The only time I ever thought about magnesium, before I became a scientist, was the summer I swept magnesium shavings off the floor at the Kaiser helicopter-engine factory. When I went to college, I learned that magnesium was an essential mineral in human and animal bodies. As a veterinary medical student, I learned that a magnesium deficiency caused "grass tetany" in cattle that ate lush, heavily fertilized grass growing especially in soils high in potassium or aluminum; these conditions reduce availability of magnesium.
Recently, a MIT scientist, Inna Slutsky reported a five year study showing that magnesium improved learning abilities, working memory and both short- and long-term memory in rats. The improvements were produced in both young and old rats. They fed rats a synthetic magnesium supplement, magnesium-L-threonate (MgT), which improved the ability of magnesium to get across the blood-brain barrier and into nerve cells.
How magnesium benefits brain function is probably related to the fact that magnesium is a cofactor for enzymes that convert adenosine triphosphate (ATP) to adenosine pyrophosphoric acid (ADP), with the subsequent release of energy. The brain is a real energy hog.
How much MgT would humans need to take is not known, but presumably somebody is working on that. The recommended daily amount of magnesium is 400 milligrams for men and 310 milligrams for women. It is estimated that only 32% of Americans get this amount in their diet. Primary food sources are green veggies, fruits, and certain nuts. Traditional nutritional supplements are not a solution. The researchers found that the magnesium in common dietary supplements does not readily enter the brain.
A commercial product, when it becomes available, may not have been tested for safety (nutritional supplements are not government regulated), On the other hand, healthy kidneys are pretty good at getting rid of excess blood magnesium. The possibility of excess magnesium in the brain from use of MgT has not been investigated.
Slutsky, I. et al. 2009. Enhancement of learning and memory by elevating brain magnesium. Neuron. 65 (2): 165-177.
Carolyn Dean MD, ND, author of “The Magnesium Miracle” and Medical Director of the non-profit, Nutritional Magnesium Association at www.nutrtionalmagnesium.org has this additional information to share that I thought you and your readers may find useful.
Both the brain and the heart are are made-up of excitable tissues that give off electrical energy and both must have magnesium to properly function.
The brain is in a state of constant electrical activity. Brain cells are controlled by switches: some switches are turned on and some are turned off by neurotransmitters. The action of these neurotransmitters could not take place without calcium, magnesium and zinc, which play various roles in the response of the nerve cells to electrical stimulation.
In a study among Taiwan residents (17,133 cases) from 1989 through 1993 were compared with deaths from other causes (17,133 controls). It was determined that the higher the magnesium levels in the drinking water used by Taiwan residents, the lower the incidence of stroke.
Decades of research show that withdrawal of magnesium from cerebral arteries causes them to spasm, whereas elevated magnesium produces relaxation.
Animal studies show that when there is normal or elevated magnesium in the brain, the damage caused by stroke is reduced and the neurological deficit is lessened. This is because magnesium blocks calcium from flooding the cells and causing injury.
As we get older we become more deficient in magnesium and therefore require more in our diet and in supplement form.
One of the most absorbable forms of nutritional magnesium is magnesium citrate powder which can be taken with hot or cold water.