The Tribe with the World’s Cleanest Arteries with Michael Gurven

Summary

The Dan Buettner Podcast
Episode: The Tribe with the World’s Cleanest Arteries with Michael Gurven
Date: March 26, 2026

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Overview

In this episode, Dan Buettner welcomes Dr. Michael Gurven, evolutionary anthropologist and author of Seven Decades: What Human History Teaches About Living Longer, to explore the health, longevity, and lifestyle of the Tsimane—a remote Amazonian tribe found to have the cleanest arteries and lowest rates of cardiovascular disease ever studied. Together, they discuss lessons from their fieldwork, the role of social bonds, physical activity, diet, and how these can inform modern life and longevity.

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Key Discussion Points & Insights

1. Who Are the Tsimane?

• Background: The Tsimane are a group of ~13,000 indigenous people in the Bolivian Amazon, living with minimal modern amenities, subsisting through a mix of hunting, gathering, and small-scale farming.
• Village Life:
  • Houses built from local materials (palm thatch, bamboo), open kitchen spaces, villages averaging about 150 people—remarkably close to the so-called Dunbar number for stable social relationships.

    “The average size of a village was about 148.” – Gurven [18:14]

  • No running water, little to no electricity, community-centered daily lives.
• Social Structure:
  • Deeply interdependent familial and neighborly relationships; sharing food is a survival necessity.
  • Constant social interaction; introversion or withdrawal is perceived as a sign of distress.

    “If you were to act like that, people would just assume you're depressed.” – Gurven [15:15]

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2. Health and Clean Arteries: The Core Findings

• Groundbreaking Discovery:
  • The Tsimane exhibit virtually no coronary artery calcification—9 out of 10 adults over 40 have zero signs of atherosclerosis.

    “Almost 9 out of 10 older adults…basically had nothing, no calcification whatsoever in their coronary arteries.” – Gurven [03:33]

• Contradicting Inflammation Dogma:
  • Unlike in the West, where high inflammation predicts heart disease, Tsimane show high inflammation but without cardiovascular consequences—likely due to balanced anti-inflammatory immune responses and lifestyle factors.

    “Inflammation doesn’t automatically lead to awful things if other aspects of the lifestyle are preserved.” – Gurven [05:23]

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3. Diet: What Do the Tsimane Eat?

• Core Foods:
  • Diet is two-thirds carbohydrates (plantains, manioc/cassava, various roots), and one-third from forest game and river fish.
  • Wild meats: paca (rodent), howler and capuchin monkeys, peccary (wild pig), as well as fish like catfish and piranha.
  • The diet is lower in fat and saturated fat than the American diet, higher in fiber, but not as diverse in vegetables or leafy greens.

    “About two thirds of the calories are basically coming from carbohydrates…They eat more protein than we do, but about half the fat.” – Gurven [24:38]

• Quantity vs. Quality:
  • Tsimane eat roughly the same total calories as Americans, but are more physically active so they don't gain weight.
  • Meat is consumed only a few times a week, less than the average American but generally wild and lean.

    “Even though you're saying a lot relative to, you know, bacon for breakfast, a burger for lunch, and a pork chop for dinner, it might not be as much as somebody living in the Midwest.” – Buettner [26:38]

• Processed Foods:
  • Strictly absent—no sodas, candy, or ultra-processed items in the traditional Tsimane diet.

    “Avoid processed foods, right? Because there’s no processed foods, no soda.” – Gurven [29:20]

• Fiber and Microbiome:
  • High fiber intake (~50g per day) leads to more diverse gut microbiomes, which may improve immunity and mood.

    “Their gut microbiomes are more diverse than yours and mine.” – Gurven [44:09]

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4. Physical Activity Patterns

• Day-to-Day Movement:
  • Physical activity is built into survival: walking to fetch water, field work, foraging, chopping wood, hunting.
  • Most activity is low to moderate intensity—16,000-18,000 steps/day—not “Olympic-level” exertion.

    “Much of their daily activity is fairly light to moderate. They’re just doing a decent amount of it.” – Gurven [39:06]

• Lessons for Modern Society:
  • Key is consistent movement, not grueling exercise programs.

    “A lot of the physical activity...is not really the equivalent of running a half marathon every day.” – Gurven [01:13] “Increasing our physical activity in ways where it doesn’t seem like exercise is really what’s needed in order to get us to move more.” – Gurven [41:09]

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5. Social Structure, Sharing, and Purpose

• Food Sharing & Community:
  • Sharing food is insurance against bad luck or illness; those who share more are cared for when sick or injured.

    “The people who are more generous than average…were much more likely to be cared for when they got sick or injured.” – Gurven [33:22]

  • Reciprocity is managed carefully; not too little and not too much sharing (“optimal generosity”).
  • Happiness and security derive from knowing your group will support you in need.

    “Having a core tribe of people that you can count on, five to six, would be quite nice…” – Gurven [34:13]

• Intergenerational Roles:
  • Elders teach skills, mediate disputes, contribute to rituals and care for grandchildren.
  • Purpose and usefulness keep people engaged, give meaning, and are associated with happiness and longevity.

    “Always being needed and useful…that’s what people get purpose and meaning out of their life.” – Gurven [73:38]

• Mental Health Insights:
  • In modern societies, happiness often increases with age after midlife, while in Tsimane and other hunter-gatherers it declines, possibly because older adults become dependent and less physically able.

    “People who are in the position where they're giving away more than they're receiving, they're happy. The ones who are dependent on others, not happy.” – Gurven [72:33]

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6. Lessons on Aging and Longevity

• Seven Decades Hypothesis:
  • The human body is "built" by evolution for about seven decades—long enough to raise not only children but also to assist grandchildren, justifying the survival of elders.

    “Our body was built to last about that long [seven decades] … there’s only certain number of ways you can increase your reproductive fitness…you can invest in existing kids and as a way of improving your biological fitness.” – Gurven [51:37, 55:27]

• Role of Elders:
  • Elders’ knowledge, mediation, and contributions are crucial—yet, once dependency exceeds contribution, harsh decisions may arise (neglect, or rarely, assisted death in extreme contexts).

    “In the literature it’s called death hastening behaviors…from mild neglect…to sometimes just outright geronticide.” – Gurven [66:48]

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Notable Quotes & Memorable Moments

• On Social Connectedness:

  “I’ve often distilled much of Blue Zone wisdom down to the balance between your own self interest and interest of your community. It’s balancing those two.” – Buettner [10:35]

• On Food Sharing:

  “Everything I got, he’d get the fries he'd given away to want to go. And…that mentality of just like, when you have food and you see others who are hungry, you're going to feed them.” – Gurven [31:46]

• On Fiber and Gut Microbiome:

  “Our good gut bacteria eats one and one thing only. Not protein, not fat. Fiber. Fiber is what fuels our microbiome.” – Buettner [45:23]

• On Physical Activity:

  “No Tsimane is getting knee replacement surgery. When I talk to the Tsimane about exercise, they just laugh. Like, why would you move your body when you don’t have to?” – Gurven [40:02]

• On Usefulness in Aging:

  “The source of happiness is being useful. Yeah, it’s giving and thereby often receiving. But being a giving person is good for your health and your longevity.” – Buettner [74:18]

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Important Timestamps

• [03:33] — Discovery of virtually no heart disease in Tsimane
• [18:04] — Tsimane village sizes align with Dunbar number (~148 people)
• [24:38] — Breakdown of diet: high carbohydrate, moderate protein, low fat
• [29:20] — Central lesson for children: avoid processed foods
• [39:06] — Physical activity: 16,000–18,000 steps/day, mostly low-intensity
• [44:09] — Gut microbiome: more diverse due to higher fiber intake
• [55:23] — Evolutionary perspective: why humans tend to live ~seven decades
• [73:38] — The happiness-purpose connection: always being useful

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Takeaway Lessons for Modern Life

• Diet: Favor whole, minimally processed plant foods, moderate (wild or lean) animal protein, and maximize fiber.
• Movement: Build light-to-moderate physical activity into daily routines; consistent movement trumps high-intensity workouts.
• Community: Strengthen small, tight-knit social networks; share, support, and build reciprocity.
• Purpose: Stay useful and engaged at any age—through work, mentoring, or community roles.
• Environment: Engineer routine discomfort (walking, manual chores) to counteract a sedentary, convenience-oriented modern world.

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Final Thought:
The recipe for longevity and wellbeing is found less in rare supplements or biohacks and more in the foundational ways of living: moving often, eating simply, living socially, and staying useful. The practices that produce clean arteries in the Amazon can inform fulfilling, long lives everywhere.

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Guest: Dr. Michael Gurven, author of Seven Decades: What Human History Teaches About Living Longer

Host: Dan Buettner
Episode link: Lemonada Media

Transcript

[A]

I've spent decades studying the world's longest of people and written several New York Times best selling cookbooks about how they eat. But here's the truth. Even I don't always have time to cook from scratch. That's the gap Blue Zone Kitchen meals fill. We now have served over 3 million of these meals built on the same principles. Whole foods, nothing processed, maniacally delicious. When you have the time, cook from scratch by all means. But when you got only five minutes, grab a Blue Zones kitchen meal from the freezer aisle or go to bluezoneskitchen.com Same principles, real life conveniences. That's how to set up your life for longevity. See you when you're a hundred. Paint a picture for us and how a typical day unfolds.

[B]

Well, the green kind of hell, right, was how outsiders used to view the jungle. And you do get this sense that if you were just to stand and wait, you would be eating a lot, right? We need to rethink what aging looks like. People are more scared of aging than they are of death.

[A]

Let's talk for a minute about physical activity.

[B]

It's not really the equivalent of running a half marathon every day. So if you kind of think, oh yeah, the Tsimane have healthy hearts, but they're doing things I can never do, that's not like that at all. In fact, much of their daily activity

[A]

is at its core. Blue Zones involves distilling the the wisdom of the world's longest lived people and providing actionable insights for you. My next guest, Dr. Michael Girvin has done something very similar. He's found a remote Amazonian tribe that have the world's lowest rate of cardiovascular disease. So like me, instead of looking for answers in test tubes or petri dishes, Michael has found real answers by looking at populations who've achieved the outcomes of we want. We actually met each other in Santa Barbara. Here we're living in the same city and you're about the only other person in the world I know of who is studying evolutionary anthropology and distilling lessons and, and we became friends. It's just a delight to have you.

[B]

Thank you so much, Dan. Yeah, I was amazed as well. I didn't realize that you were a local neighbor and was quite familiar with the blue zones and so yeah, happy that we got to connect and stay in touch over the years.

[A]

Your new book is Seven Decades. Great book. But what if you had to articulate the key findings?

[B]

Well, one of them is just that, you know, under probably non industrial conditions, you know, groups like The Tsimane or the Hadza, who are hunter gatherers or small scale farmers, don't have heart disease. And you can say, well, didn't we kind of know that already? Well, we knew that, you know, okay, blood pressure might be low. There were studies back in the 50s where you get a blood sample and looks like people's blood cholesterol is low. So there were suspicions that that might have been the case. But you never know. It could be that if you get heart disease, you don't live very long with it. And so when you have these short medical trips, maybe you're not going to see it. And so from us, from just being in the same place for at least a decade before we started some of this deeper studies into the heart, we knew that people weren't just dropping dead of heart attacks. And we will be able to go beyond just these risk factors and actually look directly into the heart through CT imaging to see in the arteries, especially the coronary arteries, is there calcification, is there a hardening, is there plaque? And what we found was that almost 9 out of 10 older adults, so this is not just all ages, but of like people 40 and older, 9 out of 10 basically had nothing, no calcification whatsoever in their coronary arteries. And in, you know, in the US and everywhere it's been studied, more coronary calcification basically means more of the soft, vulnerable plaques, which means higher risk of a heart attack or a stroke, that kind of thing. So this was sort of like, wow, this is also in the language that the cardiology world was like, okay, you're not just thinking there's no heart disease. That's like proof in the pudding that there really doesn't look like there's heart disease going on in spite of the fact that there's high inflammation. So it was a kind of the contradictory thing that not only was there just no heart disease, but the Tsimane have some risk factors, right? They're physically active yet, but they have inflammation. So again, inflammation doesn't automatically lead to awful things if other aspects of the lifestyle are well preserved. And the other kind of take home I think about that we learned was plenty of us won't get heart disease. In every population, there's healthy people, they might have the right set of genes, they're lucky. But this was at a whole population level, basically, which was just wildly, wow, that's great news, right? That means that there's hope that this can be heart disease, can be avoided through lifestyle changes. And then of course, it's the open task of, well, we're not hunters and gatherers. We can't just mimic. Exactly. But what can we lessons can we learn about the different aspects of lifestyle, the diet, the movement patterns and most importantly, I think which doesn't get emphasized enough, the social environment. Right. The communities that we're making, the meaning that we get in our lives. How do we grasp all that in ways that we can live healthier lives and have healthier hearts?

[A]

So what got you interested originally in a small Bolivian tribe? Well, I guess it's not small, 12 or 13,000 people. Were you down there looking for secrets and longevity or were you looking for something else?

[B]

What I was originally interested in was how is it in the absence of supermarkets and health insurance and life insurance, people get hurt, people get injured, people get sick. What do they do? If all of a sudden you don't have a fridge to open up and eat the food that you stored up, you can't go to the nearby market and so if you can't go out to work that day, you don't eat. So how is it that people get by and if you spend all this effort getting food and then you give a lot of it away, well, what happens in the future when maybe you're unsuccessful and others are successful?

[A]

Was this a general question or you'd already found these people, these Tsumani people, and these were people who spend their day working, gathering food and giving it all away.

[B]

I had actually been studying in Paraguay with a different group and These folks, the Ache, were full time hunter gatherers up until the 1970s. And so by the time I started working with them in the 90s, they were, they were living in these sort of semi permanent settlements and they were starting to farm, but they would still go out in the bush and just hunt and gather for weeks on end. And what would be, just curious, what

[A]

would be a breakfast of these people, these Ache people? What would they. Yeah, well, a smoothie or.

[B]

Unfortunately, no. So a lot of times it's a bit of leftovers from the night before. And the ache about almost 80% of their diet is meat. So wild game from the forest, that's a variety of monkeys, these wild rodents, pakas.

[A]

Well, the monkey and rodent diet, I can see that'll be the new carnival.

[B]

Very popular. Well, including the, you know, the little slugs that, you know, you get out of trees or like your mid afternoon snacks and some fruits. But some of the fruits are like oily palm fruits, you know, not necessarily always sweet fruits, but yeah, meat is A big is a big part of the, the ache diet. And actually turns out in tropical rainforests it's not meat isn't so hard to get sometimes it's actually carbohydrates. So when I was in the aceh, I would just like daydream fever dreams about like sweet potatoes or, or just anything carbohydrate, but even in, in that kind of world. So I didn't even know that I was sort of implicitly thinking about aging and health. But it dawned on me because I think I got the sickest I've ever gotten with the ache. When we were on a trek. I had both, in the end later diagnosed giardia and amoebic dysentery at the same time.

[A]

Wow. Had them both separately and both of them were a nightmare.

[B]

I don't even know how I could barely even stand, much less the ache. Move camp almost every night, almost every day. And I don't to this day recall exactly how I got from camp from one day to the next, but somehow I did, you know, with the tribe, with the group. And you know, I probably wouldn't be here speaking to you today if it weren't for the kind of neighborly grace and help and altruism, you know, of the ache and the thing. This wasn't because I was a special visitor, special guest. I mean, I saw this day in, day out with other people who were injured, other people who, they might have actually put a machete between their toes, right. They missed and so they couldn't walk for a few days. And you know, they're, they're being cared for. And like dawned on me, right, that part of the secret of health and longevity is, well, sociality, but in so many different ways. You know, the ways we can talk about social connections and community and what that means for us. But the reason why that is so meaningful for us. We wouldn't even make it to adolescence if it weren't for our social community taking care of each other during these periods of need, let alone just the day to day food quests. You know, sometimes you're successful, sometimes you're not. And if you pull your food at the end of the day, you can really, really increase the chances that you're gonna be having something to eat that day.

[A]

I've often distilled much of Blue Zone wisdom down to the balance between your own self interest and interest of your community. It's balancing those two. People are completely selfish. They don't do so well, and people give everything away. That also becomes a problem if it's taken to an extreme. But it wasn't the ache that had the clean arteries. Right. I mean, it was, wasn't it, the tsunami?

[B]

Yeah. So. Well, here's the thing about that. The Tsimani just happened to be who I was working with at the time, and the opportunity to work with a hospital where they had access to technology like a CT scanner, so we could actually logistically maneuver, bring people from their villages to this town where there's a CT scanner and. And look directly in their coronary arteries to see is there calcification. So it was a very direct measure of heart disease. Now, if we did that with the ache, or if we did that with the Hadza in Tanzania or other, any

[A]

number of groups, hunter gatherer, almost.

[B]

Yeah. I almost guarantee we probably would have seen the same thing.

[A]

Okay.

[B]

And so it's just that the Tsimane are the only group like this that we've ever studied.

[A]

Let's back up a second, because I want you to paint a picture. Very few of my listeners probably have a good idea of what these Chani people look like, what do their villages look like. Paint a picture for us and how a typical day unfolds.

[B]

You know, in the old days, the Infierno Verde, like, was the green fire. Yeah, well, the green kind of hell. Right. Was the. How outsiders used to view the jungle. Right. And so it is a daunting place, right? It's green, it's thick, it's humid. And you do get the sense that if you were just to stand and wait, you would be eaten a lot, right? Like the biting flies, the snakes, the fuzzy caterpillars, the bullet ants, you know? Yeah. It can be a dangerous place. But with knowledge, right, you shape a home out of this forest. You know, you clear out parts of the forest and you have a clearing. You build houses out of the trees, out of the, The. The palm thatch, you can make roofs. And so people build comfortable little communities.

[A]

And we're talking like, simple thatch roof.

[B]

Yeah, so simple, you know, like bamboo kind of walls and then palm thatch for the roofs. And sometimes it varies. The walls can be a little bit open or one open wall. Certainly for the kitchens, you don't want to be closed in. And so those are open air. And so you imagine a couple, you know, little small thatch huts, you know, surrounding an open kitchen area. You've got several families, like, forming a larger extended family homestead kind of in one little area, and a big clearing area so kids can play and hang out and then you've got, you're surrounded basically by your garden, right? You've got gardens, you've got fields. And then just imagine that all over the Amazon. So these little like dispersed hamlets where people live.

[A]

Do people have electricity and flush toilets here?

[B]

So only now is that starting to erode. Arrive in some of the villages closer to town. But most villages still do not have electricity. They have no running water. So the water is coming from the rivers and lagoons. There's no public sanitation, no one comes to pick up your trash. And yeah, no modern amenities like that.

[A]

I think most people listening to this right now who probably live in an air conditioned home or heated home, depending on where, and can toddle over to their refrigerator for yogurt or a smoothie and drive places and go to Costco for their food. Probably saying this sounds like misery, but

[B]

is it misery for us? And for me initially it was a little bit of misery, right? Cause I'm not used to it. And what I wasn't used to was a couple things. There's the physical hardships of the humid tropics, constant rain, various parts of the year. And. And if your clothes get wet and you only have like one outfit or two outfits, sometimes it's hard for anything to get dry. And so fungus, you know, that kind of thing becomes a reality. But it's also the social adjustments. You know, we're kind of used to sometimes having downtime and tuning out and having some quiet meditation time and things like that.

[A]

Putting our noise cancellating headphones on.

[B]

Yeah, exactly. Like even though like in an airplane, right, you're completely surrounded by other people, but you wouldn't know it because you're tuned out and you get irritated. Maybe if someone talks to you and sitting next to you. And it's not like that. I mean, basically, if you were to act like that, people would just assume you're depressed. And so it's almost constant where you're on. And so it's sort of the flip side of being so.

[A]

So people are coming over to your hut and talking to you. And it's social.

[B]

Yeah, it's social. And people can talk throughout the evening, throughout the night. You got a campfire and so it's fun, you know. You know, but what I was used to, right, was like sort of I had control over that. Like, okay, now I'm going camping for a few nights and then I'm coming back. But this is every day, right, the same thing. And yeah, that's an actual like, skill, not just like the ability to kind of socialize well with others. But it's like building up a muscle and an endurance. And people never run out of things to talk about. Right. There's no tv, but the stories, you know, imagine there's no, there's no Internet, there's no TV series to watch. Like, it's, it's just people's lives and experiences that you can talk about.

[A]

That's so amazing because I think people are losing the ability to tell stories. And we've had other guests on this podcast whose expertise is Vanessa Ben Edwards, whose expertise is teaching middle aged people how to connect and make friends with people. That's a skill we've lost and we need experts to help teach us. And you're saying this comes along with mother's milk, that they grow up knowing how to be social, knowing how to connect, know how to tell stories.

[B]

But they're surrounded by people they know. Family, friends, neighbors. And people are, because families are pretty large. People are connected to each other in myriad ways. Ways that will be really difficult to remember, like my second cousin once removed and that kind of thing. But Shimani aren't just showing up in a, in a random town and then starting to talk to people. That would be seen as weird. But we're kind of, when we think about socializing, it's like, oh, I'm in a supermarket line and I don't know anyone, but I should just. Some people just magically spark up a conversation and then they leave with a new good friend. That's almost like an additional level of kind of social muscles that we've sort of developed in our modern society.

[A]

You've heard of this Dunbar number where supposedly we can hold about 150 people in our immediate social network or people we care about to some degree. Did you find with the Tsumani when you were living with these villages that there were about 150 people around or what were the numbers like?

[B]

Actually it's funny because out of like the, you know, like 98 villages we have census, like the average size of a village was about 148. Oh my God.

[A]

So there's something to it.

[B]

Maybe. But you know, I do think people's knowledge, well exceeds that. Right. And you know, and there's different layers of intensity. Right. You can't be of social connected.

[A]

Yeah.

[B]

Like you can't have 100 inner. Inner core. Right. But you know, people that. Yeah. Even though we could live in a

[A]

Christmas card too, kind of.

[B]

And, and Right. You know, we live in cities of millions, but we're probably sometimes even interacting on a daily basis with fewer people than the Tsimane are, even though they live in these tiny little communities of 100 people. Yeah,

[A]

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[A]

Okay, let's get to food for a sec. So again, these are the people with the lowest rate of Cardiovascular disease and the cleanest arteries of any people on the planet. So what are they eating on a typical day?

[B]

Yeah, so now I started by telling you a little bit about what the ache were eating. And some of those same animals, you know, in the Neotropics, you know, exist in Chile. So, you know, the general rule of thumb is that people might spend two thirds of their time hunting and gathering.

[A]

Is that right? I wondered that.

[B]

But two thirds of their calories are coming from their fields, right? Because farming is just pretty darn effective way of getting calories. And it's more predictable than, you know, the food quest, you know, in the forest. But, you know, you could be surrounded by plantains and people will tell you to your face that they're hungry and there's no food. You're like, what is all that right behind you? Like, and they mean no, there's no fish, there's no meat. So meat and fish are a big solid part of the diet. And, but the meat is, you know, from the forest, right. These aren't factory farmed animals. And depending on this on the season, they could be a little bit lean.

[A]

But what are the main meat sources?

[B]

Right, so some of the same paca, you know, that kind of large rodent, you know, howler monkeys, you know, even capuchin monkeys, peccary. So we have them, you know, in our American Southwest, kind of like those wild boars.

[A]

And you've eaten all these foods?

[B]

Oh, yeah.

[A]

What is it? What, what is, what is howler monkey tastes like?

[B]

Howler monkey is not my favorite. It's, it's, it's a bit tough, the meat and it is, you know, I

[A]

don't taste a little bit too much like your neighbor.

[B]

Well, that's the thing. I, you know, primates, you know, I, I don't.

[A]

It's a little too close to home.

[B]

Yeah, it's a little bit, it's a little bit too close. But also there's a wide range of fish from, from the rivers, various types of catfish and piranha. There are some piranhas that, yes, I've had some unpleasant experiences with in the past.

[A]

Wait, wait, don't just gloss over that. What, what you did. Were you, you, was it you eating the piranhas or the piranhas eating you?

[B]

It was the latter. I was bathing in the river and, and it was one of the few times where I was like, you know, I'm just gonna go naked. I was like, yeah, famous last words, right? And yeah, the worst thing you can imagine did happen. But it's okay. I have kids. So the equipment still works.

[A]

Yeah. So they didn't finish their meal.

[B]

That's right. You know, the last thing you'd want to die in the middle of the Amazon from a piranha bite. Yeah. So a variety of fish, plantains. Right. Are like a big staple and made in so many different ways from, you know, super sweet, you know, rich, you know, bright yellow to green plantains.

[A]

Yeah. Which tastes kind of like potatoes when you cook.

[B]

Exactly. Yeah.

[A]

What percentage is. There's sort of this animal protein. And what percentage is the carbohydrates?

[B]

Yeah. So about two thirds of the calories are basically coming from. From carbohydrates. Protein. You know, they eat more protein than we do, but about half the fat that. That we do. And much less of the saturated fat.

[A]

And you know this by doing dietary surveys or.

[B]

Yeah, so we've done dietary surveys. Now, dietary surveys are a little bit tricky to do. Right. Usually kind of these 24 hour recalls. Yeah. Tell me everything you ate. So we have a decent sense of what people are eating. And. And we even just total calories wise, the Chimane are eating almost the same amount of. Total number of calories, we think, as we are, of course, they're much more physically active. And so, you know, they're not gaining the same kind of weight that. That we might. From eating that high quantity of food. So, yeah, the diet, you know, largely fish, plantains, I would say some wild game, a variety of fruits.

[A]

What kind of fruits?

[B]

So palm fruits. Again, like, just like the ache. We're eating a variety of, like, pie, kind of, you know, seed heavy fruits with just some, like, pith around them. There's like a variety of those that are available different. Different times of the year, but was actually maybe a little bit surprising. They're not eating, like, leafy greens left and right. They're not actually getting a whole lot of vegetables. And it's not a super diverse diet by, I think, our modern kind of sensibilities. And, you know, some of the big surprise, I guess, to some people who think, well, the Chimani have healthy hearts, but. But they're eating a lot of meat. And sometimes that doesn't. People have a sense of paleo.

[A]

But when you're. When you're saying a lot of meat, if you think of a portion of meat the size of a deck of cards, how many servings are they eating a day or a week of meat?

[B]

Well, I would say a few. Few times a week at least. They're probably getting a Decent amount of meat.

[A]

You know, the, the average American, by the way, eats about 240 pounds of meat a year. That, that's a bathtub full dead animal. So even though you're saying a lot relative to, you know, bacon for breakfast, a burger for lunch, and a pork chop for dinner, it might not be as much as somebody living in the Midwest.

[B]

That's right. Well, and I also.

[A]

It's healthier meat.

[B]

Yeah, it's healthier meat. So Tymani have healthy hearts. So if we look at what they eat, but that doesn't necessarily mean that our hearts would improve in their health if we ate the exact same thing that the Tsimane ate. But, you know, we live in a time where, you know, you go to, you know, even a 7 11, much less like an actual grocery store, where you can eat foods from all over the world, you know, that are available to you. And that's never happened before really, in our history where all that was available to you was what's local. And almost invariably any group when meat was available, they were probably going to eat it. Yeah, yeah. But now we actually have the ability to have substitutes because we can get all the best foods from all over the world and it might actually be a little bit healthier. I do think sometimes there's a reason why groups like the Tsimane, when they start to, you know, modernize, sometimes their health actually becomes worse than their neighbors.

[A]

Oh, I would think for sure it would.

[B]

Yeah.

[A]

You know, for most of human history, I think you agree with me on this, it was a struggle to get enough calories, so you ate what you could find in Blue Zones. They did eat meat. It was a celebratory food. They ate on average about 20 pounds a year, which amounts to just over a serving a week. The minute the standard American diet arrived, they started eating the amount of meat equivalent to what somebody in Brooklyn would eat or, or Pasadena. And so most of the time their diet was dictated by what their environment would provide. But it's useful, I think, to look at, well, this is what people were eating and this is their health outcome. Let's pay attention to that. It's not causal, but it is. Those two are going hand in hand. They're going hand in hand in with the Tumani, they're going hand in hand with the Sardinian peasant in Nicola Peninsula, Costa Rica and Okinawa. They're all fairly similar. And do they love meat? Yes. Do they eat it all the time? No. You brought your very cute son in, Oliver, today. And if Oliver, who's what, 9 or 10? If Oliver said to you, dad, what did you learn about what to eat? If I want to grow up healthy from the tsumani, what would you tell him?

[B]

Avoid processed foods, right? Because there's no processed foods, no soda. Just eliminating those things alone, you know, candy, you know. So the thing about processed foods is that they're. With each bite, you're getting almost like three times as much calories as, like, your average hunter gatherer per bite, and yet your brain isn't processing that. You're getting full. So you're much. Not only are you getting, like, worse nutrition, but you're also much more likely to overeat if you have that kind of more processed food diet.

[A]

It also occurs to me that the body is much better at using calories when you're not eating too many of them. In other words, the excess ends up in your arteries or around your midsection. It's often not so much about what. It's about how much.

[B]

We were talking about, you know, giving food away to other individuals and that type of food sharing, how that's sort of a central aspect of who we are as humans. And it's so much more enjoyable to share a meal.

[A]

What's one of your best examples of sharing that sticks out, that illustrate this point of survivability, of increased survivability, of sharing.

[B]

It's funny because the first thing that came to my mind was actually, I was in Asuncion, so capital city in Paraguay, and. And with an. Had some ache with us, and I was just going around town with a hache boy, and. Well, now this sounds probably bad on your podcast, but. But I got him a cheeseburger. He'd never had one before. You know, he wanted to try it. And I turn around because he was, you know, dragging a little bit, and I was like, where's your bird? Did you eat the whole thing already? He's like, no, I just gave it to that guy. He looked hungry. And so everything I got, you know, he'd get the fries he'd given away to want to go. And. And again, that mentality of. Of just like, when you have food and you see others who are hungry, you're. You're going to feed them. Even though, like, he didn't necessarily know when he was going to have food again. But there's this confidence that people have both in either one in their ability to, you know, I look at a forest, I don't see a supermarket, but they do, right? That having that skill brings that confidence. But then Also the other people that form their community, it's like buying insurance,

[A]

this attitude of sharing, because as you pointed out at the beginning of the podcast, people get sick and people get hurt. And if you haven't been sharing with them or, and you don't live among sharers, you're kind of screwed. You can see how sharing contributes to survivability, but it also probably contributes to a certain level of joy and happiness.

[B]

Yeah, exactly. And the same way, like with money, and you think about investment and strategies for that, it's similar with your community. Right. If I took the meat from a peccary and divided it such that each portion was so small that most people got very little, they might not have my back in the future. At the same time, if I gave everything to one person, you know, maybe I could do a little bit better. So people are strategizing of, like, how many people they might share with, who should they be sharing with? Maybe you should privilege some of the people who shared with you in the past. Right. That kind of reciprocity rather than just sort of wildly giving it away, you

[A]

know, which I gotta hand it to you anthropologists for coming up with this Dunbar number, this observation. About 150 people can live together. That strikes me as a small enough population is you can be generous to everybody and share with everybody and you can be pretty sure it's going to come back to you. Whereas if you're living in la, you could have this giving attitude and end up with nothing.

[B]

That's right. In fact, we did these fun little studies even with the ache, and it turns out that men's wives weren't so keen on when their husbands were super generous with meat that they were giving away. And so there was a sort of optimal level of generosity where if you're too generous, then even in a community that's not super huge, are you really going to be getting something back? The great thing, it was a fun study where the people who are more generous than average, even in the ache, the average is pretty darn high, were much more likely to be cared for when they got sick or injured. So they were more likely to see things go their way.

[A]

So is there some optimal level of generosity that you can deduce for the rest of us listening?

[B]

I mean, I think each person, it depends on their means and it's not necessarily like giving money away. Right. But for many of us, our time is most valuable. And so I think just having a core tribe of people that you can count on five to six would be Quite nice, because that's enough people that you can draw upon in various capacities. And that's what hunter gatherers do. They have some close connections nearby, but they also have connections with people who live in different areas of the territory that are likely to experience different types of risks and not at the same time.

[A]

Well, how about. So you've spent years in the Amazon with these indigenous tribes, and now you live in sort of the vortex of gentrified living in Santa Barbara. Is there anything that you learned among the Ache or among the Tsumani that has kind of helped you navigate the wilds of Santa Barbara and make friends or be more neighborly or.

[B]

One thing that comes from just having worked in the Amazon where I'm unskilled.

[A]

Right.

[B]

I. I can't hunt. You know, I'm terrible even at gathering. People treat me like a child.

[A]

PhD doesn't do much good.

[B]

I mean, it's not. Well, it's not even the right type of doctor. Right. That can actually save lives. Right. And so, yeah, this is humility. Right. Where you just. I wouldn't have lasted more than like a week in those areas. So not taking yourself too seriously, I think is really critical. And then it also lowers down people's guards, and then people are open to talk with you. And certainly, you know, I could have talked to a lot of Tsimane in Spanish. People's Spanish might be okay enough that they could understand my broken Spanish, but trying to actually learn people's language, you know, that was a huge investment, but it paid off in huge ways. So, like, immediately, you can almost be like an insider.

[A]

Can you say something in Tchumani for us? Anything.

[B]

Anik mahe hum warheye chimedye humtsi tsun morheyak.

[A]

That was brilliant. What'd you say?

[B]

A solid greeting to everyone out there. I'm happy to talk as a good friend.

[A]

So you really did learn. Let's move on. We talked about diet, we talked about socialization. Let's talk for a minute about physical activity. How do these guys stay fit? And I assume they were.

[B]

Yeah. So that's another, I think, big lesson. The commonality to all these different groups with wildly different diets and different parts of the world is physical activity. Every one of these groups, that's literally subsistence oriented means they have to work for their food, and the work means physical activity. Now, there's. There's both good and bad to that. From our perspective, I think the good is that a lot of the physical activity people are doing, it's not really the equivalent of running a half marathon every day. So if you kind of think, oh, yeah, the Tymani have healthy hearts, but they're doing things I can never do more than once in my lifetime or something like that, that's not like that at all. In fact, much of their daily activity is light to moderate right now. It's true, we do so little vigorous activity that the Tsimane are doing like three times as much as we are. But that's like 20 minutes compared to

[A]

75% of Americans don't even get 20 minutes of physical activity days.

[B]

Exactly. And so that I think that's really hopeful and achievable.

[A]

What are these guys? What are the men and women doing in about how many hours a day? Is it fishing or is it machete work?

[B]

It's all of that. So even just like, you wake up, right, and then, you know you're gonna cook. So you. You're literally walking, you know, to the river down these, you know, muddy banks, right? And so, and then you're, you know, getting the water and then lugging the water up the. Up the banks back to your house, making a fire. Oh, you're out of firewoods. You go back into the jungle, cut some stuff down. So you've already, by the time you even, like, started cooking your breakfast, you might already have a couple, you know, at least 3,000 steps. And then throughout the day, if you're going to go to most people are doing some level of field work on most days. And so you're going to your field, you're bringing a machete. If you're cleaning your field, if you're cutting trees, if you're going to be tempting to burn, much less harvest, you're going to be using your body and continuous work. Now, sometimes it is vigorous, like a giant tree that you're chopping down with an axe. I mean, that's really hard. And so they're breaking it up and they're taking breaks, but that only comes every now and again. So most of the activity is fairly light to moderate. They're just doing a decent amount of it. We actually put accelerometers on people and we monitor, you know, how many, what, the equivalent of steps per day. And they are getting quite a bit more than us. So the average, you know, adult is getting, you know, anywhere from like 16 to 18,000 steps a day. Right?

[A]

So but it's low intensity physics, but

[B]

it's fairly low intensity. So that's definitely achievable. And a lot of the studies out, coming out every Hour more you spend walking. Light activity makes a difference.

[A]

I think we've been fed, we've been misguided. We've been told since the 90s that we should run, you know, marathons and pump iron and crossfit and Old Intensity and. And, you know, I know from observing people in blue Zones, they're. They're shepherds.

[B]

Yeah.

[A]

Or they have a milpa. And these people are actually making it to 100 with strong hearts and operating lungs.

[B]

Well, right, exactly. And, you know, no, Chimani is getting knee replacement surgery. I mean, when I talk to the Tsimane about exercise, they just laugh. Like, why would you move your body when you don't have to?

[A]

Yeah, right. And that's the thing, not producing any food.

[B]

Well, so much of what we have to do to be healthy doesn't come natural at all. Like, lessons from hunter gatherers is like, get food and as much as you can when it's at the lowest cost. So if the Tsimane had a car and could drive to the forest, harvest everything and come back, they would probably do that. Right. Because it makes sense from an optimal foraging perspective. But they can't do that. And so they have to use their bodies and whatnot. Which isn't to say they don't feel good about doing that. Hunting is also an opportunity to get away and have some fun in the forest. So there's those aspects of it as well for us, increasing our physical activity in ways where it doesn't seem like exercise is really what's needed in order to get us to move more.

[A]

Yes. And I argue that shaping our environment to nudge us into unconscious, you know, we've. I think you'll agree with me that for most of human history, it's been a struggle to survive. We lived in an environment of hardship and scarcity, and we had to work hard or we had to work constantly to gather enough calories to survive. And now we live in this environment of overabundance and ease. You can't take more than five steps out in the real world without being confronted with a candy bar or a soda or salty chips or cookies and mechanical conveniences has engineered almost all physical activity out of our lives. And this sort of genetic urge to seek rich food and to seek to be in a restful situation, very useful for most of human history, but very bad right now. And I almost say, beware of comfort. You should be engineering a little bit of discomfort back into your life. The need to walk places, the mechanical tools in your house instead of pushing a Button for everything.

[B]

I definitely agree with you. So much of what we need to do to be healthy is like, it's more a list of things not to do and things to do because our evolved preferences and tendencies, we have to fight against them. And unless you just have extraordinary willpower. And there are some of us out there who can get themselves out there, 5am doing their workout before they go to work and then whatnot. But that's hard for a lot of us. And so the, the restructuring communities and restructuring our incentives in ways that you have to do certain things. Like I only have a hammer and a screwdriver, so I don't have the power tools. I'm going to build this thing with what I have. Or you know, don't fill up your car with gas. And so you have to walk to the market. But it does requires some planning. Right. You know, maybe you could get a bigger house, but it's further out in the suburbs and you're gonna have to drive everywhere and you get something a little bit smaller. But there's places to walk around, walk to. So taking those types of trade offs very seriously because maybe that's enough to get us out the door and walk to the grocery store and have to carry our groceries on our back.

[A]

So just to remind people you found the population with the lowest rate of cardiovascular disease, the cleanest arteries, you were able to measure that. Did you look into their immune systems or their gut microbiomes? Any insights?

[B]

The answer is yes. I would say things are still a little bit inconclusive. So I'll start with gut microbiomes. So we've looked at that a little bit and we've got some ongoing work right now. And gut microbiomes are more diverse than yours and mine. So it means they have a lot

[A]

more type strains of bacterias in their gut.

[B]

That's right. Because you know, probably they get so much more fiber in their diet. That's another one of those lessons about commonalities. And what are they getting?

[A]

Fiber.

[B]

Getting fiber. So from sweet manioc. So they, you know, eat kind of like a cassava roots. So a variety of roots. Plantain's got some, you know, some soluble fiber.

[A]

Are they digging up other roots and nuts? Are they actually gathering in the.

[B]

They are, they are doing some of that. But you know, I would say, you know, so the Hadza, so who are pure, more pure hunter gatherers are eating more fiber per day. They're getting about 100 grams per day. We estimated that you might have closer to 50 grams a day. Of fiber. So both more than we're getting, but the Hadza a lot more. Yeah, and the Hadza microbiome is actually kind of richer in diversity than the Tsimane microbiome, which is, I think a

[A]

lot of people miss the fact that our good gut bacteria eats one and one thing only. Not protein, not fat. Fiber. Fiber is what fuels our microbiome. And 90% of Americans do not get enough fiber. And therefore our guts aren't optimized, probably our immune systems aren't optimized. We're not synthesizing feel good hormones like oxytocin and serotonin. Most serotonin, by the way, is made in our gut, not in our brains. So here are people who just by their native diet are getting five to ten times more fiber. And it might be manifesting better hearts, but also maybe better moods.

[B]

That's right. I, I think so. And I mean especially, you know, not, you know, the stereotype of like, happy, go lucky, because there's a lot of adversity that people experience. So much so that it's the kind of adversity that would probably bowl over many of us. I mean, you pick any Tsimane woman of reproductive age, chances are she's had at least one miscarriage. Many Tsimane women have lost a child. People have lost siblings because mortality rates are, are higher than they are here. And so even though, you know, if you live, you know, you're, you're going to be fairly healthy, but the chance of dying is still higher at, at all ages. And the thing about immune systems, I do think the immune systems of people like the Tsimane are definitely doing something different than ours, really. And so inflammaging. Right. This increase of inflammation that you see with age, that's associated with all the chronic diseases of aging. And in some ways was believed to be this universal because even in the absence of diabetes and heart disease, you just have a growing number of these aging cells, these senescent cells, and they're not just dormant, doing nothing, they're emitting inflammatory proteins. And so it actually turns out in the tsimashare, when you look, they actually have relatively high levels of inflammation, but that inflammation is not increasing with age. And when we actually looked in more detail, yeah, the inflammatory proteins are increasing or are high, but so are the anti inflammatory ones. And the regulatory aspects of their immune system seem a little bit probably more balanced than our immune systems. And, and, and some of this could be the gut microbiome we've hypothesized that some of this is also the, the worms that are in people's intestines that you know, our immune systems don't really expel them out, but are they learn to tolerate them. And, and what that does is that helps dampen inflammation a little bit.

[A]

And so let's, let's ponder in a second. So intestinal worms, your body gets used to it and maybe usually when there's something foreign in your system, your body responds with inflammation, but your body acclimates to the worms and doesn't trigger an inflammatory response.

[B]

Some people there might be a little bit of an inflammatory response, but there's also this anti inflammatory response. So it's kind of like with inflammation it's like little bombs in your body, right? All this collateral damage because it's not a very targeted specific form of immunity like the way your, your antibodies or your adaptive immunity is targeting that, that, that wayward cell. And so if you're, if inflammation is just little bombs, you want to contain that damage. And so I do think the better regulation and anti inflammation is probably helping contain that inflammation because inflammation in many ways we need inflammation, right? Oh yeah, our body's being attacked, we get wounded. You know, you need inflammation to kind of step in as a first response and help out, but you just don't want it to kind of sit there and linger and be turned on when there's no invasion. And that's a problem in our modern society. And so the fact that inflammaging doesn't seem to be going on and increasing with age in the Tsimane was pretty instructive. And now, and luckily this isn't just the one hit wonder of the Tsimane with another group in Peninsular Malaysia who are also a range of farming and hunting and gathering communities. We actually looked at their immune systems in the same way and it looked very similar to the Tsimane. No increases of inflammation with age. So this idea that inflammaging is context dependent, it's not a universal, it's kind of like a mind blower, right? Because again, it suggests that certain things might be preventable and avoidable through lifestyle. Again, all these folks don't have magic genes that are just saving their hearts and saving their immune systems in ways that are going to lead them to be healthy forever. But that lifestyle can make a huge difference and sustained lifestyle.

[A]

I've understood that inflammation is largely the theory that inflammation drives the diseases of aging and not so necessarily the result of aging, but maybe it's a little bit of both.

[B]

I think a little bit of both. And that it gets worse with age. Yeah, yeah.

[A]

But these and this and this really kind of segues into your book. And I really want to focus a little bit on your book because it's so good. Seven decades. It is fantastic storytelling. Insights that some of which we've heard elsewhere. But this reinforces the way to eat, the way to move, the way to socialize. Many of the things we talk about in blue Zones and other scientists talk about but do so in the context. But you also talk a lot about the capacity of the human machine, the body, and why. Seven decades. How did you come up with that number?

[B]

Yeah, under sort of non industrial conditions. Over much of our evolutionary history, I think our body was built to last about that long. Now, before I get into the why, I do want to reassure your listeners that we're in a position now where that's closer to eight or nine decades. So we are healthier in a way, probably aging more slowly than we would have over most of our evolutionary history.

[A]

Are we aging slower or are we just coming up with interventions to keep us from dying?

[B]

I think it's a bit of both. I mean, there has been some delay in the onset of certain chronic diseases and our ability to kind of tolerate the onslaught. So it's not just surgical interventions, but we're in better shape. So I think our bodies can tolerate certain things.

[A]

Why would that be, Michael? Because, you know, we're more sedentary, we eat crap, your food. We're under more probably existential stress than.

[B]

Well, yeah, but I guess from more infectious past, you know, when we were sharing our bodies with lots of infectious disease that was fairly pathogenic and food was more limited. I think you had limited energy budget and you were sharing it with someone else within your body. Once the budget is now bigger and you're not sharing it with other pathogens in our body, we have the resources to invest in a stronger immune system. And yeah, there is this idea of do we have too much resources? And so, you know, it's things are too super abundant and we're paying some of those consequences. But there was a sweet spot, right? You know, before, you know, the big increases in obesity and diabetes that we're seeing, you know, in the last half century, there was probably a sweet spot where you were no longer suffering from infectious disease, but you still had a reasonably healthy kind of lifestyle.

[A]

And just to unpack infectious disease, it's diarrhea when you're a little kid, Giardia dysentery, cholera, malaria, These diseases, measles, tuberculosis, things that we've eliminate with vaccines, people vaccines. We don't have tuberculosis and smallpox and other terra polio and other terrible diseases. And maybe if I'm interpreting you right, that these, these infectious diseases that we've been able to eliminate are creating a body that ages more slowly. Yeah, perhaps.

[B]

I would say so. I would say so. And maybe going back to where seven decades came from, it actually maybe it was about 15 years ago and it was just sort of like you were doing with blue zones, where you were looking at the actual demography of populations. And so I, I was looking at not just from my own work with the Tsimane, but the other hunter gatherer groups where we know people's ages and we can actually have good detailed information on how long people lived. And it's true that lots of deaths early on in life, but if you looked kind of beyond that high mortality period early in life, you started to see this like kind of mountain of lifespans, a mountain of deaths with a peak around about seven decades. And what was really instructive is that was true hunter gatherers, whether you were in Africa, South America, farmers or herders in different parts of the world, it was even true. If you go back to some of the earliest European data that exists, like Sweden in the mid-1700s, it looks almost identical mortality pattern as hunter gatherers.

[A]

When you think, is there an evolutionary reason for seven decades?

[B]

Well, there's a couple things. One, when you look at who, you know, the ages that people have kids and the ages that people have grandkids. So that's your literal biological fitness, Right?

[A]

So you can, what are those ages?

[B]

Well, in many hunter gatherer populations, you're. The average age of first birth can be about 18. Okay, all right, so you're 18 years old, you've had your first child, by the time you're in your later 30s, you're already a grandparent, right? And then you could be a great grandparent, you know, just, you know, 18 years later. And so generations are shorter than for us. But you know, there's only certain number of ways you can increase your reproductive fitness. And that's sort of the perspective I'm coming from, that we didn't evolve to have long lives just for its own sake. Now we can recognize that's a goal, you and I, we want to maximize our lifespan, our health span. Okay, but evolution only partially cares about that, right? Because survival is one key. But so is having kids, right? Fertility, right? It's the product of those putting genes in future generations requires reproduction. And so you can either have kids of your own, or you can invest in existing kids and as a way of improving your biological fitness. And so if I look at the ages at which people have kids and grandkids, it actually turns out that, yeah, you've had all your kids by the time, you know, you're ready, like as a woman, let's say closer to 50, but the number of grandkids is still increasing. But by the time you're kind of approaching your seventh decade, the number of grandkids, say under 10, is declining. And you can say that under 10, that's like the most vulnerable ages, right? Mortality tends to be high. So you, as a grandparent, can make the biggest difference in the life of a grandchild in those first 10 years. And so those potential benefits, fitness benefits of investing in kids and grandkids are rapidly diminishing after about seven decades. And then if you think about the costs, what are the costs of moving that from seven decades to eight decades? Evolutionarily, it probably didn't seem to be worth it, right? Because if I go to, yeah, okay, your grandkids are decreasing, but maybe you have great grandkids, but each generation, they're only related to you half as much as the previous one. And so from a genetic perspective, it's not as optimal.

[A]

So if I could paraphrase it and make sure I understand what you're saying here is evolutionarily, we are around to have children, and then we're around to make sure those children make it into adulthood. And then maybe we're around to make sure our grandchildren make it to an age and they can have the children. In other words, the central goal of evolution is to have babies and make sure our offspring have babies. And by the time you're 70 years old, your ability to improve the survivability of the next generation is so diminish that evolution says you're not worth the trade off. The food you eat and the time it takes to keep you alive isn't worth it in terms of fertility, you

[B]

know, this sort of old, you know, thought experiment of like, well, what would it take to just make us immortal? And it turns out evolutionarily, it's. It's almost never worthwhile because even if you eliminated aging, right? And by that, I mean, you never get wrinkles. Yeah, you never get. Imagine you never get wrinkles, but you're probably still going to die of something else. Natural causes, natural disasters. And so part of the human story is we've actually, by Being social. Right. Taking care of each other, having the fires in our group to ward off predators, we reduce those natural disasters. And by doing that, we kind of made it worthwhile to invest in a body that's going to care about taking care of itself and that's going to have an immune function that's going to help us live to those later years. Wow.

[A]

So evolutionarily sharing in a collective mindset actually favors longevity.

[B]

Yeah, the cool aspect too, that maybe ties it together with our lifestyle. Like we thinking, okay, we got to go to school, you graduated high school, maybe even into college, and independence is so delayed. But the idea that we go through all that training because we're gonna hopefully get a job and make enough money that we'll have like a surplus and be able to pay for things and it all equals out, makes it worthwhile. Well, it actually turns out hunter gatherers came up with that first that, you know, compared to chimpanzees, our nearest cousins, shortly after weaning, chimpanzees can basically feed themselves. They don't need mothers and grandmothers in order to help feed them and to get by. That's not true in any hunter gatherer group. Basically, it's almost similar that like graduating hunter gatherer high school. That's how long it takes before you're able to start feeding yourself. Yeah.

[A]

Wow.

[B]

Almost two decades. That means those first two decades you're basically being subsidized by other group members. Like literally, it takes a village, and that's in the absence of schools. And then you start seeing that surplus kind of creep up. Because hunting and gathering is not easy. It takes a while. We've done experiments like hunter gatherer Olympics, and it's people in their 30s and 40s that are at the peak of their game. But if you imagine if you're only at the peak of your game at 40 and life expectancy, like if you expect to drop dead the next year, how would that ever pay off Evolutionarily. Right. So the idea that you would only have that kind of economy where you're in a deficit for two decades and then you start having this big surplus. That only makes sense if you could expect to live long enough into adulthood to make it worthwhile. In other words, those people in their 40s and 50s and 60s are going to be critical because they're the ones generating all the surplus that is helping everyone in the group.

[A]

And they also possess the. The body of wisdom that helps the younger generations. Yeah. When the. After this kind of rain, you can. Fishing's good over here or this is, you know, this kind of plant. When things get tough, you can actually eat it.

[B]

So that's exactly right.

[A]

Yeah.

[B]

So when I mean surplus, you know, it's easy to count calories, but I mean everything, you know, from the stories to the wisdom. I think one thing that's underappreciated is when you're surrounded by other people. We think about all the warm fuzzies of community and sociality, but there's a lot of tension and a lot of conflict. But elders, you know, they're equally related to this side and this side and this side, all these kin. And they're the ones who are best able to help others get along. And mediating conflict, I think, is an important aspect that elders excel in compared to other people.

[A]

One of the most important lessons we learn from the Blue Zone is how to eat to 100. We know exactly what people there have been eating most of their lives, and it's whole food and mostly plant based. But it's not just what they eat. It's how they eat. They cook at home, and they cook together. Cooking is never rushed. Someone is chopping vegetables, someone else is stirring a pot, and someone's telling a story you've already heard, and nobody seems to mind. That's simple ritual that turns food into connection and connection into longevity. At my lake house in Wisconsin, the kitchen is always the center of the house. Friends gather, we cook simple meals. We linger at the table, maybe play a few rounds of cards after dinner. Those evenings do more for my health than any supplement ever could. When I'm traveling, I like knowing my home can still host those moments and give the gift of connection to other families. Hosting my home on Airbnb means other people get a space where cooking isn't an afterthought. It's a reason you come together. Hosting fits naturally into my life. It keeps the heart of the home alive, even when I'm away. Your home might be worth more than you think. Find out [e-mail] so I just want to list off the benefits that older people offer in a tsumani. From what I've heard, number one, they help teach hunter gathering skills. Number two, they probably help with childcare and great grandchild care. Number three, they mediate conflicts. And by the way, if you can't mediate conflicts, you get mortality for murder. That actually adds to life expectancy. But what other things do older people contribute?

[B]

Older people also contribute various aspects of ritual. So kind of marking transitions and, you know, Many hunter gatherer societies have transitions into puberty.

[A]

How does that help with life mortality or how does that help with longevity, if at all?

[B]

It ascribes meaning and purpose to these different milestones in people's lives. And I think they're just ways of checking in puberty. It's like you're flipping a switch. Okay, now this person is now entering the world of kind of potential reproduction and marriage. Right. And so, and elders are often involved with the selection of partners and making sure things go smoothly, but also with births. Right? Making sure in a number of groups, for example, it's quite common that moms are isolated with the baby in the first couple weeks and, and it's a, you know, to mark a smooth transition. But you know, with ritual it's also, well, from midwives, but also taking care of moms and reducing maternal mortality, but you know, easing with the stress and the transition. And mom instantly knows that she's not alone taking care of that baby. She's got a community of others looking after grandma, in other words. Well, grandma, but also like others in the community are involved too. That child, you know, we're so used to like in our society, you, the parent are doing so much of the childcare and the direct care, but you know, other kids, you know, peers are who a lot of kids are playing with and they're raised as much by other kids as they are by their parents or other adults. I mean, that's pretty common, you know, free range childhoods as we call it now. I mean, that was basically the norm in lots of hunter gatherers situations.

[A]

But just to stay on this topic of grandparents for a while, are older people revered in these societies? And if so, what happens if grandma becomes, you know, demented or grandpa gets sick and can't move for the next camp? What do you do?

[B]

So, you know, I talked about the elders and the fitness, those benefits that they provide to their family and how that might have been favored by evolution. But the flip side of that is there is a point at which those benefits are rapidly diminishing. And yet you're another mouth to feed. And so what happens when there's that transition from asset to burden? In the literature it's called death hastening behaviors which can be as benign as like mild neglect. Like maybe you're the last one who's fed, you know, only when there's a surplus to sometimes just outright geronticide where people are, are literally murdered and very unpleasant and cruel.

[A]

But there's probably a reason.

[B]

Yeah. So in the Kind of harsh calculus of, you know, food limitations and absence cares and, and especially in a high mobility context, it's really difficult to, to bring and carry, you know, older people with. So yeah, it's, it's relatively uncommon. And in the few cases where there's like documented outright geronticide, it's actually sometimes a loved one who's dealing the death blow. It's an act of love, an act of mercy, especially if the person's in pain, if they're suffering. But it's something that we've been doing forever. These trade off these delicate decisions of compassion for our elders. But we want to ease suffering at the same time we have to live our lives and we have our own kids and families to sort of think about and our own well being and how do we balance it all in a way that is sort of, you know, good for all?

[A]

You know, I'll just sort of inject my own opinion. And especially now the, the pace of discovery is so fast right now with AI that the older people in our society possess this wisdom, this ability to help us remember the way humans survived over time. This link to the past that is either disappearing or is becoming so irrelevant that more and more the 80, 90, 100 year old person is. We have to look to them to make sense of our world.

[B]

Well, a couple things. One, you know, most when we, when we talk about a lot of these mismatches between like our hunter gatherer past and how we're living now, a lot of it is things that we're not doing or doing poorly. And so our health is suffering now compared to what we would have been like in the past. But there is one aspect of like mental health. We're actually doing better now I think than hunter gatherers are doing. And so it's been widely documented this sort of u shaped happiness, well being kind of relationship with age that from our, you know, midlife. Like right now I should be at

[A]

the worst point in my life between 45 and 55. Right. Least happy time.

[B]

Exactly, exactly. And so, but you know, at least I can look up at the other side and hope if I make it that, you know, things are looking up. That's not the case in hunter gatherers now that we've actually looked at that like in the Chimane, interesting things that actually get worse and you get less happy with age. Yeah, it seems to get a little bit less happy with age. Now we can, you know, debate about what do we mean by happiness and you can still have meaning in your life. Even if you're less, like, hedonically happy, but for like, life satisfaction and other aspects, you know, people, you know, after age 50, in their 60s, you know, would do say that they're less happy. Shimane and other hunter gatherers and if you think about it, you know, because there's always a paradox, like the fact that as you're entering this older age, for the most part, our health isn't really getting better. You know, we're losing family, potentially fledging kids, and we're. I mean, that could be good or bad, depending on your perspective, but sometimes, you know, some of our family members are dying. So it's sort of this paradox that if all those bad things are happening, why are our lives becoming more satisfied? And luckily, we live in the kind of context where we do have some buffering, right? We do have still, we have some Social Security, we have some insurance, we have some institutions we live in. A lot of us have jobs in a service economy or we're not like manufacturing hardcore well into our 70s and 80s. So we have that ability where our physical health can be compromised a little bit, but we can still function and we can still find joy and improve and focus on the positive and have perspective in ways which it's a little bit harder to do that because even in hunter gatherers, even though all those other things that you mentioned that elders do, they're still not like super specialized roles. You still have to eat and people are still using their physical bodies to just get around. And when you have that mobility limitation, that's when people talk about, I feel old. I'm old now because I can't do the bare minimum and no one wants to be thought. The other aspect too, of being enmeshed in a community with mutual obligations, there's stress and tension with. Now all of a sudden I feel like I need more from my community than I can give.

[A]

Yeah, that is stressful.

[B]

And that's like the big number one complaint. You'd think all else equal if I could mooch and give less. Wow. Shouldn't I be happy?

[A]

No, not at all.

[B]

Not at all. People who are in the position where they're giving away more than they're receiving, they're happy. The ones who are dependent on others, not happy.

[A]

Do you think there's any other universal lessons on happiness that come from the tsumani? As you observe these hunter gatherers, what might the rest of us be trying to emulate if we want it to be happier in younger life? I'm not talking about old age, but 20s, 30s, 40s?

[B]

Well, yeah, I think. And there's things that apply at multiple ages. And some of it, again, is not super new, but framed in this larger historical.

[A]

Make it sound new and fantastic.

[B]

Well, just, you know, this idea of, you know, like in our society, you hit this magic age and all of a sudden you don't have to work anymore and you can retire. Like that doesn't exist throughout human evolution. Like formal retirement does not exist. No, but what's sort of critical is always being needed and useful, that other people value you for something.

[A]

And.

[B]

And that's what people get purpose and meaning out of their life. And that's what critical, whether you're 65, 45, 25. And that's such a critical part of happiness of hunter gatherers. And it's a critical part of our happiness. And a lot of that feeling needed and being valued is doing more for other people.

[A]

I love that.

[B]

Doing for others. And you are maybe doing for yourself. So if we say, oh, but that's still egocentric. Well, that's the best way to be egocentric by helping others rather than just like sheer, you know, vacation mode and going from cruise to cruise.

[A]

The source of happiness is being useful. Yeah, it's giving and thereby often receiving. But being a giving person is good for your health and your longevity.

[B]

Yeah, there's this tendency to think of aging as just this decline. Right. But. But looking for happiness is looking for things you can do to help others in new ways. Ways you can connect to other people and, you know, you feel happy for a little bit and then it's good that that doesn't last forever in contentment. But you're always then looking now, what can I do? What's another opportunity that how can I be useful? And being aware of the situations like where are their needs and where are the needs not being met and how can I be helpful?

[A]

Well, so one thing that comes through very clearly in what you say is that staying useful as you age, age appropriate usefulness is really a unifying theme here. It makes people feel valuable. It gives people a reason to get up and go. It gives them a rationale to be incorporated into the larger society. It attracts people to them. And once you lose that usefulness, once you resign yourself to I'm moving down to Florida and golfing the rest of my life, then you lose the, I think, the will to live. But you also lose the attraction from others. That.

[B]

That's exactly right. And you know, some of these existing programs where, you know, elders are involved in Various form of mentoring and intergenerational work groups and such. Not only does it improve that will to live, it actually makes it easier for them to think about their diet and movement. Like their, their, their, their health improves, their mood improves, their mental health is improving. And so yeah, it's definitely a win win for, for society.

[A]

Where your work so resonates with me is that here you found a population that has low heart disease, low type 2 diabetes, low dementia. That's what kills most Americans. It foreshortens our lives. And they're also doing this very clearly definable set of things. They're eating a whole food diet, carbohydrate, rich, some meat, some fish, but mostly carbohydrates. They're moving naturally all day long. Low intensity physical activity, not pumping iron, not running marathons. They're very yule social. In other words, they look out for each other. They're very social, they tell stories, they communicate all day long. They, they get good sleep, they care about their elders. And these are none of the things that are sexy right now. It's not metformin, they're not taking rapamycin or resveratrol or running down to Central America for stem cells or any of the things that fuels the $84 billion anti aging industry. They're doing things that not only manifestly have created a situation where they have almost perfect hearts, perfect cardiovascular systems, but all those things also make life a joy. Moving your body, being connected socially, telling stories, caring about your family, caring about your neighbor. And the big takeaway for me, being useful.

[B]

I love it.

[A]

Michael, thank you very much. The book again is seven what Human History Teaches About Living Longer is right on. It's a joy to have you here. Thank you for joining the Dan Buettner podcast and I hope to see you when you're 100.

[B]

Thank you, Dan.