#35 - Nir Barzilai, M.D.: How to tame aging

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You live a higher quality, more fulfilling life. If you enjoy this podcast, you can find more information on today's episode and other topics@peterattiamd.com. Hey everybody, welcome to this week's episode of the Drive and Happy New Year to everyone. We took a week off, as you probably noticed, so hopefully everybody's ready to jump back into this fun stuff. My guest this week is Nir Barzilai, and if you're at all into the space of longevity, he'll be no stranger to you. Nir is the founding director of the Institute for Aging Research, the Nathan Schoch center of Excellence in Basic Biology at Albert Einstein. He's completed two fellowships, one in metabolism at Yale, the other in endocrinology and molecular biology at Cornell. He directs the Longevity Genes Project and in my estimate, near is probably the most knowledgeable person ever on the genetics of longevity, and we talk a ton about that during this episode. He also is leading the EFF to test metformin in a prospective clinical trial for non diabetics with respect to aging, and this is referred to as the TAME trial. We get into that obviously in detail here and also we'll use a lot of the data for that in the show. Notes this is in many ways I think Nir is probably one of the most insightful people when it comes to understanding the clinical benefits of metformin, and we talk about that a ton. We also talk about insulin resistance. I can't resist the urge, no pun intended, I guess, to get into sort of a detailed discussion on what IR is with sort of people who are really deep in this space. We talk a lot about IGF and.

Growth hormone, and I gotta tell you.

This is a topic that you've probably heard me waffle on a little bit because I'm still really kind of on the fence about this relationship of igf, gh. I think the centenarian data point in one direction, I think the epidemiology outside of centenarians point in a different direction. And of course none of this really speaks to the question I get asked constantly, which is do you think administration of growth hormone is beneficial from a lifespan or health span perspective, or do you think it's harmful? And, you know, truthfully, I've always leaned towards the harmful side. But we get into this in detail and Nir offers some great insights. Certainly for me, I was. I was really helped by this process. We do go back and talk about the centenarians. And because I'm in the midst, as some of you know, of writing this book, I'm knee deep on all that literature. And so it was really great to kind of clarify a few things that I think even if you're not steeped in this stuff, you'll find very interesting. And of course, we talk about all of my other favorite topics like autophagy, culture, restriction. We even get into a little bit of the stuff around NAD and nicotinamide riboside and things like that. So overall, I think this is a bit of a technical episode, but not that technical. We've certainly done more technical stuff. The show notes will be valuable, as always, especially for a show of this nature. So with nothing else to add, please welcome to the show, Nir Barzilai.

Hey, Nir, how are you?

I'm terrific. How are you?

I'm good. I can't believe not only did you make it down here on time, but you made it down here ahead of me at my own place.

Nice to stay young.

Yeah, this is. This. I don't know, these days this weather is so unpleasant, but yeah, you beat me here, so I was a bit. I was a bit embarrassed.

It's unpleasant for you because you're in California most of the time?

Yeah, yeah, I think that's part of it. But you're from Israel, so this has to be unpleasant for you, too.

Israel was too warm for me. I'm okay.

Got it. Well, speaking of which, so you were born in Israel, you spent how long there? Were you in the. Did you serve military time there?

Yes, I served military time. I was a nurse and a medical student. I went to the Technion Medical School. I went then to Hadassah Hospital for residency, which I finished, and only then I came to the United States. I was at Yale with Ralph Defronzo doing metabolism. Actually, I was looking at the mechanism of action of metformin in 1987 before it was approved for use in the United States. There's a serendipitous connection to that later. And then I went to Cornell for an endocrine fellowship. And then I was recruited to Einstein. And so my first part of my life was metabolism. But Then I started doing what I really was interested in, and this is aging and the biology of aging.

And I remember reading a quote once from you that said, maybe paraphrasing, but Metformin is the reason I came to the United States.

Well, in a way, it was. But this is life in retrospect, right? I wasn't really expecting. I was done with metformin in 1988. I was done with Metformin until it started again about three, four years ago.

Well, I can't wait to talk about Metformin, because they're probably. I'm trying to think. If I think of four or five exogenous molecules, which is just the terminology I use to describe anything that you ingest or take that comes from outside the body. So I would include drugs, supplements, hormones, anything in there. But when you lump all of these things together, if I were to say, what are the three or four of these that I am asked about the most frequently from patients or, frankly, anybody, If I'm at a party and I let it slide, what I do for a living, the first question is, should I be taking Metformin? And there's usually a handful of others that they want to know about. Should I be taking nicotinamide riboside? Although they usually don't say that. They usually say, should I be taking NAD or something to that effect. So it's wonderful that we will be able to speak today because few people can speak about Metformin the way you can. And so I'm really looking forward to that. But before we go down that path, I do still want to kind of understand a little bit more about your journey and your interest in endocrinology. Did you know from day one, when you entered the field of medicine, that this was the area that you wanted to study?

Yes, I was interested in aging from the time I was pretty much 13 and spend weekends with my grandfather who was telling me his life story. And his life story wasn't easy. And he did lots of physical things, and he dried the swamp and he did this and that. And I'm looking at the man who was then 68 years old that walks slowly, he's obese, white hair, and he just didn't look like somebody who did everything he told me to do. And, you know, they say that children have imagination, but most kids don't see their grandparents as what they will be. Right. They see them as. I don't know how they got there. And this really stuck with me, and I started to be interested in the biology of aging. When I was, for example, when I did my residency, I always was interested in how, not what's the age of the patient, but does he look older or younger than his age? I kind of realize intuitively that there's a chronological age and a biological age. And what is this differences between the biological and chronological age? And of course, as a physician, it looked like endocrine is a good place to start because you knew that there is a lot of endocrinology in aging and you assumed that hormones are going down or some are going up. But if you could fix that, maybe you could fix a lot of aging. Now, everything that happened in my life was fascinating from the biology of aging. Replacing the hormones wasn't really a part of it. But we'll get to it.

Going back to the hormone thread, the most obvious example of changes in hormones with aging, of course occur in women where they have this very abrupt change in one of their endocrine systems, this androgen system. Did you think about it even more broadly than that? For example, what was happening in thyroid hormone and what was happening in fuel partitioning hormones and other things like that?

Absolutely, absolutely. But I'll tell you to the point, when there was a discussion whether to do the Women Health Initiative, you know, many people thought this is a waste of time. You know, we know that estrogen is good for women. There's lots of studies like that. Of course, it's major in aging. And I didn't look at it this simply for maybe two reasons. One is men are also aging and in several ways similar to women. And that's not an estrogen story. And it wasn't the testosterone decrease wasn't really as dramatic as the estrogen decrease. So I, I didn't, I thought that there's a lot of aging that's done without estrogen. Let's start with that. And also you're replacing just one hormone with lots of hormones are changing. It didn't look like a good study to me.

Well, especially at the time. And I, I, I, I try to be temper my criticism for that study by trying to have some empathy for the fact that the investigators were dealing with what the treatment protocols were at the time. But to use oral estrogen, that's conjugated equine, to use synthetic progestin and not even actual progesterone, you could come up with a list of 18 things that in retrospect are so obvious why that study was a failure.

Absolutely true. But the other part of that is that the way to show effect of estrogen in animal models was to take their ovaries out and give them estrogen. And then you could show you could do lots of provocation. It was good. So estrogen is a good hormone on a young body. But then there were studies that were hardly published, but I was aware of them of taking old animal, you know, so you could take the young animals in just one center in Houston, they did it. You took the young animal, you took their ovaries out, you gave them estrogen, and you employed a stroke model. Okay. And when you gave estrogen, the stroke was smaller and everything. When you did the same in older animals, the stroke became worse. Okay. And they couldn't publish it for a while because they said, well, it's old animals, so they have other diseases or other things. But every experiment that had estrogen in old model wasn't. Was the opposite. Not only that, it didn't affect. It was the opposite. Which. What happened to the whi? In certain ways.

Yeah. Although I still think that it was probably the breast cancer that garnered the most headline in the whi. And actually, that's an interesting topic, which I'll be going into in great depth on another episode. There's a great book that just came out that tackles this, that goes through the history of the whi. At what point? Well, let's go back to the metformin thing, actually. So it's 1987, and you're thinking like, okay, metformin is the next line of agent we will use to treat type 2 diabetes. So metformin was already in clinical practice in Europe, is that correct?

Oh, correct. For many years.

How many years? Like 20 or 30 years.

So metformin, few years ago was 60 years. So we are talking about, you know, 1950 or something. 1950. 1960. When I was in Israel, I prescribed metformin. You know, that was the first line for type 2 diabetes.

What took so long for it to.

Come to the U.S. that's a terrible story that. That still continues. You know, the FDA said, we don't know. We don't know that metformin is going to be effective in the population in the United States. So you have to do the studies. And it was Bristol Meyer, really, that got to do the studies. And basically they had to do a phase three study again to show that metformin is effective as sulfonylurea as an indication for type 2 diabetes. And if even then, the idea was that it will be good only in obese people, which happened not to matter much because all the type 2 diabetes in the United States were obese. But it was really a matter of regulation. And part of having regulation was that the FDA asked more studies to understand the mechanism of aging and metformin. And in a certain way, maybe they are right, because metformin mechanism of action is really complicated. And I'm not sure that today, as a new drug, it would be approved.

Interesting. Why do you. Where do you think it would fail? In safety or efficacy?

No, it's not in mechanism.

In the. In the inability to elucidate the mechanism.

Right. When you come to the FDA and you say, you know, we've done that and we've done this in animal, and we've done this in cells, and you're trying to show what is the major mechanism of action, you. You would have failed. So what I showed in humans is that metformin targets hepatic glucose production or the insulin sensitivity of the liver. And that's the major mechanism of action. Unlike, for example, sulfonylurea that increase insulin secretion. Right. Or TZDs, that increase the insulin sensitivity in the muscle more than in the liver. So this was a mechanism that you could pack to the fda, but it's really not the intracellular mechanism of metformin.

So at the time, was it understood what metformin's activity was on complex one of the mitochondria?

No, not really. This came later. I don't. I don't know what year, but it came later. It came when the seahorses essays were developed to show really which mitochondria in which pathway of mitochondria you have changes.

Maybe for the listener, tell explain what a seahorse assay is.

Seahorse essay is an essay to look at mitochondrial action. Whether you extract mitochondria or even tissues. It really shows some relationship between oxygen consumption in relationship to polarity. And it's very sensitive to look at some of the effects of drugs that are interfering with mitochondria action or decrease mitochondrial activity.

It's almost like the indirect calorimetry of the mitochondria. Right?

Right. Indirect. Because it's a provoc test, really. So. Yes.

Metformin was discovered from a plant as well. Correct?

Right. It's a French lily.

And it was French lily, obviously. And this was discovered in the 40s or 50s.

Correct. The first thing that happened there was a drug by the name of metformin, a cousin of metformin, which apparently is much more potent. It's much more potent because unlike metformin, it doesn't need a transporter to get into the cells. On the other hand, it was associated with a lot of lactic acidosis and it was considered unsafe eventually. And then metformin was a safer part with much less of a lactic acidosis side effects.

What is the mechanism by which metformin caused lactic acidosis? Because in all the use I've seen of metformin clinically, I've never seen a case of it. Which is not to say it doesn't happen. I'm sure it does. And you could stack risks by taking someone with renal insufficiency, giving them contrast and tons of metformin. But in medical school, this was like the board question you got asked every single test. What do you have to worry about with lactic acidosis? What's the putative mechanism by which that happens?

So, first of all, I would tell you that in my study in the 80s, every patient that we gave metformin had an increase in lactic acid from.

What to what in millimolar.

Within the normal range. So if it's two, was the.

Yeah, the cutoff.

The cutoff. So it was, you know, between. Went from 1.5 towards the 2 and sometimes even went over the 2. But it wasn't really anything associated with acidosis.

And there was no change in physical.

No, no, no onion gap, not anything like that. And it probably has to do. I don't know that I can tell you for sure, but it has to do with what happens when complex 1 part of the metabolic effect, when complex 1 is inhibited. But there's lots of speculation and I don't really care to comment.

Yeah, yeah.

On that. But I think what became clear there is a whole. We call it endocrinologists call it mala. It's metformin associated lactic acidosis. In other words, we moved away from metformin causing lactic acidosis to the association because it's. If anywhere it described more in people that have kidney failures or have heart attacks or something and had lactic acidosis and were on metformin too. And that was kind of the association. But it's not clear to me that there are truly people who develop lactic acidosis from metformin that is just because of metformin and not associated with something else.

I'm glad to hear you say that. That's sort of generally been my bias, but I'm happy to be corrected if that bias is incorrect. But, yeah, I've always thought that, frankly, so many of the drugs that we're really interested in now as we look Back from an aging perspective, whether it be metformin or rapamycin. So many of the negative side effects that people typically associate with those drugs are very difficult to isolate from the patients in whom those drugs have historically been given. And so it's nice to hear that Mala is now being generally recognized as an alternative viewpoint to that. You know, metformin is, to me, an interesting drug from a diabetic standpoint, because. And I don't know that this was appreciated in the 80s. In fact, I would suspect it was not, because there's really two macro strategies for improving type 2 diabetes. You can, obviously, the highest goal is to control glucose levels, so to regulate the degree of glucose in the blood. But you can do that through, at the highest level, two ways. You could increase insulin either exogenously or through increased insulin production pharmacologically, or you could reduce glucose. And of course, metformin falls into the latter category of that or increasing muscle insulin sensitivity to enhance glucose disposal. Today, it's generally regarded that while both strategies will have an equal benefit on the microvasculature, the glucose lowering by insulin lowering. So the less glucose production strategy has a superior effect on the macrovasculature. And therefore metformin would be a better alternative to, for example, a drug that's going to increase insulin production out of the pancreas. Was it appreciated at the time, meaning when you were doing this in the late 80s, how potentially beneficial this drug was?

Well, at that time in the United States, it was all about insulin resistance. You know, people like Jerry Rivan, Ralph DeFronzo, the people at the NIH, Ron Kahn, were all, you know, discovering the insulin receptor, discovering insulin resistance, discovering the association of insulin resistance with the metabolic syndrome. So it was all. We all had the bias that the major problem with type 2 diabetes is insulin resistance. And, you know, we know now that it's a total collaboration. Yeah, you increase insulin resistance and the pancreas have to secrete more insulin. And we humans, at least in the condition of our environment, obesity, everything, many of us, I would say 40%, cannot deal with that, and we become diabetic. There is this startling curve of the pancreas, you know, like for the heart, that you increase insulin secretion, and at some point you cannot increase insulin secretion. You become diabetic, and then insulin secretion decrease. And so insulin resistance was a major way. And that's why metformin was a good place to come with, you know, at least it. It affects mainly the hepatic glucose production rather than the muscle. Although I have to tell you, in vitro on muscle specimen, it's an insulin sensitizer in the muscle too.

Let's talk about this idea of insulin resistance. I think there are a few terms that leave me scratching my head more than that one. So this is an example of something where maybe five years ago I thought I really knew what insulin resistance was. And I think today I'm pretty sure I don't know what it is in the sense that when you take the typical phenotype of someone who's insulin resistant, what do they look like biochemically and anthropomorphologically? Right. So they're hyperinsulinemic, they have elevated levels of glucose, they probably have some degree of obesity or adiposity. So what does that mean? Because clearly their fat cell is quite sensitive to insulin. If the fat cell ever became resistant to insulin, you could not re esterify fatty acids and you would have an endless stream of lipolysis exiting fatty acids from the fat cell. So you'd actually be quite lean. There's something going on in the muscle that clearly is resistant to the effect of insulin. But of course, there are both insulin dependent and insulin independent means by which we can dispose of glucose. And this is where, coming back to what you said a moment ago, I actually wanted to ask you that question, which is. But we'll park it. But the question was, does metformin participate in the AMPK driven insulin independent modality of glucose disposal? You're nodding. So I think that's a yes and we'll come back to it. And then there's the liver. And this is the one to me that is the most complicated and the one I'd like to begin with. So before I ask you to elaborate on the specifically what is meant by insulin resistance in the liver. Am I a complete moron for not understanding this?

No. But can I make it a little bit more interesting even because I need to bring it to aging? Yes, I would love to talk about diabetes, but let me just put up front, I'm not sure that the diabetes property of metformin are really the aging properties of metformin. Okay, this is my provocation, but let me go back to insulin resistance because in. In 1997, a science paper appeared that made it the best day of my life and the worst day of my life.

Okay, wow.

What was the paper? The paper was taking a nematode. Okay. So a primitive model decreasing the insulin sensitivity. This is known as the DAF2 model. And when you do that, the nematode accumulates fat in their intestinal cells, so they are becoming visceral, obese and they live several times longer. So why is it the best day in my life? Because you could with one genetic manipulation extends lifespan significantly. That meant going from hope, actually from nothing.

Was this Cynthia's paper?

No, that's Gary Rufkin. But at the same time Cynthia had her DAF16, Tom Johnson has had the H1 model. There are several papers that came and all of them said, hey, we can change lifespan. And the example was always insulin sensitivity.

And this mutation, to be clear, because between DAF2, DAF16 and the dietary manipulations, there are several permutations of that C. Elegans model. But just to make sure I know which paper we're talking about, this was only attenuation of DAF2, nothing to DAF16 and nothing to dietary changes.

Right, Right.

Can you just for the listener, define what is the analog of Daf2 Daf16.

In US, Daf2 is the insulin receptor and Daf16 is the Foxo. The Foxo transcription factor. But the point is, at that time.

Yeah, you took a worm that normally lives two weeks and you turned down its insulin receptor slightly. Not off, Correct.

Right, right. But you made it insulin resistant and it was accumulating fat. And what was I bringing in to the field? I was saying the major reason for aging is this insulin resistance syndrome and the main part of the insulin resistance is accumulation of visceral fat. And so the premise was good. The example was disaster to me. I had the JCI paper at that time in press really showing with MRI pictures how caloric restriction decreases the visceral fat. I was talking about the biology of those fat and stuff. And it was a major paradox for us in the field and how we continue if we're saying insulin resistance is good for longevity and everybody in diabetes knew that this is a disaster. Why am I telling you that? Because I learned later, I was thinking later on experiments that I've done. Oh, so first of all, the experiment that I've done that was very conclusive was I took bunch of rats, 150 actually, and all of them underwent surgery after puberty. In some of them I removed their visceral fat depots by surgery and in the other it was a sham procedure, so I just moved it but didn't remove it. And we had three groups in the experiment. One was ad libidum feeding, the second was caloric restriction. This is the control they would leave 40% better. And the third group was ad libidum feeding of the rats that their visceral fat was removed. And I said, you know, without the visceral fat, even with nutrients, they live longer. And they actually lived significantly longer than ad libidum by 20%, but not as much as the caloric restriction.

So just to make sure, I understand, you had a 2 to 1 ratio of your animals because you had.

No, I had three groups.

Three groups. But one of them was all ad lib fertility feeding of the visceral fat removed. That was Right. And then of the ones that had sham surgery, they were randomized to ad lib vs cr.

Correct. It really showed that visceral fat, the removal of visceral fat had major effect.

And when the animals who had the visceral fat removed were autopsied, or whatever the word is for rat autopsies, had they figured out a way to reaccumulate visceral fat or where had they accumulated fat?

No. In fact, when you do this procedure after puberty, if you do it before puberty, they accumulate visceral fat, otherwise they don't accumulate much visceral fat.

Did they have changes in subcutaneous fat?

That's a good question. Mice have it when you do it and rats do not.

What did they ultimately succumb to?

They all die from the same thing, only at different times.

Which is what? Cancer?

Yeah, it was sprayedoli. So kidney disease and cancer as well were the leading cause of death.

So you basically got half the benefit of CR by doing this, by eating.

At libidum, but without visceral fat. So you understand it's very important.

Sorry, one other question near. Was there any change in their health span or their spryness?

Yes, there was a health span. In fact, what happened to the dlipidum? The dlipidum starts losing weight at the end of their life, and the ad libidum with visceral fat have still gained weight after the others. You know, it was a significant change in weight. And then there's a whole health spender, insulin levels and other things that we've, you know, we've done in parallel. So they were. They were healthy and they were healthier for longer, which is kind of the experiments that we do with animal models.

Is it possible to take one of those rats and either through caloric restriction or other dietary restriction, get it to puberty to the point at where you did the surgery, but without any visceral fat, and then ask the question, if they've gone through that period of development without developing visceral fat. Do they have somehow protection from the diseases that come, even if you feed them ad libitum thereafter?

So we did this experiment in zucker fat animal, Zucker diabetes animal. And we took their visceral fat.

Tell people what the zucker rat looks like.

So the Zucker rats are rats that are really, really, really obese, hungry all the time.

So they have hyperphagia. They can't stop eating right because they.

Don'T have the leptin receptor. So they are hungry all the time. And they're nasty because you try to come close to them. They think your finger is food, so they're eating it all the time. And we did surgery on them before puberty because they became obese really much before puberty. And what happened is by six months, they all become diabetics. Our animals up to four months did not become diabetic. And then between four and six, they became diabetic, although we took their visceral fat. But what we found out that 80% of the visceral fat grew back. So we actually had the perfect experiment. As long as they didn't have visceral fat, they didn't develop diabetes. Once they got visceral fat, they developed diabetes. But I want to make.

And sorry, one other thing. If you took that group and who already developed diabetes with visceral fat and you just removed the visceral fat, can you reverse the diabetes?

No, I. We've never done this experiment, don't know, because we're interested in aging. But I'm telling you all that to make one point, because so far the paradox just got worse, right? The nematodes with insulin resistant visceral fat lives longer. And we showed that mammalians live longer. If you take this visceral fat and make them insulin sensitivity. Whenever we take visceral fat, we make them more insulin sensitive, okay? Until I realized one thing. It takes me few hours to make rats insulin resistant. I give them glucose, I give them free fatty acid, I give them some other things. I can make them insulin resistance very rapidly, rapidly. So at first I used it, as you see, we can do the chronic insulin resistance in few hours, okay? You just load them with nutrients, you become insulin resistant. But then I thought of the aging part. When you get glucose to the muscle, the glucose goes into the muscle. If you're not moving the muscle, it's not going to turn more glucose to energy. It will switch from free fatty acid to glucose. But that, but there's no more glucose burning, so it goes to glycogen, right? And it goes to glycogen, but you keep on putting glucose in the muscle and there's just so much glycogen that the muscle can store. So the muscle has to become insulin resistance. Okay. It's a protective mechanism.

There's no evidence that the muscle can in any way, shape or form undergo de novo lipogenesis and create any of the fatty acid.

Is there to create any of the fatty from glucose?

Is there any evidence that muscle can under, can, can, can carry out?

I don't think so. I don't think so. I'll have to think because I have a different. Yeah, yeah, I have to think about it. But, but the point is. Okay, but I understand your point. Yeah. I don't think if anything there's no much the glucose, the muscle tells the glucose, you go somewhere else, you know, you go too fat. Okay.

So the only organ that can take in completely excess amount of glucose in the end has to be the liver. Liver, because it at least has the capacity to turn excess glucose into fat, whereas all of the other organs are going to be saturated.

That's true. And that's part of, I think where the glucose is going. Okay. To fat and to liver. Okay, so what am I telling you? I'm saying that insulin resistance is a protective mechanism. It's a modulator, it's a stress response. It's something. So now I understand why a stress response mechanism in one animal cause them to live longer and in another animal it's a pain in the butt. So I went and I, I wrote this review with, with Luigi Ferrucci. I wrote this review where we took all the animals that had problems with their insulin sensitivity. The animals that are insulin resistance and live longer and the animals with insulin sensitivity that live shorter. And there's a huge list of it. Rapamycin is an example. Right. Rapamycin causes insulin resistance and the animals is the best intervention. In rodents there's a PTP1 transgenic animals. It's very insulin sensitivity and it has half the life, the lifespan of a wild type animal.

When you say insulin resistant or insulin sensitive, are you always referring to muscle? Are you referring to liver? How are you defining them?

Well, in this sense it was everything. It was IRS, for example, Iris 1, IRS 2, knockout, some of them only in the brain. So it was really insulin resistance.

Everywhere is IRS1 found in the muscle and not the liver?

No, IRS1 and IRS2 are everywhere. But IRS2 is more in Liverpool.

Yeah, they sort of have selective expression. Yeah. So I'll just translate IRS 1 insulin receptor.

Substrate.

Substrate. So let's talk about exactly how the muscle takes in glucose. So we are walking around. If I bolus you with glucose right now and your blood glucose rises from wherever it is right now, 90 to 200, let's say I give you an enormous bolus of glucose, I double it, so you're up to 180 milligrams per deciliter. This is a very high screaming high level, which by the way only amounts to an extra few grams of glucose. But nevertheless, what is the chain of events that leads to insulin being secreted and the muscle ultimately disposing of that glucose, both actively or passively?

Well, there will be obviously a secretion to insulin that's relative to your glucose level.

And so the insulin. So the beta cell is the sensor.

Right.

And out comes insulin. And now what is insulin doing to the muscle?

And insulin through the insulin receptor will get translocation of the glut, for those are the glucose transporters that are the major glucose transporters in muscle. It will go from an intracellular pool into the plasma membrane, integrate that and starts getting glucose like crazy into the cell.

And that happens quite passively. Meaning once the GLUT4 transporter is translocated across the cell membrane, glucose can passively rush in. Correct. It doesn't require ATP to bring it in against a gradient of any sort.

Correct. And in fact it has its own intrinsic activity that's not energy dependent, so it can go faster or slower by different ways.

Now, is there another method by which without insulin we can get glucose into a cell that somehow relies on AMP kinase?

Not on AMP kinase, but there's non insulin mediated glucose uptake. In other words, there's a way for glucose to get up without the insulin. And we know that from hyperglycemic clamp and from other things that when we can move the insulin or keep insulin level at basal and still there's a substantial glucose uptake that's happening. So. Yeah, we know.

What's the mechanism of that?

I'm not sure. I know.

It also seems to be enhanced by exercise.

That's true. That's true. This nimja is the non insulin mediated glucose uptake is something that is exercise dependent too.

And it seems to.

That's what. Now I understand your question. Is AMP kinase.

Yes.

Part of the DNA and I, I don't know that.

Yeah. I only have one patient in my practice who has type 1 diabetes, but he is such an interesting patient because of his incredibly strict dietary control and his unbelievable appetite. For exercise. And he. I've never seen a higher level of adiponectin in a human. I've never seen a higher level of sex hormone binding globulin in a human, which are basically. And we know how much insulin he has because he injects it. And he injects so little insulin into himself and yet can seem to, you know, he has a hemoglobin A1C below 6, using 6 to 8 units of insulin a day. And so what got me. That's what got me very interested in this non insulin dependent glucose uptake.

Yeah, I'm not doing this research anymore. I used to be in front of that. I. Glucose itself can modulate glucokinase activity in the liver. There's a lot of things that happening and of course there's coordination between the fat and the liver. And then I started being interested because we can do things to the hypothalamus and take over this insulin and muscle and fat and liver. We can do it all from the brain.

Isn't that amazing? Well, just because I'm so fascinated by this and I think it will help the listener to understand the complexity of what you just said. If I took an animal and put a lesion into the ventral part of the hypothalamus, a normal animal, what could that do? What would that change about its metabolism?

Well, that would increase basically food intake and change a lot of the peripheral physiology. But we do basically the opposite. We give insulin to the hypothalamus or glucose or IGF or leptin. Okay. And then we see what happens to the periphery. Although in the periphery those hormone levels are not increasing at all. And not only that, the liver is a good target to follow, because what you can do with the liver, you can do selective hepatic vagotomy. And everything that you did through the brain doesn't work anymore because it needs the nerves.

Right. So I'll explain to the listener what that means. So the vagus nerve connects the body through this parasympathetic system. And of course, if a patient has a liver transplant, or if you do an operation where you sever the vagus nerve, you sever that connection between the central nervous system and the periphery.

Correct. And so we can do it experimentally and it will help us see if it really.

How much of it is vagally mediated versus not or.

Yeah. Or more nerve only, you know, it's the nerves, because we do. It's not only vagotomy, we do a little bit adrenergic too, but it's through the nerves and not through a chemical reaction on the liver.

You see, this is the problem with metabolism, Nir. The more I go into it, the less I know. It drives me nuts. My absolute knowledge increases incrementally and my relative knowledge falls precipitously.

Well, I think I realized that you know what to ask, so you're undermining your own abilities. But it's really, the integrative metabolism is really very confusing to explain.

So we will define insulin resistance at the muscle, whether it be from an aged phenotype or a diabetic phenotype, as a scenario under which a fixed amount of insulin hitting the insulin receptor produces fewer GLUT4 transporters. Is that that a fair definition?

Well, the. The definition of insulin resistance is really different and very simple. It's all about the glucose uptake in the muscle, really. It's all about the ability of insulin to clear glucose. Okay. That's the only way we define clinically insulin resistance, although that totally misses the point because those insulin levels have different effects on different tissue. But for us, the insulin sensitivity is totally related to the glucose uptake.

So let me give you an example. So when I use an oral glucose tolerance test with my patients, I'm a bit of a stickler. So if they take their 75, you know, grams of Glucola, I measure their glucose and insulin at baseline, administer the glucola 30 minutes later, 60 minutes later, 90 minutes later, and if I'm feeling aggressive 120 minutes later, we re measure the glucose, the insulin and the ffa, and maybe even the C peptide. But for simplifying it, just the glucose and insulin. So let's assume you have two patients who start out with a fasting glucose of 90 milligrams per deciliter and six insulin of IU's of six. They both get their 75 of glucola. And let's again simplify this by just looking at one hour. What happens? Both of them at one hour have a rise of glucose from 90 to 130 milligrams per deciliter. One of them did so with a rise of insulin from 6 to 20. The other did it with a rise of insulin from 6 to 90. They've both disposed of glucose with equal magnitude. Would you describe them both as equally insulin sensitive?

It's a little bit complicated, you know, first of all, so let me just say for aging, 120 is not enough. In elderly, the glucosorins go. So the rise in insulin is changing throughout normal physiology and throughout individuals. And you must have, you might have missed some of the insulin peaks earlier on or later on.

Yeah, looking at 30 versus 90 is a big insight. And you're right, I mean Joseph Kraft who is a pathologist who has done a lot of work on this, he samples to five hours. Now again clinically that's challenging in the regular day to day practice, but in the laboratory that's feasible. And you're right, you can see so much happening beyond that. But I tried to pick an example that was as egregious enough in its difference that the. What I'm trying to get is the difference in hyperinsulinemia and whether that factors into how we think about insulin resistance.

Right now I don't think the clinical world is thinking like that. So I'm actually an active endocrinology I still see on Thursdays if I'm on in town teaching fellows in diabetes clinic in Montefiore Hospital. So I am involved very much in this field. And I'll tell you that we rarely measure insulin in any of our patients. But that's not really your patients.

Okay.

I'm talking about what's the use of measuring insulin in type 2 diabetic patients. So it's a different issue. But yet this is sounds like there's a different insulin response to lower the glucose to the same extent.

Because the hypothesis would be that the patient with hyperinsulinemia is now demonstrating. I mean that's basically a harbinger of the first one who's going to struggle with glucose disposal. That would be my hypothesis is the one who needed 90 units of insulin to dispose of glucose with the same efficacy as the person who needed 30. Is sooner rather than later going to have a harder time disposing of glucose.

Well, you know, there is another possibility that those are the people who get other diseases first like like heart attacks or stroke. In other words, their insulin resistance will affect a lot the way they do their atherosclerotic plaque. And you know, this hyperinsulinemia on organs that might not be insulin resistant even right on cells that not coming insulin resistance. So I would say that they could either the one who become diabetic or the one who are going to get macrovascular disease much faster.

Which brings it right back to our observation of glucose versus insulin, micro versus macular vasculature. That's a very good point. So how does insulin signaling work to get glucose into the liver?

The liver has a different glucose Transporter. It's a GLUT2, that is not translocated and that is the major way by glucose gets into the liver. So it's a little bit different, but it's not stimulated the same.

So it's constitutively expressed across the membrane.

It's not stimulated really by insulin as.

Much, so it's more gradient driven to get the glucose from the circulation into the liver.

Yes, and that's where the portal blood is. So there it's very sensitive to the increase in glucose concentrations.

Well, that's very interesting because it's certainly. I mean, there's lots of evolutionary reasons why that would be a fail safe. Right. Given the importance of you would never ever want the liver to be denied glucose, given that if you ever shut down the liver's ability to make glucose, by my calculation, you could live about six minutes.

Yeah, look, I was an intern of Sheila Sherlock, she Dame Sheila Sherlock, in England in Royal Free Hospital, very known hepatologist. And she asked a group of us, what's the main role of the liver? And I raised my hand and I said, it's to produce glucose.

That would be my answer, by the way.

And everybody laughed at me. She threw shocks at them and stuff and she said, just a minute, why are you saying that? I said, because if you take the liver out and clamp the vessels, the guy will die from hypoglycemia. Which is absolutely true.

Yeah, yeah, it's. You know, maybe it's just because I'm in the midst of writing this chapter for my book about the liver, but literally yesterday I sat here in my room and penned out the calculation of 180 pound person with blood glucose of 180 milligrams per deciliter. Clamp the liver. How many minutes until they die? It's about four under those conditions. Can you imagine that? Think about what this beautiful organ has to do.

But you know, another thing to consider in your example, right, so, for example, elderly have enough insulin to suppress glucose production. Glucose production is easier to suppress than it's suppressing lower level of insulin than stimulating glucose uptake in the muscle. The liver is more sensitive than the muscle and so elderly have the ability to suppress hepatic glucose production because they have enough of insulin to do that. But when you start giving them food during the day, they fail and they become glucose intolerant and diabetic. They might have diabetes, although their basal level are. Well, just because of this, enough insulin to suppress glucose production and not enough to increase glucose uptake. So the sensitivity of the Tissues is really to insulin is really part of of what you're describing. If you look at the basal, it's very different when you look at stimuli.

The challenge. That's such a great point. And I won't go down that rabbit hole anymore because I would love to, but there's so many other things I want to talk about near. Let's go back to metformin and let's do it now through the context of an anti aging drug. So there's going to be some people listening to this who already know everything about you, if for no other reason than the efforts you've put into tame. Obviously I want to have plenty of time to talk about that. But let's back up for a moment. Tell me when you first realized, hey, this metformin drug that I worked on 30 years ago, it's not just a great drug for people with diabetes. This could actually be a drug that helps someone without diabetes live longer. What was that epiphany for you?

So first of all, there were studies on the biology of aging in rodents. And the first guy, which I'll be embarrassed now to forget, he's a guy from Leningrad that was the first to say I've done rodent studies and animals with metformin Anatoly, I'll remember it maybe later. And he showed that a life extension increases in variety of animals, animals to which he gave metformin. That led to some studies.

What was his hypothesis? Do you remember? Why would he. What would he. What drove him to do that?

There was never any hypo.

This was just a pure fishing expedition.

It even wasn't related to glucose metabolism necessarily. He thought that maybe there's an anti cancer effect. And he looked at that. But then he got models that were hypertensive and they also live longer. So he thought those are different effect. And then he considered to aging. But at that time, this was in the 80s when he started that. And it bothers me that I don't remember his name. Okay, you'll remember, I should take more metformin. And he was pushing, he was showing up in meeting and showing. And so people have tried to do it in the United States and they showed that there is a significant effect on insulin. By the way, the effect of insulin in animals animals is 10%. Not like rapamycin, it's 24%. So there's a milder effects. But in every study they showed that healthspan is improved, you know, by 50%. So the effect on longevity was less than the effect of health by the way that's perfect for what I'm trying to say. I'm, I'm not for longevity, I'm just for health spin. Right. So if we can live healthy LT ltd die, that's fine with me.

Yeah, the so called squaring of the squaring.

Right square of the longevity. So he, he started Asimov, his name is Asimov. So that's what Asimov showed. People have started looking at that. They there several studies, three studies that gave it also to nematodes, they also lived longer and there's several effects on healthspan in the biology of aging. Now the reason there's a lot of needle threading here in my story here. Okay. But I want to tell you the, the moment that I knew we have to do this study was a publication, not in a very high impact journal, but it was an amazing study that could be done only in the uk because in the UK you can go into pharmacies and look at prescription that they gave and you could follow the.

Mortality of those patients because the NHS system allows you to centralize everything from prescription to usage to mortality.

Exactly. And they're probably, they don't need to da to be de identify after mortality. When you're dead, you, you're not private anymore. Okay, so they did this study. So what they've done their forearms to this study. They came and took patients who are on sulfonylurea. 12,000 patients. Okay. And they matched them to 12,000 people without diabetes. Okay. Same pharmacies, same doctors, controlling for some other things. And of course the people in sulfonylurea had higher mortality than their control, you.

Know, because of course they had a reason to be taking the sulfonyria. Right.

They had diabetes, so that's okay. Then they took 78000 people on Metformin and 78,000 people who were non diabetic, again matching them.

And the 78,000 on metformin was metformin. Monotherapy.

Monotherapy, first line, right. And they watched their mortality. So just to underline again, the people on metformin had diabetes. The control didn't have. They were more obese than the control. They also have more diseases than the control, but they had significant less mortality, 17% less mortality in the metformin group. And you know, the sulfonylurea group was. Okay, so if you get less mortality with metformin when the setup is diabetes, that really shows that metformin has a very important effect in humans as far as aging.

What was the median dose of metformin.

In those populations, they were over thousand milligrams.

That's it? Just a thousand milligrams?

Well, they intended more, but the average was about 15 milligrams.

You know, the average was 1500.

Yeah. No, thousand milligrams. I'm sorry, they. This is a discussion there. I don't think they really could validate.

The dose because an elegant thing to do if you have 78,000 in your database, is now stratified by dose. Absolutely. Who's taking 5001-000150-02000?

They couldn't do that. And I really cannot answer you if you can get back to the data or not. I really don't know. The dose we chose came from other studies, but, you know, that's not the only thing we know about Metformin.

What was the. What was the time course of that, by the way? Do you know how many.

Five years. Five years More time.

So five years exposure to metformin or five years of prospective mortality following?

No, it's. Well, it's all. It was all a prospective study. Okay. It was all a prospective study. When they started, okay, they went back, they looked at everybody on Metformin.

Oh, I guess what I'm asking is, do we know how long they needed to be on Metformin to achieve the benefit?

No. No, we don't know.

Okay, so we followed them for five years of mortality in a prospective cohort, but they could have been on metformin for 5 years or 25 years? We don't know.

No, no, it's newly. It's newly prescribed Metformin. They were not more than.

Oh, so we have normalized by duration.

Absolutely. Absolutely. No, they haven't been on Metformin before. Those are newly diagnosed type 2 diabetes.

So Nir. That's a pretty, to be blunt, goddamn staggering result. So my Metformin moment, nowhere near as dramatic as yours, basically came out of a research project I did with two analysts in 2013. And I don't even remember what prompted the question, but there was a question we had internally about what was the benefit of metformin. Oh, no, no. Now I remember the question. The question was, was there a relationship between hyperinsulinemia and breast cancer? This was the question we wanted to ask. And as we dug and dug and dug and dug and dug, something kept hitting us over the head over and over and over and over again, which was with or without diabetes, with or without obesity, with or without hyperinsulinemia. Any way you sliced and diced the data of people with type 2 diabetes. With and without metformin, they got much less breast cancer, which then dug us down a rabbit hole. If they seemed to get much less cancer, which was, you know, that was a big aha moment.

Right. And there are hundreds of studies that show the association between metformin and less cancers. And not only that, less. All cancer, except prostate, by the way. Prostate is hanging there maybe a little bit. And when we went. And I'll tell you later, but when we went to the NCI to make them partners in this TAME study, it was really interesting.

You tell people what TAME stands for.

TAME stands for taming or targeting aging with metformin. And it's a study that's designed to prove the concept that aging can be targeted. But also, or mainly for me, is for the FDA to give an approval to an indication that's like aging.

The first time I heard about TAME was actually here in this city. I was having dinner with Steve Austead. It must have been in 2015, maybe 1415. Steve is a gem of a human being. I consider him certainly one of the most important mentors in my exploration of this field of aging.

We're partners in many ways. He's a great, great guy.

He is. He is one of these guys that has. His knowledge is out of control. You can't ask him a question that he doesn't know where to go for the answer. I have the highest respect for Steve and can't wait to interview him here as well. But I remember him telling me about this, and my first thought was, steve, that's a crazy idea. The drug is free. Who the hell is going to pay for this study? NIH can't pay for it because they don't consider aging a disease. Pharma can't pay for it because there's no way to make money on it. I mean, I might pay, like, 10 cents a year for my supply of metformin. It's a free drug. I said, you're doing the wrong study, man. You got to do this with rapamycin. So talk to me about the challenges of this. You're proposing something that has really never been done before.

Can I just ask you, are we going back to Metformin? Because you asked me about diabetes but not Metformin action. Will you ask me later? Absolutely.

I cannot wait to dive into metformin. Yeah, we're not going to get off this topic for a while.

Yeah, so. So look, if I'm answering now, why metformin and not rapamycin?

Oh, you don't need to Answer that question. I was just sort of teasing Steve that day. But.

Well, there are people who are asking. And of course metformin. We have preliminary data, we have the cancer, we have clinical studies. You know, clinical studies of metformin, the Diabetes Prevention Program, it prevents diabetes, the UK pds, it prevents cardiovascular disease, the Alzheimer literature. There are two clinical studies to suggest that in mild cognitive impairment it improves some domain, by the way, like name recalling Asimov.

We'll up your dose after dinner.

So there is lots of. And safety. Look, if we're going to have a new indication, we don't want to kill anybody on the road with rapamycin. We won't be sure. And it causes diabetes and it causes testicular atrophy and cataracts in animals. Okay. So we have to play it safe.

So I would only add one caveat in defense of rapamycin, which is with constitutive dosing.

Right. And you're aware of the studies from John Manic, right?

Yes, of course.

The last ones. Okay, so.

So my view on rapamycin is it should not be dosed every day. It should be selectively dosed to target MTOR complex one, leave complex two alone.

Exactly. And I'll. We'll get back to that because I'll tell you what we've done with metformin for the biology of aging part. So that's why the. You look, we are a bunch of professors, including Steve Austin. We go to the fda. By the way, beautiful movie by Ron Howard. He went with us to the fda, to the Senate.

Wait, has it been released yet, this documentary?

A year and a half ago. It's.

I'm sorry that I.

It's called the Age of Aging. It's National Geographic. It's the best movie that was done ever on aging. It's really quite incredible. Ron Howard is narrating it.

I remember. I'll tell you what, I was having dinner with Steve at some point during. He was in New York for that being filmed.

Yeah. So, you know, so we're a bunch of professors that are coming to the FDA and kind of telling them, you know, you know, that aging has biology, but this biology also can be targeted. And they said, so what? We said, well, if you slow aging, then you prevent a bunch of age related diseases altogether. And I said, well, we're interested to hear. And we went through this discussion with the fda. I would say that the most interesting part, and you'll appreciate it because you're diabetes centric. I see you're.

I'm actually not I'm purely, I'm purely age centric.

You're metabolic.

But I'm, but I'm, but I'm, I'm diabetes. I, I think of diabetes as a great example of what happens when you don't fix things earlier.

So we told them, basically we came and we said, we'll do a study and what we're going to see is cardiovascular disease and cancer and Alzheimer's mortality and diabetes. I said, not diabetes. We said, what do you mean not that? He said, no, diabetes. Look, you diagnose diabetes first of all. You diagnose it on a chemical, on a chemical test. You know, you decide. Yeah, and only 40% of them, 10 years later will get complication. We're really not interested in diabetes.

Wait, did the FDA actually say this?

Absolutely, absolutely said that. And by the way, I should add that there's another bunch of people who came to tell the FDA that they should allow metformin for prediabetes diabetes because the DPP said metformin prevents diabetes by 30%. And the FDA said, well, if you think that's important, why don't you make the diagnosis of diabetes in 5.8 hemoglobin A1C? You know, it's not up to us to, to do that. And they wouldn't give them an indication for pre diabetes.

That's a very counterintuitive point of view when you consider the long term, not short term. The short term cost burden of diabetes is relatively trivial, but it's that long term cost burden that becomes quite elaborate.

You know, it's very boring with you because we have the same views. You're right. So, yeah, so, okay, but, so we had to adjust our study. We had to take diabetes as one of the outcomes.

Outcomes, yeah.

And put in and, you know, just increase the number and take diabetes out. It's not that we're not going to follow diabetes, but the FDA is not interested in diabetes. So the really, the challenge was how do we define aging in a clinical study? Because one view is, well, let's, because.

You can't use survival, overall mortality.

Well, there's no, there's no biomarkers to aging. All the diseases are, are their major risk factor is aging. You know, so how do you define it? And we basically did a lot of work and published a lot of work and showed that, okay, let's, let's take somebody who has survived cancer and he's 65 to 80 years old, what's his chances of getting cardiovascular disease? Cognitive decline, mortality. Right. The other things. And let's say it was 10. Okay. And okay, now let's switch it around. Let's take somebody who had cardiovascular disease. What's his chance of getting cancer and all the others 10. Okay. Let's take somebody with Alzheimer's. What his chances it really with aging, it doesn't matter. The disease you get first depends on, you know, your genetics and environment. If you have a mother who's diabetic and you're obese, you'll get diabetes first. Okay. But really, because we age biologically, you know, in different way, whatever it is, the next disease, you're going to get the next disease. And we don't know what's the next disease, but that's what we're going to prevent.

That's sort of like. It's a really interesting idea you proposed because it's in lending, you would call that asset value correlation. So you'd say, well, let's say near comes to my bank and he has a credit card and he has a car loan and he has a student loan and he has a mortgage and he has a personal business loan. Which one is going to default first? I don't know. I mean, I could sort of tell you. Typically people are going to stop paying their credit card before they stop paying their car and their mortgage. But boy, once you default on one, those dominoes start to fall very quickly. And so that would have what we would call a very high asset value correlation of default.

Yeah.

So it's sort of like this is the same for disease.

Yeah, I think you're right. I'm saying it a little bit different. I'm saying I'm agnostic to the disease.

To which the first one is.

Yeah, it's just I'm agnostic. It doesn't matter what you come and what you're going to have. I'm going to prevent whatever it is. That's why we have a composite. Okay. A composite.

And people get very prickly about composite outcomes.

Very.

And I'm going to get on my soapbox for a minute here because this pisses me off to no end when people get all bent out of shape about how you can't have a composite outcome. And this is the bias against aging, really, because in the end what matters is how long are you alive and how long is your health span optimized? So I'm sorry for. I made that rant as short as I normally could. Normally that would be a 10 minute rant.

Well, that would be a 10 minute rant for me too. Okay. Yeah, absolutely. And this is where we get into trouble. I'll tell you what the other pieces. But. But we had our grant reviewed at the nih and unfortunately.

And is this inside any of the groups except nia? Like, is NCI weighing in on this?

Yes. Yes. I'll tell you what we've done. I'll tell you what we've done in a second. Let me just make sure that I say that. So our reviewers were not JRSI. Because everybody is involved and we have 14 centers. Okay. So everybody is involved, involved. So the reviewers are from other place and they just. They just. Just a minute. You're saying that aging can be targeted and one drug can do it. You're crazy. Okay? There's no such thing. Why don't you do three studies? One study is metformin cardiovascular. One studies metformin, cancer. One study. And we're saying no, because what are we doing? We are trying to give aging an indication. Suppose we do.

It's just such an anthem to the way they think. And I'm not saying that to be critical of them. Right. But they're in a silo.

I know.

Which is, if you come to nci, how can you care about anything but cancer?

Right. I know the silos are really killers. But for us. So you could say, well, let's do all those studies, but for us, we're calculating the power.

I was just about to say the power analysis on that study is going to quadruple your budget. No. Well, for what they discuss for the silo.

For us, it's not only. It's not only the budget. We don't want to stop the study. Let's say that we show in two years that we, we delay cardiovascular disease. It's significant. They'll stop the study. And they said, no, everybody now has to be on Metformin. But we wouldn't be able to show the FDA that we are actually. That we are aging. For us, aging is. Stop telling us diseases. We are going to have a cluster and we're just going to delay the aging. So we'll get. We'll get the health span extended by 2, 3 years. That's what we're trying to show you. And the significance is for the cluster, not for the individual disease. And if you tell me to do individual disease, I need triple the budgets. And I'm not going to get to the FDA with the indication for aging.

So it seems to me that the biggest challenge here is not the funding, it's not the study design. It's the conceptual leap. It's A completely different paradigm of how we think about delaying death.

Correct? Correct.

Where do you stand today?

So I'll tell you a few things. First of all, we conceived it. I got my friends to what I call a prison, a French prison in Spain somewhere. We were in a parador in the middle of nowhere in Spain for several days, saying, what do we have to do in order to open the field for aging to allow us to get to treatments? And we decided several things, but one of them is to go ahead with tame. By the way, I'm saying French prison because the food was good, but it was in Spain. And I started getting those people, those clinical people together and we started really thinking through for what it takes for what it takes. And we had this whole academic and wrote papers in order to say how we're thinking, how we're thinking of cluster of diseases, how we're doing power calculations for targets, aging and stuff like that. We really spend a lot of time with the best people. Now our friends came to us and said, just a minute. Your study is $70 million. If the National Institute of Aging is going to spend $70 million, that means this. The National Institute of Aging is very small. It's just 3% of the budget, although we are 80% of the diseases. Right. Then we won't have money for the grants. And I said, well, what I'm going to do is two things. First of all, half of the money is going to come from somewhere else. That's my association with afar, where Steve and I are the scientific directors. And for afar, I got the other half.

So the 35 million is already raised. And that's mostly philanthropic.

Right. And then we went among the institutes.

So NCI should chip in a bit.

Nci, nhlbi, niddk. They didn't commit because first they have to see the review. Okay. Or they have to have the decision that the NAI wants. I would tell you though, that the NCI director, who's a good friend of mine, is waiting for TAME to come. You know, he. He's like, where's tame?

So the NCI has committed. It's basically a bunch of contingent commitments.

Yeah, I just, I just want to say committed is the wrong word because they didn't have a budget yet and the grant didn't come to them. But I know that they will give them money because their head is. Will do it.

Yeah. So that's good to hear. So realistically, when is the soonest you would begin enrolling for tame?

You know, I'm waiting for something to know Next week and if next week goes well. So I just want to let you know that we have an alternative. The alternative is non for profits. That the reason they haven't joined us is that their charter is not to fund anything that the NIH funds. They want something riskier, of course. So if the NIH is not funding because they feel it's risky, those will fund. So we can start anywhere. And it's the, the answer is early 2019. Okay. We are. We're basically all our centers are ready to go.

How many centers?

14.

How many subjects?

3,000. Age 65 to 80.

Any limitation on comorbidities?

No. In fact. Well, there are a lot. There are a lot of limitations, but we're very inclusive.

But no existing diagnosis of cancer?

No. Unless they're cured.

Okay. So you could be in remission, but you can't have active cancer, secondary prevention or primary.

You could have cardiovascular disease in the past. If you're okay now, you could have mild cognitive impairment and low speed walk will be a criteria. So in other words, we don't want the people like in my study who will become centenarians because we're wasting time on them. We want people who we know are kind of in the midst of aging and we know that it's never too late to target aging. And that's where.

So 65 years and up five years studied. And you're going to randomize one to one or two to one.

One to one.

And the placebo versus what dose of metformin?

Two grams, 1500. So you know, the. So first of all, I should tell you that Merck company from Germany is giving us the placebo and metformin.

Right. So the drug is free.

So when, when you say nobody's interested, it's true, it's generic, but actually Merck has the worldwide license for metformin and they're actually giving supply to lots of studies because they kind of realize that this is good.

And do you think there's a difference between generic metformin and branded in terms of efficacy? Is there any reason? No. So they're really. This is kind of. This isn't necessarily accretive to them because one can buy metformin generically anywhere.

They're not going to make more money from giving us this. Well, you know, I should say even now a lot of the metformin suppliers have higher sales and a lot of them are non diabetic.

Yeah.

So this thing which is, which is bad for me because I don't want too many people to know that right. I want to do this study. I don't want and I don't. I want.

Well, you'll have you know, I don't think. Hopefully it won't impair your. Your recruiting and the power analysis. I mean it's funny, honestly, near I would have guessed but this is, this speaks to the non linearity and complexity of estimating power. You can't do it without the tables. I would have guessed you needed a bigger n than 1500 in each group. You are using 80 or 90% power.

90% power. But I should tell you, look, for every disease we have almost a 30% effect and we chose 22% effect. Okay. For every disease we have preliminary data for the same.

Got it. So you lowered your threshold to call it 20% from 30% and at 90% power you've hopefully powered this. You've got buffer both on your power and effect size.

Right. And again we don't want to stop this study early either for one effect. So we carefully thought about it. We asked for a grant for six years because we don't want to overdo it. Okay. So it might finish in four or in six, but we have the flexibility to look at that.

Any non US Centers? Are they all U. S?

No, we decided to do only in the US because of communication and because look outside of the US People came and said, you know, we'll fund tame but how, you know, if they say after two years we won't fund them, you know, it's very different because. Because if it's a center they need to be of, part, part of, part of the power and we cannot afford to lose them. So we, you know, those and other consideration, we decided to stick with the United States.

So let's go back to what we really glossed over. But now I want to dive into why do you believe at the cellular mechanistic level metformin is an anti aging drug.

So let me take you through that in a, I don't want to say schematic way because we don't have the scheme here, but in a way that maybe I think will be easy to think. So I want to start by saying that studies have shown that some of the effects of metformin are through AMP kinase and some of them are independent of AMP kinase.

Yes.

Okay. Is it important? Not for metformin, but I don't know which are the ones who are relevant more for aging. Okay. And it's hard to know and it'll get complicated in a second more. So metformin gets into the cell through a transporter that's called OCT1. Okay. This transporter is not equally equal in every cell. So unlike fenformin that goes with other transporters and affect everything, metformin is peculiar in this way. But we have the preliminary data and it binds to complex one in the mitochondria.

Does it do so preferentially? Does it gain entry preferentially into the liver?

In humans only in the sense that there's a nice concentration of OCT1 in the liver, but not. Not better. But it's not. I don't think it's the top other organs have.

So basically it's more about OCT distribution and expression maybe than tissue specificity.

It's more that. I want metformin everywhere, okay? I want Metformin everywhere. And I'll tell you how I kind of prove that. So now metformin binds to complex one in the mitochondria. I'll tell you that metformin has some action, epigenetic action, that are independent of the mitochondria. You can do it with what's called row 0 cells. You can deplete mitochondria and see and measure things. And you can measure things even without mitochondria. Okay. Again, do I need them?

What type of epigenetic changes do you see in the RO cell?

In histone deacetylation? Okay. So I cannot argue that this can be important. It's not important if we use metformin, but it's important if you want to ask me, are the mechanism that form in AMP dependent mitochondria dependent?

So there's an HDAC property that we may not have even thought of before.

Right.

Okay.

So it gets to the mitochondria, and in the mitochondria, it basically changes ADP ATP ratio. And that's a lot of. It is important in the liver, but not only to the extent that there is an activation of AMP kinase and nir.

Is there a demonstrable reduction in NAD to NADH in that cell when complex one is inhibited?

Yes. Yeah, absolutely. Those studies have been done. So there's a lot that's going through AMP kinase. And I would tell you that downstream of AMP kinase there is mtor. Okay. And it depletes decrease MTOR activity and increase autophagy. And there's a whole pathway that will go to the pillars of aging.

You know, I asked David Sabatini this question a month ago, and he doesn't know the answer, but I'm hopeful that maybe one of the postdocs in his Lab will start to figure this out. I'm very curious about what the dose equivalent is between in terms of purely looking at the readout of MTOR inhibition. What is the dose to dose equivalence of metformin via AMPK vs Rapa directly? And I haven't, I mean, David didn't know the answer, which tells me nobody probably knows the answer.

Right. Look, it's really difficult. First of all, for example, lots of the non AMP kinase activities are on much higher doses of metformin. Metformin?

Well, that's my point is can you clinically match them?

And no, because you really don't know at the end how much metformin is in the cell. What we're doing now, we're doing isolated cells. In other words, we treated animals with metformin and we're taking isolated cells to just see the variability of metformin in.

Individual cells, even amongst homogeneous tissues.

Yeah. Like we take hepatocytes and look at.

The variability of expression.

Yeah, Right. So it's all kind of important question. But, but the story still. I'll tell you the story because at the end I'm going to answer you, what is that doing for aging? Okay.

And I don't want to rush this story because this is a great story. You take your sweet time.

So think about it. In a scheme, you have the metformin in the middle getting through the plasma membrane, getting to the mitochondria. And on the left side, let's say there is the AMP kinase. Okay. Now in the right side.

Oh, sorry, just for the listener, explain what AMP kinase does at the high level. It's a hormone of what? It's a hormone of nutrient deprivation. And therefore it tells the body to do what? Like when you, you don't eat for a day, AMPK goes up. Why?

Well, but it's also an exercise mimetic pathway. Yes, that's what happens with exercise. Really? That was the hope of what AMP kinase is doing. But it's a nutrient sensing that is in part upstream of mtor. Okay, but the other side of metformin is what happens to the mitochondria. Because in a way, and I hope I won't regret saying it here, but metformin is a weak cyanide.

Okay, look, what's cyanide acted at Complex 4.

Right, but. Right.

Oh, you just mean more broadly speaking, inhibiting the EC2.

Right. It inhibits. So there's less ROS production. Okay. And then there's less inflammation and there's other things that's going just because the mitochondria is less oxidative pathway going down.

So this is a great example of why binary thinking doesn't do very well in biology, right? It can't be all or none.

Well, so now I can go on and on and connect all those.

Please do.

To eventually the pillar of aging. But I want to insert another thing because other things are happening. For example, insulin levels goes down, right?

Why is it just due to the reduction of hepatic glucose output?

I'll tell you why, I think. And then also inflammatory factors are going down and there is a whole NF Kappa B action of metformin that might be part of the ros and part could be independent even without mitochondria. Okay, it's that confusing, but this is the point I want to make. I don't know which one of those is important for aging, but parts of what you're measuring is the following. You fix the aging on a cellular level, okay? So the younger the cells are younger, a lot of things are correcting themselves. So I think at the end, the lower insulin levels, the low inflammatory, are not necessarily a direct effect. And that's why we're fighting all the time about what metformin is doing, because you can measure lots of things, but the things you're measuring are because aging was fixed. And once aging is fixed, then there's whole hemodynamic readjustment or whatever you want to call it. And then you're measuring that everything. And this is not only typical to metformin, this is with rapamycin, with resveratrol. You also can see that there's a lot of things that are improving themselves. And I think we have to get used to the fact that when you have a drug that we argue what it's doing because everybody is measuring something. Some of it is true, but it's like secondary. It's. You fixed it.

Yeah.

How did you fix it? It's true.

True and unrelated. And it's funny you mentioned those three, which again, I think speaks to an advantage you have with tame. So when you look at rapamycin, resveratrol and metformin, the big advantage of metformin is you already know the dose and the frequency with rapamycin. Over dinner tonight, I'm going to give you my philosophy on the dose and the frequency, and we can discuss it, but I can't demonstrate it to you with anywhere near the validity that you could do the same with metformin. Had a wonderful discussion with David Sinclair, and bioavailability came up on resveratrol. Right. So maybe all the trials that say resveratrol is meaningless are simply not looking at what happens if you get enough resveratrol in the right place. And again, I. It's amazing to me how many times in biology we can make mistakes of the first order because of a third or fourth order omission. And this, I guess I don't think I realized it until you just gave that explanation. The value of effectively millions of patient years worth of data on metformin. Not just from a safety standpoint, by the way.

Billions. It's billions.

Yeah. So billions of patient year data on metformin. I know that from an FDA standpoint, the highest priority is safety. That's a low bar to cross. The more interesting one from the standpoint of this study is actual efficacy. And it seems like if I'm hearing you correctly, Metformin is an amazing B student. Let's not be insulted by that. What do I mean? Are there better ways to inhibit ros? If you want to hammer the ROS chain, probably. There's clearly better ways to inhibit MTOR if that's all you want to do. Are there better ways to modulate hdac? Yes, I'm sure there are. But it might be that maybe part of Metformin's beauty is it does so many things at a B plus level. Never. It's an A student, but it's not a D student. And it's never, you know, I mean, I'm sort of thinking about this sort of in a tongue in cheek way, but it seems to do so many things reasonably well.

Well, I call Metformin a tool. From my perspective, it's just a tool to show that we can target aging. Because I think that there'll be much better drugs and combination drugs than other in the future. Human lifespan is 115 years.

We argue maximal lifespan.

We argue because there's somebody 122, but you know, there's a statistics thing. So okay, we die before the age of 80, so there are 35 years that as a species without. Not that we cannot change more, but. But just now, without thinking too much futuristic low hanging fruit that we can do. And Metformin is the perfect tool to start showing the proof of principle here. But the future is much better. It's just, you have to pave the road here.

This is a beautiful pivot to something else I want to discuss with you because unfortunately I could talk about Metformin for three hours, but there's so many other things I want to discuss with you, Nir, based on your work, and you just alluded to one, which is the work that you and your colleagues have done on centenarians has been very influential in my thinking. So as I think about aging clinically, I ask the question, start with the existence principle. What does it mean to live a long life? Is there proof of this having existed? And there is. We have centenarians. They exist. My hypothesis, when I first started reading your literature, which was only about five years ago, my hope, I should say not my hypothesis, my hope was that whatever genetic benefit they had, which it became very clear to me very quickly that this wasn't about what they did, in fact, they seemed to have almost near immunity to the worst behaviors imaginable. My fear, when I read your first paper, which was a review paper, I can still see it and I still remember where I was sitting in a Sheridan Hotel reading it, My fear was whatever blessing they had, it had nothing to do with chronic disease and it had to do with something nebulous. And they had complete immunity from chronic disease. And they just died in car accidents. Like they eventually just died because something else tripped them up. And what I took away from your work was. No, their genetic gift was a phase shift in. When they got chronic diseases, they still died of heart disease, they still died of cancer, they still died of Alzheimer's disease. They Simply got a 20 year bonus, if not more, maybe 29 on average. You could calculate, call it a close to 30 year bonus.

Well, of health span, you know.

Yes, because completely functional life because they.

Had compression of morbidity. So it's not only that they lived longer and they lived healthier, but they.

Died, they died quicker.

Quicker at the end of that. And you know, it's interesting, the cdc, the center for Disease Control have looked at the last two years cost of life of people, you know, with different stuff. So they looked at people who die at 70 and after 100, and the cost of dying after 100 was third of that of dying in 70. So it's not only in our study, there's actually evidence.

Wow, I didn't know that.

To suggest that the medical. And by the way, those, when they were 70, they didn't go to the doctor. Okay. So, and this is the base of this concept that's called the longevity dividend. Okay, what, what will happen to society if we'll actually be healthier for two and a half years? And the benefits are immense. You think only of, you know, so we pay Social Security more and stuff, but there are Seven trillions dollars just in saving of medical costs if you could just live healthier.

So I know you don't spend an enormous amount of time anymore thinking about the centenarians. You know, your literature, follow it very closely. You definitely are spending much more time talking about and writing about the things that we just discussed. But if you could go back in time a little bit.

For me, by the way, that's not true.

Maybe it's just selectively where I'm reading.

Well, no, I think that's what's interesting to people now and I'm very happy about that. But I just got the, you know, the longevity, the Ibsen longevity prize. And my talk was actually about centenarians with a little bit of my hypothalamus stuff that was related to something. But the centenarians are. And we have lots of grants on the centenarians because, you know, is that.

Talk, by the way, is it something that people can watch?

No, no, it wasn't recorded. It wasn't recorded.

Oh, it's a shame.

It's a real. I thought about, about this talk. It was fun for me to give because it was reflective a little bit. You know, one of the things that's always funny for me is people say, oh, you know, I have, I can measure this thing. I'm sure that centenarians, they have, they have high level because high levels are good. And I had to put into rest the fact that the genetics of centenarians is really great for me, but the phenotype is not because you have 100 years old and you can measure something that can reflect what brought you here or the fact that 30% of them are going to die in the next year. So it could be a marker of death and not of longevity. Their phenotype doesn't interest to me. That's why I have their offspring. Because their offspring will have the phenotype or half of their offspring will have the phenotype time. But those things were something that was nice because so many people are saying we should measure in centenarians. No, we're doing a longitudinal study on their offspring and their offspring are equal everywhere to our control group. They just have half of the diseases.

Although you. By the way, that's a really interesting point. Nir. I never once thought of that. What you just said that if I have a 100-year-old centenarian in my study and, and he or she has a CTEP mutation or an APOC3 mutation and I look at the predictable phenotype because I know what you should have, if you have that mutation. Hypofunctioning. Apoc3 should have low triglyceride. But technically, without a little more longitudinal legwork, I don't actually know if what I'm measuring is the result of that. But that said, there must still be some benefit in. You know what? Now that I'm saying it, I realize you can't do it. The dream state would be to have health records and phenotypes for centenarians that go 30 years back. In other words, it would be beautiful to follow a centenarian from 70 to 100 with phenotypic data.

So that's why we have the longevity study. It's a longitudinal study of offspring of centenarians and people without longevity. And we're going forward. We're already 10 years into the study and we're starting to see the differences between those guys. It's different population, they are aging slower. Okay, the children of centenarians. So we have some of these things in mind.

What are the most important genetic differences between those either centenarians or offsprings of centenarians and the rest of us?

So it's very interesting, and so this is a part that you haven't heard so from, but it's actually the growth hormone IGF axis. We have probably 60% of our centenarians have genomic reasons.

So let's explain the normal path of that. So the pituitary gland makes gh. It tells the liver primarily to make igf.

Right. It binds to a receptor right. In the liver and igf. And so some of the effects of the growth hormone system are through growth hormone itself, and some of it is through IGF1 level. Both of them are decreasing with aging. So in this system, we identify, you know, more than 60%. And I think I'm underestimating. Okay, it's more, it's probably more. But I didn't really calculate who has several mutations. You know, I can calculate how many mutations there are, but. But not the overlap of the mutation. So I'm saying 60%. But it's the most common genomic alteration in our centenarians. And I have to tell you.

And where is it specifically?

I'll tell you in a second. And I wanted just to tell you, I wrote grants on that because I thought because there's preliminary data in nature, right? The small dogs live longer and the ponies live longer. And when you mutate growth hormone or they're born dwarf, they live longer. And when you give more growth hormone, they live shorter. So There is a lot in nature, but the human data was really confusing some diseases. You know, when you have high igf, you have more cancers, but you have.

Less Alzheimer's disease, less cancer. I mean, sorry, less heart disease and less diabetes, but more cancer.

Right. And mortality in mortality, it's like in the middle, you know, a little bit. Tending to more from kind of from.

Concerts by our analysis, which I think pulls all of your data. We found that there was a U shaped mortality curve with the nadir being between 60th and 80th percentile of all cause mortality.

So I want to tell you the problem with this association. On one hand, an individual that age quickly, okay. Their growth from an IGF goes down quickly. Okay. So you would Measure falsely low IGF1.

Level if you catch them on the wrong side of their aging curve.

Right. That wouldn't fit our theory that low IGF is good because that's their, their accelerated aging.

Yeah.

So this is a problem with an association study like that. We discovered first of all that when we take our centenarians, so they're in our study because they've been healthy at age 95, living independently. We take them at any age, but that's what they have to do. And we just look at those with the highest IGF and the lowest IGF1 level. Those with the lowest IGF1 level live twice as long. Those are already the centenarians. But only women. Men do not. And every example that I gave you, there's a sex difference. The growth hormone IGF is very sensitive for women or for females.

Sorry, Nir, let me ask you another question. It's very difficult clinically to measure GH because it's pulsatile.

Right.

So whenever you're saying growth hormone, are you really saying igf, which is easier to measure?

No, because I'm going to talk sooner, but not what I measure measuring, but where the mutations are.

Okay, but to repeat what you just said, the difference between men and women was that based on IGF level or GH level.

IGF levels.

Okay.

But we discovered in aging, we did a huge faux pas, okay, that we are now correcting. We, we studied in, in our labs, males only. We had excuses why females are menstruating. We don't know their effects. And, and we're all discovering. Look, even rapamycin, that really works everywhere is better in females than males. But acarbos is in males, right there. They're examples where we totally missed the sex effect. And growth hormone IGF is a perfect example. Except those Mice that are the snail mice or the Ames miles, they have a pituitary problem which makes them, I think, sex confuse. So, you know, they have so many other alterations. But sex difference is important. We also showed that those women with the lowest IGF1 level has much less cognitive problems, you know, third of the cognitive deficiencies of those with the highest IGF.

All right. Okay. So we had to grab our second round of Topo chico there, which, by the way, I didn't even ask you up front. This is your first time having Topo chico, right?

Yeah, I'm in love.

I mean, this is. There are few things that bring me as much joy as introducing people to this bottled water.

The Perrier has. Is much milder. I like to feel the. The bubbles.

Well, I would. I think one thing we should consider for tame is if we can have an arm that also includes Topo Chico. So there's a placebo, there's a metformin, and then there's a metformin plus topo Chico. And the question, the hypothesis will be, does that somehow enhance lifespan? Because even if it does not, I predict it will enhance happiness.

Well, I have to tell you, I'm an advisor to the Prime Minister of Singapore. Singapore is a place that can, you know, plan the future. And before going, I said, why don't you ask me questions? And one of the questions. Shall we put metformin in the water or in sodas?

Now?

Good to ask. You know, the answer is no, obviously, but it's good that you're thinking that way. So Metformin.

And should you change your mind, I think you now know which soda it should go into.

Right. Can you get it in Singapore?

Oh, I'm sure we can. Yeah. So back to sort of what you were saying. This, this igf, male, female, disconnect. Let's. Let's keep going down that rabbit hole.

So I was saying that one of the worries about low growth hormone and IGF is the effect on the muscle, because people think that growth hormone affects muscle function, muscle size. And we found that in females and males, the IGF1 level is not associated with better or worse, lots of muscle function, including grip and getting out of chair and, you know, other things. So maybe the effect of low IGF and aging are just as good as having a higher effect of IGF on muscle. It just weighs itself out. Okay, but then our study is genetics, okay? That's what we try to do. And several years ago, almost, I guess a decade ago, we found clusters of mutations in the IGF receptor Those were new mutations that haven't been found before, but we found them in nine of our centenarians, which was 2% of our centenarians. And that was kind of a proof of concept for us that clusters of mutations that are functional is what we really need to look for rather than like Everybody's doing, doing GWAs and find something intragenomic somewhere. And this was also the first proof of concept that the growth hormone IGF could be relevant to human aging people, that those 2% of our, those nine people had higher IGF1 level because they were resistant. Right. It's the IGF receptors. They were resistant to IGF, so their level was a little bit higher, but they were significantly shorter than others, which.

Is a great explanation of how that phenotype would play out. You would say, well, how can they be short statured with high igf? And the answer is if the IGF isn't as effective at the receptor.

Right. But remember that most of our people with low IGF are doing better. By the way, we take the people.

With igf, sorry, men, men also or.

Just women, Two men in those nine people. And by the way, then there are dwarfs, human dwarves that called Laurent, dwarfs that live in Ecuador and Hassi Cohen and Valter Longo and some of the people in Ecuador were looking basically were trying to find if they live longer. Too few of them to really know, but they have less cancer and less diabetes, you know, significantly less. So there's other evidence from humans came after hours that, that there is at least less age related diseases in those people.

They certainly didn't live a better life in any way that we could assess. Correct?

Right. I mean we, we always joked that they weren't happy with the fact that they are short. So they drank a lot and that's the alcoholism. And then when they crossed the road, nobody saw them.

So they died of more trauma.

But I think it's really not true. So I met some of them. We were in a Vatican conference. Everybody has to bring his patients. And Longo brought somebody from Ecuador and I brought a centenarian from Rome and, and the guy that he brought told a different story. He wasn't unhappy. He was also happily married with a big woman and had children and was. So I, I, I don't know.

Is the defect in them at the growth hormone receptor in the liver?

In the liver.

So they make normal amount of growth hormone. Their liver doesn't acknowledge it.

High amount of growth hormone because the feedback loop.

Yeah, yeah. So they have lots of growth hormone, but it's not being expressed through the.

Liver into igf, and so they have no igf. So we published last year a paper that took us 10 years to write, and basically we were looking at a relatively common mutation. I'm saying common because it's like 3, 4% in the population where they have a complete deletion of Exome 3 in the Growth hormone receptor. Okay, so one of the exomes, one of the things that are important for the integrity of this hormone. Right. Is deleted. And of course you would think that that means that the growth hormone is less effective. And Giletzman, who was fellow with me, brought me this data to suggest that while it's 3,4% in our, our control population, it's 12% in our centenarians. So I asked, so what's the IGF1 level? And he showed it's lower. And I said, and what's the height of the people? He said, well, that's the problem, they're much taller. So I said, I cannot do anything with this study. It just makes no sense. I don't know how to write.

So the people with lower igf, but the mutation was in the exon of.

Of the growth hormone receptor. Okay, so they had lower igf.

So it was a dysfunction of the receptor in theory, so less igf. And we know that it was fully penetrant all their life. In other words, we, there's no chance that it didn't start showing up until they were an adult.

Well, we'll come back to that. But the mutation didn't change these guys.

And by the way, just give me some numbers here. How low are their IGFs? I, I don't really directionally. Like, are we talking about like less than 100?

We're talking no less than 200.

Okay, yeah, 100 is about the median level of IGF for somebody over 65.

Yeah, I think in the studies that I told you the average or the mean or whatever was 94, something like that. I don't remember to answer about those people. Okay, now. Okay. So he said, what to do? I said, well, first of all, what you do with genetics, you do replication study, you know, you go to other populations and you see what's going on there. And second, you do a functional study. Let's see if it's really a functional mutation. So it took almost 10 years. Right. And in 10 years we replicated the data in three other population in Amish French centenarians, in the CHS here in the United States. And in all studies that people that live the longest had much more of those homozygosities in the growth hormone receptor. So that was a great validation. Second, the functional. So Hasi Cohen, my, my partner in usc, we send him the lymphoblast of our patients, the affected and not affected. And he is a growth hormone IGF expert. So he incubated them serum free, so without stimulation and with growth hormone, and looked both at activation and proliferation by growth hormone. So in serum free without stimulation, they had less activation and less proliferation, half of normal, suggesting. Yeah, that's the mutation, that's the function. When he incubated them with growth hormone, it totally switched.

I'm sorry, but going back, you talked about proliferation, but was there a functional difference in the lymphocyte in addition to its increasing number?

There's. Yeah, the first was activation by phospho ERK and some of the. Okay, some of the.

But non specific activation.

No, no specific to what growth hormone is doing, but erk, proliferation, it's, you know, it's a cell.

That's an easy one. Yeah.

When he incubated it with growth hormone, it was the opposite rather than this low proliferation, Low activation, it was high activation. High proliferation. What's going on? Well, what's going on? When do we have high growth hormones for puberty? With high growth hormone, something has changed in the activation. From low activation, you jump to high activation. For reason with the, the real mechanism, we don't know really. But that's what happened when you have high growth hormones. So they all were taller and then when growth hormone got down for the rest of their life, they shut off. Okay, so, so, okay, so this is 12% of our people. Then Yushin Su, who's a geneticist that's working on this, she was interested in Microrna. That's another, you know, epigenetic thing that comes. We, we haven't been thinking about it, but those are RNA that comes from certain region of the gene and they bind specifically to active region of the gene and they modulate it. Well, 30% of our centenarians have clusters of Microrna that are overexpressed by. By a lot, by 40 times, you know, just immensely activated. One of them, for example, Micronora, micro RNA 142, that's increased by 35 fold. When you incubate it with cells, it prevents the phosphorylation of the IGF receptor, decreases some other signaling, FOXO signaling and some other stuff dramatically. So there's a Microrna targeting of the growth hormone IGF receptor in about 30% of our centenarians, then 22% of our centenarians have mutation in FOXO3A. That's a common mutation in centenarians. So you start 2% and 12%.

Yeah, tell people what FOXO3A does.

FOXO3A is another, how would I say, just house homeostasis housekeeper that lets in good stuff and change things and put things in stop. It's too complicated to go more. But it is part of the, it's.

Very important factor at regulating homeostasis, cellular homeostasis. I mean, that's not a great explanation. But isn't FOXO the most prevalent genetic difference between. If you were to just isolate them by genotype. If you look at CTEP and C3 and Foxo and GH and IGF. I mean, if my recollection is that FOXO might be the single most prevalent of the.

Well, Foxo, I'm not sure that it's true. But Foxo 3A is common in all centenarians population around the world. Not every population has the same mutations. In fact, what we're doing now, when we have the exome sequencing of all our subjects, you know, almost 3,000 exome sequencing, the important thing to do is to assign them to pathways because you know, we're doing something really silly with genetics. When we had this GWAS, we said, we have million SNPs around the genome. We'll find the diseases, every disease in the world. And one of the stupidest thing we did, we took one SNP at a time. Okay, let's see if this SNP is significant. But we are not built of one SNP of a time. And in certain population there is. Down, down this pathway, there'll be another SNP that will change the function. So you need, you need to. Our analysis now is totally different than how we started.

But this, you know, I mean, I agree with you completely, but I don't think most of the world is listening near. I mean, if I had a dollar for every time one of my patients came with their, you know, complete sequence and, you know, they want me to interpret them. I have the same discussion so many times. Okay, you have 20,000 genes. To my last counting, maybe 78 of them have a deterministic relationship with the disease. You have none of them. And we know you have none of them because if you had any of them, we would know by now. There's no chance you got here with Huntington's disease and we sort of missed it. Or there's no chance you have some inborn error of metabolism that somehow got missed. And then we get into this whole GWAS morass, and it's hard to explain to people how multifactorial these issues are. And I find myself, maybe you do as well, somewhat frustrated by these discussions and the overemphasis on this genetic. It's a little bit of the drunk in the streetlight problem, right? When the guy is standing below the streetlight and you say, what are you doing here? And he says, I'm looking for my keys. And you say, did you drop them here? And he says, no, but this is where the light is.

So let me not increase the complexity, but give you another ammunition. Okay, so we did, you know, now several years ago, because of funding, we did our 44 best, you know, first centenarians, their whole genome sequencing. So think about it. We have a study without control. We just have 44 centenarians, and we do the whole genome sequence sequencing. And our question was, do centenarians have the perfect genome? I mean, maybe one out of 10,000. They just don't have all this crap from the GWAs, those snips for heart and Alzheimer's stuff. They're just great. And we went to this data set that's called Clinvar. Clinvar then had the 15,000 pathogenic mutation that most probably will cause it disease. Okay, now they have about 30,000. And our hypothesis is that our centenarians don't have any of those. Okay, we'll support the perfect genome.

Right.

44 centenarians had more than 230 mutations between them in other five to six mutations that should have caused them diseases. And none of them had this disease in 100 years of life. And some of those mutation, I'll give you the best example. They're for Parkinson's and cancer and everything. But APO.

APOE 4. Yeah. What's the E4?

We have two APOE 400 years old people that the textbook would say they're demented at 70 and dead at 80, and they're not demented and not dead at 100.

Do you think this at all explains the LPA uptick we see? Because one of my favorite topics is lipidology. And of course, LP is a very virulent lipoprotein. And yet centenarians seem to have more of it than the general population.

Exactly. So we actually showed in a paper because we found a way. So basically, obviously, we can have mutations that are protected because they have slow aging or longevity genes that protect them. Right. So how do you prove that? So we noticed that when you look cross sectionally, I hope I can make it very simply when, when we put any genotype cross sectionally, in other words, we have all the ages, from 50 to 112 is our oldest. We see patterns. If we see pattern that the genotype is declining with age, we know it's killing people. Okay. If we see that it's kind of monotonically increased with age, like with the.

It's concentrating.

Yeah. Then means the people who are surviving, are surviving with this mutation. That's why we have it more in hundreds of. Like the example of growth hormone receptor going for 3 to 12 in A, in a monotonic way. So we looked at lp. Exactly.

And this is the most confusing of them all because I don't see any compelling evidence that LP is anything other than atherogenic. And so it begs the question, why would it concentrate in centenarians as opposed to just rise commensurate with the population.

Exactly. So this is the answer. Okay, first of all, we show cross sectionally that LPA drops until the age of 80 by half. In other words, it kills half, killing.

You like crazy until it's not Right.

And then, and then you look at that and you kind of try to understand. Just a minute. Now this thing that killed, now all of a sudden centenarians have even more.

Right.

It should stay flat after 80, right? It should be flat. Why is it increasing? Well, because it's a protected aging gene.

In other words, it was obviously during evolutionary times. Are you saying that the thing that LP did for us 500,000 years ago that is no longer beneficial in this lousy environment, the centenarians have managed to tap into its properties?

No, no. So what we did what we did and it's all published in computational biology journals. We took every one of the longevity gene that we have and we did gene to gene interaction. In other words, we tried to see if there is interaction between the bad genotype and the good genotype, the good longevity genotype. And we did it to variety of those U shape. Right. I'm, I'm telling you, there's a U shape. You know, it goes down with aging and then it's good in centenarians. And we really found the statistically significant that LP is protected by people who are homozygous to a CTP mutation. That is a longevity mutation that we, we found.

That's the VV mutation.

The VV mutation. In other words, most of the people with the LP that are centenarians were also CETP mutations.

So can we tell people what that phenotype is? So I've talked on this podcast a lot about CTEP and its role in reverse cholesterol transport, et cetera. Talk to me about what does the lipid panel look like for someone who is CTEP VV plus or minus lp.

So those with CTP vv, they have higher HDL level levels, they have larger lipoprotein particle size and they have lower CETP levels. That's their phenotype. And this CETP has been protective against several age related diseases. The most dramatic is cognitive decline. And by the way, the two Apoe 4 are also CTP VV carriers.

So really the question is it sounds to me like if you are CTEP vv, that's a very protective phenotype. And the difference, if I remember the data going from 70 to 80 was basically flat. If you're CTEP VV, it really goes up when you turn 80. Meaning the concentration of CTEP VV the genotype. Yes, the genotype goes up significantly once.

You hit 80, it goes in 55, it's 8% of the population and at 100 it's 20% of the population. So it's also important to know that not first of all, the 8% that have VV, I don't know how many of them will be centenarians. Right. And also not all centenarians are vv, but it's a really, it's still very.

Impressive because the problem with HDL cholesterol is it's just such a dumb ass metric. It's so useless, it's so far downstream that it doesn't tell us much. But the hypothesis here would have to be that these people have far more functional HDL particles because I mean, we don't have to rehash this, but anytime you pharmacologically increase HDL cholesterol by inhibiting ctep, nothing good seems to happen.

Right, because you're actually impairing the reverse cholesterol transport transport. So it has to be with effect. Right. That's why it has to be a functionality functional thing of the HDL probably or the lipoprotein particle side or something.

So I understand all of that. Here's the part I still don't understand, Nir. Why wouldn't the LP phenotype or the LPA gene flatline after 80? In other words, I understand why CTEP VV is protective. I don't understand why LP should concentrate.

I think because the CTP is common and is very protective and that's why you do it? Look, it's a cross sectional. Okay. By the way, it's a good question. That's what we ask, why it's not flat. But for a person who's born and is going to be a centenarian, for them it's really not so. So they don't die when I guess I need to.

I need to do the math and we could do this over dinner. We'll sketch this out on a Napkin. You take 100 pieces, people who are going to be centenarians, 100 people who are not. 8% of each of them, call it 10% of each of them have LPA. We should do the math on if it's. Are we being fooled by the age? Because I do have one alternative hypothesis, by the way.

Oh, I'll show you at dinner. I'll show you the actual calculation computation.

Okay, so this will be good. This will answer my question. Because the other hypothesis I've often wondered is depending on. So I'll start with my question and then I'll go to my hypothesis. How much phenotyping have you done on the lpa? Do you know how much heterogeneity is with their Kringle repeats, for example?

No. And I don't have their LP level. I have just their LP genotype. So the things that we've done are though we can do. Actually we've done a little bit on the CTP levels or we've done. But those calculation are on gene to gene interaction. Okay. Taking out the people without genotype and without genotype and seeing who are the people who are the centenarians that stayed with the bed LP genotype. They were only the ones who are ctp.

Also, I see it. Do you have serum stored on these subjects?

Yeah, but, but. And I have a proteomics done and maybe we can have some measurement. I'm not sure.

I wonder if there's a clue to a very vexing question, which is why is it that some people with high LP do not go on to get premature heart disease? Many do, most do. A significant number do not. And it appears completely uncoupled from the level of their lp, which makes me wonder, are there virulent and non virulent phenotypes that at the level of expression by number or molecular weight aren't captured? And my question then becomes, is the non virulent one the one that is concentrating in the centenarians and are they the population in which we should understand that phenotype so we can better risk stratify the rest of us schleps walking around today, 10% of whom have elevated LP but we don't know how aggressively to treat them. Them?

Yeah, I didn't know that there's virulent or non virulent lp. My explanation is totally gene to gene interaction. In other words, you do another phenotype. I guess the answer is, is different. Is the, the people with the what's the lp? What's their CTP level, what's their hdl, what's their HDL particle size? And maybe you can see that generalize that if you inhibit CTP the LP is less.

I mean, I think the problem we. I agree with what you're saying. The challenge is we do not have an HDL functional assay. So right now we can measure HDL cholesterol, we can measure HDL particle number and we can measure HDL size, but none of those come close to telling us how functional the particle is.

I have a collaboration with Dan Rader who's doing HDL efflux and stuff like that.

Yeah, I mean Dan is a God in this field, so maybe.

But you know, that's not my, this is a past life for me. I moved on. So I don't really know to answer you. I didn't realize.

Let's go back to the IGFGH thing because this one still creates tremendous. Let's bring it back to clinical stuff. So I'm often asked by patients, hey, should I be on growth hormone? And my answer is I don't think so. But if I'm going to be brutally honest, I really don't know. I really have no insight into whether growth hormone is exogenous, administered growth hormone is harmful, helpful, neutral or what. Because the clinical data certainly don't give us the answer. Right. So the epidemiology, if you're in sort of, you know, Valter's camp, is that would be the worst thing you could ever do. Growth hormone is bad because IGF is bad. But again, the epidemiology tell a different story, tell a much more nuanced story that has to do with how high is too high, at what age and for what gender and with respect to what disease. So of course, how can you manipulate igf? Well, you can manipulate it. The two easiest ways to manipulate igf. The three easiest ways to manipulate IGF are to manipulate growth hormone exogenously, manipulate IGF dietarily predominantly through amino acids and manipulate insulin to indirectly impair or enhance IGF binding proteins.

Well, let me tell you, we just Published a paper in Nature a month ago, study that we're going also for a while. And what we did is we got from Amgen. Amgen, as much as other pharmaceuticals, tried to develop antibodies against IGF receptor. Because IGF receptor is expressed in many cancers.

Yeah. This was the disaster drug that they tested against metastatic pancreatic cancer. It failed. But if I recall, there was a very special little gift which is no CNS penetration. Am I thinking of the right one?

Yeah. Right. So it failed. But we're interested for aging, right? And not only we're interested for aging. Our hypothesis was that igf, you know, that you need to decrease IGF action in the periphery, but increase it in the brain because of the data. So we asked them to morinize their antibodies.

Morinize means make it available for a mouse.

Right. And we got it. And we did a longevity study that we started at 22 months.

By the way, remind me, in the human study, how much did it lower IGF in the periphery?

It increased igf.

I'm sorry. I know, I'm sorry. How much did it lower IGF activity in the periphery? Was it a reduction? By what fold? Like, was it a two fold reduction?

It's very hard to, to measure. You don't measure it like that. You measure it in, in, you know, in vitro. It's very hard to measure how much.

Got it. Okay.

And they rebounded a little bit with igf, which is not the case with aging, because with aging you don't have the growth hormone secretion. So we gave it to 22 months old animals that are 70, 75 years of age equivalent. We increase their health span dramatically and we increase their lifespan by 10% at an old age. Okay, so this is a drug that's already.

And you were able to demonstrate. I'm sorry, I missed this paper. It came out a month ago, so I'll be inhaling it this time tomorrow. You basically showed that you didn't change IGF levels in the brain or you actually increased IGF levels in your brain.

We really don't know. There is a little increase in IGF1 level in the periphery. And we're assuming that, that we didn't make it a big. I'm telling you what we thought. We didn't make it such a big deal. But obviously the antibodies do not cross the blood brain barrier. But the IGF wasn't lower, if anything was high.

Right. So if anything, IGF went up in the periphery because it was being blocked.

And therefore a little.

You could have got More into. So you could have had more CNS activity, less peripheral activity of igf.

Now again, those were aging, by the way, it was in females. In males. We started to do the studies in males. And since we didn't see any major effects and we had relatively little, you know, those are months of studies in many mice. So we eventually did the longevity only in females. We don't have data on males, but the extent of health span. And you'll see the paper, it's really. It's a great paper with lots of studies and it's impressive how much, much they did better the females with it. So there you have an example. We have all the pathway you ask what do we do here is it's been in humans, okay, the IGF receptor antibody is there. The only problem for us is aging. Could be an indication what's before aging. Like we need another indication in order to start selling it before.

But what's your hypothesis in those mice, in the female mice that they. You said they live 10% longer and.

And much healthier.

And much healthier. So they had compressed morbidity as well.

Cardio, you know, they had the cardiovascular protection. They have cognitive advantage, functional advantage. There's a whole thing. The interesting thing between male and female, the difference is the mice. The female mice that were treated with IGF receptor antibody had a lot of. Of inflammatory markers. Right when we started, they were 22 months. And those inflammatory markers were really decreased with aging. In males, we had a little bit more inflammatory markers, but they increased with the IGF treatment. So maybe the fact.

And both the males and the females had an increase in peripheral igf. Presumably the antibody was working in both.

Of them, but somehow the inflammatory response in males was different. So it's all driving. So I'm answering you two things. First of all, what do you do? Here's a good example of a drug that was in females. And we have preclinical proof of concept that it's good. But the second is in males, all those have not been shown. And in fact, you know, the functional that I told you, functional in women, it looks like the function was better for men with a higher IGF and not with lower. Not statistically significant. But you could see that it might happen. So I'm telling you from human studies, from genetic studies, I'm telling you growth hormone treatment is not beneficial. It should be dangerous for elderly people, for elderly women with men. I'm ready to say that I'm not sure. You know, I'm not sure it's not that I've shown that low IGF or growth hormone is better in males. Not in my rodent studies and not in my human studies. But it's hard to say that giving growth hormone is bad when you know, by the way, the growth hormone receptor story is a lot of them are males.

This is so interesting. I mean this is such a layer of sophistication to this question which I've largely sort of decided that I can't come up with a compelling reason for exogenous growth hormone. But I also can't see much evidence clinically that it's killing people. But of course I think disproportionately the data are in men. What do you think explains this sex difference between men and women?

I think I'm really. If you look at this inflammatory panel, lots of cytokines in lots of animals. I'm not sure we don't have the intellectual link to say what happens, but this is something we want to actually go on and examine because if for some paradoxical way that is sex dependent, low IGF increase inflammation, we want to do, we want to know why and we want to know how we can affect.

Would be great if you could repeat the study with younger mice, both male and female again because I mean the most obvious example is the biggest difference between the men and the women are the sex hormones. And the older they get, that difference is still there. I mean women will, you know, the female mice would go from having some testosterone to zero testosterone, but gosh, the men would probably still have more estrogen than the males have more estrogen than the females post menopause.

Right.

Which makes me wonder if the estrogen, the progesterone and the testosterone are somehow protective of the inflammatory effects.

So there's a, you know, we're working on a grant because the sex issue is so interesting. We, we started working on there lots of models where you can change X and Y chromosomes and stuff like that. And you know, we're looking at the way to look at it because it's, I don't think it's usually as simple as the sex hormones. You know, I think we're missing a whole biology. A whole biology. And whatever is the sex hormones, I don't understand the inflammation in that. By the way, your idea of doing it in young is good. Amgen sold this IGF receptor and we cannot get more samples, but we're interested to maybe do our own.

Wait, wait, Amgen sold the rights to the human antibody?

Right. Their whole section, actually, their whole section.

To who, Which Company owns it now.

To like a private company that we're unable to get people to, though I have to say it's not our major priority now. But. And we have some consultants that are trying to get it together with those people. So, you know, it's still an issue. But I'll tell you, if I had to develop a treatment, I would rather use the microrna142 because the IGF receptor antibody didn't work in cancer. But maybe the Microrna penetrates better in another way and maybe that's the way to decrease IGF receptor in, you know, in cancers. So anyhow, but I really answered you is that, yeah, there are things that we could do to affect the pathway.

I mean, what do you think about sort of all the. To me, the most obvious way to manipulate IGF is through fasting. So about once a quarter I fast for a week with just water only. And it has a profound impact on my IGF level. So for my age, I think I should know these numbers off by heart. But plus or minus two standard deviations of IGF at my age is about 90 to 250. And if I take my, if I measure my IGF level before a fast, right before a fast, it might be 180 to 200. And right after the fast it's 80 or 90, and six weeks later it's maybe 140, 150. So it sort of falls precipitously during the fast and then slowly rises and then falls precipitately and slowly rises. And there's part of me that just wonders if a cyclic approach to IGF is a healthier approach than say, constitutively being calorically restricted and just, you know, because you could starve yourself of methionine and eat no protein and live at a lower IGF level of maybe 110 forever. But I wonder if the real game is sort of figuring out this sort of cycle in periods of. Just as we think of autophagy, if you're always in a state of autophagy, that's a bad thing. If you never have autophagy, that's a bad thing.

So you know about the calorie or the caloric restriction that the NIA funded in three centers.

Yeah, Eric Ravison Pennington was one of the, the main PIs.

One of the things is that IGF level wasn't decreased in, in those people. Right. And we think IGF decrease is really important part of, of longevity. But we, we've, we learned something else and maybe I'm digressing because I'm sure you talked about it more that what we're doing in rats wasn't really caloric restriction. We're doing intermittent fasting because in our rodents, we would bring the food in the morning. They were hungry, right? They would eat all the food, you know, the 60%, whatever we gave to it, libidum. And they were fasting for 23 hours and, and they had low, you know, low IGF1 level. But in Eric Ravous in studies, they didn't have low IGF because it wasn't caloric restriction like that. They gave them just less food throughout the day. Okay. And I think that was a big mistake that we realized we were doing. And it doesn't answer this. They're circulating. I think what we're trying to do at Einstein is we're doing a study. We know that autophagy is improved quite fast in fasting rodents. We don't know the timeline for humans. Okay. So we're trying to figure it out. And by the way, we can do with Ana Maria Cuervo, we can take T lymphocytes and look at the autophagy on a time course in humans. And they actually reflect also autophagy in the brain. There's a lot of advantage in doing that.

What are you looking at specifically in the assay?

Well, there are several things because there are several autophagies. Right. So macroautophagy or chaperone mediated autophagy. So there are several things.

Can you measure mitophagy also?

Yeah, we can. Do we do that? Yeah.

How sensitive is it to meal timing? Like, for example, if a rodent is fasting for 24 hours, especially a mouse, I mean, that's. Gosh, that's probably the equivalent of a human fasting for a week. Presumably. Autophagy is highly, highly, highly upregulated. If you give the mouse a little bit of chow and then measure that assay, does it obfuscate? Does it erase the fact that they've been. Does it create the illusion, I guess I should say that it's erased, that they've had this high period of autophagy. Did you transiently truncate it?

You know, Ana Mare Cuervo did, and I don't know the answer. I don't know the time course. But the important thing is to find the time course in humans so that we can really say. For example, what I'm doing basically is I'm trying not to eat after dinner until like lunchtime the next day.

But do you really? I mean, so first of all, how hard is it to get an IRB at Einstein to study this in healthcare?

No, we have irb, which just wrote a grand. We need money for that. Okay.

Yeah, I guess, you know, I have a whole framework around nutrition which I'm happy to kind of walk through as we inhale. Our dinner tonight. Have you decided, by the way, if you want Indian, Turkish, Persian, yes, Greek, all of the above.

Yeah, sounds good, you know, because it's raining out. So I guess one of the things we could do to the closest.

We'll figure it out.

Yeah.

So my concern with time restricted feeding, which I practice quite liberally, is I'm worried it is not a significant enough deprivation of nutrients in humans. In other words, I think Sachin's data is so impressive in mice, you know, but I think that for a mouse to go 16 hours without eating is an enormous task. It might be the equivalent of us not eating for three days. And now that said, I'm struggling to see a downside of time restricted feeding. And I know that, you know, Valter and others have said time restricted feeding is somehow bad. I don't accept those arguments. I'm not convinced by those data. But this is a very interesting question you're asking. I would argue it's the most interesting question of all because if we understand the time course of that, all of a sudden we can program nutrient exposure. And have you looked at that assay in the presence of rapamycin or metformin?

I didn't, but, but metformin. Anna Maria Cuervo is using metformin as the control for autophagy. Okay. It activates autophagy really well. Okay, so that's it. I'm talking about in vitro essays. Okay. But we haven't measured it in patients. The one thing I should say. I just don't want to forget anything. Can I, Can I?

Absolutely.

And it's back to the metformin just reminded me it's back to metformin studies. Studies. So our reviewers were saying, you know, okay, all the data on the biology that you showed was from rodents. And we don't know that the biology is relevant to humans. Okay. Although of course the preliminary data in humans are much better than in rodents. Right. The association with diseases. So we had a clinical study, is a small clinical study which we took 15 people that are 75 years old and we gave some of them metformin for six weeks and other placebos and then we crossed over and it was blinded and we took it at the end of each period, we took biopsy from their muscle and biopsy from their adipose tissue. Okay, so not liver. And we looked at the transcript and the metabolomics, but mainly the transcripts in the tissues to see effects on metformin. And there are three interesting things. First of all, when they brought me their clinical results, you know, insulin, homa, glucose and all, there were significant effects in many of them, statistically significant effects. But I was expecting more. I started to try and break it down. And then we found out that the people who were last on metformin, although it was half of the people, had much more significant results than the whole 15 people.

Wait, explain that again, the people in the crossover who started, who went placebo.

To metformin, had better effects on metabolic.

Parameters relative to themselves or to their.

Peers relatively to themselves.

Because ever this was a person to person. This was in person to person. This is a paired T test.

And the reason is that probably the two weeks washover is not enough. When you fix the aging, it lasts for a while. Okay, so if you got metformin and then placebo, you didn't really, you, you went halfway back. Also, by the way, because metformin is associated with weight loss and they lost a little weight, that on itself really made them on the second.

Yeah, it's funny you bring that up. I'm glad you mentioned that. What do you think explains the weight loss phenotype of metformin? So when I started taking metformin, which was 2010, I didn't mess around. I just went straight to 2.5 grams a day. I didn't even mix it up. I don't think I took it bid. I mean, I took 2,500 milligrams first thing every morning. And after a month, I lost quite a bit of weight, but I was also nauseous 24 7. I mean, the thought of eating was repulsive to me. I still ate. You know, I was exercising a lot and doing all my usual shenanigans, but I clearly ate less just because of that low grade feeling of nausea. Today when I prescribe metformin to patients, I have them start at 500 qhs, then 500 bid, then 500 in the morning, 1500 before bed, then 1 gram bid is sort of standard dose. And I see far less of that nausea and I see far less weight loss. What, what other mechanisms do you think it could explain the weight loss?

So could it be lactic acid going up, you know, just like ketones you.

Get as a substrate, an Additional substrate?

Yeah, I don't know. But look, I started metformin several years ago because I was pre diabetic. My doctor did it, so it's before. I'm glad that he did, but it was before I thought much about it. And I was just surprised after three months to realize that I lost, you know, seven or eight pounds. I was surprised because I couldn't, I was nauseated, I wasn't anything. I must have eaten less, I was less hungry. I reacted better. I reacted better to my body, right to my leptin maybe. I reacted better and I probably didn't eat as much. Not totally not noticing it. It was a surprise to you.

It's funny, I tell patients not to expect that because I don't, I don't like the idea of patients thinking of this as like a weight loss drug. To me that sort of is, is not the right way to think about it. But I've never had a great explanation. And by the same token I have had, I should be clear, I've had also some patients who have, they've come back and they've lost ten pounds. And these are patients who are not overweight. This is not, you know, this is someone that by everybody's standard would be completely normal weight. You know, BMI is 24, body composition is reasonable and comes back in, you know, in three months and they've lost ten pounds. But I guess for, in my, at least in my practice that seems to be the exception and not the rule. But very, very interesting to your, you know, I guess, of course you wish that was more than a two by two, two week. You wish that was a 12 week by 12 week.

We are doing the same thing with Acarboz now and we're doing longer study with longer washing period because we want to get away from that. But back to metformin, I said that's one thing. Is this metformin last issue, the second thing that we showed that most of the transcripts changes were relative to this to the tissue. You know, in fat it was more free fatty acid metabolism in the muscle was more pyruvate metabolism. So it was appropriate. In other words, there wasn't the metformin, you know, the metformin part. But in both tissues there were genes that are not metabolic genes, you know, like BRCA1 or myofibril genes and other things that are related to aging, but they are not metabolic, they change by metformin. In other words, the concept that metformin is not only metabolic, it's aging. Okay.

BRCA one changed.

Yeah. You know some other gene genes that are associated with genet with the, with DNA repair changed significantly the second.

Did you see in the muscle by the way, if you still have biopsies, I'd be very curious to know if the lactate transporter out of the muscle. I'm blanking on it. It's MCT2. In other words, as people make more and more lactate in the muscle, do they get more and more efficient at shuttling it back to the liver? And if so you would expect MCT.

To transport gene expression changes by that?

Yeah.

You know we have the raw data. It didn't come up. I'll tell you, it didn't come up as a winner. But that doesn't mean it's not, it's not change.

And you looked at genome or you looked at, you looked at messenger as well. You looked at mRNA, it's all, it's.

Transcript, it's only mRNA.

Okay, so you should have seen it if it happened.

Well, if it was highly, I mean there hundreds of changes.

Okay, so maybe this was underpowered to see that difference.

Significant changes. So I can still answer you, I can still answer you specifically and it's RNA 6. So it's, it's really good. It will be good. You know, if, if I take that and see that it can be without taking into account that there are 400 other changes, it can be significant. The other thing though, what you do with transportation script, you look at upper regulators of the system and there's a way to do that. That's what everybody does now. So if you look at the upper regulators, you get back to the same things that are affecting aging. AMP kinase, mtor. All those pathways were affected by metformin, except that what you measured below is the tissue specific effects. But it was all related back straight to aging.

You know, it breaks my heart.

So we really connected not only the clinical data, but the biological data in humans to the TAME study.

Yeah, it's wonderful. You know, a few years ago when my father was diagnosed with cancer, I immediately put him on metformin. And you know, in his infinite wisdom, his primary care doctor took him off it because, you know, why would you put him on metformin? And in the end my father decided his primary care doctor knows much more than I do and so remains off metformin. But certainly this discussion, because I, you know, I probably know more about metformin than the average person, but this discussion has been completely illuminating. There's one other thing I want to ask you about, which is all of the discussion around nad. I mean, you're. You know quite a bit about this. What is your take right now, based on the state of the science that we have, which, admittedly, I think we're just scratching the surface of as far as, first and foremost, just at the mechanistic level, what is your belief that orally administered nicotinamide riboside can actually make it into a cell? I don't know if you've seen it, but Josh Rabinowitz's paper over the summer would suggest. No, most of this is going to the liver. So wouldn't this sort of call into question the companies. There's two of them right now, Chromadex and Elysium, that sell basically nicotinamide riboside plus or minus pterostilbene. What do you think explains the reported efficacy of those agents in light of Rabinowitz's NAD tracer study?

First of all, the Rabinovitz study was also criticized. Okay. Time course. And other things, which. Okay, I'm just saying this, but I think really the biggest issue here. I want just to use this opportunity to say that a lot of what we're doing is not based on clinical studies. Okay. And it really just underlines the fact that unless you do a clinical study, you can remain guessing. Now, I'll tell you, I'm taking a good preparation of nmn. Okay.

Tell the listener the difference between NR and nmn, because they're both precursors to nad. But there's a. There's a subtle difference.

Yeah. And I. I don't know. I don't know to explain that really. Well, I. I don't. I don't care that much.

Okay. But in theory, one is slightly more stable than the other, but.

Right. It's a stability issue, availability issue. But they'll fight. And we. We don't know which is the better, and we don't know which gets to the tissue. Right.

Yeah.

But what I want to. What I wanted to say is the following. So. So the answer is, it could also. It could all be water. Okay. It could all be this.

You say that as you hold up a bottle of Topo Chico.

Right. Sorry, you didn't see that in the microphone. Okay. But what I'm doing now is I'm opening my Fitbit. Okay. And one of the things that the Fitbit has is sleep. Okay. Do you use Fitbit?

No, I use something called Aura, which works much better.

Okay.

Yeah. This really measures sleep.

Well, do you get also the deep sleep and the rem and all that. Okay. Since I started taking NMN and it might be a coincidence, so I have to stop it and start again. But my sleep has been much better. That means I have. In the beginning of the night I have much more deep sleep, and at the end of the night I have much more rem. And I thought, if there's anything I can say about it, is that just because of this association? Okay. But I don't believe it. Right? Because it's not. It's an. It's my. It's me.

And it's empirical.

And many things could have looked. I was in vacation. I don't know. Many things could have happened.

Do you take the NMN by itself or do you also pair it with terrastil bean or another sirtuin activator?

Just nmn. But it's a good. It's a good suggestion. Maybe. Okay. But then I run into Imai. Do you know who's Shinimai? He's from St. Louis and he has his own patterns and studies in Japan on nmn. And he tells me unprovoked, he says, you know, I have 200 subjects. And one of the interesting thing is there's sleep patterns improve. They get more deep sleep in the beginning of the night and more REM at the end of the night. In other words, he tells me what I've noticed, and it makes me just think and maybe believe and maybe hope that something is getting into the cells and that there's a real effect, at least on sleep. It didn't tell me any other things, but really my answer is we don't really know enough. It's very hard to measure effect because this NAD goes and goes away. And what system can you do? It's very hard to measure that. And without clinical studies that are really well controlled, I think it's going to be hard to just support that. And that's me as a conservative scientist and one who says that even metformin, that everybody says, you have enough data. No, we have to do the clinical study to prove that. And that's where I really stand.

And it seems to me that intravenous administration of NAD is also not particularly helpful, though it seems quite popular in the sense that I'm not going to. I haven't seen compelling evidence that giving NAD intravenously makes its way into the cell either.

So I think the development. The interesting development will be to develop a drug, and the drug will be a precursor that will get into the.

Blood outside of the liver.

Outside of the liver, yeah, exactly.

So if you could give NR or NMN sublingually or intravenously, that strikes me.

As very interesting, saying that there's a lot of data in rodents where also you look, you give it in different ways. You give it some in water, but some are gavage. And maybe that's different because one of the problems, maybe if you go deep.

Enough, you can bypass the portal circulation, right?

You can bypass something. So, you know. But the in vivo studies are good studies. Okay? You just don't know what it means to humans, really.

Well, Nir, I'll do a time check here. We've been going at this for a little while. There's a lot more I want to sort of pick your brain on, but we could also just sit down and do this again sometime. I want to make sure you've said at least as much as you want to say about Metformin, because I think that to me is, you know, you're at this point arguably one of the world's experts on a drug that. Just to put this in perspective, I think Luke Cantley, who is obviously a close mutual friend of ours, and James Watson, who I don't know personally, have both said quite publicly that Metformin may have already saved more patients lives from cancer than all other cancer drugs combined, or something to that effect. This is a drug that I think with each passing day, more and more people are beginning to learn about, beginning to ask questions about. And my hope is that if nothing else, this podcast is a place that people can listen to this episode if they can't go and read 16 of your papers. And they don't necessarily want to get that far down the rabbit hole, but to hear it from you and not from me or some other schmuck who doesn't know much, I want to make sure that if there's anything else you want to say about Matt Forman that you say. So is there anything else that you want to add?

Well, let me do one practical thing and one a little bit more philosophical. Okay. The practical thing that really surprised me, I was giving a talk somewhere for lay people. So it was organized by a university and they invited people, and to their surprise, there were 300 people in the audience. And by the way, my talk wasn't about Metformin. My talk, the titles of my talk is usually how to. How to Die Young in a Very Old Age. That's what I. My title is usually if I Can Get Away With It. That's a good title. So people are coming, and as they're entering Some of them come to me and say, so how much Metformin should I take? Okay, So I started talking and all of a sudden I said, let me ask you something. Who here in the audience is non diabetic and is on Metformin? And please, you know, you don't have to just if you choose to hold. So how many? Half of the people.

Where was this talk? What university?

I don't want to.

Okay, what city? Can you say what city? Was it in the United States?

No.

Okay, fair enough.

So, you know, the. In other words, the prophecies out, which makes me a little bit worried about this study. When we first. Wall Street Journal is the first that picked on Tame, wrote an article the next week, we had 3,000 phone calls and emails of people volunteering to the study, which is what we need to do the study.

And I thought, let's just cut your. You trim that budget from 70 million down to 65. You cut all the recruiting costs.

Exactly.

Except that then you realize, yeah, it's a bias sample.

Then you realize, just a minute. Those people, first of all, we didn't advertise. They had to find my phone number and email. And second, they'll do. They're doing other things. You know, it's like with the estrogen bias, they're probably exercising and stuff like that. And then when I started getting emails like, I'm volunteering to the study as long as I'm not on the placebo, I thought, you know, if people care so much, if they'll figure out they're not on Metformin, they'll just get Metformin. So from recruiting, the 3,000, we. We outload those. Those are not in my study.

Right.

So I want to say that still, we haven't done the study. Okay. We haven't done this study. So you're between 65 and 80. Okay. Just know we haven't done this study. We don't know if it's safe as it is in young people. And so we don't have really a clinical study with evidence that this is good. And I'm. I'm just worried now that part of the reason to do this study is because if it's not good, people should know also. Right. And not take another drug. Okay.

Yeah.

Not that I believe it, but it is possible. The second thing, that is more philosophical. So I, I said before that I was invited to the Vatican. I actually was invited it twice. The second time, and I'm very close to Cardinal Ravasi, who's number four in the Pontiffs, he's in charge of science and arts, that is including science. And it's interesting because the Vatican basically says, we don't want to be in a Galileo Galilei situation again. We don't want to be in a situation where the science is so right and we're so, so wrong that we don't know what to do with it.

Okay?

And so they called me and they said, you know, we have a meeting in the Vatican. We'd like you to talk about aging. Could you come and said. And I said, sure, sure, I'll come. And then I'm going on and saying, am I, am I the keynote speaker? They said, the keynote speakers are the Pope and Joe Biden, who was vice president. I said, okay, sorry, sorry, I'm still coming. So that's how it goes. Joe Biden goes up and explains his cancer initiative and how difficult it is, because when you have cancer, you have in the cancer maybe five other genomes, and they're also different than every other cancer like that in the world. It's really a mess. Then comes the Pope and says, you know, I still hope that there'll be one little peel, cheap for everyone in the world that will cure whatever cancer they wear. Appropriate. I hope so too. But then I go up and I say, well, there is actually a cheap pill like that, and I don't know if it cures any cancer in the world, but it can prevent a lot of the cancers in the world. And actually it has a side effect that it also can prevent a lot of, of other diseases in the world. So it was like, so it was like the, you know, going back to aging and the risk of aging for age related diseases and how impactful and cheap it could be compared to treating cancer or something like that. So I think the prevention of aging is, is really a good place to be. And I think because we went from hope to promise, and we have to realize the promise, I think life is going to be very different in the next decade with our advance.

Last question, and not to end on a downer, but let's try to figure out where a blind spot could be. Where could we be wrong? Obviously, you and I share more in common in terms of philosophy and points of view than I even realized before we spoke. But where could we be wrong?

So, you know, I'll tell you what's my optimism. You know, we have, the European have nine pillars of aging, and we have seven pillars of aging, and they're all interconnected. And when I say interconnected, I Just spent the time with Ana Maria Cuervo this morning when she fixed autophagy. She fixes also metabolism. Okay. When you start doing things in any one of those pillars, you start improving the others. Now, where we could be wrong is we don't know what is the impact of each of those pathway in humans. Okay. Most of our data is kind of animal data, but I think our fallback is that we all age. The advantage of in aging is that aging is universal. Every, every animal has the skin, the hair, the skeletal, the frailty. It's very universal. And those treatments are metformin, rapamycin. You give it to any animal, it almost delays the aging there. So I don't think we're going to be wrong. I think that maybe some pathways will not be so effective. Some of them will be harder to treat, maybe. But I think we have to affect 3, 4 and we're right on our way to do better. And that's just the beginning.

And in the tame study it lit, will it be 1 to 1, male to female?

Yes.

So we'll also avoid that other. And have you powered it such that men and women are different animals?

Well, no, because all our data on metformin and we looked carefully to the DPP and other, they didn't see any gender effects on any of the outcomes. So we're assuming that.

So you're powered as though the genders.

That they're a difference like we would do, maybe rapamycin, you know.

Well, Nir, this has been fantastic. I was sick the last two days. My voice is gone. I feel like crap. I was like, maybe we should postpone it. But then when I woke up this morning, I was like, there is no way we are postponing this discussion because I cannot wait to have this discussion. So thank you so much for coming over.

It was great. It was great because you asked really great questions and, and also I'm now quite hungry and I'll be happy to have dinner with you.

Now we are going to put together a seminar on how not to calorically restrict.

Tonight. Only tonight.

All right, thank you, Nir.

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