What's Wrong With Magnesium Aspartate?

In the previous Integrated Supplements blog post, we examined research showing that magnesium supplementation was able was able to increase testosterone and reduce cortisol levels during physical exercise.

Much research, in fact, shows that magnesium may be among the most beneficial nutrients for hard–training athletes; and for this reason, we find magnesium–containing formulas often marketed within the realm of sports nutrition, as performance–enhancers.

But while magnesium, itself may offer numerous benefits, there may be a few potential problems with some forms of magnesium commonly used in nutritional supplements.

For example, one of the most–popular magnesium formulas marketed towards athletes contains a magnesium amino acid chelate called magnesium aspartate. Magnesium aspartate is a mineral amino acid chelate containing magnesium bound to the amino acid known as aspartate or aspartic acid.

Aspartate is known to be an excitatory neurotransmitter (i.e., a brain chemical that stimulates neurons to fire). At high doses, however, it can potentially stimulate neurons to the point of injury or cell death. Excitotoxicity is the term used in the scientific literature to describe this sort of neuronal damage caused by excessive excitatory–amino–acid signaling.

For decades, controversy has raged regarding the possible toxicity of excitatory amino acids (e.g., aspartate and glutamate) found in food additives like MSG (which contains glutamate) and the artificial sweetener, aspartame (which contains aspartate).

Most people – only familiar with amino acids as the “building blocks” of protein – fail to see how some of these simple “nutrients” can cause harm when ingested in high doses. But it’s important to remember that protein–rich foods generally contain a diverse array of amino acids. The “competition” for absorption between various amino acids in foods usually ensures that the excitatory amino acids don’t rise to potentially–dangerous levels in the blood stream.

However, when excitatory amino acids are consumed either independent of, or above and beyond other protein–containing foods (e.g., as components of food additives or nutritional supplements like magnesium aspartate), the blood level of these amino acids may indeed rise to one capable of causing harm. As such, the often–heard mantra that excitatory amino acids are “found in food” bears little relation to their potential toxicity.

Of course, our bodies do have some defenses to protect the brain and its neurons from the neuro–active amino acids we ingest. The blood–brain barrier acts as a selective filter which largely regulates the level of excitatory amino acids in the brain – but even this defense is less–than–perfect.

Some structures of the brain, including, and especially, the hypothalamus – which is involved in regulating things such as appetite, emotions, energy levels, and hormonal balance – aren’t protected by the blood–brain barrier. Animal studies have shown that when glutamate and aspartate were added to the water of laboratory mice, the mice voluntarily ingested enough of these substances to cause brain (hypothalamic) damage:

Study Link – Brain damage in mice from voluntary ingestion of glutamate and aspartate.

Quote from the above study:

It has been argued…that [glutamate] and [aspartate] are safe for human use as food additives since tube feeding is not a natural means of oral intake and efforts to demonstrate the brain damage in animals from voluntary ingestion of [glutamate] or [aspartate] have yielded negative results thus far. Here we demonstrate that weanling mice will voluntarily ingest large enough volumes of aqueous solutions containing [glutamate] or [aspartate] (or both) to sustain conspicuous hypothalamic damage.

The use of magnesium aspartate as a magnesium source seems all the more ironic and ill–advised due to the fact that magnesium is a major nutrient needed to counter the neuronal excitation, and potential damage caused by aspartate. Theoretically, at least, those with low magnesium levels are those most apt to be susceptible to the harmful effects of aspartate. In other words, people who may need magnesium the most (i.e., epileptics, and those suffering from migraines, depression, anxiety, fibromyalgia, chronic fatigue et al.) are among the last people who should be consuming additional aspartate.

For example, while magnesium has been shown to reduce seizure activity in many studies, some evidence suggests that excitatory amino acids from aspartame (again, a source of aspartate) may induce EEG changes concomitant with seizures in certain epileptics:

Study Link – Aspartame exacerbates EEG spike–wave discharge in children with generalized absence epilepsy: a double–blind controlled study

Quote from the above study:

Aspartame appears to exacerbate the amount of EEG spike wave in children with absence seizures.

And while magnesium has been shown to be potentially very beneficial for those with fibromyalgia, aspartate and other excitatory amino acids may worsen the condition. As evidence, we find case reports in the scientific literature showing that the avoidance of dietary “excitotoxins” (such as aspartate) may offer relief from fibromyalgia symptoms:

Study Link – Relief of fibromyalgia symptoms following discontinuation of dietary excitotoxins.

Furthermore, while magnesium has often been shown to improve depressive symptoms, studies have found that aspartame may significantly worsen depression. In the following study, for example, the depression–exacerbating effects of aspartame were so severe that the experiment was halted early for ethical reasons:

Study Link – Adverse reactions to aspartame: double–blind challenge in patients from a vulnerable population.

Quote from the above study:

Although the protocol required the recruitment of 40 patients with unipolar depression and a similar number of individuals without a psychiatric history, the project was halted by the Institutional Review Board after a total of 13 individuals had completed the study because of the severity of reactions within the group of patients with a history of depression.

Along these same lines, and as relates specifically to magnesium aspartate, researchers investigating the use of magnesium in treating major depression have noted cases in which the aspartate form of magnesium actually worsened depression, whereas the glycinate and taurinate forms had markedly beneficial effects on depressive symptoms:

Study Link – Rapid recovery from major depression using magnesium treatment.

Quote from the above study:

Magnesium glutamate and magnesium aspartate greatly worsened the 59–year old man’s depression…These magnesium compounds should be considered as neurotoxic to depressives, and perhaps all people, and should not be used during treatment of depression, anxiety or similar hyperemotional disorders.

Several forms of magnesium are remarkably well–absorbed and highly bioavailable, and are not associated with the excitatory risks of magnesium aspartate. For this reason, we feel that consuming the aspartate form of magnesium simply constitutes an unnecessary health risk.

This is why we at Integrated Supplements use only Magnesium Glycinate and DiMagnesium Malate in our Bio-Available Magnesium product.  Both Ingredients are sourced exclusively from Albion - the world leader in mineral nutrition.

Comments

[Adam Stark]

You seem to be confusing aspartame with aspartate, which is sort of like confusing grapes with grapefruit: i.e. they're DIFFERENT. Yes, aspartame contains aspartic acid, but so does chicken. So does oatmeal. So does anything and everything that contains protein! If you want to extrapolate from rat feeding studies of high-concentration aspartate and glutamate to anything that contains aspartate and/or glutamate, you need to say that chicken and oatmeal are also neurotoxic.

[Integrated Supplements]

Numerous studies show that individual amino acids (including aspartic acid) impart biological effects which are quite different from those of protein-containing foods in which these amino acids can also be found. There may be several reasons for this, including the fact that the consumption of individual amino acids can elevate serum levels beyond what would occur when protein-rich foods are consumed.

This was addressed in the post:
“However, when excitatory amino acids are consumed either independent of, or above and beyond other protein–containing foods (e.g., as components of food additives or nutritional supplements like magnesium aspartate), the blood level of these amino acids may indeed rise to one capable of causing harm. As such, the often–heard mantra that excitatory amino acids are “found in food” bears little relation to their potential toxicity.”

Additionally, isolated amino acids may interfere with the absorption of other amino acids in the same class. Research has shown, for example, that the branched-chain amino acids (in supplemental doses which some people do consume) can impart mood and behavioral changes, likely because they alter the absorption of amino acids used to produce brain chemicals and thyroid hormone.

As noted in the post as well, aspartic acid and aspartame, though different chemicals, have been shown to impart some strikingly similar neurological effects. The fact that these effects all involve NMDA stimulation gives significant reason to believe that aspartic acid is a major common denominator in the mood and neurological effects noted when each are administered.

Magnesium aspartate can contain up to 88% aspartic acid by weight, so it wouldn’t be uncommon for people to consume multi-gram doses of aspartic acid when taking such supplements. With what we know about the effects of these substances in isolation, it simply isn’t logical to assume that aspartame and aspartic acid will be as benign as amino-acid-containing foods like chicken or oatmeal.

[krisko]

What an over reaction. The study must be put into context first of all 13 of 80 patients had a reaction. How many were taking the placebo!
The next point to consider is, of those taking the supplement dosing was very high at 30mg per kilo of bodyweight averaging to 2.1grams at an average bodyweight of 70kgs.
As a genuine sufferer of depression and at an injection dosage of 3grams per day with B12 injection the benefits of Magnesium Aspartate for loss of energy, motivation, muscle soreness are profound and far outway this bunk study.

[Integrated Supplements]

Krisko,
You’ve completely misread and/or misinterpreted the study’s methodology and results. Because the adverse reactions to aspartame were so severe in patients with a history of depression, the study was halted by the Institutional Review Board after only 13 people completed the study (8 patients with depression and 5 without). Nowhere is it said or implied that 13 out of 80 study participants experienced negative side effects (which wouldn’t necessarily have been insignificant either, by the way).

It was a crossover study, so all participants consumed both aspartame and a placebo at different times, and the patients with a history of depression experienced a notably greater number of side effects from aspartame. Some of these side effects were so severe (e.g., conjunctival hemorrhage) as to warrant the discontinuation of the study.

The dose of aspartame used in the study wasn’t unrealistically high – as the study noted, 2.1 grams of aspartame per day equated to 10-12 twelve-ounce cans of diet soda. For many people (who not only consume diet soda but other aspartame-containing products and tabletop sweeteners) this dose is likely representative of what they may consume in a typical day.

As we noted in the article, aspartame and aspartate aren’t exactly the same thing, but could be expected to act similarly in many respects. As some types of magnesium aspartate contain up to 88% aspartate by weight, it is very easy to consume multi-gram doses of aspartate from supplementation with magnesium aspartate.

I’m happy to hear that magnesium aspartate seems to be helping with your depression, but I fear that these results may be short-lived. The stimulatory nature of aspartate (and similar substances) can often be mood elevating in the short term, only to exacerbate the problem in the longer term. This is true of many substances which stimulate the NMDA receptor.

Considering that magnesium has been shown to be potentially very helpful for depression, why not simply switch to a form that doesn’t contain aspartate to avoid any potential risks?

[Alex]

Thank you for this post, very useful information - I am trying to avoid glutamate & aspartame as ALS runs in my family - keeping up the magnesium levels is a good defense but not with aspartame in the mix - almost criminal!