Compared to nutrients with more interesting names like resveratrol or astaxanthin, magnesium might seem downright boring—but that couldn’t be more wrong! Magnesium is a nutritional workhorse.
It’s a fundamental ingredient in the recipe for ATP, the energy required to power every last one of your trillions of cells. Beyond that, magnesium may help with muscle relaxation and even reduce the frequency and severity of headaches and constipation. But what about magnesium for your mood?
Could something as simple as boosting magnesium intake make a meaningful impact on a condition like anxiety or depression? Let me be clear: No, gulping down a few magnesium capsules will not magically resolve debilitating mental health issues.
But to ignore the possibility that magnesium intake could influence cognitive function, or potentially increase the efficacy of psychiatric medications, would be a disservice to the millions of people living with mental health challenges. So, I say, let’s explore. Stick around for 6 minutes and you’ll learn about some interesting research on magnesium and the mind!
What is Magnesium?
Magnesium is the fourth-most abundant mineral in the body and the second-most abundant positively charged electrolyte in our cells. An adult human body houses about 25 grams of magnesium at any given moment. Between 50–60% of this magnesium resides in our bones, and most of the rest sits in our muscles. Less than 1% resides in our blood.
Among hundreds of other functions, magnesium is required to transport electrolytes across our cells’ membranes. By doing so, magnesium helps maintain an electrochemical gradient—an intricate balance of minerals and electrical charges inside of and around our cells—so that nerve impulses can fire.
That means magnesium status can affect the brain and central nervous system. So it may not surprise you that anxiety, agitation, depression, hyperactivity, irritability, and aggression are potential symptoms of magnesium deficiency. More severe deficiency can result in personality changes and sudden behavioral changes believed to come from excessive electrical activity in the brain.
Hypomagnesemia (low level of magnesium in the blood) is quite rare, but that doesn’t mean you’re getting enough magnesium. Your body works hard to keep blood levels of minerals within a very tight range, and it does this by siphoning the minerals away from other places whenever necessary.
Let me reiterate: A normal blood level of magnesium doesn’t rule out magnesium deficiency in the rest of your body—even one severe enough to result in signs and symptoms. Remember, 99% of your body’s magnesium is not in your blood.
Causes of Magnesium Deficiency
So why might someone have suboptimal magnesium status? In short: low intake, medications, or medical conditions.
Low intake is the most obvious driver of magnesium deficiency, so start by eating magnesium-rich foods. But even among people who do consume an adequate amount, there are very common factors among the general population that can reduce absorption or increase excretion of magnesium.
For example, long-term use of several frequently prescribed drugs can increase risk for magnesium deficiency. Proton pump inhibitors for acid reflux are common culprits, as are many diuretic drugs used in blood pressure meds (if they don’t specifically “spare magnesium”). I’m not saying that these drugs should never be used—in many cases, they can be genuinely helpful. That said, we also shouldn’t downplay the seriousness of potential side-effects like inadequate magnesium status.
Excessive alcohol intake, type 2 diabetes, and insulin resistance can also lead to suboptimal magnesium status. For insulin resistance, one could argue it’s a two-way street because inadequate magnesium may increase risk for poor glucose handling and insulin sensitivity.
Anxiety and Depression: Scope of the Problems
As much as 15% of the general population experiences anxiety, and depression accounts for about 40% of the neuropsychiatric disorders in the US alone. The Journal of the American Medical Association noted in 2017 that depression affects as many as 322 million people—it’s the leading cause of disability in the world.
People living with anxiety or depression often have trouble sleeping, but it can be difficult to determine whether the chicken or the egg came first. Mood disturbances can make it more difficult to sleep, and poor sleep can contribute to mood issues. Thankfully, magnesium has been shown to play a meaningful role in improving peoples’ sleep.
Will magnesium make the difference for the majority of these folks? Probably not. But it’s a readily available, inexpensive mineral. If a small percentage of a large population benefits from bumping up their magnesium intake, it could create quite the splash.
Magnesium is a Natural Relaxant
I’m oversimplifying a bit here, but think of magnesium as a natural calming agent. Calcium, on the other hand, induces stiffening or contracting. This is why one class of medication for hypertension is called “calcium channel blockers”: reducing the activity of calcium ions in blood vessels allows the vessels to relax and dilate, allowing easier flow of blood, and therefore, lower blood pressure.
Oral magnesium is a natural calcium channel blocker and affects other pathways that result in muscle relaxation. And it appears to have similar calming or relaxing effects in the brain. Why? For starters, magnesium facilitates proper neurotransmitter release and neuronal action potential conduction, which supports healthy brain function. But the actual calming effects probably come from magnesium’s ability to decrease glutamate (an excitatory neurotransmitter) and increase GABA (gamma-amino-butyric acid, a calming neurotransmitter).
This is also related to the calcium channel blocking effects of magnesium: Magnesium reduces activation of the NMDA (N-methyl-d-aspartate) receptor, which decreases excitatory activity from glutamate. Low magnesium has been said to lead to “a supportive environment for excitotoxicity,” and this “abnormal glutamatergic neurotransmission has been implicated in many neurological and psychiatric disorders” including depression and anxiety. Simply put: By blocking calcium’s role in NMDA receptors, magnesium may help reduce feelings of stress and anxiety.
Boosting serotonin is another way magnesium may help people with depression. Low serotonin levels have long been suspected to play a role in various forms of depression (although this has been increasingly called into question). In any case, for people in whom low serotonin is a factor, increased magnesium intake (from food or supplements) may be helpful because magnesium deficiency in the brain reduces serotonin levels. In fact, some antidepressant medications may work (in part) by increasing brain magnesium.
Lastly, it has also been noted that systemic inflammation is common in people with major depression. Magnesium has anti-inflammatory effects that might offer an additional mechanism for the improvement in depression seen with magnesium supplementation.
Low Magnesium in People with Depression
There appears to be a correlation between suboptimal magnesium status among people with depression. A small association was found between low magnesium intake and depression among younger adults and other analyses have found that higher magnesium intakes are associated with lower risk for depression. That’s something, but we don’t want to hang our hats on survey data—vaguely guessing at your dietary intake of magnesium isn’t very reliable.
One study, however, evaluated 650 patients with depression and found that almost 40% of subjects had suboptimal magnesium levels. This doesn’t mean that everyone with depression has low magnesium or that magnesium supplementation will always help, but inadequate magnesium seems to be more prevalent among people with depression than in those without it.
Okay, great. Plenty of possible mechanisms, and lots of folks with depression have low magnesium intake and/or blood levels. But what happens when the rubber hits the road? Does increasing magnesium intake actually help with anxiety or depression?
Does Increasing Magnesium Intake Really Help?
A randomized controlled trial showed that in subjects starting off with low blood magnesium, magnesium supplementation normalized the magnesium level and reduced depressive symptoms more than a placebo. The difference wasn’t a landslide, but it was statistically significant. And interestingly, the form of magnesium used—magnesium oxide—is less bioavailable (absorbable) than other, better forms of magnesium.
A study using magnesium chloride, which is more easily used by the body, found that supplementation led to significant improvements in anxiety and depression. Even more impressive: Beneficial effects were noted within just two weeks. Improvements were similar regardless of biological sex, age, baseline magnesium level, severity of depression, and even concurrent use of antidepressant medicines and other therapies.
Perhaps even more importantly, the results weren’t just statistically significant—the magnitude of improvement was large enough to have real-world relevance. In other words, it wasn’t mathematical shenanigans that made magnesium look good here; the improvements in anxiety and depression made a difference to living, breathing humans going about their lives.
Even more remarkable, a case series of magnesium supplementation (as glycinate or taurinate) reportedly led to rapid and profound recovery from major depression, suicidal depression, post-partum depression, and substance use disorders.
People with treatment-resistant depression (TRD) and patients who have attempted suicide are often found to have low cerebral spinal fluid magnesium levels, leading the authors of one study to write, “We hypothesize that – when taken together – there is more than sufficient evidence to implicate inadequate dietary magnesium as the main cause of TRD, and that physicians should prescribe magnesium for TRD.” What an impactful statement! Let’s tie it all together now.
When to Supplement Magnesium
Standard antidepressant (pharmacologic-only intervention) therapies fail to have a major impact in about 60% of cases. Researchers have proposed adding magnesium to enhance efficacy in these situations. It doesn’t have to be medication OR magnesium—it can be both!
The US Institute of Medicine’s Food and Nutrition Board set the tolerable upper intake level for magnesium supplementation at 350 mg/day, but higher levels are often required to induce a therapeutic benefit. Some researchers recommend 600–800 mg/day or more for people with major depression.
If you’re taking medication, work with your licensed medical professional before introducing new supplements. But it’s worth noting that you should spread your magnesium intake out throughout the day. Unabsorbed magnesium (e.g. from less bioavailable forms like magnesium oxide) may attract water from nearby tissues into the intestine or colon, causing diarrhea. Save yourself the trouble.
Based on the available science, there’s no downside to getting 400–600 mg of magnesium each day. Start with a magnesium-rich whole foods diet first and foremost, then close the gap with a magnesium malate supplement. Since blood tests won’t tell you if you’re in the optimal range here, the best way to do this is with a dietary analysis.
Track your diet with Cronometer or another app of your choice to lock in what you’re eating, and then supplement as needed. 60 mg of magnesium was one of three essential minerals we decided to include in LMNT, our science-backed electrolyte drink mix. So if diet alone won’t cut it, that could help you cross the finish line.
Magnesium may not help everyone’s anxiety or depression, but considering the degree to which these can downright demolish quality of life, it’s hard to make a case against giving this a try. Your body will only thank you for getting your magnesium dialed in.
