Transcription
All right, we're going to get to work now. We've got some great things planned. The first thing we're going to do today, as you know, over the last few weeks, we've been doing, uh, Dr. Bickman's Metabolic Classroom episodes first thing on Tuesday mornings. And we're going to talk about salt today. And I'm going to turn the time over to Ben. If you have questions during the Metabolic Classroom session, please put them in. We're streaming on YouTube, Facebook, and on our website today. So let us know if you have questions and we'll try to get to those. Okay, Ben, time's yours.
Yeah, in fact, guys, I echo Jack's sentiment with regards to so many questions. It was really fun last week where we, I sort of finished my little spiel and our internal discussion, and then we were able to get right into this to questions that were just dovetailed perfectly from this topic. So, yeah, send them in.
So this study was supported by the British Diabetic Association. It was, um, conducted, um, in, in the UK, and this is in the late 90s. What's so compelling about this study, though, was it was the first to really, um, scrutinize the advice on dietary salt restriction specifically in people with type 2 diabetes. So, as we all know, type 2 diabetes is a lifestyle disorder. Of course, genetics predispose to this problem, but it's the, the environment or the lifestyle that pulls the trigger, so to speak. Commonly, heart disease is what will kill a person with type 2 diabetes. So when, when the diabetic dies, it's not that they've died, it won't be listed as diabetes as cause of death. Commonly, it'll be heart disease. And hypertension is one of the leading problems when it comes to heart disease. So looking at what controls blood pressure in the context of type 2 diabetes, in the bigger context, is, I think, pretty rational. So I can see why they asked this question. And of course, it all fits under this almost global obsession we have with, with salt, particularly vilifying salt, where it is, it is always something that the, especially if someone has higher blood pressure, the advice will be, cut your salt, cut your salt, eat less salt. That's always, um, uh, that's always the advice.
And let me elaborate on that very briefly to, to explain why that is justified. In, at the simplest level of thinking, that's because when you consume salt, the physics of salt or any of these electrolytes is that where the salt is, the water will go as well. And so if a person's eating a lot of salt, the body will reduce its production of urine to hold on to more water. In that water, it will stay mostly in the blood. The blood is, of course, a big reservoir of our body water. And if you have more water in your blood, that's more plasma volume is higher. And then, of course, following laws of physics, if volume goes up, pressure goes up. Volume and pressure are, are tightly related to each other. And so it, that does happen. If each one of us right now swallowed a bunch of salt pills, we would see our blood pressure would be where it was before, and it would come up a little bit, and then it would come back down. It would be very temporary, this little acute hiccup in blood pressure because our body would regulate it appropriately. So, so there's some justification in saying, cut your salt.
Now let's look at what happened in the study, though, because the results, I think, are really, um, revealing into the, the problem with this general advice to cut salt. So they took this group. It was a small group. It was about 10 people, which, which just goes to show how powerful the finding is, because when you have a small group and you see a statistically significant result, that suggests that the result really must be substantial, because otherwise, if it's a modest result, you need a really, really big sample size, a really big group of study subjects in order to detect the difference. I hope that makes sense. So this difference that they detected was so significant that they were able to detect it in just what is a pretty modest sized group. So what they did, they split the group up and did a crossover design where one group got a sodium replete diet for the week, and the other group, with all macros controlled, got a sodium depleted diet. So, and they would shift kind of one week to the next, or the weekdays, about five days on each. So, so that's what we're comparing. These two control diets, one with an ample amount of sodium would be considered normal, and then one that is deficient in sodium, known, you know, very low sodium. And then they, they just kind of did a variety of tests on the people. And in order to measure insulin sensitivity, they used what is considered a gold standard. It's something called a hyperinsulinemic euglycemic clamp. This is almost purely an academic thing. It's something, it's so time and labor intensive that you wouldn't really do it in a clinic. But what they do is they start infusing a high level of insulin into the person, and then they start infusing as much glucose as they need to keep their glucose normal. Because of course, if you start dumping insulin into the system, it's going to start depressing blood glucose levels. And so they put their insulin levels at a certain amount by infusing insulin, and then they measure how much glucose do we need to put into this person to keep their glucose normal in the midst of this high insulin. And of course, if a person is more insulin sensitive, you've got to be infusing more glucose into the person, as opposed to someone who's insulin resistant, you don't have to infuse as much glucose because that high level of insulin isn't really moving the glucose out of the blood too well anyway. I hope that makes sense. So it's a hyperinsulinemic euglycemic clamp. That's how they measured insulin sensitivity, which is really considered, uh, the best way of doing it.
Now let's look, first of all, um, if we, we're going to flash up table one. And this is a good table in that it really reveals, uh, well, several interesting, um, items here. And on table one, what we see first of all, oh, I should have mentioned, so these study subjects, um, you know, tended to have slightly higher blood pressure. And we see in the first bit with systolic and diastolic blood pressure in the, in the sodium, well, we can just look across them in the sodium depleted group with low sodium or normal sodium. We can look at the very last column, the p-value. And none of those values was statistically significant. Nothing reached significance. In other words, despite eating considerably less salt, there were no significant changes in the people's blood pressure. That right there is a problem because that's why we give people this advice to adhere to a low salt diet. We say, cut your salt in order to cut your blood pressure. And it didn't really move the needle. The systolic blood pressure was hovering around 130, which is generally normal, maybe high normal, and it didn't move at all. And then we go to the very bottom and we look at what happened to their fasting insulin. And you guys, everyone knows that I'm a big advocate of looking at fasting insulin. You'll see that p-value also did not reach statistical significance, but you can see just because of the variability, but the differences are, are starting to become apparent where in the low sodium group, their fasting insulin was 93 picomoles. So this is British, so those are picomoles. It's a different unit. And then the sodium, the low sodium group, or sorry, the full sodium group was at 82. So the insulin had gone up about 11 picomoles or 11 points in the, with, with low sodium, although it was not statistically significant. So you're starting to see, however, a hint of something wrong.
And when we really, you know, pop up the hood and look at the engine, if we look at figure five, now we see a statistical, a statistically significant finding. And I would say very meaningful, especially for a group this size, where the sodium-depleted group, um, had significantly less insulin sensitivity. And let me just allow, let me say that again, just to help it really have an impact. We tell people, including type 2 diabetics who may have, you know, blossoming blood pressure, that they should cut their salt to control their blood pressure. This study suggests one, cutting the salt doesn't help the blood pressure at all. And two, an unintended consequence is that the person actually becomes more insulin resistant for no other reason than cutting their salt back in their diet. So you take the type 2 diabetic, and now we're making their disease worse. Whatever medication they're on for their diabetes, they likely have to take more of it. They have to take more insulin if they're, if they've been given insulin therapy, all because we've told them to cut their salt. Now, again, I'm not anyone's physician, none of us are. So I'm not giving dietary advice here. But I am saying perhaps this is a study you'd want to print out and take to your next doctor's appointment if you've been told that you need to cut your salt. It may have less of a benefit than you think, and in fact, it may have a, a downside here, namely making the insulin resistance, which is the basis of your type 2 diabetes, even worse.
Now, just to end this study, the concluding thoughts that we don't know the mechanism. But it could be part of, in other words, what is it about the low sodium diet that is causing the insulin resistance? It could be a result of an elevation in the hormones that are trying to tell the kidneys to keep the salt in the body. Like there's this system, for example, called the renin-angiotensin-aldosterone system. We know that angiotensin has some, and aldosterone have some direct effects on insulin and insulin signaling, including at the fat cells. And so it could be that these salt-sensitive hormones like aldosterone, when they're up, they're driving insulin to be up. We know the opposite can be the case. High insulin can push up aldosterone. And so it's likely that it's going the other direction as well. Also, although they didn't measure it in this study, the, the catecholamines like epinephrine, or sometimes called adrenaline, those are, um, anti-diuretic hormones. They tell the body, they signal the body to keep salt and water. And it could be that, um, those are up. That epinephrine or adrenaline is up as it, once the person shifts to this low salt diet, basically the stress system, the sympathetic nervous system is telling the body, hey, we're not getting salt anymore, we've got to hold on to whatever we can. And when epinephrine goes up, epinephrine is an insulin antagonist among its many effects. It challenges what insulin's trying to do and thereby might be contributing to the insulin resistance that we see develop in the low salt group. So, in the end, that's just some speculation to explain the mechanism. But the reality of the situation is, our advice to cut salt, not our advice, the general, the dogmatic advice to cut salt, may have these unintended consequences of making insulin resistance even worse than it was before.
Definitely goes against, uh, everything that we've been told for so long. Yep. Yeah, it does. One of the other, idea, one of the other, another instance of dietary dogma, um, really leading to problems when the data just don't support it. Yeah. Well, hey, just real quick before we go to questions, uh, I'm glad you mentioned that, Ben, and I'll reiterate it. We are not your doctor. Always work with your doctor before doing any, making any changes in medications or anything that you're doing that might be different than what your doctor has suggested, suggested. We are not, we are scientists and nutrition coaches. So always consult with your doctor. Rich and Carly, any thoughts about about this study or about the, the salt in terms of the questions you get from our coached clients?
Solidifies what we've known. And, you know, it's going to take time to, to break down these, these barriers of, like Ben says, dogma. And they're tough. I mean, you look at statins and, and, and in that aspect, and I mean, just the general care of diabetes and heart disease, it's, it's going to be a, it's going to be a, it's going to be a hard, long battle. But we're in for the fight, though. And this is going to, I mean, I mean, these, these, uh, studies, you know, just one more thing that we can, we can look at. I think too, when you're on a low-carb protocol, it's hard because you have a few things working against you. You have this dogma that you've been told all your life to cut salt down. But you also know that in the past, you haven't needed to eat a lot of salt to feel good. So there's something different happening in your body when you're eating low carb that requires you to focus a little bit more on your salt intake and to get enough salt. And I think as far as like coaching, this is one of the things I think people don't easily grasp because it hasn't been part of their life before now. And they, and because of the dogma, they've been told to stay away from salt, they fear it a little bit. When you lower your insulin, your body naturally, like Ben said, when you have a lot of water, your body's going to hold on to salt. And when you lower your insulin, your body's going to flush both of those storages much more freely. So you have to be replenishing water, which is what you guys talked about yesterday on your stream, and also your salt intake, your sodium, and all your other electrolytes. And if you're not replenishing those, not only will you become more insulin resistant as the study showed, but you'll feel crummy. A lot of people will feel headaches, lightheadedness, dizziness, which all are the same kind of things you'll feel when your blood pressure is low. So that's a little tricky to figure out which is which, and they kind of correspond together. But also eventually, you'll start to see with your other electrolytes getting low, you'll start to see leg cramps or diarrhea, I mean, constipation, all sorts of things, brain fog, just general tiredness or lethargy you'll feel. And so many of our problems that we have when we eat low carb can be fixed by eating salt. Just increase your salt. So it's a good topic. And Ben, what's crazy is that, I mean, not to pick on doctors, but they'll, they'll load us with medicine and pills, but they want us to not have an electrolyte that's essential for life. Yeah. Yeah, that's right. Well, in the process, they're giving you pills that the bad dietary advice is making you have to take, you know, where to cut your salt and then and then take this insulin sensitizing medication to help offset what the cutting salt is causing or at least contributing to.
Well, Jack, what frustrates me so much as a coach is that like this study, we're going to, we're going to look at later on that talks about, you know, he goes through, you know, the effects of getting on a ketogenic diet and the very end he says, well, don't do it because it's going to stunt your growth, it's going to ruin your kidneys, it's going to kill you. And I'm just thinking, okay, wait a minute. We're telling our clients to eat real food, cut down on your sugar, be hydrated. I'm like, what the hell is happening here? Are people just freaking crazy? Yes. I mean, that's tonight. Yeah. Don't, don't eat real food, right? You know, don't cut down your sugar. But hey, come over here and have a statin and all this other crap I want to shove on your body. But don't, don't do this. Don't, whatever you do, don't change the actual source of the problem. Yeah. Yeah, don't do that. Exactly.
I know for me, uh, before I was eating a low-carb lifestyle, I never thought about salt. In fact, I didn't really salt my food very much anyway. I just never even thought about it. And if I don't take some salt, though, some salt tablets, I get leg cramps a lot. And, and if I do take a little bit of salt, I, they, I don't, as long as I'm hydrated. So. But Jack, what you should do is just eat processed food. That's way better for you. This is fine. Medications. [Laughter] Everyone says, everyone says they believe in science these days. Let's take a couple questions about salt. Rochelle.