Magnesium is a mineral that the body needs a lot of. It is found naturally in many foods, added to other foods, sold as a dietary supplement, and in some prescription drugs (such as antacids). Magnesium is a cofactor in more than 300 enzyme systems that control different biochemical reactions in the body, such as protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation.
Magnesium is referred to as a “macro-mineral,” which means that our food must provide us with literally hundreds of milligrams of magnesium every day. The other macro-minerals that all humans must get from food are calcium, phosphorus, sodium, potassium, and chloride. Minerals which are required in much smaller amounts are called the “trace elements”.
People are often surprised to hear that magnesium is found mostly in their bones (60-65%). Magnesium is thought of by the majority of people as the “muscle mineral”, i.e; when you get a cramp the first thing you take is magnesium. Calcium, on the other hand, is thought of as the “bone mineral”, yet recently it was discovered that giving calcium on its own (without magnesium) could increase the risk of heart attack. Unfortunately, many medical doctors still prescribe calcium carbonate unopposed (on its own, without any magnesium) to their patient with bone loss. Calcium and magnesium are best given in equal amounts to a person who wants to build up bone tissue.
This critically important mineral has many functions in fact too many to cover on this page so we will just examine some of the most important functions of magnesium.
Like all minerals, magnesium cannot be made in our body and must therefore be plentiful in our diet in order for us to remain healthy.
Did you know that about two thirds of all magnesium in your body is actually found in your bones? Researchers have discovered, however, that bone magnesium has two very different roles to play in our health. Some of the magnesium in our bones helps give them their physical structure. This magnesium is part of the bone’s crystal lattice and is found in this bone scaffolding together with the minerals phosphorus and calcium.
The bone’s surface also contains magnesium, and this source does not appear to be involved in the bone’s structure, but instead acts as a storage site for magnesium which the body can draw upon in times of poor dietary magnesium supply. The body’s inherent wisdom will prevent a magnesium shortfall this way.
Bone health is supported by many factors, most notably calcium and vitamin D. However, some evidence suggests that magnesium deficiency may be an additional risk factor for post-menopausal osteoporosis. This may be due to the fact that magnesium deficiency alters calcium metabolism and the hormones that regulate calcium.
Several human studies have suggested that magnesium supplementation may actually improve bone mineral density. In a study of older adults, a greater magnesium intake maintained bone mineral density to a greater degree than a lower magnesium intake.
Diets that provide recommended levels of magnesium are beneficial for bone health, and for this reason, we recommend that you include plenty of magnesium rich foods in your diet and to take magnesium supplementation where need be.
Magnesium is in our muscles, but only at the rate of about 25%, as well as in other cell types and body fluids. About 1% of the body’s magnesium is in the blood. Magnesium is widely regarded by most as the “anti-cramp” mineral, since it has the ability to relax our muscles.
But did you know that your nerves also depend upon magnesium to avoid becoming overexcited? Magnesium’s ability to relax the muscles and nerves is what links this macro mineral to the maintenance of healthy blood pressure. Magnesium and its “macro brother”, calcium, act together in several ways to help regulate the body’s nerve and muscle tone.
Magnesium serves as a chemical gate blocker in many of the body’s nerve cells. Magnesium helps to oppose the activity of calcium, preventing it from moving too quickly inside the cell and activating the nerve. This balanced activity helps to keep the nerves (and therefore muscles) relaxed.
So now you see, if your diet provides too little magnesium, or if you deplete your body of too much magnesium (coffee, tea, junk foods, alcohol, sweet foods, ice cream, etc.) then your nerves and muscles will pay the price. Nerve cells become over activated (over excited) with too little magnesium because this gate blocking calcium/magnesium mechanism fails. Muscles over contract because too many messages are sent by the nerves to the muscles. This imbalance explains why a magnesium deficiency can trigger muscle fatigue and tension, muscle cramps and spasms and muscle soreness and weakness.
Clinical studies have shown that chronic magnesium depletion has direct consequences for both the heart and the blood vessels. There are 8 things to know about magnesium nutrition and heart health.
1. Heart Attacks: The heart is a very large muscle. Calcium causes muscles to contract and magnesium causes them to relax. If the body is deficient in magnesium, the heart can go into spasm causing a fatal heart attack; beat erratically causing arrhythmia; or beat too slowly (bradycardia) or too quickly (tachycardia).
2. Magnesium prevents blood clot formation and muscle spasms of the heart blood vessels, which can lead to heart attack. One major cause of angina is spasming of the heart’s coronary arteries that are lined with smooth muscles that react to a deficiency of magnesium.
3. Magnesium prevents muscle spasms of the peripheral blood vessels, which can lead to high blood pressure, another risk factor of heart disease.
4. High blood pressure can cause stroke and heart attack. Tension in the smooth muscle of blood vessels throughout the body due to magnesium deficiency is a major cause of high blood pressure.
5. Magnesium prevents calcium buildup in cholesterol plaque in arteries, which leads to clogged arteries.
6. Your body requires magnesium to maintain healthy elastin, which provides essential elasticity in your arteries. Loss of elasticity is a risk factor for heart disease. Loss of elasticity causes inflammation of heart blood vessels, which interferes with blood flow and leads to heart disease.
7. Magnesium deficiency symptoms include leg cramps, eye twitching, fatigue, constipation, insomnia, anxiety, racing heart, and chest pain.
8. Magnesium is a natural calcium channel blocker allowing the proper amounts of calcium in balance with magnesium for heart health.
“Epidemiologic evidence suggests that magnesium may play an important role in regulating blood pressure” according to The Institute of Medicine, Food and Nutrition Board. (Dietary Reference Intakes: Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride. National Academy Press. Washington, DC, 1999).
Research has shown that diets which are high in magnesium, potassium, and calcium, and low in sodium and fat are consistently associated with lower blood pressure. The DASH study (Dietary Approaches to Stop Hypertension), a human clinical trial, suggested that high blood pressure could be significantly lowered by a diet that emphasises fruits, vegetables, and low fat dairy foods.
Another study involved over 30,000 US male health professionals which involved examining the effect of nutritional factors on the incidence of blood pressure. After four years of follow-up, it was found that a lower risk of hypertension was associated with dietary patterns that provided more magnesium, potassium, and dietary fibre.
For 6 years, the Atherosclerosis Risk in Communities (ARIC) Study followed approximately 8,000 men and women who were initially free of hypertension. In this study, the risk of developing hypertension decreased as dietary magnesium intake increased in women, but not in men.
Doctors call magnesium “Nature’s calcium channel blocker” because it does the same job that Calcium channel blocker heart drugs do, to modulate vascular tone. Magnesium also stimulates nitric oxide, a mechanism at work when we exercise, helping to relax and dilate blood vessels.
High levels of calcium but low levels of magnesium can cause persons to become obese especially concentrating most of the weight gain around the stomach. These people are developing “Metabolic syndrome or Syndrome X“, and are highly likely to develop high blood pressure, diabetes and insulin secretion, known factors contributing to heart attack.
A magnesium rich diet helps to prevent as we as lower existing blood pressure
It is interesting to note that the foods high in magnesium are frequently high in potassium and dietary fibre as well.
It becomes quite difficult to evaluate the effects of magnesium on blood pressure alone independently of other minerals in this situation, but new evidence from the DASH clinical trials has given the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure the confidence to recommend the DASH diet as an eating plan of therapeutic benefit for people with high blood pressure and also for those with “pre-hypertension” who desire to prevent hypertension: DASH Diet.org
Optimise you magnesium if you are hypertensive
If you are struggling with high blood pressure, optimising your magnesium intake is highly recommended and one of the first things I recommend you do. The current recommended daily level for adults is 320 mg a day for women and 420 mg a day for men. You can also find more tips and best products for lowering your blood pressure naturally by using the search feature on this site.
Magnesium is one of the most important minerals in your body, because many chemical reactions which involve enzymatic reactions in the body rely on this crucial mineral. Enzymes are highly specialised proteins developed by your body to initiate chemical reactions. It is estimated that over 350 different enzymes in your body are magnesium dependent, and this is why the functions of magnesium are so diverse and varied in your body.
For example, magnesium is involved in the metabolism of proteins, carbohydrates, and fats. It helps your genetic code function properly. Your muscles require large amounts of magnesium in order to store certain types of fuels, and this is one of the reasons those with conditions such as tension headaches, pre-menstrual syndrome (PMS) and fibromyalgia are almost always magnesium deficient.
Magnesium has so may diverse and varied applications in your body, it is almost impossible to find a system which is not affected to a small or large degree by a magnesium deficiency. For example, your brain, cardiovascular and digestive systems, muscular and nervous systems, liver and kidneys and hormone secreting glands and even your blood all rely on magnesium for proper metabolic functioning.
Because magnesium plays such a wide variety of roles in the body, the symptoms of magnesium deficiency can also vary widely. Many symptoms may initially involve subtle changes in nerve and muscle function. These changes include muscle weakness, tremor, and spasm.
Do you eyelids “flutter” occasionally? Do you easily get tired, cramped, sore or tense muscles? Do you routinely have premenstrual pain? Does your heart feel like it is skipping or missing beats or perhaps “racy’ at times? This are all strong indications that you will benefit from more magnesium. I have also found that it is worth experimenting with 200 – 400mg of magnesium citrate about a half an hour before bedtime for those with restless sleep.
Because of its role in bone structure, the softening and weakening of bone can also be a symptom of magnesium deficiency – your bones make break or fracture much more easily for example. Other symptoms can include: imbalanced blood sugar levels (hypoglycemia); headaches; hypertension; elevated fats in the bloodstream (cholesterol levels up); depression or anxiety; seizures; nausea; vomiting; and a general lack of appetite.
It is estimated that many people do not get their recommended daily amounts of magnesium, and the concern is that many people may not have enough body stores of magnesium because dietary intake may not be high enough. Yet, symptoms of magnesium deficiency are rarely seen in many countries. Having enough body stores of magnesium may be protective against disorders such as cardiovascular and neuro-muscular disease as well as immune dysfunction.
Magnesium levels in the body are very much influenced by the health status of your digestive system and the kidneys, this mineral is absorbed primarily in the intestines and is then transported through the blood to cells and tissues. Approximately one-third to one-half of your dietary magnesium is absorbed into the body, the rest is passed out in the urine or bowel motions or sweat. For this reason, it pays to optimise these systems to increase the uptake (and prevent premature loss) of magnesium. I have found that many patients supplement with magnesium, when in fact they would be better to improve their digestive and kidney function in particular and eat more magnesium containing foods.
Gastrointestinal disorders that impair absorption such as inflammatory bowel disease or irritable bowel syndrome can limit the body’s ability to absorb magnesium. These disorders can deplete the body’s stores of magnesium significantly and in extreme cases may result in marked magnesium deficiency.
Chronic or excessive vomiting and diarrhoea may also result in not only a magnesium depletion, but a depletion of potassium, sodium and chloride as well. This is why you feel so weak and drained after you have been ill (vomiting and diarrhoea) for a day or two, you have lost a lot of your electrolytes which are the main minerals which keep you alert, providing strong and healthy vital functions.
Healthy kidneys are able to limit urinary excretion of magnesium to make up for low dietary intake or a loss due to poor lifestyle choices like excessive alcohol and caffeine. However, excessive loss of urinary magnesium can be a side effect of some pharmaceutical medications. Poorly-controlled diabetes is another prime cause of poor kidney function, leading to the loss of many minerals critical for optimal health and well being.
The earliest signs of magnesium loss include loss of appetite, nausea, vomiting, fatigue, tiredness and weakness. As magnesium deficiency worsens, numbness, tingling, muscle contractions and cramps, seizures (sudden changes in behaviours caused by excessive electrical activity in the brain), increasing anxiety and depression, personality changes, abnormal heart rhythms like heart racing or “skipping beats”, and coronary spasms (chest cramping) can occur.
Severe magnesium deficiency can result in low levels of calcium in the blood (hypo-calcemia). Magnesium deficiency is also associated with low levels of potassium in the blood (hypo-kalemia).
Blood tests can reveal this, and just request your doctor to do a CBC – Complete Blood Count. It is important for you to have your doctor evaluate your condition if you feel that you can relate to many of these signs and symptoms because many of these symptoms are quite generalised and can result from a variety of medical conditions other than magnesium deficiency. I always recommend that you get an expert’s advice before you go and treat your self.
Magnesium can be bought as a nutritional supplement in one of two basic forms: chelated or non-chelated. “Chelated” means connected with another molecule. In the case of magnesium, the most common chelates fall into the category of amino acid chelates. In these supplements, magnesium is attached to a building block of protein (called an amino acid). The most widely-available amino acid chelates are magnesium glycinate and magnesium aspartate.
Magnesium can also be attached to an organic acid (like a citrate) or to a fatty acid (like a stearate). Some companies falsely claim that magnesium stearate is not absorbed that well, due to the magnesium being “encased” in fat. The claim that stearate binders in pills may dramatically decrease “absorption of nutrients” is a mistaken idea that apparently stems from confusion about the difference between capsules dissolving “in solution” as opposed to being digested in the human body.
The body is more than capable of digesting fats, and the tiny amount found as a binder or filler in a dietary supplement is on no consequence even to those with impaired digestive systems.
The “non-chelated” forms of magnesium include magnesium oxide, magnesium sulfate, and magnesium carbonate. Unfortunately, the non-chelated forms are associated more commonly with digestive upsets than the chelated forms.
Research has also found that the ability for the body to absorb chelated forms of magnesium (magnesium citrate) is superior to that of the non-chelated forms such as magnesium carbonate and magnesium oxide.
Green leafy vegetables – There are many reasons to eat your leafy greens, and here is one of the most important reasons: Green vegetables are an excellent source of magnesium which is bound to the chlorophyll molecule that gives veggies their deep green colour. Although most green leafy vegetables are a prime source of magnesium, spinach and Swiss chard (silver beet) are two of the best. If you enjoy sea vegetables such as seaweed, they’re also excellent sources of magnesium. To get your daily magnesium, think like Popeye!
Nuts and seeds – Nuts are some of your best sources of magnesium with almonds and cashews topping the list. Dried pumpkin, sunflower seeds and even watermelon seeds are also quite high in magnesium. Try making a trail mix using pumpkin seeds and nuts to give your magnesium intake a healthy boost. They store well and are good to take when you travel along with water.
Whole grain foods – One of your best sources of magnesium is unrefined grains. Refined grains are lower in magnesium because they have been processed to remove the bran and germ which is where most of the grain’s magnesium is actually located. Do you still eat white bread? – just substitute this for whole grain bread when making sandwiches. Rather than relying on those highly processed and boxed cereals for your breakfast, what about having rolled oats or millet topped with a few almonds and honey? If you want even more magnesium then sprinkle on top some ground linseed, wheat germ or wheat bran. Amazing, but one cup of wheat bran supplies you with over half of your daily magnesium requirement.
Caution with phytates
Spinach and Swiss chard (silverbeet) are excellent recommendations for people looking to increase their magnesium intake, which should be just about all of us, but it is important to note that whole grains, legumes, and nuts are not the best way to increase one’s magnesium levels due to one very important reason. All of the foods (oats and soybeans in particular) high in phytates actually bind with magnesium and zinc and help to carry them out of the body.
The Adequate Intake (AI)levels for magnesium, set in 1997 by the Institute of Medicine at the National Academy of Sciences, are as follows:
The Recommended Dietary Allowances for magnesium, set in 1997 by the Institute of Medicine at the National Academy of Sciences, are as follows:
The National Academy of Sciences set a tolerable upper limit (UL) on intake of magnesium at 350 milligrams per day for individuals 9 years and older. This limit was restricted, however, to magnesium obtained from dietary supplements, and no upper limit was set on intake of magnesium from food sources. For more details on this, see the Toxicity Symptoms section above.
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