Megan Hall transcript

Written by Christopher Kelly

Oct. 27, 2017


Christopher:    Hello and welcome to the Nourish Balance Thrive Podcast. My name is Christopher Kelly and today, I’m joined by me scientific director, Megan Roberts. How are you doing this morning, Megan?

Megan:    I’m well! How are you Chris?

Christopher:    I am great! Thank you very much for asking. Megan is a research scientist who recently joined me as scientific director at Nourish, Balance, Thrive, where she keeps the program ‘state of the art’. She received her undergraduate degree in Exercise Biology and Masters in Nutritional Biology in UC Davis where her research focused on the effects of low carbohydrate ketogenic diets on longevity and health-span in mice. That is the topic of today’s discussions so stay tuned for more!

    In her free time, Megan enjoy reading, long walks in the sunshine. Big fan of that Megan! Weightlifting, martial arts and hiking in the Colorado Mountains. Megan, you’re so cool! I’m so happy to have you. You know, I attended these Mastermind Talks even earlier this year and one of the things that Jason Gennard says on his website for Mastermind Talks is that if you are the smartest person in the room, you’re in the wrong room. And I feel that now that you’ve joined me as a full-time employee, I’m finally in that room where I’m the dumbest person in the room and I’m very, very excited about it so thank you so much for joining me!

Megan:    Oh well, it’s my absolute pleasure.

Christopher:    I’m sorry. We can’t all be the dumbest person in the room. Somebody else has to be smarter than me and I’m okay with that. I apologize to you though.

Megan:    Oh no. I’m constantly learning from you, Dr. Tommy Wood and the rest of the team as well so it goes both ways for sure.

Christopher:    Perhaps, the important thing then is just our perception that we are the dumbest person in the room. Perhaps it’s the only thing that matters.

Megan:    I like that! I like that!

Christopher:    Let’s talk about your Keto Study! I’m very, very excited about your keto study. Take me back to the beginning. Tell me about how you decided it was a good idea for an experiment.

Megan:    Alright. So basically, kind of the background of the study is that… and I’m sure many people are aware about calorie restriction has been shown to dramatically extend longevity in many animal models. Of course, there are some potential compounders for that which you’ve discussed on the podcast before.

    So for example, there might be a time-restricted eating or a Circadian-model effect with an animal that’s calorie-restricted typically, you feed them and they clean up their meal almost instantaneously. They don’t have the opportunity to graze throughout the day. And so, that could be potential compounder in the calorie-restriction literature. And also of course, food quality. Are they really longer because they’re eating less of a crappy diet? That’s always a question as well.

    So, the impedes for the study that I did at UC Davis was we wanted to mimic calorie-restriction by manipulating dietary macro-nutrients namely, carbohydrates in our case. And so, kind of a hallmark of energy restriction across the board is this metabolic shift from carbohydrate to fat-oxidation. And so, since the mechanisms of calorie restriction are still largely subject for debate, what we wanted to do is answer this question of whether or not the shift from carbohydrate to fatty-acid oxidation contributes to the longevity promoting properties of calorie restriction. And then also, how to ketones play into that as well.

Christopher:    Very interesting. Before we get into the study design, I want you to talk a little bit more about how you realize that this experiment was going to be a fun and interesting and informative thing to do. So, you’re at a university. How do you even know about the ketogenic diet and calorie-restriction? And we hear so much that these things are not really taught to people who are on the road to medical school. So, tell me how this all went down at the university.

Megan:    Right. So, I was very lucky to A- be a part of a cohort in my nutritional biology program who had some very open-minded instructors and professors and my peers as well are also very open-minded. And so, that really helped. I could bounce a lot of views and questions off of them. And also, I was very lucky to end up in a lab that the focus was at calorie-restriction and the mechanism.

    And so, my mentor was very excited about that. And then, this kind of idea of low-carb and ketogenic diets mimic gained calorie-restriction, kind of been an unanswered question for a long time in our lab at least. So, I was very fortunate to kind of come into this project at the right time as a master student.

Christopher:    Correct me if I’m wrong here. So, this will all go down. You’ve got this mentor, some senior-academic at the university. And they’ve read all these studies and they’ve read all these studies over there. They had some questions on the first set studies and some questions from the second set. And I said “You know what, if this is true and this is true, then maybe this is true. And Megan, I want you to do this experiment. I want you to be involved in this experiment that we’re going to do to answer some of my unanswered questions.” Is that how it works or am I completely out of track over there?


Megan:    Basically, for me at least, that’s how it kind of went down. And like I said, I’m very, very blessed to have this amazing opportunity to fall onto my hands. And I came in at exactly the right time when that city started. So you know, it kind of all worked out. And Dr. Steve Finny, he was the previous professor at UC Davis. I’m not quite sure if he paved the way but my mentor, Jon Ramsey learned some stuff from him and so there’s that aspect as well.

Christopher:    Okay. This is all very interesting for me. I hope it’s interesting for my listener as well. You know, I read some of these academic studies and I watch a lot of presentations and I go to conferences for this kind of stuff. I always wonder, what’s it really like at universities when these studies started. It’s difficult to know from the outside but all you do is reading the paper. Very, very exciting. Let’s move on then and talk about the study design.

Megan:    Okay. So, first of all we did this study in mice. So, that’s very important. We used 3 different diets. So, there was a control diet which is a typical kind of chow-rodent diet about 65% carbohydrate. And then we had a low-carbohydrate diet which was 70% fat, 10%carb and 20% protein. And then our ketogenic diet was 90% fat and 10% protein and 0 carb.

    So, these mice, we started them on the diet for 12 months of age which is about middle age for a mouse. And one important thing is that all of the mice were eating 11.2 kcals per day. So, they were being fed correctly so that we could study the effects independent of either overweight or obesity because typically, when you feed a rodent, high-fat diet, then they’re going to gain weight.

    And that’s one of the issues with the traditional high-fat rodent diets. It’s that they’re both high-fat and high-carbs, neither are low-carb diets and carbohydrate relatively speaking. But traditionally, these high-fat diets that you see on the literature as being so fat and so obesity-promoting, they’re doing that metabolically because they are both fat and high-carbohydrate.

Christopher:    So this is helpful information for our listeners. You’ve got to watch out for this. When they say a high-fat diet fed to rodents, you really have to understand what that diet was. It doesn’t give you enough information to know.

Megan:    Exactly. Yeah, exactly. And one of the important parts of our study is that these mice were all being fed the same amount of calories every day. And so, it’s important to note that these optimal dietary macro-nutrients might differ between a mouse that is fed albites and one that is not. So, that’s kind of different at there. But if you think about it, humans aren’t really feed with that either. We can just eat but most of us just don’t sit around and eat all day because we’re bored which is what a mouse usually does in a cage if they have the opportunity to do so.

Christopher:    I used to do that when I went to a day job as a programmer at a hedge-farm. I used to do that all the time!

Megan:    Okay. Well, some of us do then.

Christopher:    But that’s a different problem!

Megan:    Yes, yes. Absolutely. So, kind of moving on. We had to two different arms of our study. There was a longevity arm where we basically… these mice get the good of the study where they got to live out a natural lifespan and die when they died and then we measured longevity carbs from that. And then, we also have a health span part of the study where we tested different markers of physiological function known to decline with age.

    And so, the health span part is really important. I think going forward in all of these aging and longevity studies even in animals because for translation to humans basically, the best interventions that we have will ultimately improve both longevity and also prevent the decline and physiological function that we see with age. And so, we just don’t want then to live longer, we want them to get more adequate years that we do live. And so, I think that looking at this health span part is important as well as the lifespan.

Christopher:    Okay. Let me summarize those to words. That’s really important, isn’t it? The health span is this idea of feeling good and being healthy for a long time. Or is lifespan might just mean extending life which, if your quality of life is quite low, might not be a desirable thing?

Megan:    Exactly. Yes. And so, for that kind of health-span cohort, these test of physiological functions that we did, we did them at 2 different time points so we have longer-buffed mice that we did to test on after they were on a diet for one month and one which is like middle-aged and then another group of mice after 13 months of being on a diet. That’s when they’re reaching old-old age there.


    And so, these tests that we did included grip strength, wire tests, a rearing test which measure motor functions and endurance. Also, a memory test called the ‘Noble Optic’ test. We did body composition with glucose and insulin tolerance tests. And then, we also measured energy expenditure and do digestibility. And then, also at the end, one of the mice was sacrificed. We did some tissue analysis and looked at specific proteins and liver and muscle are associated with longevity and lifespan.

Christopher:    Okay. So, I’m going to have you unpack some of these things for our listeners because I think this is fantastic. So, talk about how you measure grip strength in a rodent.

Megan:    So, we have this little force apparatus that the mice basically… it’s quite comical actually, when you’re doing so of these tests because you’re trying to get a mouse to hold on to a little metal bar and pull as hard as they can. It’s not the easiest thing in the world. And so, what we had to with it, there was this little metal bar that they held on to and we held them by their tails and then they would grab the bar with their forepaws. And what we had to do was hold their cup of food right in front of them so that they would want to get to the food and we would tug on them and then they would tug on the bar to get to the food. So, that’s how we measured their strength.

Christopher:    That’s awesome. Then, talk about the ‘Noble Object’ test. How did that work?

Megan:    So, the noble object test, basically, what you do is you have a box that’s kind of a noble environment for a mouse. And you put the mouse inside and the first is kind of an adaptation to the environment so they could be used to it. And then the 2nd day, what you do is you start with two of the same objects. So, we use boxes and bottles. So for one mouse, we would have two boxes in there and we would video-record the mouse for 10 minutes and the mouse would just explore around the boxes.

And then 6 hours later, we would replace one of the objects. We would replace a box with a bottle so the bottle is a noble object. And then, we would do another 10-minute recording at the mouse. And the mouse would be exploring and we would then and go back and watch the video-recording which is a long process. But we would watch the mouse and compare the time that the mouse spends from the noble to the old object. The idea is, if they spend more time exploring the noble object, then that’s a better indication of their short-term memory versus if they’re kind of looking at both objects the same amount of time.

Christopher:    Okay. Interesting. And then, body composition. How did you measure that?

Megan:    So, we use FMRI machine. So, you just kind of put a little mouse in a tube and then it takes about 90 seconds for each mouse and it pops out some numbers as far as fat mass and lean mass and water mass.

Christopher:    Interesting. Well, let’s talk about the results then.

Megan:    Alright. So, as far as life span is concerned, the big ketogenic diet ultimately compared to the controlled diet increased median lifespan by almost 14% so 13.6%. And it is important to note here that we’re looking at mean and not maximum. Maximum was not changed with and of the diets. And there is some disagreement among aging experts, otologists about which is more important to look at but ultimately, I think they’re both important.

    Maximum can be kind of clouded by a couple of stubborn mice that refuse to die. However, restrictions extend both maximum and median lifespan.

Christopher:    So, just as a reminder, when we say median, we’re talking about the average?

Megan:    Yes. Well, median and average are the same. Median is if you line up all the ages in numerical value and then you take the middle number. That’s the median. And so, median is an important indicator that an intervention is the delaying the onset of mortality even if maximum lifespan is not changed. And so, interestingly, exercise in rodents has been shown to increase median but not maximum lifespan.

    So basically, what it’s doing is lowering age-specific mortality. And ultimately, even if we can’t increase maximum lifespan, what we want to do is square this lifespan herb. So, we want to live a long, healthy life which ultimately will be followed by a sudden fatal death. Which is I think I little brutal but if you think about it, it’s what you want. You want to live long and healthy and then die suddenly.

Christopher:    Right. So, that’s a huge increase. That’s 3.6 in compared to control. Were you expecting a change as big as that?

Megan:    No, we weren’t. None of us in our lab were. And the low-carb diet was somewhere in the middle. I believe it was about 7% increase compared to control. But this increase by almost 14% was a surprised to all of us.


Christopher:    Right. And so, keto-best. Low-carb’s good. High-carb was the worst of all.

Megan:    Mm-hmm. Yup.

Christopher:    Okay. Well, let’s move on and talk about the preserve memory with age.

Megan:    So, this we measure, like I said with this noble-object recognition test. And so, the ketogenic mice ultimately spent more time exploring the noble object versus the old object that second time around in the test. So, that is indicating that their memory is being preserved with age. Interestingly, Walter Longo’s ‘fasting mimicking diet’ which I think you’re aware of. Yeah?

Christopher:    Yes, yes. Of course, and I will link to some resources for the fasting mimicking diet. Very interesting stuff.  

Megan:    Yeah, yeah. So, that has actually, in one of their studies, they showed that the fasting mimicking diet in rodents also improve memory in mice with this noble object test as well. So, this kind of preserved memory with age indicates that there may be potentially some kind of neuro-protective properties of ketone bodies specifically beta-hydroxybutyrate.

    And so, this is in-line with some of the literature about ketogenic diets being helpful for neuro-degenerative and psychiatric conditions. And there’s also a link in literature between beta-hydroxybutyrate and brain-drive neuropathic factor which has been coined as one of the beneficial side effects of exercise, specifically, endurance exercise.

Christopher:    And I remember that one paper that showed the increases in brain-drive neuropathic factor after exercise was caused by the increasing by the hydrazine butyrate. Am I correct?

Megan:    Yes. They’re thinking that the beta-hydroxybutyrate is responsible for that in the increase with the following endurance exercise. So, that’s interesting that maybe there’s potential effect with nutritional ketosis as well.

Christopher:    I will of course link to that study in the show notes for this episode. You can find those over in Go down to a particular episode and then you will find the show notes. I make a very comprehensive time-map where I link to all of the things that we’d be talking about in this episode. Megan, talk about the preserved motor function and coordination with age.

Megan:    Okay so, this was really exciting as well. The two areas of health span that we saw and biggest is the most dramatic effects with the ketogenic diet were of course the memory that we talked about. And then, this preservation of motor-function and coordination in the ketogenic group compared to the other 2 diets.

    And so, the 2 tests that we used to test for motor function and coordination were the wire test and then the grip strength test. And we found both of those more favorable in the old ketogenic one versus the other 2 diets. And also, when we dissected the muscles at the time of sacrifice, we found that the muscle mass in the higher limbs were greater in the old ketogenic mice.

    And specifically, the gastrodermis which is predominantly type 2 of twitch fibers. That muscle was higher in the ketogenic mice. And the importance of this is that with age, type 2 fibers are typically the first to go. And so, if we’re seeing a preservation of these type 2 fibers or at least the muscle in which type 2 fibers are more highly-concentrated, then that’s really important as far as preserving those type 2 fibers with age.

Christopher:    Okay. And we talked about this on the podcast before. Does this mean that these rodents are less likely to slip up in the shower, break a hit, end up in the emergency room potentially picking up a pneumonia and then dying early in the hospital?

Megan:    Yes, yes. If we’re translating to human, then that would be the examples that you make for sure. Also, kind of another interesting bit of information from the previous literature is that… and I believe that… I almost say Ken Port has brought this up before. I know it was brought up on the keto summit. But the keto-acetate has been shown to preserve muscular dystrophy or improve muscular dystrophy outcomes and accelerate muscle-regeneration in mice.

    And so, acetoacetate along with beta-hydroxybutyrate, it’s another ketone body, maybe an important player in attenuating with age-related loss of muscle function at UC. So, we didn’t kind of decipher between the two ketone-bodies but mechanistically, acetoacetate and beta-hydroxybutyrate might be playing a role in that.

Christopher:    Okay. Talk about ketones and exercise performance.

Megan:    So, sure. A lot of listeners are aware there’s lots of interest about either ketogenic diets or exerting this ketones in this realm of increasing exercise performance. And so, the results of our study that we saw with this preserved motor-function and coordination is that age indicates that there is potentially some correlation to ketone bodies and potential exercise performance. The exact mechanism has to be solicited but certainly, we have some hypotheses which include changes in immune-acids, metabolism and the muscle, regulating the actual muscle function, increasing mitochondrial mass and function. And also, enhancing skeletal muscle and metabolic efficiency. So, these are all properties of how ketones could be affecting muscle performance.


Christopher:    Okay. And is it a particular type of exercise performance? We need to be more specific here, that mice are going to better ironman than perhaps a cross fit?

Megan:    I would assume so, yeah. Just because of the fuel preferences with fat versus carbs, I would assume that if you were to have a mouse, run in ironman or do a workout, they would do a lot better on the ironman.

Christopher:    Okay. Talk about the keto diet glucose-tolerance and sensitivity. That’s interesting.

Megan:    Yeah so, this is really interesting. A lot of times, we hear anecdotally about this kind of impaired glucose-tolerance when you’re eating a low-carb of ketogenic diet. And it’s important to note that this is definitely a thing for some people but it’s physiological and not pathological. So, not consuming glucose if you think about it for a long period of time, kind of causes yourselves no to need that glycolytic metabolic machinery and the pathways for metabolizing glucose that needs to be working at a hundred-percent capacity because there’s no glucose around. There’s blood glucose but glucose from your diet isn’t really coming in.

    And so, this is kind of a little bit similar to something like just situational diabetes where when the mother is eating a low-carbohydrate diet and then they go in and do a glucose-tolerance test, they could potentially come out as looking diabetic where if they had potentially taken two weeks to add a little bit more carbohydrate into their diet. Then, these glucose-metabolizing pathways would have regulated and they would have looked perfectly glucose-tolerant. So, with these mice, since they had spent a long time not eating any glucose, they did look slightly glucose-intolerant but their insulin-sensitivity was not impaired.

Christopher:    Okay. So, I’m trying to be funny here switching backwards and forwards between humans and rodents but these comparisons appear, right? You see that working with clients. It is a real phenomenon. It is really happening in humans.

Megan:    Yeah, absolutely. And what does this mean for us as far as if somebody is embarking on a long term ketogenic diet and then for maybe some metabolic reasons, then they want to start eating more of a mixed-diet. Then potentially, you want to go slow when you’re reintroducing carbohydrates. You know, just the practical application.

Christopher:    And it’s funny that you pick on this example of type of diabetes because Julie is now 6 months pregnant. And midwives sent this glucose tolerance test and we agreed to popular debate because it’s silly, she’s not eating a low-carbohydrate diet. But almost certainly, much lower than many of the other women that the midwives work with, it just wasn’t a realistic test. They’re asking her to eat a ton of refined carbohydrate and then test to see if something silly had happened.

Megan:    Yup. I’m right there with you.

Christopher:    Sorry. It’s unclear who I’m talking to at the moment. So, talk about low-carb versus ketone.

Megan:    Okay so, there’s a couple of things I want to say here. First of all, if you look at the lifespan curves in the city, and I can give you a link to the study or a link to the PDF so you can post this study in the show notes and people can read it if they like. But basically, the low-carbohydrate diet didn’t significantly differ in longevity compared to the ketogenic diet. But it didn’t result in preservation of the physiological function with age.

    So, this suggests that which the metabolic changes that accompany carbohydrate restriction may help increase lifespan. There’s something going on with the ketone bodies that maybe necessary to elicit this extension of health span. So, that’s one point I want to make. And then, the other point that some people or astute readers might pick up whether reading the paper is this fact that despite the chlorotic load of all 3 diets, the low-carb diet actually caused some weight-gain despite this isochoric load.


    And this still remains a mystery today. We did food digestibility test. We did energy-expenditure test. And so, it’s kind of a mystery as to why the low-carb diet mice were specifically heavier and most of that fat came from more fat mass. So, even though it’s still uncertain as to why that has happened, there are some hypotheses out there. It could be it was just the right mix of carbohydrate and fat for a mouse to kind of elicit some fat gain. It could be the gut-microbiome. And it could also have been the consistency of the diet. So, this is potentially the most reasonably hypotheses.

Christopher:    Sorry, can I clarify? Which is the most reasonably hypothesis?

Megan:    The consistency of the diet deferred so the controlled diet, were all made of the same ingredients but the controlled diet was higher in carb and powdery. And so, the mice might have made a little bit of a mess while eating it and then the ketogenic diet was very sticky because it was fat. And so, they kind of have to work really hard at cleaning up their food whereas the low-carbohydrate diet was more like playdough.

    And so, basically, these low-carb mice could take their diet in a little bowl and kind of go into a corner of a cage and just kind of munch on it and they didn’t have to expend more calories eating it than the other two diets. Just a hypothesis, but it’s kind of interesting to think about. And then, the question from this arises, “If the low-carb diet were truly weight-match with the other two diet groups, would they have performed better in the test of physiological function?”.

Christopher:    Okay. Can you just explain that term ‘weight match’?

Megan:    Yes. So, if they were the same weight.

Christopher:    Are you talking about body mass?

Megan:    Yes, yes. Body mass.

Christopher:    Okay. Talk about ketone molecules.

Megan:    Alright. So, there is quite a bit a literature now, at least mechanistic literature explaining the role of ketone body-signaling molecules. And there’s a really good Burgee articles that I can have you posed in the show notes. But basically, these ketone bodies can up-regulate longevity promoting pathways. So, just kind of taking the step-back here, these pathways that I’m going to talk about next are pathways that we found to be upregulated in the study that I did. I’m sure there are many other pathways the ketones are working on. But as far as we found, this idea that these ketones function as they stack inhibitors.

    And basically, what that means is to elicit gene-expression. DNA is basically consistently being coiled and uncoiled around histones by adding and removing these little acetyl group. Acetyl group is CH3CO. And histones disilicates and remove acetyl groups from protein and diacetylated protein or maybe the acetyl group causes the condensation of the chromatin and then the silencing of the genes.

    And so, this can either be a good thing or a bad thing depending on which proteins are getting diacetylated. And if you think about it, HDAC inhibition is blocking that deacetylation and resulting in hyper-acetylation or at least more acetylation of these histone proteins and this is impacting DNA expression. And so, what that means in a big picture, is that these proteins are depending on the amount of either acetylation or deacetylation. This is just a little tag if you think of it as tagging the protein in the group or removing the tag in the protein and that little tag causes the gene to either be expressed or not expressed.

Christopher:    Okay. This is super-interesting and very difficult to understand in an audio format. What we’re going to do is I’m going to have a look online and I’m going to see if I could find my best video and I’ve done this before. But this is something I do quite often when somebody talks about something I don’t fully understand so I’ll go back to con-academy and I’ll look at some of the cap videos so that’s very good. And I’ve done that before on this topic. And at the end of the video, I still didn’t get it 100%. Maybe now that you’ve challenged me with this new problem, I’ll get it just a little bit more. And I’ll talk to you Megan about which are the best videos that we could link to in the show notes so that people could watch those when they’ve got a chance to try and understand this idea of HDAC inhibitors because it keeps cropping up over and over again doesn’t it? On the podcast, in the literature, whenever someone talks about ketogenic diets so I think it’s an important topic for us to understand.


Megan:    Yeah. Absolutely. You know, I’m sorry this is not the most articulate explanation.

Christopher:    No! You did a really good job and it’s a complicated topic that is necessarily best taught using this media.

Megan:    Exactly. I completely agree. And potentially, the review paper that I’ll have you post in the show notes, I don’t recall that has a good diagram but it might have an excellent diagram visualizing the process of HDAC inhibition. That can also be helpful for people. But, if we then narrow it on why HDAC inhibition is important in the context of this study is that HDAC inhibition has been shown to up-regulate these proteins which are pro-longevity.

    And FOXO-proteins basically are transcription factors that active regulators of longevity and also downstream influence signaling and insulin micro-factor signaling. HDAC inhibition has also been shown to extend lifespan in decent lives. That’s kind of how it links in with this study and beta-hydroxybutyrate has been shown to be an HDAC inhibitor. And then, in the study that we did, we showed when looking at the liver and muscle tissues, we showed a dramatically increased acetylation of residues on proteins. And this basically suggests that the butyrate is indeed acting as an HDAC inhibitor.

    So, that’s HDAC inhibition. A little bit of a mouthful but there it is. We also found in the ketogenic diet that there was an increase in Manganese super-oxide expression and this is basically a mitochondrial antioxidant. So, more antioxidants in mitochondria may be promoting this longevity effect as well.

    And finally, we come to this idea that ketogenic diet potentially is regulating MTOR signaling. So MTOR has been implicated in many lifespan models and models of disease specifically cancer. I know Dr. Ron Rosedale has talked about this sensibly and he is kind of the MTOR expert. So, maybe you can link to one of his presentation or something in the show notes.

Christopher:    Yeah. And we had him speak this year. He’s done many other good talks too.

Megan:    Yeah, yeah. So, before we get into how MTOR might be working with a ketogenic diet, I do want to say that there is a lack of understanding about this trade-off between lower MTOR for longevity purposes and then higher MTOR and maybe promoting it in skeletal muscles to protect against acapnia. So, there is this tissue-dependent manner by which we want to look at our mice. MTOR was signaling with slightly elevated in the muscle and depressed in the liver. And you would think that that would be good for longevity. It’s truly muscle mass-up but it’s lower on the liver. So, MTOR isn’t always bad but it’s not always chronic-MTOR simulation around the body isn’t always good.

Christopher:    Yeah so, this maybe important to point out here that while Nourish, Balance, Thrive, perhaps disagrees with some of the Rosedale conclusions, he was still the first person to even name it. I literally never heard of that pathway before you mentioned it. Yeah, interesting.

Megan:    Yes, yes. Absolutely. So, in our mice, we basically found that this protein called ‘REDD1’ was upregulated in the ketogenic mice. And this protein is a negative regulator of MTOR. And this REDD1 protein is activated by a couple of different things but in our case, it’s probably energy-stressed or metabolic stress. The good type of stress in the ketogenic diet that we would be upregulating this protein. And then, the upregulated REDD1 is basically inhibiting the MTOR.

    And let’s see, also the P53 protein is a two-burn suppressor protein and they found it to be hyper-acetylated in the ketogenic group. And interestingly, hyper-acetylation of P53 also inhibits MTOR by increasing REDD1 expression and this same pathway also seems to mediate the effect of metformin which is an anti-diabetic drug that has been proposed as another type of calorie-restriction in the medic. So, something’s going on with MTOR here. Again, there are many other questions to be answered. A lot of times, these studies, kind of promote more questions than they do answers. But again, it opens locked doors for more people to kind of step in and figure out what’s going on.


    And so, I briefly mentioned P53 protein that we hyper-acetylated and I do just want to say that the ketogenic mice upon sacrifice had less cancers specifically liver tumors. And so, there’s this kind of interest in the cancer-research field right now of ketogenic diets being and adjunct therapy to traditional chemo-therapy. And so, this study actually supports the fact that ketogenic diets… I don’t want to say that they are preventative cancer treatment but with ketogenic diet, we did see less cancer on those mice.

    So, there’s something going on there potentially with the Warburg Effect and lower-glucose availability. Another kind of avenue to be explored by researchers but that’s interesting as well.

Christopher:    Okay. These results, tell me. Would they likely be repeatable? So with another lab, would they find the same results?

Megan:    So, replicability is a huge issue in science. And people always are asking the question of if you see such dramatic results in one study like we did ours, this 13.6% increase in lifespan and then the preservation of the physiological functions with the age of these mice being fed the ketogenic diet. Is that replicable with another lab who independently did the same study?

    And so, kind of serendipitously, it’s a long story but I’ll make it short. I ran in to at a conference John Novick and Erick Burden who are amazing researchers at UCSF. And they were doing a similar study to my own. And the limitation of the study that I did were largely addressed in theirs and vice-versa.

Christopher:    Oh, that’s fantastic!

Megan:    Yeah. So, for instance, they matched all their groups for protein. They use a certain diet and ketogenic diet to stabilize weight-gain in the ketogenic diet group. And then, they also used different fat sources than we did for their ketogenic diet. So, that study, you can also link to the show notes but it was also published alongside ours.

Christopher:    Okay. And were the findings purely the same or different in any important ways?

Megan:    They were largely the same. Some were slightly different. So for instance, they didn’t see on the wire test the same preservation of muscle function and I’m guessing that was because the ketogenic diet group were cyclical so they weren’t cycling weight basically. They were decreasing weight quite a bit throughout the week. So, that could have had a potential detrimental effect on their muscle mass. But otherwise, their effects were largely the same and they looked at a lot of similar and also different cell-signaling. And so, if people are interested to dive in then I would highly recommend reading that one as well.

Christopher:    Interesting. Let’s talk about some of the cardias.

Megan:    Okay so, these studies are super exciting. The media definitely picked up on them and kind of ran with the conclusions that the researchers may or may not agree with.

Christopher:    Right. Let me step in here and I’ll say something. So, this paper that the scientist Megan is talking about was published in the journal which on its own is seriously impressive. And then, it was also picked up by Science Daily and many other popular science sources. So, obviously an important work so congratulations on that Megan. But okay, let’s go back to the Cavies.

Megan:    Okay. Cavies… and I know there are many Cavies that kind of highlight a couple that I think are most important here. Obviously, contemplating animal research to human research. We do recognize that we’re not mice. We don’t live like them, most of us anyway. Mice, they live a very shelter life. They’re in cages and they’re protected from their environments. They have less day-to-day variability than we do.

    And so, the optimal diet for a mouse in that kind of environment maybe different from the optimal diet of a human who’s having environmental stresses bombard them every day. Who’s doing extensive exercise training who just have day-to-day stresses that might impact them.

    And then also, there’s the whole issue of diet quality that comes up so the mice in these studies were eating processed food diet composed mainly of soybean oil, lard and that’s not something that I know anybody eats. So, diet quality is definitely an issue there.


Christopher:    So, I’m just going to interrupt you there. Why was the diet constructed in this way? I’ve made this criticism with 4 of these science rodent diets. We already know the soybean oil is no good. Why does it continue to be used in experiments?

Megan:    Excellent question. And I wish I had the answer. If I could do the next study, I would want to do a study that looks at what a wild mouse diet would look like and compare that to something else. So, the wild mice eat lots of seeds and fruits and grains and plant matters and even other animals so they’re very omnivorous versus these kinds of artificially constructed lab diet of oil and other stuff. So, I don’t have a good answer for you but it is something that people need to pay attention to.

Christopher:    Right. Could I make a suggestion? Is it because your experiment is then more easily compared to somebody else’s work because you’ve used a diet that’s constructed in a similar way. And so, it’s easier to build on someone else’s work? Could that be a potential reason?

Megan:    Yeah, I think so. For sure. We handmade all of our diets but the recipe is largely available to anybody who wants to replicate it. So, that’s probably definitely a factor there, for sure. And then, the last Cavies that I want to mention is that both of these studies were done with male mice. And so, mice and humans both age in a sex-dependent manner that’s known in the literature.

    And so, the question arises of what would these results look like with female mice as well. Anecdotally, women steam to respond different ketogenic diet than men do and that’s probably due to hormonal differences and other factors as well. So, I think that more studies need to be done on female animals to contrast the results to males.

Christopher:    And since we’re here, can you explain why male rodents are normally used for these types of experiment?

Megan:    So, it’s a lot easier to control for the hormonal fluctuations throughout the month in males. With the female cycle, we would have had to have done all of our tested physiological function at a certain time of each month to make sure that everything was controlled hormonally. So, that’s typically why males are used in different studies. But fortunately, the NIA and NIH have made it a requirement from here on out that many studies will have to include both sexes in their research, which is great. It will take a little bit more resources and time on the part of the researchers but I think they’ll give us a lot of missing information.

Christopher:    Right. This is important for people like me and our listeners to understand that I think there’s a lot of stuff that goes out said by scientists because they just know and it’s common knowledge whereas the lay public, not so much. And of course, if you don’t understand these differences, then you can run into trouble when making those conclusions. Yeah, thank you for explaining that.

Megan:    Sure. Yeah.

Christopher:    Okay so, what are the takeaways? What does this mean for the future of aging research?

Megan:    Okay. So, I’m sure many people will read the study and take their own little nuggets of information away.

Christopher:    I did! I’ve thrown away my sweet potato as you talk.

Megan:    Excellent! No, not really. We’re the fan of the sweet potatoes. So, as far as the future of aging research is concerned in animals, both of these studies are really important because they showed that an energy-controlled, hi-fat diet is not detrimental to health and kind of the ancestral health sphere, we know this. We see metabolic disease and other kind of health conditions being reversed when we’re dropping the processed the carbs and increasing the fat in the diet, once it’s the healthy kind of fat.

    We know that hi-fat diets aren’t detrimental to health but a lot of the conventional nutrition in the medical world still had yet to believe it.

Christopher:    Right. There is a dogma that needs to be displaced.

Megan:    Yes, exactly. And I think more studies in the future, especially with hi-fat diets in human subjects will make these stronger points for sure. And like what I kind of alluded to before, while this study certainly answered some important questions, it probably opens 10 times as many doors as far as new questions that need to be asked and researched in. So, I think that more studies in the future should look at the exact mechanisms by which a ketogenic diet is working to enhance lifespan and health span.

Christopher:    Oh, you’re a scientist. You always say that and so you work for some experiments to do.


Megan:    I know, I know. And then, many people will kind of be wondering “Okay, we used nutritional ketosis for our experiment. But what if you induce ketosis with exsanguinous ketones?”. There’s lots of interests in those stuff recently. And so, that’s another kind of question that needs to be answered. You know exsanguinous ketones on top of maybe a controlled diet, a hi-carb diet and how that would affect aging.

Christopher:    And what are your thoughts? I know that the science hasn’t been done yet but can I get your opinion on whether it may be possible to reap the benefits that you’ll be talking about by using an exsanguinous source of ketones or whatever that might be over of some sort of dietary manipulation.

Megan:    Yeah so, I find it hard to believe that it would be as good as nutritional ketosis. I think that’s in healthy animal or in a healthy person, especially if it was a mouse who was being fed, I think that exsanguinous ketones on top of a hyper-choleric diet is probably a recipe for disaster. If the animals were already slightly choleric-restricted, just maybe a few percent under maintenance. Then, adding exsanguinous ketones on top of that might have favorable things in that case.

Christopher:    Okay. Well, let’s move on to the $64,000-question which is what does this mean for human longevity and health span?

Megan:    Okay so, I would admit that it doesn’t mean too much for human. However, at a fundamental level, I would say that humans and mice do age similarly. So, there’s a decrease in overall organ function and the physiological function with age in both mice and humans. And then, the results of the study also tell us that dietary manipulation even without weight-loss, manipulating the macro-nutrient can impact longevity and health. Although, like I said, there are many other questions to be answered. These studies only tell us about macro-nutrients and nothing about dietary quality. So, addressing both the macros and the quality so the idea of a well-formulated ketogenic diet in either a mouse or a human could potentially yield even more profound results as far as longevity and health span.

Christopher:    You touched on something interesting there which is maybe another thing that goes unsaid amongst scientists. And that’s about weight-loss. And so, am I right in thinking that sometimes, people would assume or scientists would assume the benefits you saw were something to do with weight-loss and nothing to do with the composition of the diet?

Megan:    Exactly. Yes. And that is why we looked at this diets and isochoric fashion so that we can look at the effect of macro-nutrient manipulation without any kind of weight-gain or weight-loss. That was an important part of the study for sure. And just kind of… I guess I should ask. Do you have any more questions about that?

Christopher:    No, move on.

Megan:    I’ll move on to the next topic here. So, one thing I do want to make clear is that while we like to talk about diet in this health sphere, we know that diet is critical to good health. However, I see too many people wanting to micro-manage the details. So, asking exactly how many carbohydrates or grams they should be eating a day or exactly what number of blood ketones is optimal.

    And I personally think working with people in Nourish, Balance, Thrive and my own personal experience, just eating real whole unprocessed foods will take most people most of the way. And on top of that, we know that other things are important as well. So, not only diet but we have sleep and social connection and stress-management and circadian rhythm and all these other important lifestyle factors that play into both our longevity and health span as well.

Christopher:    Yeah. And I should clarify here that Megan is not just doing science but working with many of our clients at Nourish, Balance, Thrive. So, that show she can speak from experience so I think it’s really important that in some ways, it makes you somewhat unique, right? How many of your peers in the lab were also working with real human-beings in real life? Not many, I’m sure.

Megan:    Exactly, yeah. And you know, many, many people in my lab and many people kind of who I was talking to about this study as it was progressing switched their diet from regular, standard diet to ketones. And ketones can be great for some people especially short term. You know, people who have metabolic syndrome or diabetes, neurologic conditions, some cancer potentially could be great for endurance athletes at a certain time in their training. Can be a short-term therapy for gut dysfunction. But it’s not a fantasy yet. So, if everybody just listens to this and just takes out all the sweet potatoes from their diet, it’s not going to be fantasy yet but it certainly is a therapeutic tool for sure.


Christopher:    I feel like I’ve heard Rob Wolf after very many important words. But ‘who are you and what are your goals’ is perhaps one of the most important thing. For everyone, it’s ‘who are you and what are your goals?’.

Megan:    Exactly. Yeah. I cannot agree more with that.

Christopher:    And we talked about this the last time you were on the podcast. You tried some of the keto diets and perhaps the diet was not very well aligned with some of your training goals and it didn’t turn out pretty well.

Megan:    Yeah, exactly. And that’s not to say that years down the road, ketogenic diet might work for me. It’s going to be individual depending on what’s going on in your life and where your goals are, for sure.

Christopher:    Yeah. And you touched on another very important point which I want to reiterate which is in the beginning, I thought it was just about diet, right? 2013, I thought I figured it all out, all I needed to do was change my diet and it was all unicorns and rainbows. Everything would be fine. And then, over the years, with the help of our good friends and chief medical officer, Dr. Tommy Wood and his research, I’ve discovered all these variables. Some people call them pillars. I’m not quite sure if that’s the most appropriate term anymore because there’s so many of them to think of. time

    But yeah. It’s not just all about diet. There’s so many other part. And of course, we can only talk about one thing at a time on a podcast. But you have to listen to all of the show in order to know all of the things. Actually, maybe the best thing for people to do now is come to where Tommy is giving away this incredible playbook that he’s constructed over the years of working with his MET and of course throughout his career on traditional academia and medical doctoring. And he’s giving it away in weekly installments, you could read something, think about something “Am I doing that or not?”. Add it into your routine. And then the next week, you get something else to think about and maybe add in. And so, it’s been good to you in weekly installments.

    So, if you’re thinking “Okay, Chris. You’ve said that there’s all these other components but how do I know them? What are they? What do I do about it?”. Then, what you should do is come to and sign up for that weekly installment.

    Well Megan, this has been absolutely phenomenal! Congratulations on your work. I hope that we can continue to do science and publish some of the data that we’ve collected from that athletes that we worked with. How do you feel about that? I mean, I want to ask you “What is your purpose now?”. Is it something you want to continue doing or are you more about working with people and being a practitioner of some sort?

Megan:    You know, I have to say that I’m really passionate about both. I kind of… before my master’s degree, I was all about the clinical side of working with people and then when I got my feet wet in research, it kind of have sparked a passion there. And so, I think that if I can go forward and have one foot in a little bit of research and one foot in a little bit of the clinical side of working with people, I would be thrilled.

Christopher:    Interesting. You know, I just finished reading an excellent book which is called ‘Finding your ‘why’’ by Simon Senik that came our recently. And I think it would be really interesting to get all of us at MBT together and go through some of the methods that Simon described in that book. The goal is to find your purpose, to understand your ‘why’. Maybe one day we’ll find it because Simon thinks there is only one why. There’s only one purpose, you can’t have all the why. So, it would be really interesting to try and discover that with you.

    But for now, thank you so much for this incredible information. Congratulations on the paper being published on the journal. It’s incredibly impressive and as I said in the beginning of this podcast, we are absolutely delighted to have you so thank you!

Megan:    Oh well, thank you and it was my pleasure. For sure.

Christopher:    Thank you.



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