Have you been feeling anxious, stressed, or just plain out of it lately? Before you reach for a glass of wine, let us introduce you to another relaxing substance, namely nature’s power house: magnesium.
While we’ve seen the benefits of vitamins and minerals like calcium, vitamin C, and vitamin D touted for years, magnesium is finally having its moment. It turns out that this nutrient is quite the multitasker: It may help with everything from easing muscle soreness to calming your nerves to helping you sleep. If you’re a fan of TikTok, you may also have noticed that its boost in popularity has influencers promoting everything from magnesium pills to magnesium flakes to magnesium oil. But is the power of magnesium magic or myth? To get to the bottom of things, we asked hematologic oncologist Urvi Shah, MD, at Memorial Sloan Kettering Cancer Center (MSK) to tell us what exactly magnesium can — and cannot — do for our health, and the impact it could have on people with cancer.
What is magnesium, anyway? And what does magnesium do for the body?
Magnesium is an essential nutrient that plays a major role in disease prevention and overall health. “It’s important for more than 300 enzymatic reactions and functions throughout the body,” says Dr. Shah. (You can thank magnesium for your nerve and muscle function, blood pressure regulation, bone health, and blood sugar regulation.) Since magnesium appears to have a hand in just about every important process the human body completes, we need to make sure we consume enough of it, since our bodies can’t manufacture it on their own.
How much do I need? And what foods are high in magnesium?
The amount of magnesium you *ahem* mag-need-sium depends on your age and sex. Men over 50 should get around 420 mg a day, and women over 50 require around 320 mg per day. What does that look like in terms of nutrition? Well, an avocado has about 58 mg of magnesium, and one cup of cooked black beans has 120 mg. And good news for many of us: A one-ounce serving of dark chocolate contains 65 mg of magnesium.
Unfortunately a lot of us are falling far short of these recommendations, often because we don’t consume enough of the foods that are rich in magnesium, namely fruits, vegetables, whole grains, legumes, nuts, and seeds. “Studies have shown that almost half the population doesn’t get enough magnesium,” says Dr. Shah. “But that’s probably because most of the population doesn’t eat enough fiber.” That’s problematic for yet another reason: All those foods are major sources of fiber. So if you’re not getting enough magnesium, you’re probably not getting enough fiber, either.
Dr. Shah says that supplementation is one way to make up the difference, in terms of magnesium consumption, if you’re not getting enough in your diet. “The ideal amount will depend on your age group, but you can start with a low dose like 100mg at bedtime, and adjusting with your doctor,” she explains. “If that doesn’t make you feel better, I wouldn’t recommend continuing to take it, but if it makes a difference, then great.”
How do I know if my magnesium levels are low?
Determining a person’s magnesium levels isn’t an exact science. While you can take a blood test to check magnesium levels, the results don’t always give you the full picture. “Most magnesium is inside our bones, with very little actually circulating in our blood,” Dr. Shah explains. And if you aren’t consuming enough magnesium, your body will pull it from your bones to ensure there’s enough circulating in your bloodstream. That’s not an ideal situation: “Your body constantly pulling magnesium from the bones can lead to long term effects like osteoporosis,” says Dr. Shah. If your blood test results say your levels are low, it may indicate a severe magnesium deficiency, because your body isn’t able to pull enough magnesium from your bones to supply your blood.
On the flip side, a “normal” magnesium level on a blood test doesn’t necessarily indicate you’re consuming enough magnesium. The best thing you can do? Identify any troubling symptoms. Dr. Shah says the most common issues that lead her to test a patient for low magnesium are frequent muscle cramps, cardiac disorders, or headaches.
How do you know if you should take a magnesium supplement?
“Low magnesium can lead to muscle cramps, anxiety, insomnia and sleep issues, and general fatigue … but it’s hard to definitively say that those issues are a result of a magnesium deficiency.” Luckily, for most people experiencing any deficiency-related symptoms, supplemental magnesium won’t be harmful, although it’s best to discuss with your doctor.
What is the best magnesium to take?
If you do go looking to add magnesium to your routine, prepare to get slightly overwhelmed, as there are 10 different types. Magnesium citrate is the one you’re most likely to see in supplement form, since it’s one of the more easily absorbed forms of the mineral. But buyer beware: Magnesium citrate is primarily used for its natural laxative properties. If you’re looking to supplement magnesium orally without the gastrointestinal effects, Dr. Shah recommends magnesium glycinate, an organic form of magnesium that’s generally used for relaxation — and to treat tachycardia and insomnia — and is less likely to cause diarrhea.
Magnesium can also be absorbed by the body topically, and magnesium chloride is what you’ll most likely see in oils or skin creams aimed at soothing sore muscles. And magnesium sulfate is what you’ll find in Epsom salts, so if you’re craving a foot bath to comfort your aching arches, reach for this option.
Before you run out and fill your shopping basket with magnesium goodies, know that it’s also possible to go overboard. “People with kidney failure issues or anyone who has had a major GI surgery need to be especially cautious,” warns Dr. Shah. “If these people absorb too much magnesium too quickly, it can cause toxicity issues.” That’s why she urges anyone considering supplementing with magnesium to check with their doctor first.
Are cancer patients at risk of low magnesium?
Some of them are, so if you’re experiencing any symptoms of low magnesium, your oncologist may test blood levels. “When you have cancer,” explains Dr. Shah, “you may not be eating as well to begin with, especially if you get nausea from chemotherapy. Certain drugs used to treat cancer can deplete magnesium levels when taken long-term. Any GI-related illness that causes diarrhea is also going to limit magnesium absorption and cause levels to drop. Diabetes is associated with magnesium loss, so that may be a contributing factor in some cancer patients as well.”
Dr. Shah is quick to point out magnesium’s medicinal role in cardiovascular health. “Some studies show that magnesium levels in the normal range may improve blood pressure, and lower risk for heart attack or stroke,” says Dr. Shah. That’s why patients with heart disease at risk of heart rhythm issues usually also have their blood tested for magnesium regularly.
If you’re mad about magnesium but worried you’re falling short, just remember: The easiest way to get enough of it is simply to eat a fiber-rich healthy and well balanced diet. “Before trying a magnesium supplement,” says Dr. Shah, “I would try incorporating more magnesium-rich food.” So if better energy, mood, and sleep are on your hit list, go ahead and ask for a second helping of greens or beans. Want another option that’s a little more breakfast-friendly? Just read on.
Dr. Shah’s Overnight Oats Recipe:
In a bowl or jar, start with 1 cup of whole grain rolled oats (112 mg magnesium), and add:
1) 1 cup soy milk (61 mg magnesium)
2) 2 tablespoons chia seeds (222 mg magnesium)
3) 2 tablespoons pumpkin seeds (312 mg magnesium)
4) Your favorite fruit, such as berries, for sweetness and a drop of vanilla extract
Let it sit in the refrigerator overnight to soften. Eat the next day.
This “stick to your bones” breakfast is not only delicious: It’s positively packed with magnesium, so you can meet your daily requirement with just one serving. That means starting your day off in a better mood and ending it in better sleep, all while keeping your bones healthy.
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