Summary Magnesium: risks of deficiency, supplement options, cognitive and sleep benefits (AMA 54 sneak peek) (Youtube) www.youtube.com
3,166 words - YouTube video - View YouTube video
Peter Attia Hey, everyone. Welcome to the Drive podcast. I'm your host, Peter Attia.
n/a Peter, welcome to another AMA. How are you doing?
Peter Attia Good, man. How are you?
n/a Doing good. I think we have a good 1 Today, we get asked a lot about supplements. And I know it's not always your favorite subject to talk about, but We are actually dedicating this AMA to 1 type of supplement in particular, magnesium, which We get a lot of questions about I think there's a lot of confusion around. There's all these different types. There's all the different benefits.
n/a When do you use it? How much do you use it? How much is through food? How much is through an actual supplement? And so we decided to compile all of those together and really hit them today.
n/a And I think The reason if you're wondering why we're spending an entire AMA on it is it's 1 of the most common supplements for patients in your practice. So You place a lot of emphasis on it for yourself and for your patients. And because of that, we decided to talk about it in detail today. And I think What might be helpful as we start this process for people is at the simplest level, what is the role of magnesium in the body, And why does low magnesium matter? Why should people really care about this and listen to this full thing?
Peter Attia Everybody's heard of magnesium. As we'll talk about, there's no shortage of magnesium supplements out there. But in order to, I think, talk about this subject, intelligently, it does it does help to set the stage and and kind of get into all the things magnesium does. Now now the reality of it is Magnesium is is a cofactor, in at least 300 enzymatic systems in the body. It is very important as a cotransporter, for the movement of potassium and calcium across membranes.
Peter Attia I guess maybe I'll say a little bit about that in a moment. But first, let me just give the high level. The 3 big systems where I think magnesium matters the most is with respect to bone health, with respect to nerve transmission, and with respect to, glucose control and insulin metabolism. So, again, there are lots of things we could spend, easily 2 or 3 hours just talking about what magnesium does. We're not gonna do that.
Peter Attia We're gonna spend 3 minutes talking about that, but, those would be the big 3. So so again, like, what is magnesium? Right? So magnesium is a cation. That means it's a positively charged ion, so it has 2 positive charges.
Peter Attia And just like is a cation with 1 positive charge, and calcium is a cation with 2 positive charges. These things often have to move in opposition to each other. We'll talk in a moment with respect to nerve transmission. Let's let's start with bone health. So the bones, basically risk reflect the largest total body pool of magnesium.
Peter Attia So 60% of the magnesium in your body resides within your bones. And not surprisingly, therefore, magnesium deficiency, is a significant problem when it comes to bone health. So, Again, I wanna kinda keep this a little bit simple so that we don't get lost in the weeds, but bones are basically in a constant state of building and breaking. And, the the building cells are called osteoblasts. In med school, we remember that, b for building.
Peter Attia And, the the breaking cells are osteoclasts, and I don't know why I remembered that, but it was it seems somehow easier. So there's a balance between the osteoblasts and the osteoclasts. And obviously, if that balance moves too far in the direction of bone break down, you get osteopenia and ultimately, osteoporosis. It turns out that magnesium plays a very important role into that, both directly and indirectly. It plays a role in that directly through, the Upregulation and downregulation of osteoblasts and osteoclass.
Peter Attia It also plays a role in that indirectly through the metabolism of calcium, PTH, parathyroid hormone, and vitamin D. I'm not gonna say much more about that at the moment because that's not really the purpose of what we wanna do. I just wanna point out that magnesium deficiency is very bad for bones.
n/a And, Peter, real quick before continue on beyond bone health. For anyone who hasn't listened yet, AMA 37 was a AMA dedicated fully to bone health, It's important, all the different factors. So if you wanna learn more about that, that's another great resource for people to have.
Peter Attia Yeah. So so so let's go on to the 2nd the 2nd point, which is magnesium helps with glucose control and insulin metabolism. So Magnesium is involved in the regulation of insulin secretion in the pancreatic beta cells, in addition to the phosphorylation of the insulin receptor in the target cell. So, if if you recall, and we discussed this in great detail in the podcast with Jerry Schulman, when insulin hits the insulin receptor, that leads to an intracellular, kinase that phosphorylates, and ultimately leads to the movement of the, the the GLUT transporters that move across the cell membrane and allow glucose to flow in. And so metabolism, obviously, therefore, heavily impacted by that.
Peter Attia And and so in addition to, you know, increasing, glucose movement into the cell and facilitating the effects of insulin, I e, driving insulin sensitivity, It's also a cofactor in carbohydrate oxidation. There are a number of clinical studies, though not all of them that suggest that supplementing with magnesium and a magnesium rich diet can improve sensitivity and fasting glucose. This is gonna be a common theme in this podcast, which is that The extent to which magnesium can help in a given area, whether it be bone health or as we're talking about here with respect to metabolism, is largely a function of magnesium deficiency. In other words, the more deficient you are in magnesium, the more you will be helped by supplementing magnesium. Now We're gonna talk a lot about how to supplement magnesium and all of the different ways.
Peter Attia And I will tell you it's way more complicated, than than, I think most of us would realize. We'll also obviously talk about, you know, how do you know if you're magnesium deficient? And the the there's good news on the first question, not so great news on the second question. But Just to round out the why do we why should we care about magnesium, I would say the 3rd big bucket here is the effect that magnesium plays, in nerve transmission and muscle function. So magnesium is an antagonist of the NMDA receptor and a GABA agonist.
Peter Attia So If you think about how, nerve transduction works, imagine a couple of big proteins that sit, but, you know, spanning across the membrane of, of a cell, and they create a pore. Right? And the pore is what allows the ions that participate in the action potential to move. So, again, these things are like kind of taking stored energy in the form of the charges of the ion. And as they move 1 way across the channel, that creates a polarization of the cell, And it's the serial or sequential, firing of those action potentials that leads to signal transduction down a cell.
Peter Attia Well, it turns out that magnesium sits right smack in the middle of that receptor, and it must be removed for the excitatory signal to occur. So, when magnesium is deficient, this is a contributing factor to things like mood and other neurologic conditions, even potentially a con a a contributor to migraines. Again, we'll talk more about some of these applications later. But the point here again is that magnesium sits Very much in the center both literally and figuratively for a lot of the action as we think about, signal transduction, across across nerves, across muscles, and various other cells. Again, it all kinda factors into These the movement of these other cations I spoke about earlier, sodium, potassium, calcium, etcetera.
n/a You hinted that A 2nd ago, but I think it's now is a really good time to get to this question, which is for people who have listened to that and are now worried they have low magnesium. Are there certain symptoms or things that they can do to kinda know where they're at?
Peter Attia I'll just I'll just tell you a funny story. When I was in residency, There are certain things that you're measuring on hospitalized patients relentlessly. Okay? 1 of them is potassium. So potassium, you you measure that in the plasma, and, we cared greatly about what our patients or what our patients' potassium level was.
Peter Attia If it was too low or too high, it was problematic. If it was too high, it could be fatal. And and just to give you a sense of the narrow range in which we're looking at here, we're talking about, a normal physiologic potassium level might be between 3a half and 5 milliequivalents per liter. Don't worry about what the units mean, but the point is somewhere between 3.55, you know, units per liter. And, it's not uncommon in hospitalized patients that you have to replace pat potassium.
Peter Attia Well, if God forbid you replaced too much potassium, you got somebody up to 5a half or 6 milliequivalents per liter. The risk that you could throw them into a fatal heart rhythm was so significant That if you ever saw that value, even if you thought the lab made a mistake, you were immediately rechecking it and taking corrective actions. Similarly, if the levels are too low, you're going to see all sorts of typically, not as problematic and not necessarily fatal, but but other sorts of changes in in heart rhythm. Won't get into the whys of that because we're not really here to talk about potassium. But suffice it to say, you would not be replacing potassium in a patient without having measured the level first.
Peter Attia Now let's talk about magnesium. Most chief residents, when I was a junior resident, would scream at you if you ever measured a magnesium level in a patient with normal kidneys before giving them magnesium. The reason for it is twofold. 1, it costs more. You know, it's just it's It's not altering management, but more importantly, because we now understand and probably understood then if we were paying attention, that the The, the measurement of serum magnesium is not really indicative of total body magnesium, and you have an enormous buffer for overshooting.
Peter Attia So it's also true, by the way, that most of the potassium in a person is not in the extracellular space in the plasma. Most of it is in the cells. But because potassium and the difference between what's in the cell and out of the cell is a very important electrical gradient, if you Overshoot what's out of the cell a little too much. It can be fatal. That's not the case with magnesium because magnesium is not used to set the charge across the cell.
Peter Attia Okay. If you're sitting here listening to this saying, Peter, what the hell are you talking about? My only point here is, 1, we don't have great ways to measure magnesium. I will talk about how it's done. But 2, we don't tend to care about it very much clinically because unless a person's kidneys are really compromised And the kidneys become the acute place in where magnesium regulation happens.
Peter Attia We don't care about overdoing it. So with that said, there are basically a few ways to do this. Martin, you can measure plasma levels. And by the way, that's a test that's commercially available. I can honestly say I don't know the last time I've ordered it on myself or any of my patients, but it's you know, you can go to LabCorp or Quest or wherever and request that.
Peter Attia I think if you're really concerned about magnesium deficiency, though, you have to do these, other types of tests. So 1 of them is a urinary this is a test where you collect the urine that, is made over a period of time, say, 24 hours, and you look at the amount of magnesium in the urine, and that gives you a sense of magnesium deficiency. In other words, the less magnesium in the urine, the more likely the person is to be deficient. Why? Because it tells you, boy, those kidneys are really holding on to magnesium.
Peter Attia We have a sense of how much magnesium should come out of a person in a day in an, you know, state of quote unquote equilibrium. And if the amount of magnesium that's coming out is really low, well, you would you would surmise that that person truly has total body deficiency. The other way you do it is a more elaborate version of best test where you load the patient with magnesium. So you give them a huge IV bolus of magnesium, And then you also measure the urinary excretion. That's just a more involved test to do that.
Peter Attia And to be honest with you, I've never done either of those. It's possible that an endocrinologist might look to something like that. But again, it begs the point, which is in a person with normal renal function, You tend to on the side of assuming people are magnesium deficient. And if you have any reason to believe it based on symptoms and or signs. Right?
Peter Attia So low bone density, you know, preventricular contractions. So, you know, relatively benign skip heartbeats, things of that nature, cramps. That would be a very common thing that would give you reason to believe a person is magnesium deficient. We just go ahead and replace the magnesium anyway.
n/a Just to double click, you mentioned migraines a bit ago. Can you talk a little bit more about migraines and low magnesium? Because I think anyone who's Had migraines is willing to look at anything to help alleviate those.
Peter Attia Yeah. Earlier, I stated I hope I stated it correctly that Magnesium plays an important role in inhibiting, the the the glutamate, excitatory pathway of the NMDA receptor in the brain. And not surprisingly, migraines are associated with more excitation. So The thinking would be that if you are deficient in magnesium, you have less inhibition of an excitatory neurotransmission pathway, And therefore, you might see more, more migraines in people who are susceptible. So, looking back, we were able to find a 2016 meta analysis of all the RCTs that were done for acute migraines that, found that intravenous magnesium provided significant short term relief, I e, within 15 to 45 minutes and up to 24 hours post administration.
Peter Attia Now again, That's intravenous magnesium. We're gonna talk in a minute about oral magnesium, which is the way most people are gonna get magnesium. You know, it's unlikely that oral magnesium is going to be able to provide relief acutely for this, but intravenously and we're talking somewhere in the neighborhood of 2 to 4 grams Intravenously, again, I want you to keep that number in the back of your mind, 2 to 4 grams of intravenous magnesium, when we start talking about how much Oral magnesium you need to take to get that. Now oral magnesium treatments may reduce the frequency and the severity of attacks, but really provides, very little relief in the acute setting.
n/a What do we know about how common magnesium deficiency is? Because I think anyone who's listening is kind of curious, like, what are the odds this is going on with them?
Peter Attia Thank you for listening to today's sneak peek AMA episode of The Drive. If you're interested in hearing the complete version of this AMA, you'll want to become a premium member. It's extremely important to me to provide all of this content without relying on paid ads. To do this, our work is made entirely possible by our members. And in return, we offer exclusive member only content and benefits above and beyond what is available for free.
Peter Attia So if you wanna take your knowledge of this space to the next level, it's our goal to ensure members get back much more than the price of the subscription. Premium membership includes several benefits. 1st, comprehensive podcast show notes that detail every topic, paper, person, and thing that we discuss in each episode. And the word on the street is nobody's show notes rival ours. 2nd, monthly Ask Me Anything or AMA episodes.
Peter Attia These episodes are comprised of detailed responses to subscriber questions typically focus on a single topic and are designed to offer a great deal of clarity and detail on topics of special interest to our members, you'll also get access to the show notes for these episodes, of course. 3rd, delivery of our premium newsletter, which is put together by our dedicated team of research analysts. This newsletter Covers a wide range of topics related to longevity, and provides much more detail than our free weekly newsletter. 4th, Access to our private podcast feed that provides you with access to every episode, including AMA's, Sans, the spiel you're listening to now, and in your regular podcast feed. 5th, the Qualys, an additional member only podcast we put together that serves as a highlight reel Featuring the best excerpts from previous episodes of the drive, this is a great way to catch up on previous episodes without having to go back and listen to each 1 of them.
Peter Attia And finally, other benefits that are added along the way. If you wanna learn more and access these member only benefits, you can head over to peterattiamd.com Forward slash subscribe. You can also find me on YouTube, Instagram, and Twitter, all with the handle Peter Attia MD. Can also leave us review on Apple Podcasts or whatever podcast player you use. This podcast is for general informational purposes only and does not constitute the practice of medicine, nursing, or other professional health care services, including the giving of medical advice.
Peter Attia No doctor patient relationship is formed. The use of this information and the materials linked to this podcast is at the user's own risk. The content on this podcast is not intended to be a substitute for professional advice, diagnosis, or treatment. Users should not disregard or delay in obtaining medical advice from any medical condition they have, And they should seek the assistance of their health care professionals for any such conditions. Finally, I take all conflicts of interest very seriously For all of my disclosures in the companies I invest in or advise, please visit peter tiamd.comforward/about where I keep an Up to date and active list of all disclosures.