Boy, do we need magnesium. Like zinc, it is involved in a huge variety of biological functions. Like zinc, it has been leached from the soil by years of using artificial fertilisers containing no magnesium. This is an introductory blog which covers what magnesium does in the body, a bit about measuring magnesium levels and the best dietary and supplemental sources of magnesium. Later blogs will cover its positive effect on heart attacks, on blood sugar tolerance and on sleep.
Quoting from the Department of Health’s handbook Dietary reference values for food energy and nutrients for the United Kingdom
The physiological importance of magnesium (Mg) lies in its role in skeletal development and in the maintenance of electrical potential in nerve and muscle membranes. Biochemically Mg acts as a co-factor for enzymes requiring ATP, in the replication of DNA and the synthesis of RNA. Magnesium is intimately involved with calcium in metabolism……..The body contains about 25 g of Mg, and roughly 60% is in the skeleton.
So in brief, it is important in bone formation, for the electrical stability of cells, for energy production – literally it helps us run for that bus – and for maintaining the health of our DNA. Magnesium and calcium act together in the body, sometimes in an opposing way and sometimes together. So when a muscle contracts, calcium enters the cells. When it relaxes, magnesium drives the calcium out. However they co-operate in making ATP, the body’s equivalent of petrol in a car. When we ask our body to do something physical, from lifting a cup of tea to jumping 20 feet into the air in surprise, without ATP we would be lumpy jelly on the floor.
As Max Motyka sums up, low magnesium levels cause such symptoms as low energy; cramps; irritability; insomnia; restless leg syndrome; fibromyalgia; and added to this high blood pressure; glucose intolerance or being on the path to developing type 2 diabetes – plus those 2 combined: high blood pressure and glucose intolerance which is called metabolic syndrome.
As ever, it seems, the best dietary source of magnesium is a surprise. For once it is not red meat (venison 21 mg) or liver (chicken liver 19mg) or even oily fish (wild salmon 31mg). It is not even cabbage (12 mg). It is cocoa powder, weighing in at a whopping 499mg per 100gm. The next thing behind cocoa powder is spinach – so Popeye was onto something – which has 70mg.1 Now this is pure cocoa powder we are talking about, so a drink made with cocoa powder with hot water and a bit of sugar or honey is probably the best way of getting our magnesium through our food. Plain dark chocolate will still be a reasonable source of magnesium, with the minimum darkness of 70%. Milk chocolate is not a good source of magnesium since it contains less cocoa powder.2 So apart from coughing our way through spoonfuls of cocoa powder, as Max Motyka says, the diet does not provide good sources of magnesium.
Whole grains contain magnesium, but the phytates in them bind to the magnesium – and to the calcium, zinc and iron – and remove them from the body. Ditto with nuts – however, if we soak our nuts before eating them, this removes the phyates, so nuts are a source of magnesium. Hard water contains magnesium which is why it has been found to have a weak correlation to a reduction in heart attacks occurring in men.
There is a problem measuring magnesium levels in the blood. The usual way of testing magnesium levels is by measuring the levels in the blood serum – the clear fluid found in blood. Magnesium is essential to keep the heart beating, so the body will cannibalise itself to keep adequate magnesium levels there. It usually leaches it out of the bones, the biggest store. So if blood serum shows magnesium deficiency, we do not have long for this world. This is being realised and several new methods of measuring magnesium are being trialled. Probably the easiest one to ask for is the Red Blood Cell or RBC magnesium count.
Supplementing with magnesium is also not completely straightforwards. As the previous blog on how to spot a good multi went into, most minerals are uptaken by the body best if they are bound to an amino acid and these are the forms that cause least problems. As an example of a readily available magnesium supplement that is not in an amino acid binding, we can take magnesium citrate; it does supply some magnesium, but it also tends to give the taker the trots, which is rather off putting. Magnesium is better when bound to amino acids such as taurine, glycine, orotate, aspartate or fumerate. Another successful way of taking in magnesium is through the skin as a cream, to be rubbed in, or Epsom Salts can be added to the bathwater. Either the bath or the cream will calm a fractious child. Additional supplementation with Vitamin D3 and natural Vitamin E will further aid the uptake of magnesium.
Magnesium is a vital mineral that we are all short of. If we supplement successfully, the biggest difference will be that we will sleep much better. That it also helps our heart, our energy levels and our sugar handling abilities is less immediately obvious – this takes a little longer for the levels to build up sufficiently. However, magnesium is an important plank in basic supplementation to make us slimmer, healthier and happier.
- All measures of magnesium in the foods mentioned are per 100gm of the food, raw if applicable [↩]
- Information about the nutrition of foodstuffs can be found on US Dept Agriculture. There are difficulties with finding the nutrition of prepared foods since it is an American source, so will talk about things like Hershey bars. [↩]