Can humans really live to 160?

Jay: The aging intervention that I've been advocating for since 1990 isn't an option. It's a requirement in the world of public health, and we have to pursue it aggressively. Otherwise, we're not going to like what we see among future cohorts that make it to older ages in the next few decades.

Brent: Welcome to The Life Lab by Death Clock. I'm your host, Brent Franson. The mission of Death Clock is to help 100 million people live ten years longer. Today, we speak with Dr. S. Jay Olshansky about the limits of human lifespans. Dr. Olshansky is a professor emeritus at the School of Public Health at the University of Illinois at Chicago. He is on the board of directors of the American Federation for Aging Research, and he has recently transitioned into a private sector role.

Brent: He has been studying human lifespans and what drives them for over 30 years. The thing I think is important to pay attention to in this conversation is that everything he's referring to, he's referring to at the population level. So when we talk about average human lifespans, what they are today, and how long they might be, he's really talking about averages.

Brent: I think it's important not to view him as being skeptical or for it to be disheartening. Regarding some of his concerns about how much we can really increase the average age at the societal level, I don't think you want to let that weigh too much on you individually. Individually we can make a lot of changes, even though it might be harder to do that on average across an entire population.

Brent: He's a wonderful guest. I hope you enjoy.

Brent: Dr. S. Jay Olshansky, welcome to the show.

Jay: Thanks for having me.

Brent: You're very relevant for the topic of health and longevity. You've spent your career studying life expectancies, the biology of aging, and the impacts of an aging population—how we might think about the social, political, and economic ramifications of that.

Brent: And so I'm excited to dive in and get your perspective on what you think is happening. Before we do that, can you give us a sense of your background?

Jay: Well, for the last quarter century, I've been a professor of public health at the University of Illinois at Chicago, where I focused on the fundamental question of how long humans can live. I helped to develop the field of biodemography about 20 years ago, which is an effort to understand the underlying biological forces that drive duration of life in humans and other sexually reproducing species.

Jay: Ten years prior to that, I was in the Department of Internal Medicine at the University of Chicago, and prior to that, I was in the environmental sciences section at Argonne National Laboratory here in Illinois.

Brent: Okay, wonderful. Let's start with answering that basic question: in your mind, how long do you think humans can live?

Jay: Let me step back a second on why I became interested in answering this question, because it's an interesting story. I was in graduate school at the University of Chicago taking a class from a well-known professor by the name of Bernice Neugarten, who asked me to try to answer a basic question for her: what would happen...

Jay: This was 1979. What would happen if the government succeeded in finding a way to slow aging in people? She and her colleagues were really some of the first scientists to address this issue of how long humans can live. I took on the challenge and wrote a paper that was thick, and Bernice, my advisor, suggested I turn that into my master's thesis, which I did.

Jay: Then I ended up writing a dissertation on the topic. That was back in the late 70s. I became enamored with this question of how long humans can live. There's a long history dating back thousands of years of claims that people were going to live 100, 200, 500, or a thousand years—as long as Methuselah from the Old Testament at 969 years.

Jay: I quickly came to discover that the vast majority of all the literature devoted to this question was based on embellishment and exaggeration. The timing of death in humans and other sexually reproducing species is highly controlled by genetic forces associated with the timing with which we reproduce as a species. When it comes to humans, we live about 29,000 days on average.

Jay: That's about it. I know you're going to take 29,000 divided by 365 and see how many years that is. Isn't that what you're doing?

Brent: Yeah, that's what I'm doing.

Jay: So I've seen that before.

Jay: It's about 79 or 80 years, and that's about where we are today. But it's important to realize that number is so high today because of modern medicine. If you strip away modern medicine and all medical technology—pharmaceuticals, dentistry, medicine—and let the natural limit to human longevity play itself out...

Jay: I think the natural limit for human longevity is somewhere between 30 to 60 years. We're living on manufactured time now. We're making it out to 80 years primarily because modern medicine has enabled us to manufacture a considerable amount of survival time. The question is, how much more can we manufacture and how healthy will we be along the way?

Jay: Those questions right there have been the focus of my research for the last 45 years.

Brent: I was at a longevity event earlier in the week, and someone gave a presentation about getting to 160. Their logic was that we've already had two doublings, and they think there's one more. At some point, you reproduce in your teens, then die a violent death or die of bacteria or a virus.

Brent: And then it became 40. Then with modern medicine, average life expectancy went from 40 to 80, and we can go from 80 to 160. They had three pillars for how you get to 160. What's your sense of the upper limit? Because I know you're a skeptic on the 160 number.

Jay: That line of reasoning is more than just a little naive. You really need to understand why the doublings occurred. I get this all the time from some of my colleagues who say, "Take me back to 1900. Who could have predicted that we would live to 80?" They're right, of course.

Jay: No one could have really predicted that we would live to 80. But keep in mind, we know why we live to 80, so we know why the first doubling occurred. We know why we got from 20 to 40, and why we got from 40 to 80. To go higher requires something fundamentally different. We can't do the same thing.

Jay: We have to do something fundamentally different than what we've done in the past. That something different has to be a modulation in the biological rate of aging itself, which has never been done. So it requires a technology that does not exist. And even if a technology did exist that could slow the biological rate of aging, we would have no way of knowing that it could make us live to 160, 120, or 100.

Jay: The reason is that it would take too long to test any therapeutic they might be thinking of to answer the question. So when somebody comes up with 160, they made it up out of thin air. I guarantee you with 100% certainty they made it up out of thin air, because there is no science behind any number higher than what we live today.

Jay: It's largely an untestable scientific hypothesis. I sort of laugh when I see somebody come up with this number of 160. "Oh yeah, we did it once, we did it twice, so there's a third doubling." You could make up any words that you want. Why don't they come up with 250 while they're at it?

Jay: Or 500 or 1,000, which I've seen some people propose. "If you double or triple the lifespan of a mouse, why don't you just do that for humans?" It's easy to say, but it's not easy to do.

Brent: If I were to push back just a little bit—not defending the 160 number—if we were to go back 100 years, the average was 40, but there were some 80- and 90-year-olds around. If we went back 500 years when the average was 20, there were still some 80-year-olds.

Brent: There probably weren't very many of them, but it's really just been increasing the percentage of people who can live that long. When I look around today, average life expectancy is roughly 80, but we know there are 90-year-olds, 100-year-olds...

Brent: There are even some people who are 110-ish. Why are you stuck on 80? Why wouldn't you say we can probably push it to 90 or 100?

Jay: Let me explain why I'm giving you a definitive no. I'm going to take you back to 1989. In 1989, I attended a conference run by George Martin, a scientist in the field of aging. At that conference, the issue of the upper limit to human longevity came up.

Jay: I didn't have a lot of ideas at the time on what that might be. But one thing that occurred to me was a way to try to answer that question: instead of trying to figure out the approach you took, I decided to reverse-engineer the answer. I decided to figure out what death rates would have to be in order to get to a life expectancy of 100.

Jay: What would death rates have to be in order to generate a life expectancy of 100? A life expectancy of 100 comes from a life table, which is based on observed death rates in a given time period. So there is no ambiguity or getting around the answer: to get a life expectancy of 100...

Jay: In any human population, death rates would have to be about 15% of what they are at all ages today. To give perspective, you would essentially have to transform a 90-year-old into a teenager in terms of mortality risk. You would have to eliminate all causes of death—heart disease, cancer, stroke, Alzheimer's—and even if you eliminate all of those, you still don't get to 100.

Jay: The reason you don't get to 100 is because there is an underlying biological process of aging percolating beneath the surface of all these diseases we see at later ages. Right now, we can't alter that biological process of aging. Maybe we'll be able to do so in the future.

Jay: I'm trying my hardest to make it happen. But unless that happens, it is neither mathematically nor biologically possible to get a life expectancy of 100 in a human population. That was the conclusion we came to in our 1990 article in Science: once enough people make it beyond age 65, aging gets in the way.

Jay: About a year and a half ago, we published an article in Nature Aging confirming our original hypothesis in Science was correct. It cannot happen unless we do something fundamentally different. In the meantime, we must stop making up numbers.

Brent: Okay, but I feel that you're putting up a wall at 80.

Jay: If you read our Nature Aging paper, we said women can make it to about 90 and men to about 84. So 87 is about the best we can do on average, but we're not there yet. Right now we're at 80. I'm not saying we can't get from 80 to 87, but getting from 80 to 87 requires an enormous effort in reducing mortality.

Jay: It goes way beyond anything achieved by eliminating many of the major causes of death today. So let's start with the correct numbers: 80 is where we are today, not the ultimate limit.

Brent: Your answer is 90 for women and 84 for men. How do we explain socioeconomic differences? The top 1% live substantially longer than the bottom 1%. That's not a biological difference; that's access to healthcare, lifestyle, and environmental exposure.

Brent: Those things feel solvable. It feels like you can democratize those factors from the top 1% down to other cohorts. Why can't we get there by making available the resources that allow the wealthy to live longer?

Brent: Let's just make that available to everybody.

Jay: So make all poor people rich, is that what you're saying?

Brent: There's the classic question: would you rather be a king 500 years ago or an average person today? You'd rather be the average person today because of access to better healthcare. Technology tends to get democratized, and the life of the average person is way better than 100 years ago.

Brent: So one can assume that people won't need immense wealth to have access to better healthcare.

Jay: Let me address your underlying premise. Take the subgroup of humans who are the wealthiest, most educated, and do everything right regarding diet and exercise. Under the best conditions, women in that group can get up to an average of about 90.

Jay: Keep in mind that's an average; half of that population will die before 90. You seem to be arguing that we can make everyone live as long as the right side of the distribution by giving access to healthcare, and that's foundationally incorrect.

Jay: If you give perfect healthcare, technology, and food to everyone, females reach about 90 on average and males about 84. Half still die before those ages. Why can't everyone live as long as Jeanne Calment?

Jay: Jeanne Calment made it to 122 in southern France. People say that's the maximum, so we should all shoot for that. But that's like saying we can all run as fast as Usain Bolt. Have you ever tried running as fast as Usain Bolt?

Jay: Why can't you run a four-minute mile if others can?

Brent: I'm guessing I could have if I trained for it in my early 20s.

Jay: I seriously doubt that.

Brent: I could have run a five-minute mile.

Jay: Running a four-minute mile is a quantum leap. The two-word answer for why everyone can't do this is genetic heterogeneity. Genetic variation exists in the population. It's why some people can live a perfect lifestyle and die in their 40s, while others live dangerously—like Jeanne Calment, who smoked for 100 years—and make it to 122.

Jay: Populations are genetically diverse and heterogeneous. The reason you or I can't run a four-minute mile is that our bodies weren't designed to run that fast. Some people have a body design capable of running that fast or living exceptionally long, but the vast majority of us do not.

Jay: It is biologically naive to suggest that we can all run as fast as Usain Bolt or live as long as Jeanne Calment.

Brent: To make it more practical: I think there are two groups in longevity. Group one believes we can live to 160 or live forever; they're bleeding-edge and ahead of the science.

Brent: Group two is the incremental decade camp. They believe that if you pay attention to sleep, diet, exercise, wear a seatbelt, don't smoke or drink excessively, and get cancer screenings, you can gain an extra ten good years.

Brent: Where did you come up with that ten-year number?

Jay: Where did you come up with that number? Tell me you didn't make it up.

Brent: It's a round number, but there's logic to it. It's not crazy to see someone live to 85 or 90, whereas life expectancy today is around 75 due to high rates of preventable chronic disease. Adding years by treating yourself well doesn't seem unreasonable.

Brent: What's your perspective?

Jay: It's not crazy; you can manufacture time. One way is to avoid losing it—don't smoke cigarettes or become obese, which shave off time.

Jay: It doesn't apply equally to everyone, but avoiding things that shorten life should be rule number one.

Jay: Then adopt healthy lifestyles, and third, manufacture survival time by monitoring your body through screenings.

Jay: My wife and I have doctors who evaluate different parts of our body annually.

Jay: I had my life saved by a surgical procedure in January. I am living on manufactured time, as is much of the population today thanks to medical technology.

Jay: The question is: how much more time can we manufacture? Once populations succeed in getting enough people to live past age 65, you run into a currently immutable force.

Jay: You still age and die. The longer we live, the more difficult it becomes to manufacture additional survival time.

Jay: In epidemiology, this is called competing risks—like a game of Whac-A-Mole. In your 80s or 90s, age-related diseases accumulate: knock one down, and others crop up.

Jay: It gets increasingly difficult to manufacture survival time. Over the last 30 years, while life-extending technologies accelerated, the rate of increase in longevity actually decelerated. We proved this in our Nature Aging paper.

Jay: The data clearly show that our ability to manufacture survival time is waning.

Jay: But our ability to manufacture survival time is waning.

Brent: If you cure cancer, heart disease is still there. If you cure heart disease, something else gets you. You have to cure all diseases, and then there's still the underlying process of aging.

Brent: What do you believe is the incremental time gained from healthy behaviors if not a full decade?

Brent: And so what is it for you, the incremental what if it's not the incremental decade.

Jay: Months and years. We can manufacture relatively small amounts of survival time on average. For a 20-year-old saved from cancer, you manufacture 50 to 70 years. But today, we're primarily manufacturing survival time for people who are already 70, 80, or 90.

Jay: The next doubling requires something fundamentally different from anything done in the past. Incremental gains are possible, but the amount of survival time we can manufacture is getting smaller.

Jay: And you have to understand what got us here to begin with in order to appreciate what's required to get us further. So yeah, I'm with you. Incremental gains are possible. This is the manufactured survival time that I've been talking about, but the amount of survival time that we can manufacture is definitively getting smaller. And smaller. That was what we proved a year and a half ago.

Brent: When speaking about months and years, you're talking about population averages. Saying a seatbelt adds 10 minutes to life expectancy sounds small because it's averaged across the entire population, even though for an individual involved in a crash, it saves 50 years. Statins might add weeks on average, but save decades for specific individuals.

Brent: You're like, well, then why would I wear my seatbelt? Well, it could be for you that you lose 50 years, but we're averaging all that time across the population, and that's where you get the ten minute number. Or if you hear some idiot on Twitter talking about taking statins is only going to add, you know, two weeks to your life or whatever it is that's on average.

Brent: But there's some person who started taking statins, didn't have the heart attack, and they gained 25 years or, you know, 40 years or whatever it might be. So the averages can make things seem small.

Jay: Exactly. That's the difference between individuals and populations. GLP-1 agonists will manufacture significant survival time for individuals by lowering risks of diabetes, cardiovascular disease, and cancer.

Jay: Can we get past 90 for women and 84 for men at the population level? I don't think so. These advances delay diseases rather than cure them.

Brent: We're making medical advances, public health progress on smoking, reduced drinking, and awareness of processed foods. How is that playing out in year-over-year population life expectancy?

Brent: We seem to be drinking less, were more aware of, how unhealthy processed foods are and things like that. It does seem, from just a general health perspective that we are headed in the right direction. How is that playing out on, I don't know, year over year changes in population level life expectancy.

Jay: Those are cohort effects. More educated cohorts make better health decisions and have better healthcare access, leading to lower death rates as they age.

Jay: That happened during the 20th century. Now cohorts reaching old age have better medical care and technology, yielding incremental improvements at the population level.

Jay: At the individual level, gains can be significant. You want to aim for the right side of the distribution. Healthspan—how healthy you stay as you age—is now the dominant goal in aging science, because life extension without health extension can be harmful.

Jay: So it's important to distinguish between, what's going on at the population level and what's going on at the individual level. At the individual level, of course, the goal is to make it to at least the right side of the distribution. When I say right side, that means the longer side of the half, right? And so if the we're talking about females living to 90, yeah.

Jay: You want to be on the right side of that, or at least you'd prefer to be on the right side if you're healthy. And this whole issue of health spending, how healthy you are along the way, is now become the dominant, mantra in the world of aging science, because we realize life extension without a health extension is, for many people, harmful.

Jay: The rise in late-life diseases isn't a failure; it's a consequence of living long enough to experience conditions that weren't previously observed.

Jay: It's like, let's say that there's like if you drive a particular type of car where the only way you can see something. This one particular problem with it is if you drive it for 150,000 miles. Well, yeah, most cars aren't driven for 150,000 miles. But if suddenly a lot of cars are driven that long, you get to see this problem emerge.

Jay: That problem is not a consequence of doing something wrong. It's a consequence of doing something right, enabling the car to to operate longer. It's the same thing with human bodies. We get these bodies to operate longer. We see things go wrong that we otherwise wouldn't see.

Brent: Much of today's health conversation centers on diseases of abundance. We doubled life expectancy from 40 to 80, so now we see these conditions.

Brent: Obesity and sedentary lifestyles are byproducts of our success as a species.

Jay: That's right. You also see aging in household pets and zoo animals—something rarely seen in the wild.

Jay: And so we're we're conducting this experiment not just on ourselves, but you see it in, our pets and you see it in zoos and laboratory animals, where you get to see aging with increasing frequency. And guess what? The same things that go wrong with us, go wrong with.

Brent: If we travel 50 years into the future and Dr. Olshansky is proven wrong—we do reach 160—what gets us there if there's another doubling?

Brent: What do you think that is? It's Yamanaka factors. It's you know everybody's sitting in their hyperbaric chambers sucking down straight oxygen. And everybody started taking the supplements and doing the full body scans. Let's say you're wrong. What do you think gets us there if there is another doubling if you had to bet on it today.

Jay: I would study subgroups of humans who already live long, healthy lives to understand the genetics behind exceptional longevity. Decelerated aging isn't a mystery; it has always been present in centenarians.

Jay: There have always been people that have lived out to older ages. In today's world, we see, you know, some super centenarians, although they're mostly not very healthy. But we do see some centenarians.

Brent: Super centenarians would be over 110.

Jay: Supercentenarians are over 110 and typically very frail. It's difficult to imagine bringing someone back from that level of frailty to make them young again.

Jay: Initial breakthroughs will likely come from studying the genetics of centenarians and their slower biological clocks. While it won't push us to 160, it holds potential.

Jay: Proposing 120 or 160 requires reversing brain aging, as we lose brain mass starting relatively early in life.

Jay: It's naive to suggest all body parts can last 160 years when certain parts have replication limits.

Jay: So imagine getting knees to last for 160 years. Well, I don't think that's going to happen. How about hips?

Brent: The brain seems to be the limiting factor, whereas we can replace hips and knees.

Jay: Exactly. We can replace knees and hips, but muscle fibers and brain neurons do not replicate.

Jay: We would have to stop or reverse aging in all these non-replicating tissues to get bodies to last that long.

Jay: It's fun to talk about. And there's lots of movies on that topic, but, I think it's sort of ridiculous to to have that discussion.

Brent: What about Yamanaka factors and research pointing to reversing cellular aging?

Brent: But there are some lines of research that seem to point to the ability to reverse aging at the cellular level. Do you feel it's too early or you'd be skeptical of those?

Jay: I am excited about research aimed at altering fundamental aging mechanisms beyond standard body limits—an argument I've made since 1990.

Jay: I hope I'm wrong and that we can push survival beyond current estimates, but it requires doing something fundamentally different.

Jay: But unless we do something different, it can't happen.

Brent: Could population-level lifespan extension be solved generationally through genetic screening? For example, I'm an ApoE e3/e4 carrier with a higher risk for Alzheimer's, whereas e2/e2 carriers have a protective profile.

Brent: If you mandated genetic screening of embryos to select for optimal genetics, wouldn't that significantly raise life expectancy?

Brent: And I think maybe I don't get us to 100, but I think I, you know, I get us pretty far. Why is it genetic screening? The answer setting aside whether that's a very dystopian or utopian concept. Yeah.

Jay: In fruit fly studies, selecting females that remain fecund later in life leads to extended lifespan over generations. The same principle would likely work in humans by shifting the reproductive window.

Jay: And you only allow, the females that are fecund later and later to reproduce than you would experience life extension. And of course, this would likely work in humans that if you only allowed females that were fecund at 50 to produce the next generation, then you took those generation of females and only allowed the ones that were fecund until 51, and then the next generation 52, and so on.

Jay: And until you only had, sorry.

Brent: What is fecund? What does that word mean?

Jay: Fecundity means the capability to reproduce. Women who reach menopause later tend to live longer. Manipulating the reproductive window alters lifespan, but widespread artificial selection won't happen in the real world.

Brent: Contraception separates sex from reproduction, so intentional reproduction could increasingly occur through IVF and screening.

Brent: And you know, that society's not that hard to picture limit.

Jay: Pre-pregnancy genetic screening has occurred for decades to prevent conditions like Tay-Sachs. However, broad population-level embryo selection remains highly limited and constrained by real-world ethics and behavior.

Jay: So we were very careful, about that. That's been going on for a long time. You have to realize that if you get screened after, the the females are already pregnant, then you're talking about selective abortion, and then it gets bizarre, right? Because if you're only selecting for longevity and health or IQ or whatever it is that you're selecting for, then you're doing selective abortions, you know, against people that don't have those attributes.

Brent: I thought, I mean, we're doing this today with embryos, right? Prior to implantation. We're doing some some limited amount of it.

Jay: It's very limited. What I'm talking about is, screening of females that got pregnant naturally and using selective abortion as a way, which not only would I be dead set against that for a variety of reasons, it's also not going to happen, in the real world. But you can do incremental screening and you can certainly, you know, you could do that.

Jay: Some of the screening you could do before you try to have offspring, before you try to have children, like, all right. What do you carry? What do you carry? You know, we need to be cognizant of the possibility that we may be producing a child with a high risk of, of a particular disease or disorder. Maybe they'll decide not to have children and adopt, as a result.

Jay: That's the kind of screening that I, I think could work in theory, but in the real world, you're not going to get populations to, to, you know, use embryonic screening. It's just not going to happen. It's there's some movies. There have been some really good movies that have come out that have that have have done this. I'm trying to remember Ethan Hawke.

Brent: Gattaca. Well, I so if I were to repeat back here again, let me just be clear. I'm not advocating for this. I'm it's more of the just the intellectual exercise of thinking how one how it might happen. And so but if I were to repeat back your argument, what I hear you saying is, okay, everybody doing IVF and forgoing reproduction through sex, that's not going to happen.

Brent: And so in the case where there is natural reproduction, then you're talking about selective abortions based on, you know, whether or not somebody got an E4 or whatever it is. And that's not going to happen either. So we will do some increased screening. We screened for X, y, Z today and then maybe there'll be a, b, c tomorrow.

Brent: And so that'll change things a little bit. But this is not going to get you from 87 to 100. But let me ask the question. So but you're not. It's not technologically impossible to get from 87 to 95 using crazy IVF screening. You're just saying there's no way it's going to happen.

Jay: Theoretically, altering the reproductive window and selecting traits can extend lifespan, as proven in fruit flies. But in practice, societal implementation won't happen on a scale that shifts averages to 100.

Jay: You start manipulating that reproductive window. You're likely manipulating longevity along with it. So is it theoretically possible? Yeah. Of course. And it's great stuff for movies, but I try to operate in the real world and in the real world. It's not going to happen.

Brent: What are you most excited about or currently working on in this space?

Jay: First, helping people realize that aging is inherently modifiable. Medicine and public health have spent over a century trying to manufacture survival time.

Jay: No one has accepted aging. The world of public health, all of medicine, all of public health has always been devoted to combating what we, you know, what many used to think was inevitable. It's been going on for for hundreds of years. And so I reject that concept outright, that there's some sort of death cult. There never has been a death cult.

Jay: While legitimate science shows aging can be modulated, predatory actors sell products with false claims, and some scientists exaggerate results to attract investor funding.

Jay: But then you get these folks that are trying to sell products to the public with false or misleading claims that it's going to add this number of years to your life, or it's going to do this, or it's going to do that, and all they're trying to do is separate you from your money and with false or misleading claims.

Jay: I remain optimistic that a valid therapeutic modulating biological aging will eventually emerge. It will be the most valuable public health intervention in history.

Jay: Without an intervention targeting aging, future cohorts reaching older ages will face extended periods of frailty and disability. Intervening in aging is a public health necessity.

Jay: It's a requirement in the world of public health, and we have to pursue it aggressively. Otherwise we're not going to like what we see among future cohorts that make it to older ages. In the next few decades.

Brent: With people living longer and fewer younger people to care for them, it creates a perfect storm.

Jay: I see myself as a realistic optimist. We must recognize biological limits rather than relying on unfounded claims of living to 160 through basic lifestyle changes.

Jay: First. You have to recognize that these bodies were not designed for long term use. If you don't recognize that, then you come up with these cockamamie, you know, concepts of living to 160 just by, you know, eating right and exercising. And it's a real naive, perspective among those who have no sense of history. They don't know how we got here.

Jay: They don't know where we're headed. All they know is, is that they they they they can make up numbers very easily, you know, 160 or whatever it is, without understanding that mathematically, it's not even possible to get to 100, let alone 160. And so I, you know, honestly, I just laugh when I see that and I see it all the time.

Jay: Unfortunately, even among some of my colleagues who will make up numbers and, you know, I'm, you know, my eyes are rolling in the back of my head going, oh my goodness. If they still haven't learned their their lesson that there are inherent limits on how long these bodies can last.

Brent: You're following the data and math. A fundamental breakthrough is required to go beyond current limits.

Brent: It just is what it is. I'm hoping for a breakthrough. I'm rooting for a breakthrough. I think, you know, but it's going to be some fundamental difference. The same way that we got to from 40 to 80. It's not going to be that way that we get from 80 to 160. And until there's some obvious path from 80 to 160, the information we have is the information we have.

Jay: Life expectancy increases operate on an exponential scale rather than an arithmetic one. Producing each additional year of life expectancy becomes exponentially more difficult the longer we live due to diminishing returns.

Jay: This was one of our conclusions, by the way, in our 1990 article in science, we referred to it as entropy in the life table. I know some of my colleagues don't like it when I use the word entropy, but I think it's actually conceptually a pretty good way of understanding the concept of diminishing returns. Life expectancy just does not rise on an arithmetic scale.

Jay: Rise. The rise of exponential scale. I can't remember what word I use before, but it's an exponential scale and and it's easy to throw out numbers. Oh yeah. We'll just go from 90 to 100. Well guess what? Going from 90 to 100 is, is like going from here to Pluto in 15 minutes. It just is. So beyond the the realm of possibility is why are we even discussing it?

Brent: Dr. S. Jay Olshansky, thank you so much for your work and your time.

Jay: Thanks for having me.

Brent: The Life Lab by Death 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.