Magnesium is one of the most important minerals for human health and is required throughout the body; but by far the largest quantities are found in the bones and muscles.
Almost all the bodys enzymes are dependent to some degree on adequate supplies of magnesium, and these enzymes are essential for several hundred vital metabolic reactions; amongst the most important being the production of energy within cells through the metabolism of dietary proteins, carbohydrates and fats. Magnesium is also needed for the synthesis of protein, the activation of genes and the transmission of impulses between nerve cells.
In addition to the above general functions, magnesium is a vital element in the complex of nutrients required for the production of glutathione, one of the bodys most important fat-soluble anti-oxidant enzymes. Glutathione protects those parts of the bodys cells which are composed of fat, such as the membranes, by neutralising any free radicals attacking these delicate structures.
Magnesium may therefore be regarded as an important anti-ageing nutrient in its own right, but it has also been the subject of extensive research into a number of more specific health functions.
Adequate levels appear to be particularly important in ensuring the proper take up of calcium by the bones, and low levels of blood magnesium have been shown to be linked with correspondingly low levels of calcium; and to have an inhibiting effect on the action of vitamin D, which is itself essential for the proper functioning of calcium. Logically enough, therefore, some research has suggested a link between supplements of magnesium and increases in bone density.
There is some research evidence to suggest that low levels of blood magnesium may be a risk factor for the development of high blood pressure, and also that magnesium supplements can be of benefit for reducing blood pressure in sufferers who have inadequate intakes of dietary magnesium, but orthodox medical opinion maintains that more work is necessary before this link can be definitively established.
Low levels of magnesium intake are also associated with a significantly increased risk of diabetes, but there have been conflicting results from research studies into the question of whether supplements of magnesium may be useful in managing the disease.
Likewise, the benefits of the use of high doses of intravenous magnesium in the immediate aftermath of heart attacks remain a matter of controversy, but there is good evidence that oral supplements of magnesium may reduce the risk of dangerous blood clots in individuals suffering from cardiovascular disease.
There is also a known association between low levels of blood magnesium and recurring migraine headaches, and there is some evidence that supplementation may reduce the frequency of attacks.
Supplementation has also been shown to help alleviate the symptoms of pre-menstrual syndrome in more than 70% of women.
Unprocessed whole grains such as brown rice or cereals are the best food sources of magnesium. A serving of oats or bran, for example, may typically provide as much as 90 mg or more of magnesium per serving; a cup of brown rice a little less, and a serving of wheat cereal perhaps 60 mg or so. Dark green vegetables such as spinach may provide up to 80 mg; and beans and nuts are also a useful source, a single ounce of hazelnuts or peanuts, for example, supplying almost 50 mg of magnesium. Milk may also supply around 30 mg.
But despite these apparently widespread and rich sources, there is evidence that many people do not obtain sufficient dietary magnesium and that the diets of older people, in particular, are likely to be inadequate. The European Recommended Dietary Allowance (RDA) for magnesium is 300 mg, but in the US higher levels of 420 mg for men and 320 mg for women have been prescribed. Given the importance of magnesium within the body, these findings are a cause for concern, and indicate that most adults should be considering supplementing with magnesium.
However, some caution needs to be exercised when taking extra magnesium in this way; because 350 mg per day has been established in the US as the upper safe limit for supplemental magnesium for adults. Below this level there should be no risk of the relatively minor, albeit unpleasant, gastric side effects, principally diarrhoea, which have sometimes been noted when higher dose supplements have been taken.
Its important to note, however, that more serious consequences of excess magnesium have been observed in those already suffering from kidney problems. Such individuals appear to have a higher sensitivity to concentrations of the mineral, and may suffer further deterioration in kidney function and possibly blood pressure problems as a result.
No such problems have been observed to arise from high levels of magnesium consumed in the diet, and it needs to be remembered that like all other nutrients, magnesium does not operate in isolation within the body and interacts closely with other vitamins and minerals.
Any supplementation should therefore be taken as part of a comprehensive multi-mineral. And for the maximum anti-oxidant effect through the production of glutathione, this should be taken alongside a good quality multi-vitamin preparation.
