Live Long and Master Aging podcast



Using epigenetic clocks to determine biological age

Morgan Levine: Yale School of Medicine


We are all used to feeling younger than our years and occasionally older than our birth date would suggest.  In effect, we have two ages – chronological and biological. Chronological age simply states the number of years that we have been alive, whereas biological age is a measure of how well our bodies are performing, in relation to the rest of the population. 

So how is it determined?  LLAMA host Peter Bowes delved into the science with Elysium Health, which has developed Index, a DNA test that tracks how fast we have been aging, based on our epigenome, which regulates the way genes work. 

In this episode, Peter meets Dr. Morgan Levine, an assistant professor of pathology at Yale School of Medicine and an advisor to Elysium Health. They discuss the background to Index, its use of epigenetic clocks to put a number to our biological age, as well as the test’s accuracy and implications for healthy living. 

Recorded: April 21, 2021 | Read a transcript 

Connect with Dr. Levine and Elysium Health: Bio at Yale School of Medicine | Research and publications | Index | Elysium Health | Instagram | Twitter | Facebook  

Topics covered in this interview include:

  • Defining biological age and chronological age. 
  • Age as a risk factor for death and disease
  • Having an older parent and developing an interest in aging 
  • A lack of consensus over what exactly is meant by aging.
  • How much of aging can be defined as damage to the body, at a cellular level, as we grow older?
  • How do we measure biological age?  
  • Genes, genomes and the epigenome.
  • Developing systems that determine biological age based on epigenetic clocks.
  • Exploring the Index epigenetic, at-home saliva test, to determine biological age.
  • Privacy concerns related to sharing personal medical information.  
  • Revealing Peter’s biological versus chronological age. What does it mean? 
  • Interpreting the test results and taking action based on the findings.
  • Does the test reveal information specific to potential medical conditions?
  • How do doctors – primary care physicians – respond to the information gleaned from such tests? 
  • The paradigm shift from disease treatment to interventions that delay illness. 
  • Lifestyle interventions that promote a long, healthy life.  
  • The reliability of biological age tests. Do repeat tests over a short space of time generate the same results? 
  • To what extent do results vary between young and older people? 
  • Lifespan and healthspan aspirations. 

Disclosure:  For review purposes, Elysium Health provided Peter Bowes with an Index test kit, free of charge .

  • This episode is brought to you in association with Clinique La Prairie, the award-winning spa-clinic – and pioneering health and wellness destination – nestled on the shores of Lake Geneva in Montreux, Switzerland. Combining preventative medicine with bespoke lifestyle and nutrition plans, Clinique La Prairie offers a holistic approach to living fuller, healthier and longer lives.

The Live Long and Master Aging podcast, a HealthSpan Media LLC production, shares ideas but does not offer medical advice.  If you have health concerns of any kind, or you are considering adopting a new diet or exercise regime, you should consult your doctor.


Morgan Levine: [00:00:00] What we usually do is wait for someone to develop some disease or have some really abnormal lab test, and then we pay attention to them and treat them, whereas this is kind of flipping that and saying, can we see how you’re doing prior to ever developing some disease?

Peter Bowes: [00:00:20] Hello again and welcome to LLAMA. LLAMA is Live Long and Master Aging. I’m Peter Bowes. This is our podcast where we explore the science and the stories behind human longevity.

SPONSOR MESSAGE: [00:00:30] This episode is brought to you in association with Clinique La Prairie. The award winning Spa Clinic and pioneering health and wellness destination nestled on the shores of Lake Geneva in Montreux, Switzerland. Combining preventative medicine with bespoke lifestyle and nutrition plans, Clinique La Prairie offers a holistic approach to living fuller, healthier and longer lives.

Peter Bowes: [00:00:55] Now, how old are you? I don’t mean how many years have you been alive or indeed traveled around the sun, I’m thinking of your biological age. You may be 50, but the physical condition of your body may be more akin to that of a 40 year old or a 60 year old. Our chronological age is something we can do nothing about. But our biological age, sometimes described as our second age or phenotypic age, is a barometer of our state of health. To a large extent, it is in our own hands. My guest today is Dr. Morgan Levine, an assistant professor of pathology at Yale School of Medicine and an adviser to Elysium Health, which has developed what it calls Index, a DNA test that tracks how fast you’ve been aging. I did the test a few weeks ago and I will reveal the result a little later in this conversation. Dr. Levine, welcome to the Live Long and Master Aging podcast.

Morgan Levine: [00:01:52] Thank you, Peter. It’s great to be here.

Peter Bowes: [00:01:53] Yeah, it’s good to talk to you. And I gave a little summary there of the difference between biological and chronological age. Perhaps you could elaborate for us and tell us why it’s important.

Morgan Levine: [00:02:04] Yes, exactly. So kind of how you said it your chronological age is just the time you’ve been alive since you were born. And this is something we can’t do anything about and unfortunately has come to have a negative connotation in our society. And that’s because traditionally it’s actually one of the biggest risk factors for death and disease. But truly, what matters is not your chronological age, but actually your biological age. So all the ways biologically that you have changed over time. And that’s actually what is giving rise to disease risk. And that’s actually what we should be measuring and caring about more than just the time we’ve been alive.

Peter Bowes: [00:02:46] Exactly. So I want to dive deep into that with you in a moment. First of all, let’s just talk about you for a while. Your background, your interest in aging and your education. How did you get to this point?

Morgan Levine: [00:02:58] So I actually did my Ph.D. in gerontology, so I started studying aging when I began my PhD it was something I was very interested in, even from a young age. So I think thinking back on it, part of why I was probably interested in aging is that my father was much older when I was born, so he was in his mid 50s when I was born. So it was something I was always very aware of and for that reason, also very worried about in terms of, you know, my father’s aging process and, you know, will he be here to see me graduate high school, college, etc.? And then I’m also just interested in aging, because to me, it’s it’s basically a fundamental question of what is life. So is it’s to me in the same kind of genre. And it’s just something that fascinates me as the scientific question in general

Peter Bowes: [00:03:50] And studying gerontology. What did you specialize in? Because that’s that’s a big word and it’s a big area of study and and education – was there one particular area that you focused on? 

Morgan Levine: [00:04:04] Yes. So actually, at the time, I was very interested in this question of can we measure and track biological age? I started in what’s called the Mathematical Demography Lab. So we were interested in, within populations, what are things that give rise to differential risk of disease or mortality among people? And this is kind of how I got into can we actually measure the biological aging process and does that actually track with differential lifespan or what we call healthspan as well?

Peter Bowes: [00:04:37] And this is the age-old question, and I’m sure you’ve been asked it many times and you must have thought about it a tremendous amount as well in terms of a definition of aging. Is it possible to encapsulate what it is and just talking to other people in similar positions to you? I’ve noticed how that definition can change in terms of perhaps your understanding of it and throughout your period of education.

Morgan Levine: [00:05:00] Yeah, I mean, I think there’s no consensus on how we define aging or what it actually is that we’re all interested in studying. The way I like to think about it is, is that as an organism, we’re actually just a very complex system and that complex system is optimized to work in a certain way. So all the things have to be kind of arranged and working together in a very specific manner for us to be healthy and vibrant. What we think of as youthful, however, over time, due to just either random errors or other things, the system, its properties are going to change. And I just define aging as kind of the divergence from that original maybe what we might think of as perfect system. And this over time will give rise to the risk of the system failing altogether or just not working quite as well as it once did.

Peter Bowes: [00:05:54] And so the accumulation of damage plays a key role and the fact that as we grow older our cells don’t always replicate properly. So that’s it’s crucial to growth and it’s crucial to maturity of the body. But as we get older, faults occur and they’re not always repaired in the way that they might have been when we were younger.

Morgan Levine: [00:06:16] Yeah, so so I think, you know, some of it is damage. I actually am not in the camp that I think everything in aging is actually damaged. I think the system was not set up to be able perhaps to last at least for humans, you know, more than a hundred years and maybe change. So some of it is just changes that are allowed to happen because we’re not optimized to live, you know, whether it’s two hundred years or whatever it ends up being. So, yeah, some of it’s damage, but some of this just the natural changing in the system.

Peter Bowes: [00:06:50] And I think it’s fair to say, I think you’ve already touched on this, that aging per se is the most important risk factor when it comes to developing those potentially killer diseases, diseases that have the potential to end our lives. So heart disease, diabetes, cancer.

Morgan Levine: [00:07:08] Yeah, all the major diseases that people tend to die from are age related. Aging is by far the biggest risk factor. I always like to start when I’m teaching to ask my students what the biggest risk factor for lung cancer is. And a lot of people think, oh, it’s smoking. But actually I think aging, if you compare a 20 year old to a 70 year old, the that risk, I think is close to four hundred fold the difference between a smoker or a non smoker for something like lung cancer. So, yeah, I think people forget that that is just such a major risk factor. And I think, too, we don’t see a lot of people don’t assume that it’s anything we can do something about. We just it’s something we just kind of take lying down and assume. We yeah, we can’t intervene in the process in any way.

Peter Bowes: [00:07:58] So let’s delve into biological age and chronological age. And as you explained clearly, chronological age is not going to change. That is set in stone. We have lived a certain number of years and we will at some point die and that will end our lives. Biological age represents our state of health. And so the key question that we’re going to talk about is how can we discover what our biological age is?

Morgan Levine: [00:08:23] Yes. So there’s actually, again, not a consensus on how we actually measure biological age. I would actually argue that you don’t have a single biological age, you know, in the way that you might have a single chronological age. But actually, no depends on which part of the system we’re actually measuring. But what we like to do is kind of measure as many things as possible and get an overall estimate of kind of how you’re doing as a whole. And so we measure biological age using what we call epigenetic data. So this is distinct from kind of your genotype, which is the nucleotide sequence A, C, G and T, but that in epigenetics we’re actually measuring chemical modifications that are happening to the DNA. And what we found is that those actually change very dramatically with age and are actually a good way to try to get at this estimate of biological age or how physiologically robust your system might be.

Peter Bowes: [00:09:24] That’s an important distinction. I think that you mentioned the genome per se is not going to change, but there are external factors that can play environmental factors, exercise, I guess, food that we intake, perhaps toxins in the air. Who knows everything that bombards our body could affect our genes.

Morgan Levine: [00:09:44] Yeah. So your your DNA sequence is more or less that for life. Of course, you know, there are a few mutations that pop up. But even I like to talk about how every cell in your body has essentially the same DNA sequence. But what changes one cell type from another is your epigenome and same thing. What changes a young cell from an old cell is also your epigenome. So the epigenome is really what’s dictating the the phenotype of your cells. And, you know, one of those phenotypes is kind of the agedness or robustness of the cells. So we can actually pull that information out by looking at the epigenetic pattern across thousands or millions of cells within a given sample.

Peter Bowes: [00:10:27] And this is important because everything really comes down to our cells. They are the basic building blocks of our body. And if there’s something wrong, if there’s if there’s a defect that can it could be like a roller coaster effect, I suppose, in terms of how it would affect our outward health.

Morgan Levine: [00:10:44] Yeah. So when I when I think of aging, I really like to think of it from this kind of idea of biological levels of organization. So at the very lowest level is kind of the molecular level. And then, you know, the changes that happen, they’re going to affect the changes at the cell level. And then, you know, all the changes for your cells are going to affect tissue level. And then eventually this will be up to kind of the level what we define as the organism, which is how we define us and where we actually can visually see aging manifest. But that really stemmed from all these changes happening at much lower levels that are just kind of emerging as, you know, what we think of in terms of when we can visually see aging or the diseases that arise with aging.

Peter Bowes: [00:11:31] So there’s been a tremendous amount of work, a lot of science and research put into developing systems that can help us discover what our biological age or, as you say, may be a number of biological ages. But can you talk us through that science that’s led to the development of these systems? And I mentioned Index, which has been developed by Elysium Health. How they work.

Morgan Levine: [00:11:53] Yeah. So the ones that I was discussing, again, based on this epigenetic data, the first one was actually developed in 2011. And originally the way that people developed these is they just looked at which how did these patterns change as a function of someone’s chronological age? So can they predict someone’s chronological age using an epigenetic pattern for an individual? And you can actually do that quite well. We can predict chronological age within three to five years on average for most people. But when I started to work in this field, what I realized is, again, we don’t want to predict your chronological age. What we actually care about is your biological agent. And of course, there’s no way to directly measure that. So we had to figure out kind of how do we get a measure that’s a better approximation of that versus chronological age. So what we did is we looked at what patterns are dictating differential risk of diseases, of Healthspan, what patterns are predicting lifespan and we figured that those are the ones that are probably better representation of your biological age. So we’re talking what I’m talking about are things called epigenetic clocks. And again, there’s been a number of these that are developed, but most of them are actually predictors of chronological age, whereas where we’re trying to make the distinction is predicting biological age. And we found that the clocks that we’ve developed or the ones that are also trained to predict biological age are better indicators of either current health status or also future kind of health and wellness outcomes.

Peter Bowes: [00:13:33] Now, of course, it’s very likely and maybe you could tell me statistically, very likely, of course, that someones is biological age and chronological age are not going to be the same number, that some people are going to be higher or lower. Do you know from population studies on average to people tend to have, for want of a better phrase, younger bodies than their actual chronological age? Or are we a little bit older and then you would assume less healthy than perhaps our chronological age would suggest?

Morgan Levine: [00:14:03] Yes. So on average, when we look at a population because of the way these are actually developed, the average person will be equal to their chronological age. However, what we usually see is that most people will diverge between plus five years or minus five years. So that’s kind of what we call this one standard deviation in your difference between biological and chronological age. And then you see some people as far as 20 years difference, but the majority of people will fall within five years, either higher or lower of their chronological age.

Peter Bowes: [00:14:37] But so statistically, most people would come down to the same number. And that surprises me a little because I would be wrong in this. I would assume that obviously if your biological age is younger, that you’re in a better state of health, knowing that we have populations around the world that are generally unhealthy and obese, especially in the Western world, I would have expected that most people would come out with a biological age actually older than their chronological age.

Morgan Levine: [00:15:03] So the way we actually are defining biological age is actually it always is in reference to certain populations. So it’s basically saying you have the biological profile of the average person this age in a population.

Peter Bowes: [00:15:16] I see. 

Morgan Levine: [00:15:17] So because the average 30 year old will have the biological age of the average 30 year old within a population and ends up actually having kind of having this mean around zero in terms of year difference between biological and chronological age.

Peter Bowes: [00:15:33] So I understand it now. So it’s not taking the average based on what you would expect from optimum health. It’s taking the average from what is the reality of the state of health of a person in a population.

Morgan Levine: [00:15:45] Yes, it’s putting in reference to everyone else or at least everyone in our reference population that we used to estimate these different measures.

Peter Bowes: [00:15:53] So as I mentioned, I took the Index test a few weeks ago and as I say we’ll talk about the result that it produced in a few moments. But for people, obviously, who are not familiar with that test, maybe you could talk it through what it involves.

Morgan Levine: [00:16:08] Yes. So this, again, is one of these what we call epigenetic tests are based on epigenetic clocks. So basically what we do is this is an at home saliva test. So people will get a tube, spit in the tube, send it back to the lab. Then what we do is we actually sequence the methylation levels at about two hundred and fifty thousand sites across your genome that we specifically picked out, because we think these are actually informative for things like biological age. And then we combine them in our algorithm that we’ve developed and validated. And it spits out a biological age that you’ll end up getting an email, that it’s available and it’ll be in your kind of personal profile that you create on the website.

Peter Bowes: [00:16:54] One thought that might come to mind for a lot of people when thinking about doing something like this is privacy and the sense that you’re actually giving away a lot of information about yourself. Should people be concerned about that,do you think?

Morgan Levine: [00:17:09] I mean, I think it’s something that’s always a valid concern that people should have. We also have the option that at any point, if someone wants their data completely destroyed, we’re more than willing to do that. So it’s not this kind of lasting profile that’s going to remain online. It can remain. And you have, you know, your own password protected way to actually access this. We actually don’t ask for any other identifying information. And and again, because we’re not actually looking at your genotype, the methylation, because it’s a dynamic thing, we actually can’t identify people from this information. So it’s not like some of these other things with genetic testing where people can identify, you know, relatives or, you know, use the actual sample to match it to something else. These are things that are dynamically changing for every individual. So, you know, whatever your profile is at a given point of time is not something that defines you in any way.

Peter Bowes: [00:18:07] I think that’ll be reassuring to a lot of people because we do live in this world where we share an awful lot about ourselves. And I think it’s important to have that concern, equally, and I come into this category, I think the science is there to be exploited. And if it can tell us useful information, well well, let’s go for it. And so that’s what I did. And I did your test and you get an email a few weeks later. And in my case, it told me that I don’t know whether you know, the results of my tests or not, but it tells me that I have a biological age of 52 as opposed to a chronological age of 58, as I was at the time of the test. I’m actually now 59, so 52 as opposed to 58 when I did the test. How should I interpret that?

Morgan Levine: [00:18:52] So that’s great news for you. So I guess I would say that you’re about six years younger, biologically than chronologically. So as I mentioned before, the average person is going to get exactly the same as their chronological age. And and most people will be within kind of a five year window. So you’re just outside that. And basically the way that you can interpret that is that on average, you actually have the health risks that are associated with someone who is 52 as opposed to what your actual chronological age is, which, you know, was 58, now is 59.

Peter Bowes: [00:19:30] So I have the the health risks associated with the average person, let’s say, living in the Western world or the average male person. Do you distinguish between sexes or the average person generally?

Morgan Levine: [00:19:43] Yeah. So it’s the average person generally we don’t distinguish by sex, race, ethnicity or any of those things. They do on average, women tend to be younger based on this test than men, but it’s not, you know, across the board.

Peter Bowes: [00:19:57] So that’s how to interpret it. How should I use this information to my benefit?

Morgan Levine: [00:20:03] Yeah. So I think, again, the exciting thing about this is that biological age or epigenetic age is actually modifiable. So some people just like to get the information and say, OK, I’m doing pretty well. Or, you know, maybe I’m doing about what I’d expect. And they’re just happy with that reassurance. But there’s definitely other people who are using it to try and actually optimize their health. So whether they want to try an intervention or see if, you know, what they’re doing in their everyday life is actually having an impact is what you can now use this information for. And where you can actually do is come back. What we’re recommending is maybe once a year to take this test and actually see where you stand the following year. And the important thing we’re doing that is because it’s not necessarily your level today that’s, you know, really matters. What it is, is actually how fast kind of the pace of your rate of biological aging relative to chronological age over time. That seems to matter.

Peter Bowes: [00:21:06] Yeah, I can see why that would be important. You can imagine a graph over the years in terms of how your number changes. And I guess for people like me who end up with a biological age a few years younger than the actual age, there’s certainly a feel good factor there that you must be doing pretty well and you must be reasonably healthy, I guess, for people. And the number comes back and it’s significantly higher. Let’s say it was six years higher for me. So I’m the equivalent of someone in their mid 60s. That’s not going to be positive news and there isn’t going to be a feel good factor there. And for some people, it could cause a lot of concern. What would you say to those people, people in that group, how they should respond to that negative information?

Morgan Levine: [00:21:48] Yeah, I mean, I think, you know, no one wants to find out that they’re actually doing worse than average. But I think, again, the the important thing to keep in mind here is that it’s not like a genetic test that says, you know, you have a risk allele for this disease and there’s not much you can do about it. Again, these are things that we’ve actually found are not not highly genetic and actually environment and behaviors and things like that actually play a bigger role in what your number is than your genetics. So what I would suggest is if someone actually gets a number they’re not happy with is to critically think about, you know, what they’re doing in their everyday life. You know, we’ve listed a number of things that when we look at populations tend to be associated with differences in these measures. So things like smoking, diet, physical activity, sleep. So all the things that people kind of know they should be doing, but maybe we’re not always as accountable as we should be. And then, you know. See you can make small changes and see, you know, come back and check your biological age, you know, six months a year later, see if that made an impact. And the other thing that’s important is you can kind of use this to decide how much it’s worth to you. Right. If I if someone might not want to be completely plant-based diet their entire life. But what if it afforded you, you know, 10 years versus one year, then would it be worth it? So it’s actually a way to kind of contextualize how much effort you might put into different facets of your life as well.

Peter Bowes: [00:23:30] And just to be clear, the algorithm that you use does it in any way, is it specific? Cannot tell someone that they are producing a biological age older than their chronological age because it’s something to do with their heart that isn’t optimized or their muscles or other aspects of their body or even at a cellular level that isn’t the equivalent of the average person of their age.

Morgan Levine: [00:23:57] So the version you got does not have that. But actually we are on the precipice of releasing something very similar where we’re actually looking more specifically at systems and looking more at a profile of an individual where we can say, you know, on average you’re doing this well. But really the point you’re kind of weak versus strong suits are, you know, this or that. And based on that, I think in the future, people, you know, you can talk to your doctor, but also in the future, our goal is to actually use this information to make perhaps predictions of what someone should do based on their personal profile. So you can actually say once you have a big enough database, people who have your profile on average benefit from some behavioral change. We’re not quite there yet with the data, but we are at the point where we can start looking. As I mentioned before, people don’t have one biological age. But looking at kind of your multiple biological ages and really trying to pinpoint where you’re doing well and maybe where you could see some improvement in the future,

Peter Bowes: [00:25:09] I think it’s probably important to emphasize, though, that the number that you’re producing at the moment is is quite general. And it’s perhaps just a warning sign that perhaps that could be more you could do to improve or something you could do to improve your state of health. And you also mentioned talking to doctors. And I guess the the key and very sensible advice would be that if you do a test like this and you get a number that you think could be better than perhaps the person you should speak to first is your doctor. And so I’m curious how many doctors acknowledge tests like this and actually understand what they’re about and their relevance.

Morgan Levine: [00:25:45] So I think I think it’s growing. There are definitely doctors that are become interested in this kind of science and this kind of way to use tests like this for disease prevention. But I do think it is a little bit of a paradigm shift in terms of medical health and health care in this country, where what we usually do is wait for someone to develop some disease or have some really abnormal lab test, and then we pay attention to them and treat them. Whereas this is kind of flipping that and saying, can we see how you’re doing prior to ever developing some disease and actually intervening? So we make that time between now and when you develop your first disease longer. So, yeah, I think, you know, not all doctors will understand the test, but again, they could follow up with additional clinical lab tests or just give, you know, or look at kind of what you’re doing in your everyday life and probably make recommendations based on that as well.

Peter Bowes: [00:26:46] As you have progressed through your career and you’ve delved into this particular area of science, is there something that you personally have learned that you, through science, that you apply to your own lifestyle now, how you live your life, obviously interested in aging? I’m sure you’re interested in your own aging and longevity and how you’re going to progress over the years. Is there something you can pinpoint.

Morgan Levine: [00:27:07] I mean, I like to practice what I preach. It’s kind of boring. I don’t have any, like, real secrets on like this is the one thing people need to know about that they never heard. It’s basically things that most of us have heard about. I eat a mostly plant based diet. I would say I don’t need any meat, but I eat 90 percent plant based. I do intermittent fasting every day. So I only eat my meals between a six to eight hour window each day. I try to be physically active as much as I possibly can, try to do it every day. Of course, some days I’m with work, can’t get around to finding that extra 30 minutes. And then I think for me, the the place I struggle most with is probably sleep. And I think it’s a place that people often take for granted, but I’m actively trying to have a better sleep schedule. But again, it’s you know, there aren’t any, you know, secret recipes. It’s things that most of us have heard about. And I think having these biological age tests actually just keeps us much more accountable.

Peter Bowes: [00:28:14] I think it’s fascinating what you just said. And, you know, you and I have met before. We haven’t talked before. And I didn’t know anything about you that you just described. It pretty much describes my lifestyle in terms of certainly my diet exercise regime, which is quite a lot. But sometimes it falls by the wayside because of work. And sleep is often a struggle. And I think a lot of people have that kind of dichotomy in their lives and struggle with it, but have come to the realization and I try not to I certainly don’t want to be preachy about it. But from all of my research and the scientists like yourself that I’ve spoken to, the plant based diet often is the thing that becomes the common denominator, that that seems to be what a lot of people have settled on. It might not be 100 percent plant based diet. There might be a little bit of dairy, in my case is a little bit of fish, maybe once a week. But that’s all and certainly no red meat. It does seem to be a positive intervention. If you want to start doing something to affect your health start with a diet.

Morgan Levine: [00:29:11] I agree. And I think, too, that’s the other thing with these tests is, you know, we get in this mentality of all or nothing. So if I’m not doing it all the way, it’s not worth it because I can’t do it. But, you know, what people can do is start to make small, incremental changes. So maybe you eat a traditional Western diet and you say, OK, I’m going to try and eat plant based three days a week and see what that does. Or maybe I’ll just cut out red meat, but I’m not ready to cut out, you know, chicken and dairy yet. And I think the thing here is you can actually get feedback potentially on whether even these small steps are making an impact, because I think we often, again, get in this mindset that if you’re not doing everything perfectly, why even try? Because you’re not going to benefit from it. But I think having the positive feedback that they actually all the things you do could potentially benefit you. You will help people, you know, make these changes and stick to them for more than, you know, a month after New Year’s or whatever it may be.

Peter Bowes: [00:30:12] And can I ask you, I think I think you use the phrase practice what you preach, and you don’t have to answer this if you don’t want to. But have you taken the test yourself, the index test?

Morgan Levine: [00:30:20] I have, yeah. I actually take it quite a bit to track more than what we recommend people. But I’m also doing it just to make sure the test is stable. And, you know, people don’t get sick because that’s another really important thing to us is, you know, if you take the test twice, really close together, you’re going to get the same result. Are your numbers going to bounce all over the place? So I’ve taken it. I, I’m not doing quite as well as you are. I think I was five years younger

Peter Bowes: [00:30:52] That’s close

Morgan Levine: [00:30:52] biologically compared to chronologically. Yeah. So yeah. I need to take it again. But yeah for a while I was taking it once a month just to make sure that things, you know, don’t jump all over the place. And I got almost exactly the same result every time I took it, which was reassuring to me.

Peter Bowes: [00:31:08] I was actually just about to ask, is that’s what you found, that you can repeat the test within a short space of time and get a very similar result?

Morgan Levine: [00:31:16] Yeah, so so actually, when we were developing this test, we were very careful to make sure it had high what we call reliability. So we did a lot of work looking at, you know, I take the same sample from an individual and run it multiple times. Are we store one of them and run it in a week? Do I get the same answer? And, you know, I will say that most of these epigenetic clock measures are highly unreliable. And actually, my lab just put out a paper on how much they can fluctuate. It’s often like five to seven years fluctuation just if you randomly test something twice. So we we actually developed an entirely new way of quantifying epigenetic age that actually reduced this kind of noisiness in the measures to make sure that if people are taking this twice, that it is giving you a reliable measure. And also, if you are going to do a test retest, you know, you change your diet for six months and that if you do see a decrease, that that’s a real decrease that you can be confident about. And it wasn’t just kind of a random kind of jumping around of your data.

Peter Bowes: [00:32:29] And you I’m just curious. I think you’re probably significantly younger than I am. Do you see a difference in the variability between chronological age and biological age, between younger people and and older people? Do, for example, older people tend to be or at least there tends to be potentially more variation from their actual age.

Morgan Levine: [00:32:47] Yeah, exactly. When you’re in younger populations, there’s there’s a. A little bit of a limit for how much you can actually vary because you haven’t had enough time to kind of get to that, you know, plus five, minus five or ten. And we do see as we look at older population, there’s a lot more variance and kind of what their biological age is. And this gets back to this idea of it’s not what your value is now, it’s the rate. So over over someone, you know, population’s lifespan, these differences in the rate at how fast people age are actually what’s going to create the variation as you get older. So, you know, if we imagine everyone starts from the same place and then you just let them diverge over time, that’s kind of why we see this and why, you know, if we know your rate of change is, you know, some given number and you’re chronologically some age, we are not making huge projections. But you can hypothetically use that to kind of project out, OK, what might I look like in 10 years? Because we actually expect the difference to increase as a function of time, not not necessarily, say, stable across your lifespan.

Peter Bowes: [00:34:01] Morgan, I think this is fascinating science. Just one final question in closing, as you clearly are very interested in aging and longevity as you look ahead through the decades to come for you. Do you have personal aspirations as far as your own healthspan and longevity are concerned?

Morgan Levine: [00:34:19] Yeah, I mean, I think like most people, I would like to stay healthy as long as possible. For me, again, I placed more emphasis on healthspan than my lifespan, even if even if I end up having the average lifespan of what’s typical today, I would be very happy if basically I could stay healthy right up until that point. And yeah, I think, you know, most people, they want to be able to continue to do what they love to do and have, again, that’s why I think we actually chronological age is something we should celebrate. We all want more chronological time and more meaningful chronological time where we can do things and explore and spend time with our family and contribute to society. So, yeah, I think any way I possibly can to just, you know, prolong that, but in a healthy way is really what matters to me.

Peter Bowes: [00:35:08] Yeah, I’m totally with you that Dr. Morgan Levine. This has been really fascinating. Thank you very much indeed.

Morgan Levine: [00:35:14] Thank you so much Peter.

Peter Bowes: [00:35:15] And if you’d like to dig a little deeper into this, I’ll put a link to Index them to Morgan’s research in the show notes for this episode. You’ll find them at the Live Long and Master aging website, That’s In social media. You’ll find us @LLAMApodcast and you can contact me @PeterBowes The LLAMA podcast is a Healthspan Media Production. You’ll find us at all of the major podcasting platforms, including Apple Podcasts, Stitcher and Audible. You might listen to books there, you can also download this podcast free of charge. Wherever you find us,take care, and thank you so much for listening.

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