Magnesium - for your bones, energy and brain

Magnesium is in the center of the chlorophyll molecule – just as iron is in hemoglobin. How impressive is that!

Magnesium is abundant in green vegetables (think chlorophyll), beans, whole grains, nuts, edible seeds such as pumpkin and sunflower, bananas, chocolate and many other unrefined plant foods. How can it be that a recent report from the US Department of Agriculture indicated that only 32% of us were getting adequate magnesium in our diet? Perhaps this is because we are not following Michael Pollan’s rule “If it came from a plant, eat it; if it was made in a plant, don’t.” A lot of us are filling up on things our ancestors would not recognize as food.


Bones: Magnesium is stored in bones; if there is not enough, bones become more brittle. A study from Tufts University of 900 elderly men and women found higher dietary magnesium intakes were associated with increased bone mineral density at the hip. Eating an unrefined plant based diet gives abundant magnesium as well as potassium, and will help bone strength by creating a more alkaline urine, thereby minimizing calcium loss.

Energy: The body provides energy for all metabolic processes by transforming carbohydrates and fats into a molecule called ATP, which exists as a complex with magnesium. A study from the Agricultural Research Service in North Dakota showed that people with inadequate levels of magnesium need more oxygen during exercise, and tire more quickly, than those with adequate levels.
Heart: Magnesium helps to maintain a normal heart rhythm. Magnesium supplements are sometimes suggested by cardiologists for people with intermittent atrial fibrillation or with cardiac failure. Studies have shown that a high dietary intake of magnesium (lots of unrefined plant food) may decrease blood pressure. This kind of diet is also rich in potassium and calcium, so it is difficult to sort out the factors involved.

Brain: An international study Tsinghua University in Beijing, University of Toronto, MIT, and Tel Aviv University showed that increased levels of magnesium in the brain enhanced learning and memory (in rats). The researchers used a new supplement that passed the blood-brain barrier and entered the brain. While this supplement is not available, they stated that people should get their magnesium from dietary sources – noting that half of all people in industrialized countries have magnesium deficiencies.. A better, plant-based diet may delay the cognitive impairment of aging.

Getting Enough Magnesium (Mg) It’s easy to get plenty of magnesium by eating green vegetables, beans, nuts, seeds and whole grains. Taking Mg as a supplement can be dangerous for people with kidney disease – especially for older people - so check with your doctor. The Institute of Medicine has set a ‘tolerable upper intake’ for Mg pills at 350 mg/day, and many women take that amount with their calcium supplements. Higher levels can cause diarrhea and gastrointestinal discomfort. Magnesium citrate is commonly used as a safe supplement in sensible doses. Two forms of Mg are laxatives and should not be taken regularly – magnesium sulfate (Epsom salts) and magnesium hydroxide (Milk of Magnesia).. Final word – here's another reason to go for the greens!
Sadja Greenwood MD, MPH Back issues on this blog