The Body’s Demand for Magnesium
Having trouble sleeping? Struggling to switch off? You may be deficient in magnesium. Today, so many people are magnesium deficient. Common conditions such as stress, cardiovascular disease and diabetes increase the body’s demand for magnesium. This increased requirement is often not met due to reduced dietary intake of magnesium-rich foods, poor soil quality and malabsorption issues. Also, with the increased processing of foods in the Western world and the refinement of grains, foods are now containing significantly less magnesium than they did a hundred years ago.
What is Magnesium?
Magnesium is an essential mineral in the human body and serves as a cofactor in about 325 enzymatic reactions in the body. It is used for energy production, maintenance of lean muscle, muscle contraction and nervous system function. This important mineral also helps your heart by supporting and regulating healthy blood pressure and blood sugar levels, as well as maintaining a steady heartbeat.
The adult body contains approximately 24g of magnesium with half stored in the bones and almost all the rest locked inside our cells. Only about 1% of magnesium is in the bloodstream.
Signs and Symptoms of Low Magnesium
Scientific research suggests that subclinical magnesium deficiency is common and that it is in fact, one of the leading causes of chronic diseases including cardiovascular disease and early mortality in the world. Subclinical magnesium deficiency is where your blood magnesium levels appear normal but you still have an underlying mineral deficiency.
In addition to inadequate dietary intake, poor soil quality and malabsorption issues, magnesium depletion in the body may be caused by or worsened by:
- Excessive alcohol consumption can also lead to imbalances of electrolytes, causing the body to release more magnesium than usual.
- Excessive intake of sugar, salt and caffeine and carbonated drinks
- Profuse sweating
- Hyperaldosteronism, hyperparathyroidism with hypercalcaemia, hyperthyroidism, diabetes mellitus
- Pregnancy, lactation, excessive menstruation
- High levels of intense exercise
- Imbalance of other nutrients such as calcium, B vitamins and zinc
- Intense, chronic stress- the activation of the stress response increases the use and elimination of magnesium from the body
- Coeliac disease, Inflammatory Bowel Disease, malabsorption disorders, partial bowel obstruction, pancreatitis, infections such as parasitic infections
- Certain medications (such as antibiotics, diuretics, steroids and proton pump inhibitors)
Risk Factors for Magnesium Depletion
Early detection of low magnesium levels may assist in the prevention and improved management of certain health conditions. Some signs and symptoms of low magnesium levels include:
- Stress, anxiety and nervousness
- Lethargy and fatigue
- Loss of appetite and weakness
- Muscle tension, twitches, cramping and spasms
- Tension headaches and migraines
- Chronic fatigue
- Irritability and excitability
- Poor memory and cognitive ability
- Reduced pain threshold
- Menstrual problems such as PMS
- Low blood levels of calcium and potassium
- High blood pressure
- Insulin Resistance and Diabetes
- Chocolate cravings
- Kidney stones
- Weight gain
- Pregnancy complications
- Heart palpitations or disease
- Numbness in the limbs
Benefits of Magnesium
Not only is magnesium essential for 300 different reactions in the body from making cellular energy and transmitting nerve impulses to balancing your blood sugar levels, it also plays an essential role in the prevention of numerous health conditions too.
Improved heart health
Magnesium deficiency has been associated with a long list of cardiovascular disorders including high blood pressure, abnormal heart rhythm and cholesterol-clogged coronary arteries. In fact, a 2017 meta-analysis of 11 studies published in Nutrition Journal concluded that lower levels of magnesium circulating in the blood are associated with the incidence of heart disease and hypertension. Inversely, researchers were able to determine that higher levels had a protective effect on heart health and that specifically, for every 0.1 mmol/L increase in circulating magnesium, there was a 4% lower incidence of hypertension.
Magnesium is essential to a healthy heart as it plays a role in transporting other electrolytes, such as calcium and potassium, into cells. Electrolytes are minerals that carry an electrical charge and spark cell function throughout the body. They support hydration and energy production and they’re also responsible for stimulating muscle contractions, including your heartbeat. In a review published in 2019 in Cardiology Research and Practice, researchers found that magnesium deficiency is associated with atrial fibrillation where a malfunction in the heart’s electrical system causes the upper chambers of the heart to quiver. A 2005 meta-analysis which reviewed 20 RCTs, found that administering intravenous or intramuscular magnesium prior to heart surgery was effective in preventing post-operative atrial fibrillation which can lead to blood clots, stroke and heart failure.
Magnesium also exerts beneficial effects on the cardiovascular system by improving glucose and insulin metabolism, enhancing endothelial-dependent vasodilation, acting as an anti-inflammatory and antihypertensive, improving lipid profile and by acting on transmembrane ion transport pumps. Ion pumps actively build gradients across the membrane which are then used to pump nutrients into cells, regulate synaptic transmission, regulate cell volume and secrete electrolytes into the cerebrospinal fluid.
May assist with muscle tension and athletic performance
Magnesium has long been promoted for its ability to enhance muscle relaxation and to relieve spasms. While a lot more research is warranted in this area, cramping, which is caused by increased neuromuscular excitability, is a classic feature of magnesium deficiency. It is suggested that magnesium relaxes your muscles and stops cramping by counteracting the contracting effects of calcium. Some cross-sectional surveys demonstrate a positive association between magnesium status and muscle performance, including grip strength, lower leg power, ankle extension strength, maximal isometric trunk flexion, rotation and jumping performance, suggesting the potential for the use of magnesium supplementation for athletes to improve performance.
Reduced risk for osteoporosis
A tight control of magnesium and calcium balance is crucial for bone health, so it makes sense that either low or high magnesium levels can have a harmful effect on the bones. Magnesium deficiency contributes to osteoporosis by acting on crystal formation and on bone cells and by impacting on the secretion and activity of parathyroid hormone as well as by promoting low grade inflammation. A 2017 study examined associations between skeletal muscle mass, grip strength, bone density, and dietary magnesium among 156,575 participants ages 39-72. The researchers found a significant correlation between magnesium intake and bone health, suggesting that getting enough magnesium in the diet could help maintain musculoskeletal health as you age and prevent osteoporosis and bone fractures.
May help prevent type 2 diabetes
Findings in a 2017 meta-analysis suggest that circulating magnesium levels are inversely associated with incidence of not only heart-related conditions, but also type 2 diabetes. Furthermore, a recently published systematic review and meta-analysis reported that oral magnesium supplementation improved insulin-sensitivity and glucose parameters in those who were at high risk of diabetes.
Improves sleep patterns and quality
Magnesium may improve sleep patterns and quality as it is known to calm the stress response as well as assist with muscle tension and restless legs, which may affect sleep. It helps you feel less anxious by producing GABA, a calming neurotransmitter which helps you switch off your mind and relax your body. A study published in the Journal of Research in Medical Sciences found that 500 mg of supplemental magnesium, taken daily for eight weeks, resulted in improved sleep patterns among elderly patients with insomnia when compared to a placebo group. Although total sleep time didn’t significantly differ between the two groups, those who received magnesium reported higher sleep quality and less waking throughout the night.
May reduce and prevent migraines
An ample amount of evidence supports the use of magnesium in the treatment and prevention of migraines and tension headaches. A Cochrane review regards magnesium as one of the most strongly recommended treatments for migraine headaches. Oral magnesium has been shown to reduce the frequency, duration and severity of migraines by 41% compared to placebo at 15.8%. It is believed that magnesium deficiency may trigger waves of altered cortical activity and cerebral artery spasm, clumping of blood platelets in the brain, constricted blood vessels and release of certain pain mediators and other neurotransmitters that can prompt migraines.
May help to regulate mood
Magnesium is important for central nervous system function and may play a role in Alzheimer’s Disease, diabetes, hyperactivity deficit and stroke. Previous studies have associated magnesium with glutamatergic transmission in the limbic system and cerebral cortex, brain regions that play important roles in the pathogenesis of depression. A study published in 2017 in PLoS One set out to determine if over-the-counter magnesium chloride supplementation improved symptoms of mild depression among 126 adults in outpatient primary care clinics. The participants received an intervention of 248 mg of magnesium per day for six weeks and then for six more weeks, they received no treatment as the control. Using the Patient Health Questionnaire-9, researchers found that magnesium supplementation resulted in significant improvement in depression scores. 61% of the participants also said they would continue using magnesium in the future.
Another mechanism involves magnesium’s ability to influence the gut microbiota, thereby eliciting changes in the oxidative and inflammatory response. As inflammation and oxidative stress both also play a role in the progression of depression, the evidence for magnesium as a treatment also mounts. Finally, magnesium could potentially help in depression indirectly due to its effects on melatonin levels and the circadian rhythm.
Helps to support a healthy stress response
Magnesium may also help support a healthy stress response as it has the ability to reduce the release of adrenocorticotrophic hormone (ACTH) and modulate adrenocorticotropic sensitivity to ACTH which is preventative against the hyperactivation of the HPA axis. Dysregulation of the HPA axis in adults has been strongly linked to elevated cortisol. Magnesium is also essential for the brain’s dopaminergic synthesis. Dopamine imbalance can affect mood and can lead to overwhelming anxiety.
May support female health
Several vitamins and minerals including magnesium are essential for neurotransmitter synthesis and hormonal balance. Studies have reported reduced circulating magnesium concentrations during the luteal phase among women with PMS, suggesting that magnesium deficiency may be involved in the underlying pathogenesis of PMS. Magnesium also helps to prevent bone loss approaching menopause by reducing the inflammation and free radical damage that can drive bone weakening occurring post-menopause.
While it is important to make sure you are consuming enough magnesium-rich foods in your diet, it is equally important to make sure your body absorbs it well. Approximately only 30-40% of magnesium from your diet is actually absorbed for various reasons:
- Other nutrients and compounds eaten with magnesium-rich foods compete for absorption e.g. phytic acid, which is a natural compound found in many plant foods including nuts, seeds, legumes and grains. Eating foods rich in vitamin C at the same time can neutralize phytic acid and assist with magnesium absorption.
- It’s best to eat calcium-rich foods and magnesium-rich foods separately as they compete for absorption. Separate by 2 hours.
- Cooking your foods at high temperature can result in mineral loss
- Vitamin D deficiency as vitamin D is a co-factor and is needed for the intestinal absorption of magnesium.
How Much Magnesium do you Need?
The recommended dietary intakes for magnesium are:
- 0- 6 months: 30 mg
- 7-12 months: 75 mg
- 1-3 years: 80 mg
- 4-8 years: 130 mg
- 9-13 years: 240 mg
- Boys 14-18 years: 410 mg
- Girls 14-18 years: 360 mg
- Men 19+ years: 400-420 mg
- Women 19+ years: 310-320 mg
- Pregnant women: 350-360 mg
- Breastfeeding women: 310- 320 mg
While eating a magnesium-rich diet can go a long way for your body’s magnesium homeostasis, a supplement can be a great way to top up your diet, support an increase in demand or address a deficiency.
When looking at supplement labels, look for how much elemental or equivalent magnesium it contains- 300 mg per dose is the standard ideal amount although you may want slightly higher doses depending on what you require it for.
Magnesium Toxicity and Interactions
You’re unlikely to overdose on magnesium unless you’re taking supplements. Your kidneys are usually able to filter any excess from dietary sources. Large doses of magnesium from supplements may cause diarrhoea, nausea and abdominal cramping. In fact, magnesium is sometimes used to alleviate mild constipation as the unabsorbed salts in the intestine and colon stimulate gastric motility and make things move pretty quickly through your system. The forms that are most likely to cause diarrhoea include magnesium carbonate, chloride, gluconate and oxide.
Early signs of excessive magnesium intake include low blood pressure, facial flushing, depression, urine retention and fatigue. If left untreated, this could lead to muscle weakness, difficulty breathing, irregular heartbeat and in some rare cases, cardiac arrest.
Hypermagnesemia which can result from extremely high doses or high levels of magnesium in the bloodstream, can become fatal if your kidneys are not functioning properly. Large doses of laxatives and antacids are the biggest culprits, especially when they’re providing more than 5000 mg of magnesium per day.
Be aware that magnesium supplements can interact with certain medications too such as bisphosphonates, some antibiotics, diuretics and proton pump inhibitors. Interactions may include excessive loss of magnesium, diarrhoea, formation of insoluble compounds, and reduced efficacy of the medication.
Magnesium Rich Foods
Getting enough magnesium in your diet is very important. The main food sources of magnesium include:
Spinach (cooked) 1 cup- 166mg, swiss chard (cooked) 1 cup- 160 mg, tamarind 1 cup- 116 mg, Edamame (soy beans) ½ cup- 70 mg, potato, with skin, cooked 1 medium- 50mg, bananas, 1 medium- 40mg
Grains and Legumes
Quinoa 1 cup- 120 mg, tofu 100 mg- 90 mg, red kidney beans 1 cup- 89 mg, lentils ¾ cup- 52 mg
Nuts and Seeds
Pumpkin seeds 100g- 90mg, Brazil nuts 30g- 115 mg, Sunflower seeds ½ cup- 230 mg, Almonds 30 g- 70 mg, cashews 30g- 70 mg, pine nuts ½ cup- 140 mg, flaxseeds 2 tbsp- 111 mg, sesame seeds 2 tbsp- 68 mg, Amaranth seeds 100g- 260 mg
Dark chocolate 50g- 100mg
Some other ways to get magnesium into your body include:
- Taking a bath with Epsom salts
- Applying magnesium oil to your skin