Blue Zones

David: We live in a country that has been both intentionally and unintentionally designed to be a place where you have to have money to buy a house. And so there's ways we can sort of chip away at that.

David: Income is inside the house, how you ask? Because it doesn't.

BrentWelcome to Death Clock. I am your host, Brent. Today we speak with Doctor David Rehkopf. Doctor Rehkopf is an associate professor of epidemiology and population health at Stanford University. He's been doing some pretty interesting studying of blue zones, particularly the blue zone in Nicoya, Costa Rica. We really focus the conversation on longevity, because the length of life is so long in these blue zones.

BrentAnd what we can learn from the health of the people in the blue zones that we can apply to our own lives if we want to live longer. He's a wonderful guest. Hope you enjoy.

BrentDoctor David Rehkopf, welcome to the show.

David: Thanks for having me.

BrentWe're going to talk about Blue Zones today. I'm so excited to dive in. But before we do that, can you give us your potted bio?

David: I started out as a molecular biologist, grew up in Seattle, Washington, and then started getting curious about things in the world and how people behave. I had a really bad ski accident and almost died, so I got interested in medicine from there. But then after thinking about individual medicine, I got interested in things in the environment—really, why do we live a long time?

David: Why are some people healthy? Why aren't other people healthy? And then I found statistics and data as a way to make inquiries about that.

BrentAnd where are you now? What's your day job?

David: Yes, I'm a professor at Stanford. My home department is epidemiology, which is studying the distributions of disease—why some people are healthy and why other people aren't. But then I also have appointments in health policy, pediatrics, medicine, and sociology.

BrentI can't help but ask—and you can tell me if there's something you don't want to get into—as you list off what you're doing, what do you think about the Make America Healthy movement? What's been your view?

David: I was amazed. I read the executive order for Make America Healthy Again, and there's a lot of really good stuff in there. I've told my colleagues that 80% of it could be written by the dean of a school of public health. There's another 20% in there that I don't agree with.

David: And I don't think it's based on sound science. There are some important things being ignored for political reasons. But on the positive, glass-half-full side, the focus on prevention, primary care, and thinking about the influence of health behaviors on health is really important.

David: Now, there are a lot of details that are very general. But in that general sense of focusing on prevention, that's something I think is important and we should be doing more of.

BrentRFK is a radical change maker of sorts, or I think many would describe him as that. But what you're saying is 80% of it is what the dean of public health would say. Why weren't we doing it before? What's been wrong with public health policy?

BrentAnd if it was so obvious, why did it require this kind of radical person to get us there?

David: Straight public health 101 is that it's hard to get paid in a market economy for preventing things. If you prevent things, there's no profit motive there. What you learn in economics is that this is a market failure.

David: There's something really important we need to do as a society to keep people healthy and prevent disease, but it's hard to make money doing that. It's much easier in our system to make money by treating disease, so it incentivizes those actions. It's always been a struggle for public health.

David: One of the really concerning things right now is the cuts being made. It's completely inconsistent with Make America Healthy Again to cut what public health departments are doing to prevent disease and research primary prevention. The NIH budget had a proposed 45% cut, and a lot of that research is on prevention.

David: That's exactly what Make America Healthy Again talks about. So there's a huge disconnect between what's being said and the funding for it.

BrentWhen you say there's more money in treating disease than preventing it, my initial response is that the government is supposed to think about public policy that isn't incentivized by dollars. Pushing prevention wasn't happening before.

BrentDo you think lobbying was getting into public policy? Did it take a radical change maker to say they don't care about lobbying, pharmaceutical dollars, or big food dollars to start changing things? Is that part of what you're saying?

David: That could be it. I think about the evidence when changes were made allowing direct-to-consumer television advertising of drugs. You saw drug advertising skyrocket. Rather than physicians deciding what's best and having general consumer education, you had marketing for junk food, cigarettes, and drugs.

David: I'm not saying there isn't amazing, important work being done by pharmaceutical companies, but direct-to-consumer advertising has had an effect. I think there's some of that. On the flip side, there needs to be public funding for prevention because of these incentives.

BrentTo summarize before we chat about blue zones: as an expert in public health policy, MAHA is 80% good, with lots of great stuff public health experts agree with, and 20% that people disagree on. However, we're slashing the budget of the NIH, where a lot of prevention research happens.

BrentAnd prevention is the thing missing from public health. So it feels like a mixed message—two steps forward, three steps back.

David: Yeah, that's a really nice summary. There are a lot of good things in there, but it doesn't look like there's actual support for doing them.

BrentLet's talk about blue zones. What comes to mind for me as someone not deep on blue zones is that there are places on Earth where people live longer and better, reaching 100 at higher rates than elsewhere.

BrentBefore we dive into why that is, can you tell us what blue zones are, how we define them, and where they are?

David: It's an interesting shift that Dan Buettner built on work from scientists and his own investigations. Instead of just thinking about what makes an individual live longer, it asks why there are places where populations live longer.

David: He and others went around the world looking for these places. The idea has been around for a while, though some earlier claims were debunked because people lied about their age back in the 70s.

David: The work I do in Costa Rica uses really good death records and mortality data, so we can verify it. These are places bigger than a single town but smaller than a whole region where we see people living longer.

David: And so then Dan and other folks have, started investigating why that is.

BrentThe one that comes to mind most for people is Okinawa in Japan, and you're referring to Nicoya in Costa Rica. How many of these outlier places are there—5 or 10?

David: Dan has talked about five main ones in his book, but others are still being discovered. Colleagues in Denmark ran statistical scans and found a few regions there where people live longer. In some ways, we're limited by data availability.

David: There may be many more, but we focus on places with good mortality data. Right now, there are around 5 to 10 known ones. We found another small area in Costa Rica when we looked.

BrentWhat is the population size of a blue zone like Nicoya?

David: On the order of 5,000 to 10,000 people—somewhere in that ballpark.

BrentSo one characteristic is that they are rural.

David: I'm not aware of any located in major cities. These places tend to be more isolated—often on islands, peninsulas, or in the mountains.

David: In Sardinia, for example, it's not the coastal cities but the mountain areas. Nicoya is a more mountainous, isolated region. It's not about elevation itself, but geographical isolation.

David: One thing that potentially destroys blue zones is rapid urban development. While development raises standards of living in good ways, it can also reduce physical activity and introduce fast food and ultra-processed foods that negatively impact health.

David: Because unhealthy food and reduced natural activity tend to concentrate in cities, you don't see blue zones forming there.

BrentIs that the core reason people live longer in blue zones—they are insulated from the side effects of modern economic development, like car-centric infrastructure and industrial food systems?

BrentDoes that isolation keep them active and eating locally grown food?

David: That describes it well. It's a sweet spot: you don't want to be so isolated that food is scarce and infectious disease or accidental death is high before basic development arrives.

David: It's a sweet spot where people have access to basic healthcare, primary care, and sanitation without the negative side effects of modern lifestyle development.

David: There's also social connectedness, which is a major factor.

BrentSo it's not simply that living old-fashioned equals living longer. Technological innovations like basic sanitation, vaccines, and reducing infant mortality drastically increased life expectancy.

David: Exactly. You want those public health advancements without the negative lifestyle trade-offs.

BrentHow much of this can be replicated outside of Nicoya? If someone lives in New York City, how much can they replicate, versus something unique to Nicoya itself?

David: Dan Buettner has extracted key principles to create personal blue zone habits. My research on predictors of mortality aligns closely with those findings. As a scientist, my goal isn't to tell everyone to move to Nicoya, but to figure out what habits people can apply in their daily lives to be healthier and happier.

David: As you know, I'm not like promoting everyone moving to Nicoya. You know, it's sort of about what you can do in your own life, in your own sort of daily routine to, to be healthier and happier.

BrentOkay, so let's just hit some of the basics one at a time. What do we know about diet in the blue zones.

David: First, there are very few highly processed foods, fast foods, or sugar-sweetened beverages. Beyond blue zones, broader health research consistently confirms that eliminating these is beneficial. People also get protein from beans and other plant sources. They do eat meat, but the diet is plant-forward.

David: It's not like they're all vegetarians, but they do tend to be a little bit more plant forward in their diet as well.

BrentSo limited processed foods, plant-forward diets, not strictly vegetarian—basically Michael Pollan's advice: "Eat food. Not too much. Mostly plants." In places like Okinawa, there's talk of a fish-heavy diet. Do we see that consistently across all blue zones?

Brent: Is that is that not the case? We don't see that across these different blue zones.

David: There is some of that, though I haven't seen strong evidence that fish specifically is the driving factor across all regions.

BrentWhat about so physical activity. Yeah.

David: People tend to be naturally active throughout the day. They aren't training for marathons, but they are constantly moving. When visiting Nicoya, I saw a 100-year-old woman sweeping her porch and walking down to town.

David: It's amazing to see people stay active across their whole life. That low-intensity movement is what many people miss due to modern sedentary habits and busy schedules.

David: Yeah. To really, really help folks out here in the US a lot more.

BrentIs consistent movement throughout the day key? Many people exercise intensely for an hour and sit for the rest of the day, creating high spikes and low troughs of activity, whereas people in blue zones maintain a steady baseline of movement.

BrentAnd so I'm technically in shape and I'm reasonably physically active. But if you were to look at my physical activity over the course of the day, I'd be very low and then spike very high and then be very low. And it sounds like if I were to look at the physical activity of somebody in Nicoya, it would just be at some like pretty reasonable baseline.

BrentThey probably wouldn't spike as high as I do, like run into the top of one of the mountains around here, but their average would be much more consistent at a higher level. And so do we think it has something to do with that? Because it doesn't seem like, you know, it's like we could look at ultra marathoners or whatever.

BrentWe could look at people who are probably in much better shape than the people in Nicoya. But don't live as long.

David: Recent research measures total sedentary time as an independent risk factor for health, separate from high-intensity exercise.

David: Anecdotally, when I wore a continuous glucose monitor, light physical activity after meals significantly blunted glucose spikes. How your body metabolizes sugar changes depending on post-meal movement.

David: Many cultures traditionally take a walk after dinner, which turns out to have real metabolic benefits.

BrentModerate activity after eating makes sense, as opposed to sitting immediately after a heavy meal.

David: Even light household chores or walking around the house for a bit after eating makes a noticeable difference.

BrentWhat about sleep? Is there less artificial light exposure, or consistent sleep schedules in blue zones?

David: Sleep is emerging as a critical factor for health and longevity. While I don't have direct sleep data from my studies, rural communities naturally have a slower pace of life, fewer late-night distractions, and more time spent winding down with family.

David: I mean, it was a little bit of a kind of a slower pace of like, you know, there weren't places to go out to at ten at night and, be wandering around, stuff kind of shut down early. People at home, with family and friends. And so, yeah, there might have been a little bit of a less, and a little bit of like that, you know, that time pressure, among folks to kind of try to fit everything in in a day.

David: That environment naturally supports better sleep quality and regularity.

BrentI once did a rafting trip through the Grand Canyon sleeping under the stars. Staring at the night sky helped prevent ruminating thoughts and helped me fall asleep quickly. Modern artificial environments seem to separate us from natural cycles.

BrentI kind of my thoughts can race and keep me up. And when you're in the Grand Canyon and you, there's no light pollution. You can see the stars. You can immediately want to focus on the stars and you just lose yourself. You're out of your head and you fall back asleep very quickly. And it struck me that there's something in the these artificial environments that we've created for ourselves, like we've lost our connection to the sky in a way that I think that matters.

BrentAnd not in this, like religious. Maybe it does in the like the kind of woo religious sense, but I'm more mean just it's very practical. Oh, you can't sleep in the night. Like we'll stare at this tapestry of stars and you'll fall asleep pretty quickly. You know, maybe you're saying the studies don't have sleep, but do you think there's anything to the natural light and the obstruction of the sky?

BrentIs that a ridiculous, hypothesis?

David: Not at all. Studies demonstrate the importance of morning daylight exposure and natural evening light for circadian rhythm. Looking at screens when waking up at night is counterproductive; stepping outside into natural dark air works much better.

David: I can't, you know, I go to my computer or something like that was like the absolute worst thing you could do. I've literally actually started doing that same thing. I go outside, I sit back out on my porch for a little bit and it's like, wow, yeah, for me, that does work a lot better. So, makes sense to me.

BrentWhat do we know about community? The Harvard Study of Adult Development highlighted that social connections matter for longevity. What do you see in blue zones?

David: There is strong social connection and multi-generational interaction. We conducted a study examining telomere length, a biological marker of aging. People in Nicoya generally had longer, healthier telomeres. However, Nicoyans who were socially isolated had telomere lengths no different from the rest of Costa Rica.

David: Without social connection, they lost the longevity advantage of the blue zone. Living with others and spending time with family and children made a clear biological difference.

David: In data-driven mortality prediction models in the US, major risk factors like smoking and alcohol abuse rank top, followed by financial hardship and unemployment. But close behind are social connection indicators like family support, marital stability, and regular interaction with children.

David: Social factors are harder to quantify, so studies often overlook them. But when we measure social connection, it proves to be a critical predictor of health and longevity.

David: There's not data on them in studies. So we don't kind of study them and don't know. But in the studies where we have looked at them, you know, I found them to be particularly important for for health and longevity in longevity.

BrentThere's a trend toward high-tech screening, full-body scans, and tracking obscure biomarkers. People in Nicoya likely aren't doing high-tech screenings, yet they have lower cancer rates. How does healthcare function there?

BrentThey would say, no, I don't do any of that. And so I would assume there are lower rates of cancer, but I mean, or are they really good at screening for cancer for some reason.

David: Costa Rica invests in community-based primary care. Healthcare workers visit every household annually for routine checkups. They check blood pressure, monitor environmental risks like standing water for malaria, and check overall well-being.

David: It's a complicated thing to study and try to tease out whether it's causal or just associational. They're in Costa Rica, but it was interesting to see that. But what they do is sort of, you know, they look for standing water that would be, you know, have, related to malaria, infections. They take a blood pressure, they kind of check in how they're doing.

David: It's straightforward primary care and preventative outreach, keeping people connected to basic care without requiring extreme technology.

BrentCan you explain telomeres and DNA methylation? How are those metrics used in health research?

David: They are useful for tracking population-level aging trends before chronic disease manifests. Currently, individual-level measurement error is too high for these to provide actionable insights for single individuals.

David: I don't track my own telomere levels for that reason. But in research, these metrics help measure how environmental factors compound over time to accelerate or slow biological aging.

David: And so the sort of overall metrics.

BrentWhat actually is a telomere, and what is DNA methylation?

David: Telomeres are repetitive DNA sequences at the ends of chromosomes that shorten each time a cell divides. They act like the plastic caps on shoelaces, protecting coding DNA from degradation.

David: DNA methylation involves chemical tags (methyl groups) added to DNA that regulate whether genes are active or suppressed. The DNA sequence itself needs methylation signals to determine which proteins are expressed.

David: So the methylation helps control that gene expression, which then changes the proteins that we have which make us what we are.

BrentSo is the limitation mostly about measurement precision, or is the biological metric itself unreliable at the individual level?

BrentYou understand the distinction. The question I'm making like is it the measurement that's the problem, or is it the underlying thing for looking at this at the individual level?

David: It's primarily measurement error at this stage. As diagnostic tools improve, they will become more clinically useful for individuals. We also need more longitudinal studies clarifying which exact pathways directly cause health outcomes.

David: And so getting all of that kind of teased out also needs to happen. So a bit of both, but it's a little bit more just on this sort of measurement error side.

BrentIn the nature versus nurture debate around longevity, what is the argument for genetics? Could isolated communities simply share protective genetic lineages?

BrentAnd those genes have been passed down and the population hasn't, you know, had, I don't know, that much genetic diversity that would that would make that worse. And this is just genetic.

David: My collaborator in Costa Rica, Luis Rosero-Bixby, conducted research showing that individuals born in Nicoya who moved away lost their longevity advantage. If it were strictly genetic, moving away wouldn't remove that benefit.

David: That strongly indicates environmental and lifestyle factors are driving the phenomenon.

BrentThat's like a natural twin study. Moving away eliminates the advantage. How does this connect to your public policy work?

BrentBack to some of the core of the core of your work on public policy, like, and how much of how much of what's happening in these places is being protected from bad public policy? I imagine that there's some benefit to like, you know, some well-intentioned policies that don't have great outcomes. And if I'm in Nicoya, I'm kind of less susceptible to those.

BrentAnd then maybe some disadvantage for like, I don't know, good public policies, but like, how do we connect the to what we know about Nicoya and public policy and how how are you thinking about the intersection of these two things?

David: Individual choices are important, but environment plays a massive role. Public policies must shape healthier community environments and disincentivize urban developments that undermine health.

David: And I think we've we've failed in a lot of ways on that in the US. And so it's thinking about the communities we live in, making that healthy for everybody. You know, public policies, as you said, that we can have that promote those things and that sort of disincentivize some of this negative development that, leads to poor health.

David: Yeah, it is that argument for something beyond just the individual and thinking about what we can do for places.

BrentAspen trees appear individual above ground, but connect underground as a single system. In individualistic societies, we often overlook systemic interconnectedness.

BrentAnd after there's a fire here in Colorado, the first thing that comes back is the aspens, because it's like this whole network of roots just kind of pops back out. And so they kind of have this hybrid existence where they are individuals. You can cut down a single aspen tree, and if one's got bad light or whatever, it's not going to do as well as another one.

BrentBut actually they're pretty hyper connected. And there is that health of the system, too, even though you have these little individuals. And maybe, maybe in this individualistic society, we live in, like we're kind of forgetting that there is some interconnectedness and the health of the, the whole system that that matters more than sometimes we think.

David: I agree completely. The US ranks around 43rd globally in life expectancy—a poor performance for a developed nation. Many Americans die prematurely from preventable chronic and infectious diseases.

David: And, yeah, if we want to do better, I think we need to, do exactly what you said.

BrentWhat public health changes would you recommend? If you were running health policy, what would you prioritize?

David: Focusing on social determinants of health yields the largest impact. Ensuring basic economic security, housing stability, and community support gives people the fundamental resources needed to maintain health.

David: It is difficult to practice preventative health when struggling to pay electricity bills or afford food. Addressing social determinants is both cost-effective and essential.

David: We need a "Health in All Policies" approach across housing, education, and social services, rather than treating healthcare as an isolated sector.

David: And that really seems, you know, again, based on the data, the best way to improve health in the US.

BrentIn our Death Clock app, income correlates heavily with life expectancy in the US—the top 1% lives up to 15 years longer on average than the bottom 1%.

BrentAnd so we share the day. And that's like kind of novel and fun. But I think what's what was most depressing maybe is the wrong word, but I don't know, multifaceted emotion associated with it is, at least in the US, the thing that matters most for how long you're gonna live is how much money you have. And people have more money live longer, and the top 1% live 15 years on average, longer than the bottom 1%.

BrentYet blue zones aren't wealthy areas like Monaco or Aspen. How do you explain that disparity?

BrentOkay, we get it. So how do you think about that disparity where it seems with social determinants of health and what we see in the US on life expectancy, like money does matter for how long that you live. It probably matters for better health care. However, the blue zones aren't necessarily like these really wealthy places.

David: Costa Rica has income inequality, but income doesn't dictate health outcomes there the way it does in the US. In the US, system design effectively requires wealth to purchase good health.

David: We can reform our policies so high income isn't required to achieve longevity. Twenty years ago, income was far less predictive of health outcomes in the US than it is today.

David: Because policy changes created that tie between wealth and health over the last two decades, policy changes can also decouple them.

David: Making health independent of wealth should be a bipartisan goal.

BrentIf you had to bet on average life expectancy between 1,000 Nicoyans versus 1,000 American billionaires, which group would live longer?

BrentAnd the thousand billionaires obviously aren't in Nicoya or any other blue zone. Which group are you betting on?

David: They would be very close. High income in the US allows people to buy healthcare resources and stress reduction that brings them up to roughly the baseline longevity achieved naturally by average citizens in Nicoya.

David: Nicoya. So the so they're about the same point. Yeah. And then the richer Nicoya, it's not buying them any better. It's just like everybody is kind of like at that level in Nicoya.

BrentWhere can listeners find you and your research?

David: You can search for David Rehkopf on Google Scholar to find my papers, or email me via the Stanford faculty page.

BrentThank you so much for joining us. It was a wonderful conversation and thank you for your work.

David: Yeah. Appreciate your questions. It's great to talk.

BrentDeath Clock is recorded in Boulder, Colorado and San Francisco, California; produced by Patrick Gudino; music by Patrick Lee; and hosted by yours truly, Brent Franson, founder and CEO of Death Clock.