Have you heard recently that magnesium can cure your insomnia and calm your anxiety? Have you wondered if this is true? Today we’ll discuss all things magnesium from its discovery, ancient and current uses, its different forms, and whether this mineral really is a miracle cure!
M: I’m Professor Megan
S: and I’m Professor Susan, and we’re
Both: Your Nutrition Profs!
M: We are registered dietitians and college professors who have taught more than 10,000 students about health and nutrition. We have answered a LOT of questions about nutrition over the years –
S: Some questions we get asked every year and some are rarely asked but very interesting.
M: We’re here to share our answers to these common (and uncommon) nutrition questions with you.
S: So bring your curiosity and let’s get started.
Both: Welcome to our class!
M: Hey Susan, have you heard the news?
S: News– what news?
M: About magnesium! Apparently it can help you sleep better, reduce depression and anxiety, and improve exercise performance.. all sorts of amazing things!
S: Wow! Magnesium has been all over the news and social media lately.
M: And as of last year the #magnesium hashtag has more than 1 Billion views on TikTok.
S: Whoa!
M: Yeah, I’ve seen posts espousing the benefits of magnesium for all kinds of things, mostly anxiety and sleep.
S: I’ve actually seen some suggesting magnesium as a treatment for long COVID.
M: Wow.
S: Have you seen that one?
M: No…
S: Diabetes–
M: Yes…
S: It can treat diabetes, hypertension, and it’s even good for weight loss.
M: Yeah, I’ve heard those too.
S: You got to love the internet.
M: But are these claims true? That is the question we’re answering today: Is magnesium really a magical cure for all these maladies?
S: I hope so, that would make things easy.
S: But, let’s give a little bit of background about magnesium. It’s a mineral. It’s the 7th most abundant element in the earth’s crust and the 8th most abundant element in the universe. But it’s never found free in nature. It’s always hooked to something. And it’s commonly found in rocks like dolomite and canallite, it’s found in seawater and, of course, it’s found in living organisms, like us.
M: So how was magnesium discovered? Joseph Black, a Scottish chemist first proposed magnesium as an element in 1755.
S: But it was British chemist Sir Humphrey Davy in 1808, who first isolated pure magnesium. He named it magnium after the mineral magnesite, which is found in Magnesia. Wow, say that 10 times fast. Magnesia is a district of Eastern Thessaly in Greece. But magnium eventually came to be called magnesium.
M: And if it's been a while since you took chemistry, you may be wondering, how is magnesium a metal? I mean, we don’t go around eating large chunks of metal, right?
S: Right, I hope not. Well magnesium exhibits metallic properties, and that’s what makes it a metal. So it specifically, is an alkaline earth metal. So it’s recognized as an essential nutrient at the same time because the human body requires it for various functions... And we’re going to talk a lot more about those functions in just a bit.
M: So as we said, magnesium is an alkaline earth metal. Other elements in this category include calcium, barium, and radium.
S: Magnesium is also very lightweight and often you’ll see it combined with aluminum to form alloys. And these alloys are strong but malleable. So you can find magnesium-aluminum alloys in things like cars, airplanes, lightweight luggage, power tools, and even cameras.
M: And we can’t forget about all the different types of magnesium. For example there’s magnesium oxide also known as magnesia. It’s used in antacids to treat heartburn and GERD. It’s even used as a laxative… ever hear of milk of magnesia?
S: I have and we mentioned it in our ulcers episode a few weeks ago. There’s also magnesium sulfate, better known as Epsom salt and that's used for so many things!
M: Another type, magnesium carbonate is used in some types of paints and inks and it’s added to table salt to prevent caking.
S: And magnesium fluoride is applied to optical lenses to help reduce glare and reflections.
M: So many diverse, but important uses!
S: Oh my gosh, I knew magnesium was important, but honestly, until we really researched this episode I didn’t realize it was so versatile and such an amazing element.
M: I agree. So let's get back to nutrition.
S: Yes since that’s what this podcast is about– we’ll talk about some nutrition. OK. It is estimated that there are 4-6 tsp of magnesium in the human body. So a teaspoon is about the size of the top third of your pinkie finger – so 4-6 of those. It’s our fourth most abundant mineral after calcium, phosphorus, and potassium.
M: Magnesium has been recognized for its therapeutic effects for thousands of years.
S: The ancient Greeks and Romans believed magnesium had healing properties and they incorporated its use into their medical practices, including as a laxative, kind of like we do.
M: In the early 1600s, a farmer, Henry Wicker, in Epsom, England attempted to give his cows water from a local spring but the cows refused to drink. Apparently the water was quite bitter. It was also observed that animals who waded in this spring would experience faster wound healing. Once the water was evaporated the substance that remained became known as Epsom salts!
S: So that water was magic?
M: Yes.
S: Wow! So, soon, a facility was built for “convalescents” that eventually became a “spa resort”. So like a spa in the 1700s, that’s so cool! Visitors would either drink the water to improve several disease conditions from gout to its purgative or laxative effects.
M: Unfortunately, the spring dried up by the early 1700s.
S: Oop, too bad.
M: I know… the magic’s gone. But epsom salt began to be manufactured commercially by the 1750s.
S: I actually got a recipe from my Dad several years ago and it’s for weed killer that uses epsom salts, vinegar, and dish soap to be honest, it works pretty well!
M: My mom always had me soak small cuts or wounds in epsom salt and even help with muscle cramps… As a kid, if I complained about what felt like anything, my mom’s response was “soak it in epsom salt.” If you’d like to learn a bit more about epsom salt and its purported benefits, check out the blog on our website.
S: Wow, I’m really loving this episode!
M: Me too. So magnesium is really again being touted almost as a cure all just like back in the 1700s
S: You know I’m not really sure about “cure all” but magnesium is extremely important for a number of functions in the body.
M: Yes, it’s required to activate vitamin D and to help more than 600 enzymes carry out a wide variety of biochemical reactions, from building protein and bones to regulating your blood pressure and nerve functions.
S: Magnesium serves as a cofactor in numerous chemical reactions within the body. And the term "cofactor" is a sciencey word that is used to describe a compound that is essential for helping an enzyme carry out a chemical reaction.
M: And every organ in the body needs magnesium. It’s required for energy production (turning our food into usable energy) as well as DNA and RNA synthesis and repair.
S: It is also necessary for muscle contraction, maintaining a normal heart rhythm, and regulating our neurotransmitters. So all in all, it’s a pretty important mineral. And since it’s considered essential nutrients that means we have to eat it or drink it.
M: Fortunately it is found in a wide variety of foods but plants high in fiber seem to be the best source. So these are foods like leafy greens, beans so like black beans, pinto beans, or soybeans, potato, and brown rice.
S: Nuts and seeds are also good sources. An ounce of pumpkin seeds which is basically a handful provides almost 40% of your daily magnesium needs and a handful of chia seeds provides almost 30%.
M: And for animal sources your best bet is fatty fish. There is a tiny bit in meats and poultry, but they’re not considered very great sources.
S: You can also find magnesium in water as we spoke about earlier, but the amount can vary widely by source, whether it’s tap water, mineral water, or bottled water, and brand makes a difference too.
M: And it’s found in fortified foods and some dairy products.
S: So how is it used medically? I mean, have you seen it used in the hospital where you work Megan?
M: Yeah, I’ve seen it given primarily through IV for things like really severe malnutrition, kidney disease, even to cardiac patients with arrhythmias.
S: I’ve also read that magnesium is also given to women with preeclampsia, which is a condition that can occur in the later stages of pregnancy that involves a sudden rise in blood pressure and this can lead to seizures. I’ve also seen it can also be given for severe asthma as a sort of last resort when conventional treatment doesn’t work.
M: And as we've mentioned earlier, it also works for constipation. Milk of magnesia, right? Well it works by drawing water into the intestines and softening the stool and it should help you “go” within 30 minutes to an hour.
S: That could be a miracle… What about just regular chronic use for other conditions? We’re going to talk about those for which there may be some evidence. And let’s start with blood pressure.
M: A large clinical study of over 8000 women found that higher magnesium intake from food was associated with decreased risk of high blood pressure or hypertension.
S: In fact, magnesium has a qualified health claim from the FDA related to blood pressure. And if you saw it on a dietary supplement, it may say something on the side panel or somewhere on the bottom, on the back. It’ll say something like: “Some scientific evidence suggests that diets with adequate magnesium may reduce the risk of high blood pressure (or hypertension), a condition associated with many factors. The FDA has concluded that the scientific evidence supporting this claim is inconsistent and not conclusive.”
M: So there’s some evidence, but it’s not very strong evidence.
S: Exactly, that’s a qualified health claim. So if you have high blood pressure, like me, I would not expect magnesium supplements to “cure” it unfortunately…
M: Unfortunately… Ok not to come out of left field but…Susan, when you ask your students to name some nutrients that are important for bone health? What– what do they typically tell you?
S: Well the first thing everybody, you know, bursts out with is calcium.
M: Absolutely.
S: Of course. And then a few of the better students will say oh vitamin D…
M: Which is, of course, true. But magnesium is also very important for our bones. More than 50% of the body’s magnesium is stored in the bones. It helps with building bone but also with regulating calcium levels.
S: There’ve actually been some observational studies that suggest that those who consume magnesium rich foods have greater bone density. But clinical trials have had mixed results regarding whether taking supplements will improve bone density or reduce your risk of fractures.
M: So for both of these, the high blood pressure and bone, the research supports the importance of adequate magnesium intake from food, but not necessarily from supplements. But, there doesn’t seem to be much evidence that more is better.
S: Right. And the same is true for those with type 2 diabetes. If you’re not getting enough magnesium in your diet, increasing your intake may improve your symptoms and reduce insulin resistance. But unfortunately, it won’t “cure” your diabetes either..
M: Yeah, well let’s talk about something I struggle with… headaches. I’ve seen posts all over Tik Tok and Instagram about how magnesium can cure headaches, even migraines.
S: Yeah, I’ve seen that too. And there actually is a little bit of evidence for that!
M: Nice.
S: Amazing, right? Magnesium citrate and magnesium oxide supplementation has been shown to be protective against migraines in randomized double-blind controlled trials (also known as RCTs).
M: Yes, and remember, RCTs are the gold standard in research.
S: So that’s pretty good evidence.
M: Yeah.
S: What about depression and anxiety? I’ve seen a lot of things for that too.
M: Yeah, I think this is the most popular one I’ve seen recently. Well in my research I found a small study of 126 participants reported improved depression symptoms after 6 weeks of magnesium chloride supplementation.
S: But just 126 participants? That doesn’t seem like it would be very generalizable to the whole population.
M: Probably not. Another study found that magnesium supplementation improved depression in, get this, patients with magnesium deficiency…. So, no surprise there.
S: Right, it makes complete sense that if you have a documented low magnesium level and you bring tha level up to normal that your symptoms would improve.
M: Absolutely.
S: And those kind of benefits, if you brought your magnesium levels into the normal range–that would be– you'd have more benefits than just for depression and anxiety.
M: True. And a review of 18 studies evaluating magnesium on anxiety and stress, found that although some suggested benefits, they were for the most part, poor quality. So things like small sample sizes, short intervention length, lack of a placebo, and even just a wide variety of dosage and forms.
S: So clearly more research is needed. So it may (emphasize the may) help with mild anxiety and depression, especially if you are already low in magnesium, but it doesn’t seem to help if your symptoms are severe.
M: Ok but what about better sleep? Can magnesium help with insomnia? If you believe the hype on social media it can.
S: Unfortunately…
M: Oh no!
S: Oh no! …the scientific evidence is, again, pretty weak. Some studies show that those who consume a magnesium-rich diet sleep better, but these people might also have other good habits like exercising regularly which can also benefit sleep. So it can’t be attributed to this one mineral.
M: So a few small studies have shown some benefit, but when they do rigorous randomized control studies (remember the gold standard)--
S: Those RCTs!
M: Yeah, they don’t see very many sleep benefits from magnesium supplementation.
S: So it seems like we can ignore the hype for magnesium and sleep… at least for now.
M: Yeah. There are many other supposed benefits to taking magnesium from improved exercise performance and recovery to a reduction of PMS symptoms to treatment for long-COVID even fighting inflammation, treating fibromyalgia and chronic fatigue syndrome, so many things. But again, for most of these the evidence is weak.
S: So that was an overview of known and claimed benefits of magnesium. The evidence is best for headaches, not too bad for blood pressure, but the rest– the evidence is pretty weak.
M: And that's referring to supplementation.
S: Right, Right, but clearly, magnesium is an important mineral, how much do we actually need to get?
M: So men need about 400 mg and women need about 320 mg per day, and during pregnancy that goes up a little bit.
S: Some studies, I’ve seen, suggest that about half of Americans are consuming less than the recommended amount.
M: But remember, the human body, especially the kidneys, adjust our storage and excretion helping to regulate our magnesium levels.
S: Wow, I mean to me, the human body is so incredible.
M: It really is. Because of this ability to regular itself severe magnesium deficiency is pretty rare. Even more rare is deficiency so severe that it causes obvious symptoms. The sciencey word for magnesium deficiency is hypomagnesia. Remember “hypo”means low.
S: Severe deficiency is really rare. Mild deficiency may be a little bit more common. I mena, for one thing, as food is processed, as much as 85% of the magnesium can be lost. I mean, even just cooking or boiling produce can significantly reduce magnesium.
M: Yeah, diet definitely plays a role.
S: But there are other reasons a person may be at risk for magnesium deficiency. Certain medications like some antibiotics, diuretics, if you’re on chemotherapy, if you’re taking immunosuppressants, or you’re using proton pump inhibitors if you have GERD or ulcers like we discussed previously in another episode. All of those things might increase your risk of being deficient in magnesium.
M: And you may also be at high risk if you have intestinal conditions such as Crohn’s disease, ulcerative colitis, or celiac, also if you chronically abuse alcohol.
S: Or if you have insulin resistance or type 2 diabetes you may actually excrete more magnesium than normal, so that would also put you at higher risk for deficiency.
M: And as we age we don’t absorb vitamins and minerals as well from the foods we eat. So older adults may also be at an increased risk of magnesium deficiency.
S: Magnesium absorption from foods also varies quite a bit. If you’re taking high dose zinc supplements or if you go crazy and greatly increase dietary fiber intake, these can decrease magnesium absorption. On the other hand, there’s some evidence that vitamin D may improve magnesium absorption and retention.
M: So with all these possible risk factors, how would you know if you’re deficient in magnesium?
S: Well you probably wouldn’t.
M: Oh no!
S: Symptoms of mild hypomagnesia are pretty generic and non-specific. So just things like loss of appetite, nausea, vomiting, fatigue, and weakness.
M: You can do a blood test to determine your serum magnesium levels, but it’s not considered part of any routine blood panel.
S: And unfortunately blood levels of magnesium really don’t reflect your actual body levels very well cause remember, almost all of your magnesium is in body cells. 99% of your magnesium is stored in bones, muscle, and soft tissues. So unless blood levels are super low, you wouldn’t really know for sure if you were deficient in magnesium.
M: So what should we do? Well we recommend putting the focus on your diet. Based on the research studies we mentioned, if you eat a well rounded diet including lots of veggies and leafy greens, nuts and seeds, soybeans or soy milk, and fatty fish you should be OK.
S: I feel like that’s true for a lot of things! That sounds like a really healthy diet.
M: That’s what we’d recommend for everybody.
S: Right. But if you eat primarily fast food or highly processed food, or if for some reason you aren’t able to eat enough food, then you may need to supplement.
M: But, there are about a dozen forms of magnesium supplements to choose from. And the form can affect the bioavailability and dissolvability. So you can find them in capsules, liquids, lotions, soaks, sprays even. Liquid magnesium supplements, however, seem to be better absorbed than some of these other forms.
S: So, probably the most bioavailable and most common magnesium supplement sold is magnesium citrate. This is magnesium that is stuck to citric acid and it’s found naturally in citrus fruits. This type of magnesium’s particularly helpful as a laxative used to treat constipation and it’s also one of the forms recommended for migraines.
M: But there’s also magnesium aspartate, magnesium lactate, magnesium chloride, and magnesium malate that are considered to be more bioavailable than certain other forms like magnesium oxide which is the other form recommended for migraines. So magnesium malate is often recommended for muscle aches and fatigue.
S: And then there is our friend epsom salt, or magnesium sulfate. You can take capsules or you can dissolve it in water and drink it to treat constipation. And of course, it’s often used externally to soothe muscles and to treat wounds. But it’s not very well absorbed and has low bioavailability, so if you need something for constipation, you’re better off going with magnesium citrate, then magnesium sulfate.
M: Magnesium L-threonate has been all over social media lately.
S: Yeah, it has.
M: Yeah, this is probably the most popular one right now. This form is highly bioavailable and is unique in that it crosses the blood brain barrier. It’s thought to increase magnesium concentrations in brain cells, although this has really only been found in animal studies.
S: One small study of just over 100 adults found that supplemental magnesium L-threonate… it did improve memory and cognition compared to the placebo so there is some hope that it may be beneficial for certain brain disorders. But more research is definitely needed…. Are you seeing a theme here?
M: Oh, absolutely. Alright, there’s also magnesium glycinate. It combines magnesium and the amino acid glycine and is also considered fairly easily absorbed. It’s another supplement that is sometimes recommended for– specifically for symptoms of anxiety and depression.
S: So this was just a small sample of the forms of magnesium supplements that you can find out there. And if it’s making your head spin, you are not alone. I mean, you practically need a degree in biochemistry to figure it all out!
M: Absolutely, and that’s why we recommend seeing a physician or registered dietitian to get more information if you need to be taking magnesium.
S: Oh definitely, good– that's good advice.
M: So even if magnesium doesn’t do all these wonderful things that are claimed because it’s a mineral and “all natural” that means it’s perfectly safe to take, right?
S: No….not necessarily.
M: There is an upper limit to how much magnesium (from supplements) we should take…
S: So remember the RDA for magnesium for men is about 400 mg/day and for women is just over 300 mg/day. The upper limit for magnesium is 350 mg for everybody over the age of 18!
M: So you be like “Whoa, whoa, whoa wait! The RDA for men is more than that! How is that possible?” Well–
S: And that's an excellent question.
M: Exactly. That is because the upper limit only applies to supplemental use.
S: Right, I mean, you have to be careful to not go crazy with supplements because that extra magnesium from supplementation can interfere with some medications. Meds like digoxin, which is a heart medication, it can interfere with some antibiotics, and some medications for osteoporosis, thyroid or kidney disorders, and HIV.
M: And since one of its most common uses is for constipation, there are some gastrointestinal side effects to watch for like abdominal cramping and diarrhea. Particularly from magnesium carbonate, chloride, gluconate, and oxide forms.
S: But remember the human body manages the magnesium obtained from food very well, so excess amounts from food are excreted in urine, but it’s not particularly true for supplements. There is the possibility for toxicity. So the extra magnesium can sort of override the body’s natural function of excreting extra.
M: Yes. So that’s why we have an upper limit for those very reasons.
S: If you are taking a whole bunch of magnesium supplements, watch for signs of toxicity like low blood pressure, nausea, vomiting, urine retention, muscle weakness, difficulty breathing, and even cardiac arrest.
M: But the good news is that the most severe toxic effects only occur when intake exceeds 5000 mg/d and that’s 14 times the upper limit of 350.
S: Oh my gosh, I hope nobody’s taking that much magnesium!
M: Oh absolutely, and remember guys, all of the other possible risks with taking supplements.
S: Right.
M: Those are things you should consider as well.
S: Mmm-hmmm.
M: Ok, so we’ve shared a lot of information about magnesium today. Let’s bottom line it.
S: Ok, bottom line. Magnesium is an essential mineral that plays many important roles in the human body including protein synthesis, bone formation, and enzyme action.
M: It’s found in a wide variety of whole foods including legumes, nuts, seeds, whole grains, and leafy green vegetables. It’s also found in many fortified foods, such as fortified breakfast cereal, and several dairy products.
S: The human body does an amazing job of regulating magnesium by modifying absorption and excretion in urine as needed.
M: There are some medical reasons to take magnesium such as constipation, some heart conditions, and migraines. There are also several popular claims about magnesium benefits including improving symptoms of depression, anxiety, and insomnia.
S: But… there’s always a but.
M: Yep.
S: Those definitely need more rigorous scientific research to determine whether or not those claims are actually true. The current science really has not convinced us.
M: And you could take supplements but there are so many different forms on the market to choose from and the bioavailability and use vary widely.
S: So will magnesium cure all your ailments? No. Should you take magnesium supplements? Maybe… But if you think you’re deficient in magnesium or need some more, your best bet is to consume more magnesium-rich foods.
M: That’s good advice for everyone!
S: It is! So that’s it for our deep dive into magnesium. Join us next time when we will answer the question: what is the deal with body mass index?
Both: Class dismissed.
S: We hope you enjoyed this episode. You can find the show notes and a list of sources on our website, yournutritionprofs.com.
M: Your homework is to follow us at your nutrition profs on Instagram and to listen to our next episode. You can listen on Amazon Prime, Apple Podcasts, Spotify, YouTube, or anywhere podcasts are found. We’d appreciate it if you’d “like” us, write a review, subscribe, and invite your family and friends to join us too.
S: If you have a nutrition or health question you’d like answered, let us know! We may even do a show about it! Send an email to [email protected] or click on the “Contact Us” page on our website.
M: Thanks to Brian Pittman for creating our artwork. You can find him on instagram @BrianPittman77
Both: See you next time!