As someone who has generalized anxiety, I can tell you it’s a bitch sometimes.
The best and most important hurdle I won was identifying that I had it. Before then, certain situations caused me to experience uncomfortable feelings that would make me reactive, impatient and defensive with a diffuse sense of urgency. Research shows that this is how the majority of humanity lives day to day. On auto-pilot, we are reacting to our feelings and emotions without much thought given to them or having any insight about them.
Like all emotions, they are generated from the workings of your neurons. You have about 85+ BILLION neurons firing continuously; communicating with each other via neurotransmitters which ‘jump’ across some 100 TRILLION synapses. This is your brain at work.
While you may not have thought about it, your brain, like the rest of your body needs to be nourished to be structurally sound. Structure (anatomy) influences function (biochemistry and physiology). What you eat and drink counts. When it comes to emotions like anxiety, many nutrients are central to good mental health, such as magnesium.
What is magnesium?
Simply put, magnesium is a mineral like iron, selenium and zinc are. Magnesium is no shrinking violet though. It’s the fourth most abundant mineral in your body after calcium, potassium and sodium (1). Not too shabby.
Your body contains about 25 g of magnesium, most of which is found in your bones (50-60%), the rest is found within your muscle cells, red blood cells and soft tissue (2).
What does magnesium do?
Magnesium is involved in over 325 different biochemical reactions. Because of this, it has far-reaching benefits when it comes to health. Conversely, when you’re not getting enough magnesium, it can take its toll and a functional deficiency [suboptimal intake] can show up in many ways.
Broadly speaking, magnesium…
- is needed by the pancreas to make and use insulin; an important hormone in blood sugar regulation.
- the body needs magnesium to activate vitamin D into its active form; without enough magnesium, the body can’t use all the vitamin D it gets.
- magnesium helps with the movement of calcium, potassium & sodium ions across cell membranes
- a process that’s important to nerve impulse conduction, muscle contraction and normal heart rhythm (6).
- it supports biochemical reactions such as protein synthesis, muscle and nerve function
- helps to regulate blood pressure, is needed for neurotransmitter synthesis and function
- is part of the bone matrix and is needed for energy production
- it’s required for the synthesis of DNA and RNA, important features of cellular repair and growth
For all the hats that it wears, magnesium reduces the risk for many common health conditions such as cavities, stroke, diabetes, dementia, depression, osteoporosis, kidney stones, heart disease, high blood pressure, migraines, asthma, muscle cramps and more.
Magnesium deficiency causes.
Most who eat a standard American diet (SAD) tend to miss the mark when it comes to meeting the minimum recommended intake of magnesium (anywhere between 360 to 420 mg/day depending on ages between 14 to 51+ years). In Canada, according to the Canadian Community Health Survey, some 35-70% of males and 40-60% of females fall short. Magnesium deficiency is considered the most common in developed countries second only to vitamin D*.
Actual signs of magnesium deficiency – hypomagnesaemia – overlap and are rather non-specific. Because it’s assumed that people can easily meet their magnesium requirements through a typical diet, a functional magnesium deficiency is often overlooked.
There are several contributors to a deficiency. Risk factors for a suboptimal intake of magnesium include:
- insulin resistance (“pre-diabetes”) or diabetes [due to an increased loss of magnesium in the urine] (10, 11, 12, 13)
- a diet that includes a lot of refined white flour products instead of 100% whole grain or intact grain foods
- a high intake of highly processed foods
- a low consumption of nuts, seeds, and pulses (“legumes“): chickpeas, lentils, dried peas & beans
- if you regularly eat foods or drink beverages with a lot of added sugars which may displace magnesium-rich foods
- regular consumption of alcohol (14, 15, 16)
- if you follow a calorie-restricted diet
- if you skip on green vegetables, dark green leafy vegetables in particular (17).
- regular use of antacids like H2 [stomach acid] antagonists [Zantac] or proton pump inhibitors [Prevacid etc] (18).
- if you have a digestive health related issue like Crohn’s, ulcerative colitis or Celiac disease
- use the antibiotics Gentamicin or Amphotericin (19).
- if you’re taking diuretics such as Lasix, Bumex, Edecrin or hydrochlorothiazide (20).
- if you’re an older adult due to a decreased absorption and decreased dietary intake of magnesium
Signs and symptoms of magnesium deficiency
With frank (overt/clinical) deficiency, the following symptoms are possible* (21):
- cardiac arrhythmia
- weakness and fatigue
- ataxia (loss of control over body movements)
- muscle spasms and twitches
- low blood levels of calcium, potassium and vitamin D
Possible symptoms of mild, chronic magnesium deficiency include:
- osteopenia and osteoporosis (22, 23, 24, 25)
- kidney stones (26)
- high blood pressure (27, 28)
- possibly preeclampsia and eclampsia (29, 30)
- migraines (31, 32, 33, 34)
*Testing Nutritional Status. The Ultimate Cheet Sheet (affiliate)
Assessing magnesium status
There is currently no reliable indicator of magnesium status. Despite this, the three ways that are used in clinical practice are:
1. Serum (blood) magnesium
Less than 1% of total body magnesium is found in the blood and like calcium, magnesium concentrations are tightly controlled. What does this mean? Testing blood magnesium tells you nothing about magnesium status; the amount of magnesium that’s in bones, soft tissues and cells like muscle, red blood cells, heart, and brain (neurons) etc.
Despite this, the most commonly used and easily available method used to “assess” magnesium status is a blood test. Serum levels will decrease in very severe deficiency. But, because serum magnesium is 1] tightly controlled by hormones, 2] reflective of what’s released from bone & red blood cells, and 3] influenced by the amount excreted in urine, serum magnesium it’s not as sensitive as red blood cell and urinary tests.
2. Red blood cell (RBC) magnesium
Magnesium is found in RBC, about 3x higher concentration than what’s in the blood. Measuring the amount in the RBC is a proxy of magnesium status. Like all tests, there are factors that can influence the amount of RBC magnesium. For example, low RBC magnesium just might mean magnesium is not getting into the cell and not that’s there’s a ‘shortage’ in the body.
Despite this, RBC magnesium is a more sensitive test than serum because RBCs act as a magnesium reservoir. RBCs help to help maintain serum magnesium levels by releasing some. When this happens, RBC magnesium can be low despite adequate blood concentrations. Magnesium supplementation effectively restores RBC levels underscoring without changing serum, making the RBC test better.
3. 24-hour urine magnesium
Also known as the magnesium tolerance test, this is considered the gold standard. It determines magnesium retention following an intravenous infusion of magnesium by measuring urinary output. Interpretation has to be considered with serum levels in mind and this interpretation varies depending on blood levels before, during and after the test. This is time-intensive, much more expensive and complex and is best left to endocrinologists.
Dietary & supplement intake
Magnesium adequacy involves assessing dietary sources of magnesium and supplement use in the context of signs, symptoms, and risk factors for magnesium inadequacy and deficiency.
If you’re a clinician, you may want to consider getting yourself a copy of Testing Nutritional Status. The Ultimate Cheet Sheet (affiliate) by Chris Masterjohn PhD. This is a no-nonsense resource that covers labs, interpretations and how they’re used in an easy to use format. It cuts right to the chase. I love mine.
What is anxiety?
Like all emotions, anxiety is neither good nor bad. It’s simply a normal emotion that everyone experiences. Like all emotions, anxiety can be beneficial or it may manifest in a way that interferes with normal day-to-day life.
Some people experience a greater degree of anxiety both in terms of frequency (e.g. most days, or for months at a time) and intensity. For those folks, anxiety can create significant disruption in their lives.
Anxiety vs depression
Depression and anxiety disorders are not the same. However, people with depression often experience symptoms similar to those of an anxiety disorder.
Similar symptoms include nervousness, irritability, problems with sleeping and concentrating. Each disorder has its own causes and behavioural symptoms. People who develop depression often have a history of an anxiety disorder but there’s no evidence one disorder causes the other.
Magnesium for depression has been explored with some compelling evidence(35, 36, 37). Whether magnesium benefits a co-presentation of anxiety and depression is unclear; but it’s not unreasonable to think that magnesium’s beneficial role on depression would also indirectly benefit anxiety.
Brain fog symptoms
Most in main stream medicine hate the term “brain fog”. They either feel it’s not real or because it can’t be measured, they take a “there’s nothing to see folks, move along” approach.
Also, gut barrier dysfunction, a.k.a. as increased intestinal permeability, can lead to an increase of LPS translocation and increase inflammation. LPS translocation is nothing more than the increased movement of resident gut bacteria endotoxin moving into the general circulation (40, 41).
Stress, HPA axis dysregulation, inflammation and oxidation can lead to feelings of decreased mental clarity that can accompany both depression and anxiety. Magnesium may play a role in reducing this cascade (42).
Magnesium for anxiety
Can a magnesium deficiency cause anxiety? It’s a fair question given magnesium’s role in both brain cell/neuronal and neurotransmitter function.
In the synapse, the space between brain cells is where communication happens; magnesium aids in nerve signal transmission. This helps neurons work together concert to produce thought and emotion.
Magnesium, per the diagram below, works as an “antagonist” to calcium and glutamate; preventing the neurons from being overly stimulated. By doing so, the ying and yang between excitatory and inhibitory activity is balanced.
If there’s less than optimal amounts of magnesium in the synaptic space, synaptic dysfunction can occur, leading to depression and other mood disorders.
Lower intakes of magnesium have been associated with an increased risk for anxiety (43, 44). When it comes to magnesium and anxiety, getting more magnesium by food and supplements may help (45, 46, 47).
Food sources of magnesium
It goes without saying that good health rests on a foundation of a healthy diet. A dietary pattern that’s based on nutrient-dense, wholesome foods.
Unfortunately, many of us miss the mark. There are several reasons why our intake of magnesium has decreased over the past several decades (too many to list). The good news is, there are still good sources out there, it’s just about being a little more conscientious and consistent about your choices.
What about supplements?
Supplements aren’t just for reversing deficiencies. When it comes to nutrients, consistently getting an amount that’s be shown to have a therapeutic effect can sometimes be tricky from food alone. That’s where supplements come in; they supplement your usual intake (diet) to help you reach a particular target.
Like other mineral supplements, magnesium needs to be ‘attached’ to something in order for it to be delivered to your body. This can include amino acids (chelated) or other compounds (magnesium salts). Because of this, not all magnesium supplements are created equal.
Different forms are broken down and absorbed differently. The goal of any supplement therefore is to provide your body with the best form possible for optimal delivery of a nutrient to your tissues and cells. 🙂
Which form of magnesium is best?
What readers want to know is, what’s the best magnesium for anxiety? In short, the best type of magnesium are those forms that are rapidly absorbed, effective at increasing magnesium blood levels and that can also reach the brain.
For more on the topic of absorption, check out this super comprehensive (granted 241 pages!) resource: Magnesium absorption in humans
One of the challenges in answering this question is that a good chunk of the relevant studies on magnesium and anxiety used magnesium oxide and magnesium lactate. Studies looking at specific forms and specific doses are needed to determine the best magnesium for anxiety. Despite this, we have hints given the reasonable criteria of needing effective absorption and distribution of magnesium in your body.
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Contains 10% magnesium by weight or 10 mg per 100 mg dose.
Magnesium aspartate might not be the best for anxiety however because the amino acid aspartate is an excitatory neurotransmitter. This may make anxiety worse.
Contains 11% magnesium by weight or 11 mg per 100 mg dose.
This is a very common form of magnesium. It’s the supplemental form I’ve historically. Magnesium citrate is more bioavailable than others forms of magnesium (51, 52, 53). Magnesium citrate has been used in anxiety research, but some of those studies were not well-designed so drawing iron-clad conclusions is impossible (46).
As point of comparison, most relevant studies on magnesium and anxiety used magnesium oxide but magnesium citrate is absorbed better (54). So while we can’t for certain that magnesium citrate is best, given its decent bioavailability, it would be a good choice if you wanted to give magnesium a try.
When it comes to magnesium citrate, you don’t have to spend a lot of money. As an example, two solid brands can be found here* and here* . The powdered forms mix well with liquids, so it’s a magnesium citrate is popular for that reason such as this brand*.
Contains 14% magnesium by weight or 14 mg per 100 mg dose.
Also goes by “magnesium bisglycinate”, people often make a distinction between the two. As a chelate, magnesium is attached to the amino acid glycine. This form of magnesium also has a high bioavailability (55). It hasn’t been studied specifically for anxiety but it has for depression which can overlap with anxiety; some therefore may find this form helpful (56). It’s also the most gentle on the stomach and gut so it’s easy to tolerate given a significantly less chance of common GI side effects (57).
Contains 5% magnesium by weight or 5 mg per 100 mg dose.
Despite it having good bioavailability and being well tolerated, like other gluconate-based supplements like iron and zinc, magnesium gluconate has much less magnesium per dose compared to other forms listed here.
For example, one 500 mg tablet only provides 25 mg of magnesium. It would take 16 tablets to get 400 mg of magnesium, twice as many tablets with a typical 250 mg magnesium gluconate tablet that’s found in many drugstores.
This results in a lot of pills to be take to get the therapeutic amount of magnesium to help with anxiety. Most won’t want to take that many pills, a typical barrier to treatment referred to as “pill burden”.
Contains 60% magnesium by weight or 60 mg per 100 mg dose.
The one form of magnesium that everyone loves to hate is magnesium oxide given how poorly it’s absorbed despite having more magnesium by weight. Given it’s poorly absorbability, it’s not the best for anxiety due to its limited ability to raise serum or brain levels of magnesium (53). Magnesium oxide for anxiety? Pass on this one.
Magnesium l threonate
Contains 7.7% magnesium by weight or 7.7 mg per 100 mg dose.
In recent years, a new form of magnesium, called magnesium L-threonate (MgT), has become available. Consider it the new kid on the block. One of benefits of this form of magnesium is its superior ability to pass the blood brain barrier and enter the brain (58).
Most of the research has looked at it impact on memory and enhanced learning where it’s shown to have benefit (59). Its rapid absorption and ability to enter the brain suggests this magnesium may alter some functional aspects of neurobiology and improve aspects of brain aging (60, 61, 62).
Research on anxiety has been indirect of sorts. Studies have used animal models of anxiety, as well as, treatment of anxiety in those with mild cognitive impairment. The results are both interesting and promising but still too early to draw meaningful conclusions for different forms of anxiety (63, 64, 65). At the every least, MgT’s ability to pass the blood brain barrier is something to keep on your radar. Anecdotally, it’s the form I’m going to switch.
Lypo-Spheric magnesium l threonate
Contains 7.7% magnesium by weight or 7.7 mg per 100 mg dose.
Liposomal technology encapsulates a compound (could be a nutrient or drug) in a liposome (small bubble) of phospholipids. This enables efficient absorption because the liposome can bond with the cell membrane and unload its contents without energy (no active transport). Liposomal technology has been used with other nutrients (vitamins C, D, B complex etc) and magnesium l threonate has joined the pack. Whether or not liposomes add any benefit for anxiety above the already superior bioavailability of MgT is unknown.
This product is under review by Health Canada for sale in Canada. The leaders in this technology is LivonLabs. Liposomal magnesium threonate is available right now for those living in the US. For more information on this product, check out LivonLabs’ product page.
Contains 15.5% magnesium by weight or 15.5 mg per 100 mg dose.
Magnesium malate has excellent bioavailability, even more so than citrate (66). This may make it a good choice for anxiety given it will effectively raise serum magnesium levels. Unlike magnesium oxide and magnesium lactate, the malate form hasn’t been evaluated specifically for anxiety. Despite this, it would be a good option to consider given how well it’s absorbed.
Magnesium dosage for anxiety?
What’s the magnesium dosage for anxiety? That’s the million dollar question. Unfortunately, there is a lot of heterogeneity [differencez] between studies when it comes to dosing. Doses range from a paltry 46.6 mg up to 600 mg per day in some studies (46). Drawing a simple conclusion is difficult but then it’s likely ideal doses will vary from person to person.
The bottom line is we just don’t know. In the absence of kidney disease, where excess magnesium can’t be excreted, there are really no safety concerns to use doses ranging from what have been used in studies (be sure to speak to your doctor or license nutrition professional before treating yourself). Typical doses of magnesium range in the 200-600 mg per day. If you’re planning on a higher dose, like 400 mg, it’s best to divide the dose for better absorption.
As mentioned, as long as you have healthy kidneys, the signs and symptoms of overdoing it with magnesium are largely one of inconvenience than toxicity (67)
The Institute of Medicine has set the Tolerable Upper Intake Level (UL) at 350 mg per day from supplements only (not a total from all sources) (68). This is a conservative number based on the fact that when determining the UL, some subjects experienced loose stools with intakes in the 250 mg range.
PRO TIP: The ‘L’ in UL stands for “Level”, not “Limit”. Many are still confused about this. The UL is not an absolute cut-off or toxic level.
The catch is that the type magnesium salt and an individual’s bowel tolerance can cause huge variation in the amount needed to loosen stools. Most folks easily tolerate higher intakes but it was set at 350 mg to ensure that those who might be sensitive, not consume higher amounts.
Forms of magnesium most commonly reported to cause diarrhea include magnesium carbonate, chloride, gluconate, and oxide (69). Magnesium salt that I wouldn’t recommend anyone use if they want to experiment with magnesium to support anxiety managemente. The diarrhea and laxative effects of magnesium salts are due to the osmotic activity of unabsorbed salts in the intestine and colon and the stimulation of gastric motility (70).
Toxic hypermagnesemia, presenting with hypotension or muscular weakness, is only seen at oral doses of 2500 mg of elemental magnesium or higher. Significantly more than the UL (71)
Like with any other organ, the brain needs a lot of nutritional TLC. We know that what we eat and drink has a direct impact on brain anatomy (structure), and brain physiology (function).
Vitamins and minerals support neuronal repair and maintenance, are needed for the production of endogenous antioxidants, and enable neurotransmitter-based communication between neurons via synaptic functioning.
One key nutrient in all of this is magnesium. A mineral that many of us are not getting enough of for various reasons. Magnesium supplements can help to bridge the gap between what we need and what we’re getting in the modern diet.
While many things affect how magnesium is absorbed from both food and supplements, not all supplements are created equal (72). Good choices though include magnesium citrate, glycinate, l threonate, liposomal and malate.
Because a sudden, larger intake of magnesium may cause gastrointestintal upset, it’s best to start slow; 100 mg twice a day for example and working your way up to doses safely used in studies. Aim for a total magnesium intake in the 200 to 600 mg range. If you have any kidney impairment, avoid magnesium supplements altogether.