Recently, Natural Calm Canada published a white paper on magnesium absorption – an arm’s length review of the peer-reviewed literature, by a PhD in microbiology, Dr. Jon-Paul Powers.
The white paper discredited certain claims in the natural health industry, particularly by marketers of magnesium glycinate – a good form of magnesium, but not one that has been proven superior.
Dr. Powers’ research made it clear that no credible studies have been published to date comparing magnesium glycinate with citrate. What research does exist suggests that the two are comparable, or that magnesium citrate may be more absorbable.
Shortly after, a leading magnesium glycinate brand released a document entitled “Magnesium Bis-Glycinate: Redefined. Redesigned.” and later, “Magnesium a Complete Primer”.
The papers came to our attention when we were asked to account for a study therein comparing magnesium glycinate to magnesium citrate. The study, however, was not available on PubMed, suggesting it had not been published or peer-reviewed.
Again, we outsourced the scientific analysis to experts: this time, to Dr. Alison Smith, PhD. The following is her critique of the primer and the study cited therein.
We also append a critical review of “Magnesium Bis-Glycinate: Redefined. Redesigned.”
Review of the White Paper: “Magnesium a Complete Primer”
By: Alison Smith, Ph.D
General Comments:
- Magnesium a Complete Primer is a 68-page white paper released in May 2017 by a Canadian magnesium glycinate company. It contains information pertaining to magnesium function, dietary sources, deficiency, absorption, and the brand’s magnesium products. The current analysis will focus on the topic of magnesium absorption on pages 35-40.
- The document contains some references (pg. 50); however, most of the information pertaining to magnesium absorption is not referenced. The one reference used to support their claim is misleading and does not meet appropriate scientific standards.
Specific Comments:
- Pg. 36.“…the further away you travel from the stomach, the less acidic the environment becomes. The less acidic the environment, the harder it is for magnesium ions to remain soluble.” This information is not referenced and is therefore misleading. The author uses this statement to build toward their claim that magnesium amino acid chelates (like magnesium bis-glycinate) are superior to magnesium salts (like magnesium citrate etc.); however, there are no studies to support that claim.
- Pg. 37. “Magnesium amino acid complexes (or chelates) behave differently than magnesium salts…they use other transport sites called dipeptide channels.” Unreferenced claim. Even if chelates can use different channels than dissociated magnesium salts, where is the evidence that this possibility results in superior absorption of chelates?
- Pg. 37. “Mineral amino acid complexes are actually quite common in nature and a natural way we get magnesium from our diet.” This claim is unreferenced. It misleads consumers into believing amino acid complexes are the best type of magnesium supplement to take.
- Pg. 39. “…we can reliably investigate how well different magnesium types are absorbed through the intestinal walls.” This statement is misleading, unreferenced, and contradictory. The author argues in the previous paragraphs — leading up to this statement — that it is difficult to measure magnesium levels in the blood serum, blood cells, and urine. Since these are the only methods to measure absorption of magnesium in humans, this statement is completely contradictory.
- Pg. 39-40. Starting on page 39, the author describes an experiment performed by Albion Laboratories Inc., written by Hartle, Morgan, and Poulsen (2016). This study used an artificial experimental method of predicting intestinal absorption of various types of magnesium by using a simulated intestine model. The simulated model placed intestinal cells on a welled plate. Magnesium of varying types was then placed into the liquid of the model. The author of the white paper argues that the movement of the different types of magnesium through the simulated membrane predicts how well those types of magnesium will absorb in the human intestine. The experiment tested the difference in absorbability between: Mg bis-glycinate, Mg bis-glycinate with Mg oxide, Mg citrate, Dimagnesium malate, Mg oxide, and a control. The authors, however, do not reference any studies that attest to the validity of this method. In a 2012 PubMed listed article by Etcheverry et al. (2012) the validity of in vitro models of intestinal absorption (like the model used in the Albion Minerals experiment) are evaluated. The authors point out that, “in vitro models of intestinal absorption cannot make any assumptions about the bioavailability of the nutrients used in a study” and “None of the [in vitro] methods currently used to assess magnesium bioaccessibility/bioavailability have been validated against human absorption studies, and no method has been used extensively.” Therefore, simulating intestinal cells on cultured plates cannot possibly substitute the human intestine, and it cannot be used to claim which form of magnesium is the most effective.[Etcheverry, P., Grusak, M. A., & Fleige, L. E. (2012). Application of in vitro bioaccessibility and bioavailability methods for calcium, carotenoids, folate, iron, magnesium, polyphenols, zinc, and vitamins B6, B12, D, and E. Frontiers in Physiology, 3, 317. https://doi.org/10.3389/fphys.2012.00317]
- Pg. 40. The authors use an abstract by Albion Laboratories Inc. written by Hartle et al. (2016) to support their claim that Mg bis-glycinate and buffered Mg bis-glycinate are more absorbable than Mg citrate or Mg oxide. You can read the abstract by Hartle et al. here: https://www.fasebj.org/content/30/1_Supplement/128.6.short
- Pg. 40 of the white paper…“The chelated magnesium bis-glycinate and buffered magnesium bis-glycinate…were much better absorbed than other forms of magnesium like magnesium citrate and magnesium oxide on its own.” There are several issues with this claim: (i) It is misleading. The experiment by Hartle et al. (2016) is not published as an article. The abstract was presented at the Experimental Biology 2016 Meeting (conference), but this does not mean that the results are valid, since abstracts are not peer-reviewed as published articles are. Abstracts cannot be used to support a claim because the data may not pass inspection during the peer-review process. Please see note about how scientific articles are published in point #8. (ii) Albion Minerals supplied the magnesium glycinate brand with the data for the graph on page 40. Using experimental results from their vendor, Albion Minerals is a serious conflict of interest.
(iii) The graph on Pg. 40 does not indicate which magnesium types are significantly different from each other. There is an ANOVA result listed, but what does it pertain to? In published scientific data, there would be asterisks above the bars that are statistically different from each other. The abstract by Albion is also unclear about which tests were significantly different from each other.
(iv) The authors are misleading readers into believing that an artificial intestine model on a welled plate can reliably show which form of magnesium is best absorbed. The current scientific literature states that this method cannot reliably support this type of claim.
8. Note about publishing a scientific article: Publishing a scientific article is quite difficult. An article is submitted to a journal and evaluated by the editor-in-chief in addition to at least three different, independent, academic, peer-reviewers who are unknown to the author. The reviews’ job is to tear the paper apart, spot errors, suggest changes, demand more data and novelty…in essence, their job is to prevent publication. Scientific journals only want high calibre articles, so this process makes sense.
There are two types of abstracts: those that accompany published articles, and those that accompany posters presented at a scientific conference. The abstract by Hartle et al. (2016) from Albion, is an abstract that was presented at a conference. This type of abstract is not peer-reviewed. It’s just a way to show the community your latest work. A conference abstract cannot be used to support any type of argument because the results and data are not peer-reviewed.
Review of “Magnesium Bis-Glycinate: Redefined. Redesigned.”
By: Laura Young, Clinical Research Expert
To earn respect in the scientific community, a paper requires peer-reviewed
references. The authors of this paper have neglected to include references to support the claims stated in this paper.
Further, a clinical research study must be performed and documented to demonstrate the behaviour of a product in the human body. Several statements in this paper have not been proven by results from clinical research. These include:
- “Each blend employs the best mix of salts and complexes to maximize the supply of magnesium while maximizing the use of all the absorption channels.” (p. 5)
- “But there is also free glycine. Mimicking your natural digestion process, glycine can form complexes with the magnesium ions in your gut. Once formed, they too can use the abundant dipeptide channels.” (p. 5)
- “Compact molecules react faster and diffuse across cell membranes more rapidly than larger ones. Many molecules in pharmaceutical drugs are designed to be small for this very reason.”
- “As a magnesium complex, it is more quickly absorbed in the intestine.” (p. 5)
- “The strong configuration of bonds in magnesium glycine complexes protect the mineral from unwanted reactions with these agents.” (p. 5)
- “As a pH buffer, Glycine can help keep pH lower for longer down the intestinal tract. This allows for the better absorption of magnesium ions.” (p. 5)
Glysine is a non-essential amino acid. It is synthesized by the body in addition to obtaining some sources from the diet. The language used in this paper leads the reader to believe that supplementation with glysine is beneficial, which is not supported by references.
Finally, the authors claim Magnesium oxide as a “great source of magnesium once it’s combined with glycine” (p. 5), which contradicts the research. (see below)
- Walker et al. (2003) demonstrated superiority of organic forms of Magnesium in terms of bioavailability over Magnesium oxide. Walker et al. further reported the bioavailability of magnesium oxide relative to placebo. The authors state, “A small amount of magnesium oxide can be a great source of magnesium once it’s combined with glycine.” (p. 5)
- Fallingborg, J. 1999. Intraluminal pH of the human gastrointestinal tract. Danish Medical Bulletin. 46(3), 183-96. [Study]
- Walker, A.F., Marakis, G., Christie, S., Byng, M. 2003. Mg citrate found more bioavailable than other Mg
preparations in a randomized, double-blind study. Magnesium Research. 16(3), 183-91. [Study]
