Written by Christopher Kelly
Aug. 6, 2015
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Christopher: Hello and welcome to the Nourish Balance Thrive podcast. My name is Christopher Kelly and today I'm joined by Dr. Tommy Wood. Hi, Tommy.
Tommy: Hello.
Christopher: Thanks for coming on, Tommy. I really appreciate you being here. Today, we're going to talk about carbohydrate and specifically carbohydrate supplementation for endurance exercise. So the reason I wanted to talk about this was I have my own interesting story. Back a few years ago, I had a terrible experience with supplemental carbohydrates and a high carbohydrate in general. I had a coach tell that maltodextrin as a supplement was a good idea. And based on the research that I've looked at very recently, I think that was completely justified.
I think the research does show that exogenous glucose or maltodextrin or any type of sugar does improve exercise performance. But my experience with it was that I eventually became more and more hooked on the glucose and I got to the point where I couldn't do more than 40 minutes of endurance activity without taking another maltodextrin gel. And if I didn't get that gel, I had severe hypoglycemic symptoms. I felt nauseous and I felt dizzy and I felt weak and generally very, very horrible. The problem went away when I took another gel.
Obviously, this was a problem. And that set me off down this road of trying to find a better solution. But before I go any further, would you agree with that statement that supplemental carbohydrate has been shown to have an ergogenic effect for endurance performance, Tommy?
Tommy: Yeah, absolutely. I think if you look across all the studies that had been done to date and usually it's with cycling because that's very easy to do in the lab, maybe with running. And once you're getting above something like 45 to 60 minutes and often they'll do something like two hours of steady state, maybe like 60% of VO2 max and then you'll do a time trial, so 15, 20, 30 kilometers time trial after that. And you'll have some kind of carbohydrate source during that or a placebo, so it's something like water.
Any kind of carbohydrate, be that maltodextrin, glucose or a mixture of those with fructose or sucrose, all of those improve performance particularly over those kinds of extended time period. Traditionally, we think that for longer endurance activities then taking some supplements of carbohydrate during that activity absolutely increases performance.
Christopher: Okay. So we had an interesting conversation yesterday about short term versus long term benefits and I'm wondering whether this applies here also. So you see a short term improvement in performance but a long term maybe deleterious effect on health. At least that certainly what I saw. I'm just wondering, do you think that could be true for everyone or am I just a special flower?
Tommy: Well, so you're special flower. But it's possible. And we know that a lot of people who do very intense training for long periods of time do have an increased risk of glucose handling abnormalities, we could say, or either type one or type two diabetes further down the line. Usually, you probably have to have a very high training load and a very high stress load for that to happen but somebody like Steve [0:03:45] [Indiscernible] himself to type one diabetes, probably with a combination of factors including that and probably including the way that he fueled himself.
However, we don't really have any evidence of that. Nobody has done those kinds of studies. When we're talking about the studies, we are looking at increased performance. It's absolutely that. It's well trained cyclists, often a lead cyclist, because I have access to those in sports labs. Maybe eight of them. And they do the different trials with the different carbohydrates. We have groups with different -- One group taking one maybe glucose and the other group taking sucrose or maltodextrin or something.
And then you just look at that time period up until the end of the performance. Then we look at what then happened. So if you repeat that, if you repeat that cycle of training or fueling for months or years, which is what these guys end up doing, so we just don't know really.
Christopher: Okay. Yes, so my advice to anybody using these supplements -- It doesn't really matter whether you're talking about Red Bull or some other energy sports drinks that contain maltodextrin, they're all really sugar. They all get broken down once they're inside your body in the same way. And my advice would be to monitor your blood glucose, your blood sugar when you're off the bike or you're not running or you're not swimming. And then in particular, pay attention to your fasting blood glucose.
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And in my case, I got to the point where it's pretty reliably about 120 milligrams per deciliter, which I think -- I mean, what would you think if you check someone's fasted blood glucose and you saw that, Tommy?
Tommy: So, on a more traditional thinking, you probably would think 120 is not that bad. But in reality, we know that you ideally want it to be under probably 100 or maybe even less, maybe even 90. To sort of ensure optimal long term metabolic health, we probably think at least under 100 is likely to be better and maybe even slightly lower than that. So 120, if that's going to be your fasting blood glucose every day for the near future, then you probably want to look at ways to try to improve that.
Christopher: Okay. So that's how I got into this. That's how I started down this road of starting to understand the biochemistry and maybe some of the physiology of how supplemental or carbohydrate in general works for endurance performance. Some of the research led me to a product called UCAN SuperStarch and I've talked about this product on the podcast before and I've even had the Director of Nutrition on to the podcast to talk about UCAN Superstarch.
I won't go into too many details there but I'll say that it's still a type of carbohydrate but it seems to be a type of carbohydrate that didn't have as big an impact on my blood sugar as the maltodextrin did. And originally, I used it as a gram for gram replacement for the maltodextrin. So I would go out with some of these horrible chalky powder mixed up with water and I would take as many grams of that as I was the maltodextrin.
Initially, that worked well but I didn't really notice any changes. And then as time went by, I found that my blood sugar became more under control in general and I started eating less and less of the UCAN SuperStarch until one day I went for a big long hard ride with a local fast guy and I forgot my UCAN SuperStarch. I used to carry it around. In fact, I still carry it around on race day in this -- It's called a Hydro Flask. It looks like a sort of tube of toothpaste but it's not. It's made of vinyl and it's a big bigger.
The reason I like this container is because you can manipulate it. The SuperStarch, it doesn't form a solution and it forms a suspension and eventually it settles out. And so you need to be able to manipulate the container to shake it back up. So I forgot this thing. I left it home one day and I thought I'm doomed, I'm going to bomb for sure. And I didn't and I was absolutely fine. In fact, I didn't even really notice the difference. And so at that point I realized something quite profound had changed with my biochemistry and with my physiology. And I know now that I become a more fat-adapted athlete. Maybe, in all that time we talked about this, that this hormone insulin has played rather a large part in this change.
Tommy: Yes. Insulin has become this thing that everybody wants to talk about and it's become almost -- I think it's become almost demonized particularly in this sort of the low carb and maybe the Paleo communities with some reason but maybe I think there's a little bit of sort of [0:08:38] [Indiscernible] there as well. The one we're talking about, the fuels you use for endurance exercise, ideally if you're going to go for a long period of time, we're now starting to think that you want to rely on fat as a fuel source rather than glucose particularly because your body stores up glucose as glycogen so they're in delivery in the muscles. But if you're going to run something like that a marathon, you don't have enough glycogen to cover that. So then you need to take something extra.
However, if you're going to do that, if you are nicely fat-adapted and you did it purely on fat, you have something, depending on how much fat you have, but you have tens of thousands of calories, of stored fat, even people who are very, very lean. So there's a huge amount of potential energy you have there. And if you could tap into that, then you potentially don't need to take anything extra.
Christopher: Yeah. I really like the analogy that Peter Attia used. Actually, it's funny that you should say that the kind of insulin has been villainized. His blog is still called The War on Insulin. I'm sure that's slightly tongue in cheek but definitely anything like that, there's an element of truth to it. But the analogy that I first heard from him that he's used in presentations is that of a petrol tanker.
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Where there's a vehicle which is transporting fuel but it's unable to access the fuel that is the payload for the vehicle. So the gas tanker has its own petrol tank or gas tank, as they're called it here in the US. In theory, the gas tank could run out of gas even though all of the payload is still there. And this analogy applies to stored fat when we're performing endurance exercise. So you have all this energy on board in the form of stored fat but you can't access it because you're permanently on this glucose trip and you, therefore, have to keep adding in the glucose. And that's a problem. And if you could only get access to the fat then you would be a better athlete.
Tommy: Yeah. If you were to say people are talking more and more about fat-adaptation for endurance exercise, there are lots of sort of very famous athletes who are now performing very well particularly in very long endurance feats as purely sort of using fat as fuel. I think that there is some benefit to maintaining some level of muscle glycogen or liver glycogen to maintain performance particularly if you're not -- I mean, as long as you're not going for days and days and days, something like maybe the races you do four or five or six hours. Or if you're doing cyclo-cross, which is often just under an hour.
Then I think having some muscle glycogen is very, very important and will improve performance, particularly if you're then trying to do some sprints or you want to try and push through the finish line. But you want to try and defend that glycogen for as long as possible. And you don't want to rely on that first and then run out of glycogen and bonk like you would, like people talk about hitting the wall, say often.
And what regulates, one of the key regulators of using is insulin, like you say. So insulin controls fat storage and fat burning much more tightly than glucose storage. I mean, we talk about it mainly in terms of glucose storage and regulating blood glucose. But actually, you need much less insulin to turn off fat burning and turn on fat storage than you do to turn on glucose storage. So if your insulin goes above maybe six, seven, eight micro units per mil, and people might recognize those units if they've ever done a fasting insulin test, once you get above that kind of level then you're probably relying more or you're more in storage mode and you might be relying on carbohydrates as a fuel source than fats. So if you can keep your insulin levels low during endurance exercise then you're much more likely to rely on your fat storage rather than turn to muscle glycogen.
Christopher: Interesting. Okay. So you just allowed me to quantify a problem here which I think is really interesting. Lots of people listening to this will have done a blood chemistry. And if you chose a more expensive blood chemistry, the fasting insulin should be on there. They're the same units. We're talking about the same thing. And so from what you just said then, if I see more than five, six, maybe seven as sort of upper limit of micro IU per milliliter of insulin on my blood chemistry, then you can be pretty sure that you're not burning fat at that time.
Tommy: Yeah. Then you're probably somebody who's more relying on exogenous glucose sources. Potentially we've seen some people or talked to some people that are actually relying on breaking down muscle tissue to provide some glucose. And that's just because their insulin levels end up being higher than what would be allowing them to burn fat.
Christopher: Interesting. I love the way that you can measure this and quantify and we'll get into that later. The next thing I wanted to talk about was the scientific study on UCAN SuperStarch. I have to be honest that I didn't really pay too much attention to it in the beginning. I took the advice and authority from Peter Attia, if I'm perfectly honest, and maybe authority is not the best type of advice to act on. But anyway, that's what I did. Only later on did I see this discussion on Facebook where somebody was asking: Has anybody had any experience with UCAN SuperStarch? Of course, I said, "Yes, I have. It's been a fantastic product for me. I highly recommend it to anyone. At least give it a try."
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And somebody chimed in, somebody, a professional nutritionist, somebody with a Ph.D., I believe, said, "Oh, the study on UCAN SuperStarch is not meaningful. The results were not statistically significant. Anybody who buys a sports supplement without scientific validation is basically buying on faith, which is a terrible idea." I don't know. What do you think about that? Is that true?
Tommy: I saw this or you kind of introduced me to this discussion on Facebook. Initially, I thought that it was a fairly -- I thought the comments were a little bit unnecessary. But actually, when you dig into the science behind UCAN, you kind of start to see this guy's point. And I think one thing that's worth saying, to start with, is the fact that the study they've done is no worse than the 90%, 95% of the studies done in sports science particularly in terms of performance and fueling for endurance exercise.
What they normally do is they have -- So we can use the UCAN study as an example. They have nine male cyclists. These are nine guys. They were fasted for ten hours and then they were going to do 150 minutes at 70% VO2 max and then they were going to cycle to exhaustion. So after they've done sort of like that pre-exhaust for two and a half hours, then they're going to cycle for as hard as they can until they're exhausted.
And what they wanted to do is they wanted to compare UCAN with maltodextrin to look at things like blood glucose, insulin. They looked at glycerols. Basically, if your blood glycerol goes up, that shows that you're separating the fatty acids from the triglycerides. So triglyceride is obviously three fatty acids attached to a glycerol. So as your free glycerol goes up, that's because you're burning those fatty acids and you're releasing glycerol right into the blood because that become sort of -- That becomes spare.
And they also looked at fatty acids in the blood and they looked at things like cortisol as well. These guys, they took one gram per kilo of either UCAN or maltodextrin half an hour before cycling and they did their test and they took another dose afterwards and they kind of looked all atthe same things during recovery. And a number of problems come up in this type of study. If people can go on the UCAN website, you can download, they have all their papers available. And this is the only real published they've done. The others are sort of they talk about internal studies they did but they don't really give you the data. They just kind of tell you some vague numbers.
I'm inclined to not just really believe those at all because they're not really showing you the data. They're just kind of telling you what they want you to know. And the problem is that these studies or guys who are behind UCAN and promote UCAN and people like Peter Attia and Jeff Volek, and these are huge guys in sort of the low carb high fat, particularly Jeff Volek in terms of the sports performance side of things. These are people that we really trust to do high quality science. If you look at the graphs -- So you could go to any of the gross in the study, if people want to go in and look.
Christopher: Yeah, I will link to this in the show notes actually because it takes a little bit of poking around on the UCAN site to find it, so I'll link to it in the show notes for this episode too.
Tommy: Okay. And so what they've done is at every time point, they plotted the mean in each group of whatever it is, say it's blood glucose. And mean is basically like a normal average you do where you add up all the blood glucose for everybody and you divide it by the number of people you have. And then they plot that with or without something they called the standard error. It doesn't really matter what that is but mean plus or minus standard error is the way you plot your data to make it look the nicest.
It's kind of a trick that people use, and particularly, I've seen in almost all these sport science studies done looking at fueling and performance. It just makes your graph look nice and tight. So you can see the blood glucose goes up higher in the maltodextrin group versus the UCAN group. But they've manipulated the data and plotting it as a mean isn't really allowed if you got such a small number of people. Eight people group, you want to be plotting it something like the median which is basically if you rank all the numbers, you pick the middle one.
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And then you're not swayed by what we could outliers. So people who are very, very different from the average.
Christopher: I've got good analogy for this. If Bill Gates walks into a crowded room, on average, everybody is a millionaire, right?
Tommy: Absolutely. Yeah. But if you took the median instead, then that will be a much more -- Because his billions shift the average up so high that it becomes -- You could say that a room with 150 people and all earn $40,000 a year, they would all be millionaires on average because he's in the room. But actually, if you took the median, you take the middle guy and that will be a much better -- You remove the effect of those kinds of outliers.
Christopher: Right. This is really interesting, I think, for a number of reasons. I mean, we don't know anything about who is in which group. So we don't know that maybe there was some better fat-adapted athletes in the UCAN group versus the maltodextrin group, right?
Tommy: Yeah, absolutely.
Christopher: I was going to say it's like, I mean, what number of people -- How many people are actually going to look at the study at all let alone know that they've used the wrong type of statistics to present the data. I think it's probably worth pointing out that you do actually do peer review, right?
Tommy: Yeah. That's something that's just part of my job. If there are studies in my field, I will sort of read through them and make sure they're doing all that right, the quality of the science is good and the statistics is good. That's sort of part of the process of getting things published. So one of the things that -- Again, you mentioned the statistical analysis. And that's because we talked about these studies before. What they do is at each time point, they just compare UCAN versus maltodextrin with something called a t-test.
And people might remember a t-test from basic math in high school or something. Maybe you do that towards the end. But again, if you're doing a t-test, it relies on your data being normally distributed. A normal distribution is basically like if you took all the weights of everybody in the world, they'd follow a nice bell curve. And height is the same thing. Some people are very short, some people are very tall but most people are just either side of the average. So then you have a nice bell curve.
And if your data is shaped like that, then you could use a t-test. And that's perfectly fine. But because you've only got eight data points in each group, it can't be normally distributed. So then you have to use different types of statistics, something called non-parametric statistics. And that doesn't really -- How you do it doesn't really matter but what the problem is that when they've done so many individual t-tests, and they've literally done probably over 100 because they just compared the two groups at each different time points for various things be it insulin or glucose or cortisol or whatever.
But if you're doing that many comparisons, you have to adjust for the fact that you've done so many comparisons because what happens is the more comparisons you do, the more likely is you get a result by chance, just by accident. Because based on statistics, everybody talks about P values -- People have heard of P values from studies -- they'll say the P value is less than five or 0.05, so 5%. And if the P value, you do a statistical test and a t-test, and the P value is less than that, you stay statistically significant. So the two groups are significantly different.
Christopher: Right.
Tommy: But the problem is that works on the premise that you have -- So what you're saying is that you have a 95% chance that they're different and has not occurred at random. That means that 5% of your results are going to have occurred at random. So that means 5% of statistically significant differences actually are kind of random. So if you're doing 100 different comparisons, at least 5% of those comparisons or five of those comparisons, the result is just random and it's not actually necessarily true.
Christopher: Okay. And so we're looking at P values much larger than an 0.05, right?
Tommy: Yeah. If they get a significant result, so say here we have insulin, half an hour after ingesting the different carbohydrate sources, so it's just before they start the cycling intervention, and insulin is significantly higher in the maltodextrin group versus the UCAN group. And the P value is an 0.012. So that's less than an 0.05. The problem is because they've done so many comparisons, they haven't adjusted for the number of comparisons they've done. Because that's difficult to do, so they just ignore it and don't do it. Let alone the fact that they've done their own kind of test than doing a t-test.
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They also haven't adjusted for a number of comparisons they've done. In reality, every significant difference they find, we just don't even know if that's true. It could all have happened at random. They're using the wrong test. They're not adjusting for a number of tests they've done. You can kind of look. You can look at it and see a trend. You can definitely -- If you look at the graph, you would believe that insulin goes higher in maltodextrin versus UCAN. I believe that. That makes perfect sense because of the way they're broken down.
But in reality, there's not much else you can get out of a study like this just because the number of people they include is so small and the analysis they've done is just not correct. I'm not saying that these guys are doing terrible science. They are doing the science that is the standard for their field. And that's the problem. That's the problem with it, is all of these studies do exactly the same thing. Then actually, when you're trying to really look and find some useful results there, there's just not that much to find.
One of the big problems that I have with this study, and this kind of come on to me with the fuel sources, potentially we'll talk about afterwards, is the fact that their UCAN is -- They're trying to sell it as a source of carbohydrate for endurance exercise and particularly for athletes that are fat-adapted, to try and provide a small influx of carbohydrate but not to increase insulin which would switch off fat burning. And then in order to make that point, they've done a study where they compared UCAN to maltodextrin.
And maltodextrin has a GI of 150 to 160 or maybe 110 to 160 depending on whose results you believe or which study you look at. They basically picked the one carbohydrate that will increase your blood glucose the most and increase your insulin the most. And they chose and they want to compare it to that because that makes UCAN look even better.
Christopher: Okay. So this is a bit like -- I've heard Ben Goldacre talked about this before and he's written some fantastic articles in The Guardian and he has a number of good books too. This is a problem where, okay, so I'm bringing out this new drug and I publish this trial and the new drug is like -- There's already another drug on the market but I'm going to use placebo as the comparison and make my new drug look really, really good. But that's not really fair because there's something else which already does a better job than placebo and so it's not a fair comparison.
Tommy: No, absolutely. So the question they're asking, which is looking for a carbohydrate source that minimizes increases in insulin and minimizes increases or changes in blood glucose. You don't want blood glucose to go up a lot but you also don't want it to drop a lot, which tends to happen if you have a very high GI carbohydrate. So if you have maltodextrin, your blood glucose shoots up but then it also drops precipitously low and then you need to take more maltodextrin to keep your blood glucose up and you get into that kind of cycle and needing more gels the more you sort of continue with exercise.
Christopher: Okay.
Tommy: They've kind of stacked the deck by comparing UCAN to maltodextrin.
Christopher: Right. Okay. And so this is a problem, isn't it? I guess, any time someone is trying to sell something, maybe that's where the other studies went, right? Maybe a publication bias going on here too. They talked about these other studies, but where's the data?
Tommy: They're sort of internal things so maybe they're difficult to publish. So they compared to the -- First, they have something called, they call it study one. And they compared UCAN to glucose and Argo, which is like basic corn starch that you could buy in the shop, you buy in the bakery aisle or something.
Christopher: You're thickening the gravy with it.
Tommy: Yeah, exactly. And so compared to Argo, UCAN had a smaller impact on blood glucose but only 13% smaller. That's not that much considering you pay $2 or $3 for a dose of UCAN and Argo starch costs literally nothing. Then you could end to the point like fine, it's less, but is that physiologically significant? And they don't give you the data to say that. So if I look at the study, I've got, "Oh, maybe I should just take Argo starch and save my money." And that's perfectly possible.
Christopher: Okay. It turns out that I was an idiot before for using maltodextrin and then I developed diabetes. And then I thought I was being clever by using this UCAN SuperStarch but it turns out I'm still an idiot for not paying close attention to the science. And I'm not sure I could have done -- In fact, I know I couldn't have done this. I would have looked at this chart and I probably would have looked at the arrow bars, which don't look like they're touching, the two different series, two different lines on the chart. There's arrow bars on this. But they're not really touching. And so I would have looked at that and make the conclusion that this UCAN SuperStarch makes perfect sense.
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Tommy: Do you have to pick a carbohydrate source from what we've got? Say, off on here, like maltodextrin which is obviously the kind of industry standard. Or actually you'd use maltodextrin plus fructose. Because when they've looked at studies comparing maltodextrin alone to maltodextrin plus fructose, then adding fructose appears to give a performance benefit. So then if you want to look, if you want to take something that will minimize insulin responses and maybe allow you to burn more fat while you're doing endurance exercise, then UCAN is better than that kind of industry standard. I'm not saying that that's not the case but just based on the science that we have, it's almost kind of -- It's as much based in theory and conjecture as is sort of actual hard scientific results.
Christopher: Yeah. I think we're being kind of smart here. But when you go to an event, when I go to a bike race, I see nothing but maltodextrin. And then some other companies who are -- They're trying to market themselves as being a healthier alternative that have less sugar in them, and I won't name any names, but basically rather than using maltodextrin plus fructose, which is being quite well demonstrated to be effective in the studies, they're using just basically table sugar. They're using sucrose but just less of it.
Tommy: Yeah.
Christopher: So now, you're paying $60 for a tap of sugar, literally sugar, flavored sugar.
Tommy: And to be honest, if you look at the studies comparing something like just sucrose to maltodextrin or maltodextrin plus fructose, the performance benefit is minimal. So if you're the kind of person that's--
Christopher: [0:31:40] [Indiscernible].
Tommy: Yeah. No, but if you're the kind of person that is doing that and you don't have a huge amount of money and you're not -- They're looking for that last 0.05% that will get you to the finish line first, just mix up some sugar. It will do the same thing.
Christopher: That's interesting. Okay. We've got some plan here that maybe we can talk about to try and figure this out. I think this is going to be a really interesting experiment. I guess you described it as N equals one. So where there was nine cyclists in the UCAN study, there's only going to be one cyclist in this study and that cyclist is me. What we're planning on doing is trying to figure out which is the best source of carbohydrate. Is it UCAN SuperStarch or is some of these other cheaper types of corn starch? Are they just as good or is there a big difference?
The other alternative we've been thinking about is just pure fructose. Maybe before we get into the details of the experiment that we're going to do, do you want to say something quickly about fructose, why it might be a good candidate source of carbohydrate that would keep insulin low enough to allow for fat burning?
Tommy: Yeah. So this was something when we were talking about potential -- We talked about UCAN and we talked about other potential fuels that you could use. Because obviously, you're a pro mountain biker. Anything we can -- We're going to try and create something that will get you an optimum performance benefit and maybe doesn't cost a lot of money or doesn't have any kind of side effects and then you can go faster than that or something that will be really beneficial to you particularly.
So one of the first things I thought about was rather than -- So, UCAN is basically as a corn starch they modify with some temperature and different boiling conditions and some special cooling procedure and they get some highly complex branched starch molecule, which means it takes a very long time to break down. And one thing that I thought you could potentially use instead, which is very, very similar, something called Waxy Maize Starch. So you're starting with a similar product but maybe they don't -- It's not as complicated a processing method.
And Waxy Maize Starch is something that you can get from any kind of sports or online sports supplement company and it's very cheap. But the problem is that nobody has done a huge -- Again, with Waxy Maize Starch, nobody has done a huge amount of research but we did find one study where they were comparing Waxy Maize Starch to glucose to resistance starch to a sweetened placebo. And what you see is that glucose dramatically increases serum insulin, to above 75 micro units per mil. And Waxy Maize Starch only increases it, looks like to about 25, about 30 or 35, which is above that point where you're getting fat burning. But this is before your starting exercise. But then once exercise starts -- So this is in steady state cycling, then in the Waxy Maize Starch group, insulin goes below five. So you're back in that range where you get fat burning. But it's close to ten in the glucose group.
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So during exercise, Waxy Maize Starch didn't have a different effect on insulin as the [0:35:12] [Indiscernible]. It was an artificially sweetened placebo. So there was no glucose in there, no carbohydrate source whatsoever. And the Waxy Maize Starch and placebo were pretty much the same and the insulin level was probably around the range you'd want it to be to allow fat burning.
Christopher: Okay.
Tommy: So they didn't use this in the UCAN study but we've kind of found it on other studies and there's potential that it's good enough and it's much cheaper. So that was one thing that we considered because it has a much lower glycemic index. It's about 60 compared to 120 from maltodextrin.
Christopher: Okay. And I'll link to this study in the show notes as well so people can look at this.
Tommy: Yeah. And this study is done, has exactly the same problems as the UCAN study in terms of the number of people involved and the way they do the statistics. It's not really any better but if this is the best that we're doing with then it kind of looks like Waxy Maize Starch is a potential candidate that we could try.
Christopher: Okay. And then what about fructose?
Tommy: Yeah. If you add fructose to glucose and maltodextrin, in all the studies that have been done, you seem to see an increase in performance. And it's not always statistically significant. But if you sort of lump all the studies together, and you do a big math analysis or something, it seems like fructose gives an added benefit. And why that is actually uncertain because some people say that you actually get a lower carbohydrate burning, which would suggest that you actually get more fat burning. And some say that adding fructose allows you to burn more carbohydrates.
Overall, that I'm not really that certain. But what we do know about fructose is that fructose itself doesn't have any effect on blood insulin levels. So you get a big ole dose of fructose and your insulin doesn't really shift at all or at least not very much. And everybody is really worried about fructose because -- We talked about high fructose corn syrup and sweetened sodas and diabetes and all that stuff.
Christopher: I have fructo-phobia actually.
Tommy: Along with insulin plus fructose, a kind of like the big bad guys out in the world at the moment and you sort of say, you could just have, you could just take fructose as a fuel and then you go, "Oh, what about the diabetes?" And frustose has very different effects based on whether your liver is full of glycogen or not. So fructose is very good at maintaining liver glycogen. And liver glycogen is kind of like the buffer for muscle glycogen. There'd been studies they've done before where you give fructose during exercise and you actually spare liver glycogen for longer.
Christopher: I'm going to link to that study too, actually.
Tommy: And that allows you to spare muscle glycogen. So even though you're not getting a direct carbohydrate burning effect in the muscles, what you're doing is you're allowing yourself, without increasing insulin, you're allowing your sort of glycogen stores to be saved for longer. The problem is that in traditional studies that they've done, fructose in itself hasn't really given any huge performance benefit. But when you're talking about somebody who's a fat-adapted athlete who probably has low level glycogen stores, because if you don't eat any carbohydrates, your liver glycogen empties pretty quickly, you might maintain a sort of 60% to 70% of muscle glycogen as somebody eating a low carb diet, but your liver glycogen will empty pretty quickly.
So if you're that kind of person then taking some fructose can up your liver glycogen and then maybe help you defend your muscle glycogen longer and then you can need that for that sprint or the final race for the finish line. Not many people have looked at fructose on its own because it's not something you'll directly burn in muscles. But in this kind, for the fat-adapted athlete, theoretically, it might be useful carbohydrate source to help you maintain liver and muscle glycogen for longer during the face.
Christopher: Okay. So now, we've got three candidate sources of carbohydrate. Tommy, I didn't even know that this test existed but Tommy found on -- So LabCorp or Life Extension, which is a company that we use often in Nourish Balance Thrive, they offer this test they called the glucose tolerance test with eight insulin samples. Actually, it's eight samples total, isn't it? It's four of glucose and of four of insulin. Did you go poking around looking for something or did you already know that this test existed?
Tommy: I knew that this existed but I was basically poking around the website to find something that we could use to do this. So, a normal oral glucose tolerance test will just look up blood glucose in the hours after you take a glucose load. It's usually 75 grams of glucose you take as a drink and then you follow your blood glucose.
[0:40:02]
And that's one of the ways that we use to diagnose diabetes, or gestational diabetes in pregnancy. But what you really want to know, if you want a really thorough assessment in terms of your risk of type two diabetes and your blood glucose handling, you want to track insulin over that same time period. And there are some people who had done a lot of studies looking at a different profiles of insulin received after glucose and then later metabolic health. So this is actually fairly well studied but there's just nobody really does the test because it's slightly more expensive than the normal oral glucose tolerance test.
Christopher: Okay.
Tommy: But actually, tracking insulin dynamics is probably better predictor than glucose dynamics after an oral glucose tolerance test in terms of metabolic health.
Christopher: Okay. So the way this test works is you order it and they send you a lab slip and then you turn up at LabCorp and they take a measurement of your glucose and insulin. And then what happens next? They give you these 75 grams of glucose, right?
Tommy: Yes. So you basically do a fasting sample. Then 30 minutes before the next sample, they give you 75 grams of glucose as a drink. And then they take further samples one or two hours after that. So you end up having four total samples. And each sample they do a blood glucose and a blood insulin, each spaced an hour apart.
Christopher: Okay. So this is what I'm going to do with the different types of carbohydrates that we've been discussing. I have no idea whether this is really going to work because I'm doing something that the test was not designed for. So I don't know whether LabCorp are going to get funny with me when I -- They're going to try and provide the glucose for the tolerance test, right? So,75 grams of pure glucose.
We were joking earlier but I am going to have to do this like pour into one of the pot plants in the waiting room and then take UCAN SuperStarch or Waxy Maize or fructose in its place. And then I'm going to do the rest of the test as per their laid out. And then we're going to find out what happens to my insulin and glucose. and then I thought it would be kind of fun to measure my ketones as well since I'm hoping that I'm pretty much in ketosis all of the time with a few exceptions when I do occasionally have carbs. Would you think it would be interesting to look at ketones at the same time as these tests are done?
Tommy: Oh, absolutely. I think that your, with each of them, your ketones will probably drop off and certainly probably faster with the Waxy Maize Starch than with the others. But it will be interesting to see what happens. So what you're going to do is you're going to turn up, take your fasting sample, wait half an hour, take your selected carb source of the day, wait another half an hour, then you're going to take your second sample. So to look at your initial blood glucose and its response. And then we're going to do an exercise protocol.
Christopher: Right.
Tommy: To look at the effect of exercise on those metrics.
Christopher: So I'm going to get on my bike. So what's supposed to happen is you're supposed to be in the waiting room reading a book in between these different samples. And I'm going to ask to go to the toilet, climb out the toilet window, climb onto my bike and then do some integrals or something to kind of replicate either a hard workout or maybe a bike race and so you're going to see some -- I mean, obviously, that's going to make some changes to my glucose disposal and insulin and such.
And then I'll come back to the lab and do -- Hopefully, I'm going to end the exercise as close as I possibly can to sample number three. And then I'm going to sit there for another hour and then finally do another final reading. So I have four sets of reading in total.
Tommy: Yeah, for each.
Christopher: For each carbohydrate source. So I'm going to do this on three different days. How far apart do you think I need to do this to sort of--
Tommy: I'd do them at least a week apart.
Christopher: At least a week apart.
Tommy: And also, Julie, your wife is going to blind you. She's going to make the [0:44:19] [Indiscernible].
Christopher: Yeah. So this is going to be fun. I think it's going to be useful for me to not know what type of carbohydrate I'm consuming during the test. So Julie, being a really good cook and a food scientist, is going to do all of her best to make all three of these drinks taste the same. I think that's going to be a bit of a challenge actually. They're all fairly -- So UCAN is definitely not sweet at all, at least the type that I get. And then the Waxy Maize I'm not really expecting to be sweet all either. The fructose will be mildly sweet, I think.
Tommy: Yeah. So fructose is actually sweeter than glucose.
Christopher: Is it really? But does it taste it? Interesting.
Tommy: It will be a challenge but I'm sure she'll figure something out.
[0:45:03]
Christopher: Yeah, she'll figure something out. I think it's also going to be difficult to get a consistency right as well. So I mentioned earlier that UCAN doesn't form a solution. It forms a suspension. So I think I just need to take an opaque bottle and then just shake the hell out of it no matter what it is.
Tommy: Make it some kind of a gel or paste and then drink water afterwards.
Christopher: Yeah, that's a good idea.
Tommy: Then its solubility and water doesn't affect you knowing which it is.
Christopher: That is a good idea. I will pass on that information. I've no idea whether LabCorp are going tell me to take a running jump. They might do but I doubt it because I'm paying the money and I'm letting them draw the blood, so I don't see why they would really care. So, yeah, I'll collect the data and then maybe we should reconvene and do another podcast and we'll let you know which is best either Waxy Maize or is fructose or is it UCAN SuperStarch, at least in this individual, quite how you would [0:46:02] [Indiscernible] like that out to yourself, I'm not quite sure. But I think it will still be interesting.
Tommy: Actually, we're not looking at absolute performance in this particular test. Just sort of to see how they affect your blood glucose and insulin and ketones during that time period.
Christopher: Excellent. The other thing I wanted to add to this already complicated conversation is the potential impact on the gut microbiota. And so I know that -- I talked to Grace Liu quite regularly and she already expressed her concern with UCAN SuperStarch potentially being -- She thinks it's RS3. That's a problem with all of these types of carbohydrates, is nobody really knows what they are. We know that not all of the -- Do you think that's true that not all of the carbohydrate in UCAN SuperStarch turn into glucose in the blood? Like some of it is being fermented or not absorbed in some way.
Tommy: Yes. I mean, if you take any kind of starch molecule and then you heat it up and then allow it to sort of cool down and crystallize. You will generate some RS3, so resistant starch three. And it's really difficult to tell from the data they give you but it almost looks like compared to an equivalent amount of, say, maltodextrin which is all completely absorbed, it looks like you get smaller total blood glucose from the UCAN. We suggest that some of that glucose, which is trapped in the starch, isn't actually broken down into glucose because it's maybe a resistant starch.
Christopher: Right.
Tommy: It's impossible to say exactly but it kind of, from the graph they give you, it kind of looks like that might be the case. And just because of the way you create and process the starch to make it into that kind of SuperStarch that I'm not actually surprised. I thought exactly the same thing about UCAN, that some of it is probably turning into RS3.
Christopher: Right. Yeah, so Grace's concern was she's not a big fan of these concentrated powdered forms of resistance starch that give you like huge doses of a particular type of fiber that would never be seen in nature and potentially could cause some imbalances by feeding not so beneficial species or types of bacteria. That might be something to consider in the long term too. Maybe I'll have to do some uBiome testing to make sure that I'm not destroying my gut flora by long term use of any of these types of carbohydrate.
Tommy: Yeah. So anybody who has any kind of metabolic problems already, probably not best to taking any huge doses of fructose. And again, if you have something like small intestinal bacterial overgrowth placebo, then a huge dose of fructose probably isn't going to be good for you either. And you might get a lot of bloating and diarrhea type symptoms as well. So large doses of fructose only for the metabolically healthy probably with a reasonably functioning gut.
Christopher: Maybe the fructose is going to get -- Maybe I won't do the fructose. I don't know which type of carbohydrate are given.
Tommy: That's the whole point, yeah.
Christopher: Yeah, that's going to be interesting. We'll see. Well, this has been great, Tommy. Thanks so much. I really appreciate this conversation. I think it's going to be a fun experiment. I can't wait to see the results.
Tommy: Yeah, me too.
Christopher: Okay. Cheers then. Bye.
Tommy: Bye.
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