Magnesium - The Facts
Because most presentations of magnesium are in the form of food supplements, rather than licensed medicines, there are strict limitations on the claims manufacturers can make, and these are determined by the European Food Safety Authority (EFSA)[i]. The EFSA allowable claims for magnesium are:
· Magnesium contributes to a reduction of tiredness and fatigue
· Magnesium contributes to electrolyte balance
· Magnesium contributes to normal energy-yielding metabolism
· Magnesium contributes to normal functioning of the nervous system
· Magnesium contributes to normal muscle function
· Magnesium contributes to normal protein synthesis
· Magnesium contributes to normal psychological function
· Magnesium contributes to the maintenance of normalbones
· Magnesium contributes to the maintenance of normal teeth
· Magnesium has a role in the process of cell division
Impressive list eh? Reading this, you realise how versatile and essential magnesium is to our body processes, and as these are allowable claims, they must be based on substantiated clinical evidence.
Magnesium - The Theory
There is also a list of EFSA non-authorised claims for magnesium, which make interesting reading:
· Magnesium contributes to meeting the increased requirement for magnesium in pregnant women, so it could help the normal course of pregnancy and delivery and birth of a healthy baby
· Magnesium contributes to the maintenance of hormonal health
· Magnesium has antioxidative properties. It prolongs the ageing process
· Magnesium is necessary for normal blood clotting
· Magnesium maintains healthy immune system
The reason for most of these claims being “non-authorised” is that the scientific research on which they are based, has not been substantiated ….. yet!
There has been considerable interest as to whether there are other possible benefits of magnesium, in management of chronic pain, fibromyalgia[ii], and also management of migraine, particularly in combination with malic acid as magnesium malate.
How much do I need?
According to UK government guidelines[iii], the required daily intakes of magnesium is 300mg for men and 270mg for women (both aged 19+). The figures here refer to elemental (ie pure) magnesium, rather than taking a magnesium salt. For example, taking 300mg magnesium citrate(a form of magnesium commonly found in supplements) provides 90mg elemental magnesium.
We should all be able to obtain sufficient magnesium for our daily requirements from a varied diet, and green leafy vegetables, nuts, brown rice, bread (especially wholegrain), fish, meat and some dairy foods are the best sources of dietary magnesium. Nowadays so many of us don’t eat properly balanced diets, and increasingly need to rely on food supplements in order to obtain our essential nutrients.
Confused by the different types available?
There are many forms of magnesium available, and not only for taking orally. Nowadays there are bath salts, creams and lotions which claim transdermal absorption (through the skin). Here I will concentrate on oral supplementation, and the most commonly found oral magnesium supplements are magnesium oxide and magnesium citrate.
Magnesium oxide has the potential for laxative side-effects, not surprising as it is closely chemically related to magnesium hydroxide (the active ingredient in the old family favourite for “digestive upsets”, Milk of Magnesia), which is not recommended to take for the purposes of magnesium supplementation!
Much of the research on magnesium has been conducted using magnesium citrate, which also has potential for laxative side effects but in the dosages usually encountered in oral supplementation (for example 300mg) these are usually well tolerated.
Both of these variants offer manufacturers a convenient solution because the raw ingredients contain a relatively high percentage of elemental magnesium, so the amount needed to produce the required capsule dosage often fits into one daily capsule.
But perhaps we should be looking for the salt that gives the consumer the optimal benefit, rather than the manufacturer! A recent research paper[iv]compared five different magnesium salts to see if they could establish which of them gave the best results in terms of how long the magnesium lasted in the body. Magnesium malate came out as the clear winner in terms of time-dependent absorption, and tissue penetration, and remained high for an extended period of time. Magnesium oxide and magnesium citrate had the lowest bioavailability when compared to the study’s control group.
This study on its own is not conclusive evidence of magnesium malate being the best form of magnesium to take as a supplement, but it does appear to be well tolerated and possibly less likely to produce gastro-intestinal side effects than some other forms.
In summary, on the face of it, Magnesium Malate seems to have a lot going for it, but we are going to need to wait for a while before we get confirmation by way of results from controlled clinical research before we can be sure of the real facts.
[ii]Guy E Abraham & Jorge D Flechas (1992)Management of Fibromyalgia: Rationale for the Use of Magnesium and Malic Acid, Journal of Nutritional Medicine, 3:1, 49-59, DOI: 10.3109/13590849208997961
Government recommendations for energy and nutrients for males and females aged 1 – 18 years and 19+ years.
(Public Health England; August 2016)
Uysal, N., Kizildag, S., Yuce, Z. et al. Biol Trace Elem Res (2019) 187: 128. https://doi.org/10.1007/s12011-018-1351-9