Magnesium the most misunderstood mineral
Magnesium - The Most Misunderstood Mineral
Magnesium is a critical mineral in the human body governing the activity of hundreds of enzymes encompassing ~80% of known metabolic functions. Despite the importance of magnesium, it remains one of the least understood and appreciated elements in human health and nutrition. The current RDA (recommended daily allowance) of magnesium are ~400 mg/day for a healthy adult. but it is currently estimated that both adults and kids in the UK do not reach this (UK National Diet & Nutrition Survey) and the average magnesium intake is somewhere around 230 mg/day for women and 320 mg/day for men. This is a pretty substantial shortfall for men, and particularly women! The average intake drops even further below the RDA for elderly demographics. Its important to note that in general RDA value is based on the absolute minimum amount necessary in order to prevent severe diseases. Even if you meet that 400 mg/day threshold you are still only running at the bare minimum necessary to avoid obvious consequences (as compared to say, potentially subclinical ones).
So what is the consequence of running our body on low magnesium? Magnesium is key to correct calcium and potassium transport, cell signaling, energy metabolism, genome stability, DNA repair and replication. Inadequate intracellular magnesium reduces the capacity and efficiency of our mitochondria - the energy powerhouses of our cells. It also helps your cells have the highest oxidative capacity and is one of the factors determining the correct structural and function of our proteins and DNA. That translates to muscle cramping, excessive soreness, inadequate force production, disrupted recovery and sleep. Altered immune response is a frequent manifestation of magnesium deficiency. Magnesium is found to be lower during systemic inflammation, and conditions associated with both increased inflammation and impaired antioxidant enzyme expression and activity. Hypomagnesaemia is now associated with many diseases including high blood pressure, heart disease, type 2 diabetes, osteoporosis, and several neurological disorders.
Magnesium (Mg) deficiency is very common but many people still want to know if this can be tested or confirmed in any way. The published literature says that “there is no simple, rapid and accurate laboratory test to indicate the total body magnesium status.”1 The commonly used blood tests (i.e. serum magnesium) are not sensitive enough to pick magnesium levels inside various cell types (red blood cell, muscle etc.). It is important to point out that a person can still have “suboptimal” total magnesium levels without any lab finding that is out of range.Despite its importance, magnesium remains one of least investigated minerals, and while it is starting to get more attention, this still pales in comparison to the level of investigation into other macronutrients such as calcium or iron. The root cause of this oversight likely lies in the fact that deficiencies in other minerals present with more overt and well recognised symptoms, whereas magnesium deficiency manifests with more subtle signs that cumulatively over time precipitate problems, or are overshadowed by co-morbidity such as diabetes or heart disease. Other mineral deficiencies are more readily diagnosed by commonly used, and clinically validated, diagnostic assays which mainly use blood. Detecting a magnesium deficiency is further complicated by the facts that 99% of your body's magnesium is located in bone, muscles, and soft tissue, with the other 1% is found in plasma and red blood cells. But there is a current lack of a standardised test that accurately assess the status of magnesium which no doubt contributes to the relative anonymity of magnesium and further contributes to magnesium deficiency and its sequelae.
*Magnesium deficiency as defined by serum blood levels: “normal” being considered as 0.7–1 mmol/L and hypomagnesaemia as <0.7 mmol/L
Reasons we are starving for magnesium.
#1 - Decline in soil
Even the most health conscious amongst us are at risk of being low* on this essential mineral. This is attributed in part to a steady decline in general magnesium content in cultivated fruits and vegetables, a reflection of the observed depletion of magnesium in soil over the past 100 years. This loss of mineral content across “healthy” food choices has been compounded by a rise in the consumption of foods which impede magnesium absorption.
#2- Reduced intake of magnesium rich foods.
Magnesium is part of chlorophyll, the green pigment found in plants, so green leafy vegetables are particularly high in magnesium. Reduced intake of magnesium rich foods has fallen amongst the general population.. In addition to green veggies, pumpkin/squash seeds, brazil nuts, peas & black-eyed peas, sunflower seeds (& butter) and tempeh/fermented soy are amongst the rich sources of magnesium but the bio-availability is much lower than that of green leafy vegetables.
#3- Poor digestive absorption.
Due to the complex nature of magnesium absorption, segments of the gastrointestinal tract can vary in their contribution to absorption. Meals containing carbohydrates and medium chain fatty acids will increase magnesium uptake but will also increase the demand since magnesium is critical to glucose breakdown and insulin release. Solid meals, by prolonging GI transit time, can also enhance magnesium absorption. Gender also contributes to magnesium status as estrogen enhances magnesium utilization. Renal function is a key player in magnesium homeostasis. Once magnesium is absorbed in the intestine it is distributed around the body for storage in bone and muscle with little detected in the blood. Suboptimal magnesium status is a frequent condition in older persons.
#4- Excessive excretion of minerals.
The kidneys play a major role in maintaining the body’s magnesium levels, reabsorbing depending on the body’s needs Anywhere between 5% and 70% filtered magnesium may actually be excreted in the urine depending on ever changing variables such as dietary intake. Ion channel transient receptor potential membrane melastatin 6 and 7 (TRPM6 and TRPM7) play a central role in magnesium homeostasis. Common genetic variants of these transporters is associated with low magnesium and higher type 2 diabetes risk. But there are a few other factors that can alter how much the kidneys reabsorb.including alcohol, inflammatory bowel conditions, excessive exercise or kidney problems. .
Efficacy of Magnesium Supplementation - Myth or Reality?
Magnesium compounds are widely used as medicinal and dietary supplements. The effectiveness of oral magnesium supplementation for the treatment of magnesium deficiency presents some unique challenges. Usage of poorly ionized forms of magnesium could be one factor to blame. Magnesium oxide, an inexpensive magnesium complex in popular dietary supplements has fractional absorption in the gut. Magnesium citrate, a relatively well absorbed magnesium compound, provides an absorption rate of 50% at most. And yet, realistic absorption rates from oral magnesium supplements are rarely taken into account. Inconsistencies in bioavailability from one form of magnesium to the next aside, nearly all magnesium supplements share a common tendency to create a laxative effect. A recent meta-analysis identified that a supplement of more than the >370 mg magnesium/day showed greater efficacy than a lower dose in improving blood pressure.
Magnesium supplements that are enteric coated are absorbed 67% less than non-enteric coated supplements. In a study that compared four forms of magnesium supplements, data suggested lower bioavailability of magnesium oxide, with significantly higher absorption and bioavailability of magnesium glycinate, magnesium lactate, and magnesium citrate.
Transdermal Magnesium Delivery.
Transdermal magnesium is a practice which avoids the risk or inconvenience of oral therapy (negates pills & their potential gastrointestinal upset). There is increasing claims of the effectiveness & superiority of transdermal (through the skin) magnesium over oral as the ultimate way to replenish cellular magnesium levels. It passes directly into the tissues via the skin, where it should quickly be transported to cells throughout the body. Transdermal absorption of magnesium in comparison to oral application is presented as being more effective due to nearly 100% absorption, & presenting fewer side effects bypassing the gastrointestinal tract (note that this was funded by transdermal Magnesium company Better You).
Here are some options for using transdermal magnesium:
Epsom salts bath is a popular form & commonly used for decreasing muscle soreness. Epsom salts deliver magnesium sulfate, which is particularly helpful with post-workout recovery.
Magnesium chloride is even more effective than Epsom salts. Dissolve pure magnesium chloride flakes or crystals in a bath makes for an extremely relaxing and soreness relieving soak. Alternatively, if you don’t want to hop in a full bath, after a long run or ride, you can simply soak your feet in a magnesium chloride footbath.
Topical magnesium chloride spray is my personal favourite. I use 8-10 sprays each on my shoulders, arms and legs after a hard workout, and rub on my abdomen & back before bed for restful sleep. Just be aware that this can cause tingling of the skin in some people.
Magnesium Glycinate is another preparation. Glycine is a well-known calming amino acid. This combination has good bioavailability and does not have a laxative effect since glycine is actively transported through the intestinal wall. Due to the calming and relaxing effect of both glycine and magnesium, this combination has been used successfully for chronic pain and to promote relaxation.
Magnesium malate is a less well-known combination has been studied for use in fibromyalgia. Since malate is a substrate in the cellular energy cycle, it can help improve ATP production; there is some preliminary evidence that it may reduce muscle pain and tender points in fibromyalgia patients.
There are other preparations including Magnesium Taurate, L-Threonate & picolinate that are less common & each have their own unique properties in addition to replenishing whole body magnesium.
Overall, due to its broad ranging beneficial effects, magnesium has really emerged as a quintessential health supplement with an excellent safety profile that can be included in addition to regular consumption of magnesium rich foods.