's not the blue zones.

Kirtly: No. We have the epidemiology studies following people over time and seeing what happens to them, but what do we know in the lab? Well, we can follow people into a functional MRI, which shows what parts of the brain is working. An MRI can be stressful, as you're in a dark, noisy tunnel. People who had a trusted friend hold their hand were much calmer and had lower cortisol or stress hormone levels and activated parts of their brain, the calming parts of their brain.

And people who have close friendships are 50% more likely to live longer, be more resilient in the face of loss and disease, and aren't lonely, which is an independent risk factor for depression and frailty and death.

Studies on positive social interactions show they increase natural killer cells, which fight off viruses and even some cancers. The beta-endorphins, part of that feeling warm in your chest, are the fast response to the presence of a good friend. And that strengthens your immune system and creates calm. Good friends lower your blood pressure, lower your stress hormones like cortisol, and that helps you maintain good glucose levels.

Katie: Yeah. I mean, we are definitely hyper-social. So many different ways that we communicate: with our voice, with our hearing. And the thing that we do where we have this shared intentionality where we are kind of thinking about what is in somebody else's mind, we can . . . Even if we are both imagining a thing, that we can do that together really separates us from any other animal, at least that we know of, in terms of how they communicate. So, yeah, we are hyper-social.

And it's an interesting feedback loop, right? We're social, and we're dependent on that social cooperation to be who we are. So we've evolved to be cooperative, and we need to be cooperative to survive.

We talked about this a lot in the last series on the fourth trimester, because in some ways it sort of starts with babies. Babies are the ones that get this communication going. And so if you haven't listened to that fourth trimester series, I'm going to just put a little plug in for it.

But yeah, being connected to each other defines our species, and you end up seeing it in our anatomy. So, for example, our eyes. We're the only great ape with white sclera, the white part of our eyes. So chimpanzees, bonobos, gorillas, they have dark sclera.

Michael Tomasello has done these experiments with a variety of primates and with humans, adults and babies, and figured out how you know where to look. So apes rely on which way the whole head is turned to figure out where to look. So you can get them to show you there's something over there interesting to look at, but the whole head has to turn. With humans, the head doesn't have to turn. You can just shift the eyes, and the baby or the other human will look where those eyes are pointing. And so it might be that the white part of the eyes is part of what's making that possible.

Now, whether or not that's why eye whites evolved is a little bit more controversial. But it's clear that the shape of our eyes, the anatomy of our body, is really helpful in creating that shared attention and coordination with others, which is pretty cool.

So, yeah, we're wired for this thing that social scientists call social synchronization. And this is this unconscious alignment of physiological, neural, and behavioral patterns between individuals. So sort of what you were talking about, about calming somebody down, it's that shared neural communication.

I think social synchronization is super interesting. So when friends or even strangers walk together . . . And again, I just came back from this really long walk, but I was thinking about this from a book I read previously. People's footsteps will unconsciously sync up, even though you might have two people who have completely different leg lengths and different natural gaits.

And so this was something I was kind of thinking about in anticipation of this podcast and paying attention to as I was walking with people. Just automatically, our steps would sync up. So people would walk at the same pace even though it wasn't quite . . . Maybe I was walking a little bit faster and my new friend was walking a little bit slower. But I think that's really interesting that we just automatically start to mirror each other.

And it's not just walking. We do it with posture and gestures, and it goes deeper. Especially when friends are interacting, their brain waves will align, and heart rates and breathing patterns will as well.

Kirtly: Oh, I didn't know. That's new for me. I didn't know that. But that's going to get back to how do we synchronize? We have to have our whole brain firing so that we can use our whole brain to do this kind of connection.

Katie: Yeah. But then we certainly do a lot of other interesting things. I have a picture of myself with my best friends in junior high and high school, and we all have the same Farrah Fawcett haircut. I think wanting to be like our friends explains a lot about how fashion trends sweep through our populations and why behaviors cluster in social networks or ideas spread.

There was a paper a while back. It's a little controversial, but there was a paper that looked at weight gain, and it sort of said if your mutual best friend gains weight, so will you.

Kirtly: Oh, this is repeated in Europe as well. One of the biggest predictors of whether you're overweight is whether you're in a social group where people are overweight.

Katie: Yeah. So I think there are so many ways that our friendships have an impact on our health, for better and sometimes for worse.

Happiness is another thing. The Framingham Heart Study looks at how far away your happy friends are, and it turns out the closer they are to you, the happier you are. So having a happy next-door neighbor is . . .

Kirtly: I was so sad when you were in Scotland. I knew you were far away.

Katie: Aw. This is one physical topic about friendship that I really wanted to talk about. This is this persistent myth that just won't go away, and I thought, "Well, this is an opportunity to talk about something." It's one of those things you just really want to be true, but it turns out it's not. And that is menstrual synchrony.

Kirtly: Well, if you walk in synchrony, and if you wave your hands in synchrony, and if you smile in synchrony, why can't you synchronize your period? Seems natural to me. I want it to be so.

Katie: As a provider in GYN spaces, I hear this a lot from patients. So I'll have patients come in, a menopausal woman, and she's like, "Oh, my daughter came home, and I had stopped having periods, and she came home, and she forced a period." And I'm like, "Oh, no, we need to work that up." She just understood it as the daughter caused a period.

So I hear this a lot, and I think it just reflects how much we want our bodies to reflect those social bonds.

The reason we have this myth is it traces back to the '70s when an anthropologist named Martha McClintock did a study in 135 college women. And the study actually gets named after the college where she did it, the Wellesley Effect, if you want to look it up. And she documented this idea that the people who spent the most time together synchronized their menstrual cycles over an academic year.

She had this hypothesis that there were pheromones, these chemical signals, that would be responsible for this. And it captured the public imagination, and it hasn't gone away, even though we have decades of follow-up research that have tried to replicate this or even that just looked at the math that she did and completely debunked it. It just doesn't hold up.

So when you control for all the other things, you can't replicate the study. People have done much bigger studies, and they've used much more sophisticated kind of tracking data, and it doesn't happen.

The truth is what happens is if you have a period that lasts three to seven days, and people have different cycle lengths, and everybody has a little bit of variability, there are going to be times when people's cycles overlap. And of course, there are going to be some people that have a 28-day cycle that just happen to be on the same rhythm.

If you're looking for that everybody syncs up, that doesn't happen, but you will find that some people overlap. And so I think mostly what happens is people notice when their periods align and forget the times that they're not in sync.

And there is something really appealing about the idea that female friendship is so profound that we're going to sync up our menstrual cycles. But if that were the case, we'd all menstruate together, and we just don't. Somebody's on their period every single day.

Kirtly: Well, sheep do that. Now, sheep only ovulate maybe once a year, and there are probably weather cues and lengths of the day.

Katie: Daylight of days, yeah.

Kirtly: But if you have a herd of sheep, they're all going to ovulate about the same time. You've got to get your ram that's really ready and able to impregnate all of them. And if you ever watch some great TV shows about sheep, you could . . . But anyway, we're not talking about sheep, we're talking about humans.

Katie: I mean, there are these fascinating kinds of synchrony that we've talked about from how you cut your hair and what you wear to actually matching up your steps. I think from an evolutionary perspective, matching our steps was important for being able to walk in a group and hunt together and avoid detection. And that does make sense that we can do that.

The neural communication that you were talking about, it's what helps us cooperate and communicate and bond.

But menstrual synchronization probably just doesn't actually serve us that well at all. But the fact that that myth persists, I think, really talks about how profound our desire for that connection is. And so the fact that we want that to be true, I think, is still really an interesting thing.

So it's a health thing. If you think your daughter has caused a period you're not expecting, please call and see your healthcare provider if you're menopausal.

So, yeah, it's a fascinating phenomenon about what makes us human, but we really do connect with others of our species.

Kirtly: We do.

Katie: Yeah. I think it happens just automatically. It's part of just being in sync with somebody else.

Kirtly: Well, it doesn't happen exactly automatically, but I mean, we're literally wired that way.

So, Katie, you're talking how we connect and we just do this. Well, we don't just do this. It's actually neuronal work and . . .

Katie: Right. It feels like we just do it.

Kirtly: Yeah, it feels like it just happens, but believe me, your brain is working.

Anyway, these superagers had a lot of imaging studies, and as expected, they had bigger brains, more brain tissue than normal 80-year-olds, and certainly more than people with dementia. But they also had brain studies done after they died, and what was a surprise and new science for me was that these superagers had more Von Economo neurons, VENs.

And VENs, named after Professor Von Economo, are interesting neurons. They're big neurons in special parts of the brain that are particularly important in the fast connections with other parts of the brain. They are especially important in processing social interactions.

These neurons are not found in all mammals, but they're found in great apes and some whales and elephants. They seem to be important in species that have social connections in large groups. Of course, orangutans have them, and they aren't particularly social, but maybe it's just an evolutionary hangover from being related to the great apes.

Now, these neurons are first seen in the brain in late fetal life, about 35 weeks gestation. They multiply in the first eight months after birth, with their peak number at about 8 months. Then they decline a little as a lot of pruning is done in the first couple of years of life, and they reach their adult levels at about 4 years of age in humans.

Now, clearly, these aren't big studies, because they have to have . . . These are brain studies after maybe a baby has died. But we have these studies in humans, and they seem to correlate with the size of the brain and the social structure of the species. In people with frontotemporal dementia, they lose their ability for social connections and empathy, and they lose their VENs.

And the work on the role of VENs continues. But the part of the brain where these neurons are found seems to be important in empathy and social touch, like hugs, and maybe part of the connections required to be social, to cry when someone is crying, to walk in step, to make your hands move, to smile, all of these things that are so automatic for us.

Humans have a lot of these VENs, but cetaceans, whales and dolphins, have about three times as many. I really like videos of watching dolphins in social groups. They kind of rub up against each other. Not always close members of the family, but they just like touching each other. Anyway, whales and dolphins have three times as many. Of course, they're big and they have big brains.

Superagers have a lot of these VENs. What we don't know is if these neurons stay healthy with use, meaning more social interactions keep them busy, or that if you have more VENs, you're more happy being social. So it's hard to know which comes first, the chicken or the egg. But the consequences of having these VENs and being social is having a happier, more satisfied, and longer life.

Well, we've talked about women's health over these podcasts, and we've noted that health is a function of good genes and good environment and good habits and good luck. Now we'll add what might be the most important factor, and that's good friends and neighbors and community.

So check in with the upcoming episodes of the 7 Domains of Friendships. We'll be talking about friends with our brothers in the men's health podcast, "Who Cares About Men's Health." And we'll talk about men's and women's best friend, of course.

You can find our podcasts on the "7 Domains of Women's Health" at womens7.com, or wherever you get your podcasts.

And thank you, Katie. You warm my heart.

Katie: Aw, thank you.