A guide to foods high in magnesium and potassium

From the desk of Robb Wolf

I’m a big believer in getting most of your nutrients from food. When thinking about electrolytes, this means eating plenty of foods high in magnesium and potassium. If you’re primarily supplementing these nutrients, you’re missing out on both the wonderful taste and <a href="https://academic.oup.com/ajcn/article/89/5/1543S/4596924" target="_blank" rel="noreferrer noopener">natural synergies of food</a>. That’s right: Your body tends to absorb nutrients better in food form. The omega-3s EPA and DHA, for instance, are <a href="https://pubmed.ncbi.nlm.nih.gov/30550388/" target="_blank" rel="noreferrer noopener">best absorbed</a> when consumed with fat. Food also contains a spectrum of compounds — tannins, flavanols, anthocyanins, and more — that exert antioxidant, anti-cancer, anti-inflammatory, and other beneficial effects. And while you can even supplement many of these compounds, the doses found in food are typically safer. Back to magnesium and potassium, I’m not advising against supplementation. It can definitely help, but it’s wise to prioritize dietary sources first. Let’s talk about each of these minerals a bit more, and then we’ll cover nutritional strategies. <h2>Why Magnesium Matters</h2> Without magnesium, your body would struggle to function. Why? Because magnesium <a href="https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5926493/#!po=11.8421" target="_blank" rel="noopener noreferrer">serves</a> as a cofactor for over 300 enzymatic reactions, which are critical for daily functioning. Producing ATP (cellular energy), breaking down body fat, synthesizing DNA, and repairing DNA are just a few examples. Many more reactions depend upon magnesium too. Magnesium also proves useful as an electrolyte, a charged mineral that conducts electricity in various bodily fluids. Electrolytes like <a rel="noopener noreferrer" href="https://drinklmnt.com/blogs/health/is-sodium-good-or-bad-for-you" target="_blank">sodium</a>, <a href="https://science.drinklmnt.com/electrolytes/potassium/" target="_blank" rel="noreferrer noopener">potassium</a>, <a href="https://science.drinklmnt.com/electrolytes/calcium/" target="_blank" rel="noreferrer noopener">calcium</a>, and <a href="https://science.drinklmnt.com/electrolytes/magnesium/" target="_blank" rel="noreferrer noopener">magnesium</a> all share the vitally important function of enabling cellular communication. Magnesium is especially important for regulating the electrical activity of the heart. When magnesium status falls, cardiac arrhythmias, heart palpitations, and other electrical disturbances <a rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5786912/" target="_blank">may follow</a>. Other <a rel="noreferrer noopener" href="https://science.drinklmnt.com/electrolytes/magnesium-deficiency-symptoms/" target="_blank">symptoms of magnesium deficiency</a> include weakness, fatigue, <a rel="noreferrer noopener" href="https://science.drinklmnt.com/did-you-know/what-causes-muscle-cramps/" target="_blank">muscle cramps</a>, hypertension (high blood pressure), increased inflammation, kidney stones, osteoporosis (brittle bones), and more. On the flipside, magnesium sufficiency brings many benefits. Some examples will help illustrate: <ul> <li>First, <a href="https://drinklmnt.com/blogs/health/electrolytes-and-heart-health" target="_blank" rel="noopener noreferrer">heart health</a>. Magnesium <a href="https://www.nature.com/articles/1601689" target="_blank" rel="noopener noreferrer">suppresses</a> needless inflammation and <a href="https://pubmed.ncbi.nlm.nih.gov/29793664/" target="_blank" rel="noopener noreferrer">regulates</a> calcification, clotting, and blood vessel relaxation. All are crucial for cardiovascular longevity.</li> <li>Second, <a href="https://science.drinklmnt.com/did-you-know/osteoporosis/" target="_blank" rel="noreferrer noopener">bone health</a>. Higher intakes of magnesium (and potassium, by the way) are <a rel="noopener noreferrer" href="https://pubmed.ncbi.nlm.nih.gov/10197575/" target="_blank">correlated</a> with better bone mineral density.</li> <li>Lastly, higher intakes of magnesium are also linked to <a href="https://science.drinklmnt.com/electrolytes/magnesium-for-sleep-and-anxiety/" target="_blank" rel="noreferrer noopener">better sleep</a> and lower rates of <a style="font-size: revert; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen-Sans, Ubuntu, Cantarell, 'Helvetica Neue', sans-serif;" rel="noopener noreferrer" href="https://pubmed.ncbi.nlm.nih.gov/17645588/" target="_blank">diabetes</a>, <a href="https://science.drinklmnt.com/electrolytes/magnesium-for-anxiety-and-depression/" target="_blank" rel="noreferrer noopener">anxiety</a>, and <a style="font-size: revert; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen-Sans, Ubuntu, Cantarell, 'Helvetica Neue', sans-serif;" rel="noopener noreferrer" href="https://pubmed.ncbi.nlm.nih.gov/19085527/" target="_blank">depression</a>. From <a style="font-size: revert; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen-Sans, Ubuntu, Cantarell, 'Helvetica Neue', sans-serif;" rel="noopener noreferrer" href="https://drinklmnt.com/blogs/health/magnesium-for-anxiety-and-depression" target="_blank">mood</a> to sleep to blood sugar regulation, magnesium affects it all.</li> </ul> For a deep dive on magnesium benefits, check out <a href="https://drinklmnt.com/blogs/health/magnesium-benefits-and-best-sources" target="_blank" rel="noreferrer noopener">this article</a>. Time to switch gears to potassium. <h2>Why Potassium Matters</h2> Most people don’t get enough potassium. Only <a href="https://www.ncbi.nlm.nih.gov/books/NBK545438/#:~:text=The%2075th%20percentile%20of%20usual%20potassium%20intake%20exceeds%20the%20potassium%20AI%20for%20most%20adult%20DRI%20age%2C%20sex%2C%20and%20life%2Dstage%20groups%2C%20indicating%20that%20between%20one%2Dquarter%20and%20one%2Dhalf%20of%20U.S.%20and%20Canadian%20adults%20exceed%20the%20AI%20(see%20Table%207%2D4)." target="_blank" rel="noreferrer noopener">20–40%</a> of the population meets the National Academy of Medicine’s <a href="https://www.ncbi.nlm.nih.gov/books/NBK587683/" target="_blank" rel="noreferrer noopener">adequate intake</a> of 3.4 grams for men and 2.6 grams for women. And “adequate” doesn’t exactly mean “optimal.” To my eye, the <a href="https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC6181280/" target="_blank" rel="noopener noreferrer">evidence</a> for potassium intakes between 3.5–5 grams per day is strong. Getting enough potassium can reduce the risk of high blood pressure (hypertension) and kidney stones. Like magnesium, potassium powers your nervous system as an electrolyte. Potassium is also crucial for maintaining the distribution of water in your body. This is called maintaining fluid balance, and it’s the goal of <a href="https://drinklmnt.com/blogs/health/how-to-stay-hydrated" target="_blank" rel="noopener noreferrer">healthy hydration</a>. Potassium works together with sodium to regulate your blood volume, a chief determinant of blood pressure. If you’re deficient in either mineral, blood pressure goes up. Along these lines, the hallmark of potassium deficiency is <a rel="noopener noreferrer" href="https://drinklmnt.com/blogs/health/does-potassium-help-lower-blood-pressure" target="_blank">elevated blood pressure</a>. And high blood pressure is a <a rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC6477925/" target="_blank">well-established</a> heart disease (and dementia) risk factor. Another consequence of low potassium intake is more calcium in the urine, which <a rel="noopener noreferrer" href="https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/" target="_blank">raises the risk</a> of kidney stone formation. Potassium is also crucial for bone health. Again, lower intakes <a rel="noopener noreferrer" href="https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/" target="_blank">can create</a> a higher risk of osteoporosis. Anyways, there’s no downside to getting enough dietary potassium and magnesium — and there’s plenty of upside. Let’s see which foods unlock that upside for you. <h2>Foods High in Magnesium and Potassium</h2> Here’s how we’ll do this. First I’ll cover foods high in each electrolyte, then I’ll cover foods high in both electrolytes. <h3>Magnesium-Rich Foods</h3> The trick to getting enough magnesium is to eat dark leafy greens. Greens are green because they contain chlorophyll, and magnesium sits at the center of the chlorophyll molecule. Nuts, seeds, and some grains are also high in magnesium, but these foods contain a compound called phytic acid that <a href="https://pubmed.ncbi.nlm.nih.gov/25694676/" target="_blank" rel="noopener noreferrer">inhibits</a> mineral absorption. The magnesium from leafy greens is more bioavailable. With that in mind, here’s a list of <a href="https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/" target="_blank" rel="noopener noreferrer">magnesium-rich foods</a>: <ul> <li>Spinach (157 mg per cup)</li> <li>Swiss chard (151 mg per cup)</li> <li>Beet greens (98 mg per cup)</li> <li>Sunflower seeds (114 mg per cup)</li> <li>Pumpkin seeds (190 mg per ¼ cup)</li> <li>Summer squash (43 mg per cup)</li> <li>Black beans (120 mg per cup)</li> <li>Edamame (100 mg per cup)</li> <li>Brown rice (84 mg per cup)</li> <li>Soymilk (61 mg per cup)</li> <li>Baked potato (43 mg per 3 ounces)</li> <li>Avocado, cubed (44 mg per cup)</li> <li>Broccoli (24 mg per cup)</li> </ul> <h3>Potassium-Rich Foods</h3> Fruits, vegetables, and meat are all high in potassium. Here’s a list of <a href="https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/" target="_blank" rel="noopener noreferrer">potassium-rich foods</a>: <ul> <li>Dried apricots (2,202 mg per cup)</li> <li>Avocado (690 mg per avocado)</li> <li>Banana (422 mg per banana)</li> <li>Cantaloupe (428 mg per cup)</li> <li>Spinach (271 mg per cup)</li> <li>Asparagus (271 mg per cup)</li> <li>Tomato (292 mg per tomato)</li> <li>Potato (610 mg per medium potato)</li> <li>Lentils (731 mg per cup)</li> <li>Salmon (624 mg per 6 ounce filet)</li> <li>Chicken breast (332 mg per 3 ounces)</li> <li>Beef (315 mg per 3 ounces)</li> <li>1% milk (366 mg per cup)</li> </ul> <h3>Foods High In Both Magnesium and Potassium</h3> If you want a double dose of these electrolytes, eat dark leafy greens. Spinach in particular is an excellent source of both magnesium and potassium. But don’t forget fruits (avocado, banana, apple), starchy vegetables (potatoes, yams, carrots), legumes, and meat and fish like chicken, beef, and salmon. Depending on your carb tolerance, budget, and digestive health, consider dabbling in each of these categories to reach your daily magnesium and potassium targets. <h2>How To Assess Magnesium and Potassium Status</h2> It’s good to know which electrolyte-rich foods to target. But how do you know you’re getting enough electrolytes overall? The first step is to conduct a dietary analysis. Use an app like <a rel="noopener noreferrer" href="https://cronometer.com/" target="_blank">Cronometer</a> to log your meals, review the results (it automatically calculates micronutrient status), and adjust accordingly. Ideally, you’re shooting for 3.5–5 grams of potassium and 400–600 mg of magnesium daily. If you’re a little short, that’s okay — supplements can fill the gap. But if you’re very short, review the food list and make adjustments. The other data point is how you feel. This can be tricky to unpack because magnesium and potassium deficiencies often present asymptomatically. Are you experiencing symptoms? And if so, are they characteristic of magnesium or potassium deficiency? If your blood pressure is mildly elevated, that could be a potassium issue. If you’re weak, fatigued, or crampy, magnesium could be the culprit. But if you feel okay, it doesn’t necessarily mean you’re in the clear. That’s why I favor the food log in this analysis. What about <a href="https://drinklmnt.com/blogs/health/how-to-test-electrolyte-status" target="_blank" rel="noopener noreferrer">blood electrolyte levels</a>? It’s a common misconception that they reflect nutritional status. Let me clear that up. They don’t. Serum levels are too important to let fall. Life-critical functions depend on them. So when blood electrolytes are low — or if you simply don’t consume enough electrolytes — your body pulls them from bone to normalize serum levels. As you can imagine, that’s bad news for bone health. The important takeaway is that you won’t learn whether or not you are <a href="https://drinklmnt.com/blogs/health/electrolyte-imbalance-or-deficiency" target="_blank" rel="noopener noreferrer">electrolyte deficient</a> from a blood test. But your body will notice it months or years down the road. <h2>Getting Enough Magnesium and Potassium</h2> Getting enough magnesium and potassium involves two steps: <ol> <li>Consume plenty of foods high in magnesium and potassium</li> <li>Supplement to make up for any shortfalls</li> </ol> For step 1, green vegetables are your best friend. Fill your plate with spinach, chard, and kale and you’ll be in the top 1%. Yet you still might fall short of your targets. We did – which is why we chose to include 200 mg potassium and 60 mg magnesium (along with a 1000 mg hit of sodium) in each stick of <a rel="noopener noreferrer" href="https://drinklmnt.com/products/lmnt-recharge-electrolyte-drink" target="_blank">LMNT</a>, our zero-sugar electrolyte drink mix. We carefully formulated LMNT to get folks closer to their electrolyte needs. The ultimate goal was to help folks stay hydrated for better performance and overall <a rel="noopener noreferrer" href="https://drinklmnt.com/blogs/health/do-electrolytes-give-you-energy" target="_blank">energy</a>. You don’t need to use LMNT, of course. You can supplement ad hoc or <a rel="noopener noreferrer" href="https://drinklmnt.com/blogs/health/the-best-homemade-electrolyte-drink-for-dehydration" target="_blank">make electrolyte home brews</a>. The important thing is to get enough electrolytes. Do that and you’ll be well-positioned to feel and function your best.