Magnesium Deficiency and Whole Foods

Unfortunately, it is difficult to reliably supply our bodies with sufficient magnesium, even from a good, balanced whole foods diet. First of all, modern agricultural methods favor the universal use of NPK fertilizers (nitrogen, phosphorus, and potassium). Both potassium and phosphorus are antagonists of magnesium in the soil, and on calcareous soils create a relative magnesium deficiency (the magnesium present is bound and therefore unavailable to the crop). On sandy or loamy soils that are slightly acid, an actual magnesium deficiency often exists, as the magnesium leaches from the soil and is also unavailable to the crop. This leaching also occurs in response to acid rain. Magnesium, in fact, is one of the most depleted minerals in farm soils. To add insult to injury, new plant hybrids are continually introduced that have been bred to survive on these mineral-depleted soils. Of course, when mineral-depleted crops are eaten by animals or by us, they will sooner or later cause disease. Even though organically raised crops should be a better bet nutritionally, this isn’t always the case, and it pays in terms of your health to learn how your farmer replenishes the minerals on his fields.

Magnesium and other nutrients are diminished or lost in produce after harvest, through handling, refrigeration, transport and storage, even if all these steps were done “properly.” Buying produce and then storing it for days in your own refrigerator continues the nutrient loss, whether the produce is from the supermarket or your local farmers’ market.

Food processing causes enormous loss of magnesium in foods that are commonly fairly good sources of it, such as leafy greens, nuts, seeds and whole grains. Most of the magnesium in grain— found in the bran and germ—is lost in milling whole grains for white flour, which is used nearly exclusively for hundreds of devitalized processed food items. When nuts and seeds are roasted or their oils extracted, magnesium is lost. Cooking greens causes whatever magnesium they might contain to leach into the cooking water. Foods tend to lose less calcium than magnesium through these processes, adding to a troublesome dietary calcium overload that we will discuss shortly.

Fluoride in drinking water binds with magnesium, creating a nearly insoluble mineral compound that ends up deposited in the bones, where its brittleness increases the risk of fractures. Water, in fact, could be an excellent source of magnesium—if it comes from deep wells that have magnesium at their source, or from mineral-rich glacial runoff. Urban sources of drinking water are usually from surface water, such as rivers and streams, which are low in magnesium. Even many bottled mineral waters are quite low in magnesium, or have a very high concentration of calcium, or both.

A diet of processed, synthetic foods, high sugar content, alcohol and soda drinks all “waste” magnesium, as a lot of it is required for the metabolism and detoxification of these largely fake foods. According to Dr. Natasha Campbell-McBride, the body requires at least twenty-eight molecules of magnesium to metabolize a single molecule of glucose. Phosphates in carbonated drinks and processed meats (so-called “luncheon meats” and hot dogs) bind with magnesium to create the insoluble magnesium phosphate, which is unusable by the body.

Tannins, oxalates, and phytic acid all bind with magnesium, making it unavailable to the body unless extra care is taken to neutralize some of these compounds during food preparation. It is interesting to note that foods commonly containing magnesium (provided they were grown in mineral-rich soil) also contain lots of these anti-nutrients, such as spinach (oxalates) and whole grains (phytates).

Many commonly prescribed pharmaceutical drugs cause the body to lose magnesium via the urine, such as diuretics for hypertension; birth control pills; insulin; digitalis; tetracycline and some other antibiotics; and corticosteroids and bronchodilators for asthma. With the loss of magnesium, all of the symptoms being “treated” by these drugs over time inevitably become worse.

Magnesium absorption is impeded with the use of supplemental iron. If you take calcium supplements, your need for magnesium increases, and in fact calcium will not be properly absorbed or metabolized if adequate magnesium is missing, and will mostly end up dangerously deposited in soft tissues. Magnesium is responsible for converting vitamin D to the active form that allows calcium to be absorbed, and also regulates calcium’s transport to hard tissues where it belongs. Lactose is another inhibitor of magnesium absorption (and milk is not a good source of the mineral to begin with), along with excess potassium, phosphorus and sodium.