Finding good sources of magnesium is increasingly important as daily consumption of this mineral is widely deficient in the industrialized world. To find the best combination of magnesium sources to meet your daily magnesium requirement, take a look at the following guidelines on:
- Magnesium food sources,
- Magnesium absorption, and
- Magnesium sources for correcting deficiency.
Food Sources of Magnesium
The food sources highest in magnesium are:
- Seeds and nuts,
- Legumes (e.g., beans),
- Whole grains, and
- Many vegetables, including leafy green vegetables like spinach.
Among the highest magnesium levels in foods (per gram) are found in certain seeds, including pumpkin and squash seeds, flax seeds, sunflower seeds, and sesame seeds.1 Similarly high levels of magnesium are found in nuts, especially almonds, cashews, brazil nuts, pine nuts, and walnuts. Relatively high levels of magnesium are also found in legumes, including soybeans, lima beans, peanuts, black-eyed peas, lentils, and kidney and pinto beans.
Among whole grains, relatively high amounts of magnesium are found in quinoa, oats, wheat, bran, and rice. Vegetables highest in magnesium include chard, spinach, okra, parsley, arugula, avocado, burdock root, dandelion greens, kale, and mustard greens.
Note that among vegetables, green leafy vegetables contain relatively higher amounts of magnesium because they contain more chlorophyll. The chlorophyll molecule is built around elemental magnesium. Sea vegetables such as kelp and wakame can also be good dietary sources of magnesium when consumed in sufficient quantities.
Additional sources of magnesium in food include various spices, cacao (chocolate), and tea. Among animal foods, certain species of fish (e.g., halibut) contain higher levels of magnesium. In general, however, plant foods rich in magnesium provide far more magnesium than animal foods. Because magnesium is a relatively soluble mineral, foods (especially vegetables) that are boiled or cooked provide lower levels of magnesium than raw or lightly steamed foods. Therefore, even high-magnesium foods can suffer major losses of magnesium when cooked.
Dietary magnesium is absorbed through the small intestines.2 However, rates of absorption depend upon the amounts of magnesium available from foods. Many other factors, including digestive health, enzyme viability, and the balance of minerals available in the diet affect the amount of magnesium the body absorbs.
The fact that the majority of people do not receive adequate magnesium indicates that there are difficulties in obtaining sufficient amounts from available food sources of magnesium. It is important to understand that food processing significantly reduces the amount of magnesium available in foods. For example, refined grains contain little magnesium. The increase in consumption of processed foods during the past fifty years may help to explain the decrease in magnesium levels in typical American diets.
Foods with Magnesium on the Decline
In addition, modern industrial agriculture engages in practices that deplete soils of magnesium and do not replenish it after losses. Reliance on chemical fertilizers further depletes magnesium from soils and from crops grown in magnesium-poor soils. Given these changes in food production, it is no surprise that magnesium levels have declined in soils and foods.3 Whereas conventional agricultural methods have produced foods that show significant magnesium losses over time, organic agricultural methods that fail to replenish already depleted soils cannot be expected to increase magnesium levels in food crops. Agricultural methods that are truly sustainable would replenish or increase magnesium levels in soils.
The problem of depleted magnesium levels in soils and in the food supply relates to modern agricultural methods. When we consider this problem alongside the increasing consumption of refined and otherwise processed foods, the reasons for widespread magnesium deficiency become clearer. Magnesium deficiency directly relates to dietary factors such as impoverished diets (often high in refined and processed foods), poor food choices, and to poor availability of foods that provide adequate magnesium.
Given limited options currently available to the general population for significantly improving magnesium intakes from food sources, it is unlikely that foods alone can provide levels of magnesium needed for good health. Expectations that foods will provide the levels of magnesium required for health are not well founded given typical diets based on magnesium-depleted foods, and the fact of widespread magnesium deficiency.
Other factors contributing to reduce available dietary magnesium include overconsumption of cooked foods (especially vegetables) because cooking destroys magnesium content. In addition, certain foods and substances are known to increase magnesium excretion. These include alcohol, caffeine, sugar, diuretics, birth control pills, and vaccines.4
Magnesium absorption can decrease significantly during extreme physical stresses, conditions of poor health, and injuries such as:
- Liver disease
- Malabsorption problems in the intestines5
It is also known that acid-alkaline balance is important for retention of magnesium. Research suggests that metabolic acidosis is responsible for magnesium losses whether or not magnesium intake is adequate.6 High acid to base ratios are caused by acid-forming foods (including refined, processed foods) and many prescription drugs.
In addition, soft drinks, sodium, extreme athletic training, intense sweating, physical and emotional stress, and other factors can contribute to dwindling health and magnesium depletion.
Complicating this picture of mass deficiency is the fact that it is easier for persons who already have adequate magnesium levels in their bodies to successfully maintain those levels.
Therefore, persons who exhibit magnesium deficiency have difficulty correcting their deficiency states using dietary sources of magnesium alone. In fact, magnesium deficiency by itself inhibits the body’s ability to absorb magnesium.7
Magnesium Sources for Correcting Deficiency
When an individual has fallen into a state of magnesium deficiency, it can take weeks, months, or years to reestablish adequate magnesium levels from dietary magnesium sources alone, including oral magnesium supplements.
This significant time-delay factor raises additional questions about the ability of persons deficient in magnesium to assimilate magnesium quickly enough, even from foods and other dietary sources that contain high magnesium. In other words, the body’s difficulty in assimilating magnesium quickly once a person has fallen into a state of deficiency indicates that even if someone in a deficient state obtains foods or supplements containing high amounts of magnesium, the amount of time needed to actually raise cellular magnesium levels may be significant. This time delay can be especially harmful if persons suffer from health conditions related to magnesium deficiency that would benefit from faster repletion of magnesium.
The time delay characteristic of oral supplementation of magnesium represents one downside of attempting to reverse magnesium deficiency states in a timely way only using sources of magnesium in food or supplements. The magnitude of this problem becomes apparent when we consider the known fact that majority Americans are already deficient in magnesium.
Under these current circumstances, dietary sources of magnesium (and in many cases oral supplements) are unlikely to provide timely relief, especially in cases of extreme, chronic, or long-term deficiencies. A new form of magnesium, skin-absorbed magnesium oil, also known as transdermal magnesium, has been developed to fill this gap. Easily applied magnesium oil spray provides a way to enhance existing dietary magnesium and achieve the full benefits of a wide variety of sources of magnesium.
- See http://www.nal.usda.gov/fnic/foodcomp/Data/SR21/nutrlist/sr21a304.pdf [↩]
- See http://ods.od.nih.gov/factsheets/magnesium.asp [↩]
- See http://en.wikipedia.org/wiki/Magnesium [↩]
- Sircus, Mark, Ac., OMD. Transdermal Magnesium Therapy (2007), 27. [↩]
- Sircus, 27. [↩]
- Acid-Base Status Affects Renal Magnesium Losses in Healthy, Elderly Persons. Ragnar Rylander, Thomas Emer, Shoma Berkemeyer and Jürgen Vormann. 2006 J. Nutr. 136: 2374-2377. [↩]
- Sircus, 39. [↩]