Diet Rich in Magnesium
by Sue Kira, Naturopath & Clinical Nutritionist
– What influences magnesium levels?
– How much magnesium do we need and what depletes it?
– Things to avoid to keep your magnesium levels high
– Symptoms of magnesium deficiency
– Absorption of magnesium is dependent on these nutrients
– Magnesium supplementation
Magnificent magnesium…yet its importance and benefits are so unknown!
Magnesium is an essential mineral that accounts for about 0.05% of the body’s total weight, with nearly 70% of the body’s supply stored in the bones together with calcium and phosphorus. The other 30% is found in the soft tissues and body fluids.
Magnesium is involved in many essential metabolic processes, with most magnesium found inside the cells (intracellular) where it activates enzymatic processes necessary for the metabolism of carbohydrates and amino acids (protein).
Magnesium helps to promote the absorption of other vital minerals such as calcium, potassium, sodium and phosphorus. It also helps in the utilization of vitamin C and B group vitamins as well as vitamin E. Magnesium also aids in bone growth and the functioning of muscles including the heart, and can also be associated with the conversion of blood sugar into energy and body temperature balance.
What influences magnesium levels?
The parathyroid hormones influence absorption of magnesium, and vitamin D is necessary for the proper utilization of magnesium. The adrenal glands secrete a substance called aldosterone which regulates how much magnesium should be excreted via the kidneys. Therefore losses of magnesium can occur from the use of diuretics as well as the consumption of alcohol, soft drinks/sodas and caffeine (all diuretics).
High stress levels also deplete the body of magnesium. Stress can be in the form of physical (exercise) emotional, or mental stress. Because emotional stress is related to increased urine output, there can also be depletion of magnesium this way. Anxious people suffer from low magnesium and the twist is that when you are low in magnesium you become stressed more easily. Now that’s a vicious cycle. Incidentally, stress not only depletes the body of magnesium but it also depletes the body of the B group vitamins and vitamin C.
How much magnesium do we need and what depletes it?
Around 300-350mg of elemental magnesium per day is a good amount to consume, with higher amounts needed during pregnancy, lactation, times of stress and around period time for ladies (and maybe for their partners).
Therapeutically, some people may need up to 2000mg of elemental magnesium a day. The need for magnesium also increases with diets high in cholesterol and for high protein diets.
Certain bone tumors and cancers can raise magnesium levels, but usually it is rare to have too much magnesium in the body as excess is excreted via the kidneys and colon commonly resulting in diarrhea.
Certain food components bind to magnesium making it less available for the body. These are oxalic acid found in uncooked spinach and phytic acid found in grains and other things listed below.
Magnesium deficiency is common in diabetes, pancreatitis, alcoholism, cirrhosis of the liver, kidney disorders, chronic diarrhea or vomiting, as well as those consuming a high carbohydrate or high protein diet. Some drug hormones can also deplete the body of magnesium.
Things to avoid to keep your magnesium levels high
- Gluten: the phytates in gluten grains block the absorption of magnesium
- Spinach (raw): contains high levels of oxalic acid – reduced by cooking
- Cooked foods: cooked foods can strip minerals from the body. Instead, try to eat plenty of raw foods (vegetables and soaked/sprouted nuts and seeds)
- Alcohol: a diuretic that flushes magnesium out of the body
- Non-organic farmed foods: these commonly come from deficient soil that uses herbicides and pesticides that can deplete magnesium
- Refined sugar, corn syrup and any artificial sweetening substances
- Stress, especially long term: magnesium will leech out quickly if the emotions aren’t brought back into balance
- Cheap common table salt: replace it with good quality Himalayan crystal salt or Celtic Sea salt
- Tap water: can be laced with sodium fluoride and chlorine. Invest in a good quality water filter
- Refined stuff of any kind, including unfermented soy products
- Regular and decaffeinated coffee or black tea
Symptoms of magnesium deficiency
- muscle twitches, muscle weakness and cramps
- restless legs syndrome
- insomnia and trouble sleeping
- irregular heart rhythms
- hypertension and cardiovascular disease
- painful periods and contractions in the uterus
- kidney and liver damage
- behavioral disorders and mood swings
- tooth cavities
Magnesium is important to control electrical charges in the body, which is why it is useful for muscle twitches, neuromuscular disorders, nervousness and tremors.
Magnesium also helps nutrients flow in and out of cells. It also helps to protect the body against an excess of calcium in the urinary tract to prevent stone formation. It is magnesium and not calcium that helps in the formation of strong tooth enamel. Magnesium is also very alkaline so can be useful as an antacid alternative but only if you have first checked with your doctor.
Calms the nervous system and settles anxiety
Magnesium is vital for GABA function. GABA is an inhibitory neurotransmitter that that has a very calming effect. Certain hormones and neurotransmitters regulated by magnesium are crucial to calm the brain and promote relaxation, which is one reason why a magnesium deficiency can lead to restless sleep or insomnia.
Magnesium can help quiet a racing mind to make it easier to get to sleep and have a good night’s sleep. Decreased magnesium consumption and lower absorption due to aging, stress or inadequate diet can put many at risk for insomnia.
Helps to increase energy
It’s interesting to see that magnesium not only helps with sleep, but also with our energy levels. This is because magnesium helps to relax our body. but it isn’t a sedative, so in a relaxed state we can have less muscle tension and more energy.
Magnesium is also used to create energy in the body by activating adenosine triphosphate, also known as ‘ATP’ which is the energy centres or batteries of our cells. With insufficient magnesium you don’t have the energy you need and can suffer from fatigue more easily. Inadequate magnesium intake also means you tire more quickly due to needing more oxygen during exercise.
Magnesium helps to relax muscles within the digestive tract including the intestinal wall which helps reduce cramping and contraction of the colon walls. Insufficient magnesium slows down the passage of waste from your body. Magnesium is also hydrophilic (draws water to itself) which allows the stools to be softer as they move through the colon on its journey out of our body and into the dunny (Aussie slang for toilet). Too much magnesium, usually from supplements, can cause diarrhea.
Magnesium rich foods usually don’t have a laxative effect (unless you have a big smoothie full of green vegies with little else). Once I had so much spinach in the garden I didn’t want to waste any, so I made a large green smoothie. Bad idea? Bad diarrhea! I had a massive clean out about ½hr later. Even though I felt good after it settled down I didn’t repeat the experience!
Because magnesium helps to regulate muscle contractions and neuromuscular signals, when you don’t have enough magnesium, your muscles can go into cramps and spasms. Magnesium helps muscles to relax and contract so you can function and move around.
Magnesium can also help balance the calcium levels in the body. High doses of calcium, usually from supplements, can create problems with muscle control especially to control a very important muscle, the heart. As a supplement, calcium is often taken in a higher ratio to magnesium which can result in the potential for intense muscle pains, cramps, contractions and weakness.
Regulates calcium, potassium, sodium and glutathione levels
Together with the right balance of calcium, potassium and sodium, magnesium regulates many biochemical reactions in our body. Magnesium helps transport calcium and potassium into the cells, making magnesium vital for nerve impulses, muscle contractions and normal heart rhythms. Magnesium, with calcium, is required to produce RNA, DNA (our genetic coding) and glutathione (a powerful antioxidant).
Important for Heart Health
Magnesium is very important for heart health, because the heart requires a high amount of magnesium, especially in the left ventricle. The reason that the left ventricle needs more magnesium is because the left ventricle is the ‘big boy’ of the heart’s chambers; its job is to pump blood all over the entire body, whereas the right ventricle only has to pump blood to the lungs.
Magnesium, along with calcium, supports proper blood pressure levels and prevents hypertension. Without a proper balance of magnesium and calcium, a heart attack can occur due to severe muscle spasms. Many people with angina (heart spasm) could do well by adding more magnesium to their diet, alongside their prescribed medication. But consult with your doctor before changing your diet or taking magnesium supplements.
Prevents and can settle migraine headaches
Magnesium is involved in blood circulation by reducing the constriction (tightening) of the blood vessels that raises blood pressure in the head. Magnesium can also help control migraine headaches by releasing pain-reducing hormones and relaxing blood vessels. Taking supplemental magnesium at the onset of a migraine can help to reduce the length of its time, and can sometimes nip the migraine in the bud and stop it from progressing to full-blown.
Helps to prevent osteoporosis
Magnesium is essential for healthy bone formation and influences the activities of osteoblasts and osteoclasts which are cells that break down old bone and re-build new bone tissue, thereby maintaining or increasing bone density.
Magnesium also plays a role in balancing blood concentrations of vitamin D, which is a major regulator of bone density. Studies show that a higher magnesium intake correlates with increased bone mineral density in both men and women.
This list provides the recommended daily allowance of milligrams of magnesium for different age groups and sexes. Following is a list of foods rich in magnesium. By using the lists together, you can calculate what foods you need to maintain the daily allowance.
- Children to 6mths: need 30mg
- Children 7–12mths: need 75mg
- Children 1–3yrs: need 80mg
- Children 4–8yrs: need 130mg
- Children 9–13yrs: need 240mg
- Teenage males 14–18yrs: need 410mg
- Teenage females 14–18yrs: need 360mg
- Men 19-30yrs: need 400mg
- Women 19-30yrs: need 310mg
- Men 31+yrs: need 420mg
- Women 31+yrs: need 320mg
- Pregnant women: 360 to 400mg
- Breastfeeding women: 310 to 360mg
- Black Beans (cooked): 1 cup = 120mg
- Mung Beans (cooked): 1 cup = 97mg
- Almonds: ¼ cup = 97mg
- Cashews: ¼ cup = 91mg
- Potatoes: 1 large = 85mg
- Pumpkin Seeds: ¼ cup = 42mg
- Avocado: 1 = 39mg
- Bananas: 1 = 37mg
- Broccoli (cooked): 1 cup = 32mg
- Brussels sprouts (cooked): 1 cup = 32mg
Other sources of magnesium include kelp, buckwheat, Brazil nuts, dulse, filberts (hazelnuts), millet and pecan nuts.
Absorption of magnesium is dependent on these nutrients
Apart from not consuming magnesium blockers like phytates in grains and oxalic acid found in spinach (unless cooked), and avoiding tea and coffee (especially with meals), it is important to ensure you get enough of these nutrients below to be able to absorb, utilise and retain good levels of magnesium in your body.
- Vitamin D3
- Vitamin B1 (thiamine)
- Vitamin E
- Vitamin B6
You may notice in the RDA list above and the list of foods rich in magnesium that it can be difficult at times to get enough magnesium, especially during stressful times when you need higher levels, so a supplement may be appropriate to help support your body during these times.
A combination of diet and supplementation may work best as it can be difficult to obtain all of the co-factors (supportive agents) needed for good absorption from supplements alone.
Excessive quantities of magnesium supplements can result in diarrhoea. Some people regulate the dosage of their magnesium supplement by their bowel activity, taking less if they get loose stools or more if they become constipated. But for some, even tiny amounts of magnesium may be rejected by the body, which means they could still be deficient.
This is commonly due to the type of magnesium taken. Speak to your practitioner about this as there are different types that suit different people. Commonly in the past I have prescribed magnesium gylcinate or bis-glycinate (amino acid chelates – meaning they are bound to an amino acid for better absorption). Other times magnesium citrate has worked better.
I suggest avoiding magnesium oxide which usually causes diarrhoea, so it’s only good for constipation and not well absorbed into the cells. Also avoid magnesium carbonate or magnesium aspartate. These forms of magnesium supplements are generally cheaper and less effective.
Magnesium deficiency is one of the most common mineral deficiencies in humans worldwide with 80% of the population thought to be deficient. So it may benefit you to take a magnesium supplement in conjunction with a good magnesium rich diet.
Incidentally ‘normal’ blood testing for magnesium levels is not a good indicator of what is inside your cells. Magnesium is an intracellular (inside the cell) mineral so the level in the blood (serum) only represents around 1% of your total magnesium, and the body will actually rob magnesium from cellular reserves to maintain blood levels.
Intracellular blood testing can be more accurate with a whole red blood cell test (not commonly requested) which will indicate the amount of magnesium in your blood for the past 4 months. Did you know that we have totally brand-new blood every 4 months?
A hair mineral analysis is another way to find out if you need more magnesium, but this needs to be assessed by a practitioner who is experienced in reading the results as many factors need to be taken into consideration. For example a hair analysis may show high levels present but that may be because a lot of it is being excreted and not necessarily going inside the cells. When looking at the ratios between other minerals, a practitioner can get a better understanding. Also your symptom picture can provide clues.
Important: Before you commence a new diet, see your medical or health care professional for qualified guidance about what foods and supplements are best for your body. While on the diet do not stop any medications or supplements previously prescribed unless advised otherwise by your medical or health care professional.
Note: During the early stages of a new diet, you may experience symptoms such as fatigue, headaches or body aches, which may occur because your body is detoxifying. However, if you are unsure about a symptom at any time, check immediately with your medical or health care professional.