Is magnesium that important? Don't we all get enough magnesium?
Increased bone mineral density and bone mineral content in postmenopausal women have been positively correlated with intake of supplemental and/or dietary magnesium. Women with postmenopausal osteoporosis show significant reductions in bone mineral content and serum magnesium compared to age-matched controls. Insufficient magnesium stops bone growth, and leads to osteopenia and bone fragility.
Magnesium makes bones and teeth dense, strong, resilient (not brittle), and hard. Research indicates dietary intake of magnesium has decreased in the United States, from 475-500 mg per day in 1900, to only 215-283 mg per day in 1990. Even those 1990 figures may be too high, since refining and cooking further reduce the magnesium content of foods. A high-fat diet, soft drinks, laxatives and many other common dietary practices all can seriously compromise magnesium absorption and retention. Other factors, such as high alcohol or sugar intake, elevated stress chemistry in the body, diuretics or high amounts of sodium or calcium can reduce re-absorption of magnesium in the kidneys. Additionally, acid rain washes magnesium out of the soil, fluoridation depletes it from drinking water, and the processing of grains and other foods lowers their magnesium content.
A 1988 U.S. Government study concluded that the Standard American Diet (SAD) only provided 40% of the daily requirement of magnesium. Some experts believe this is a major root cause of the myriad chronic health conditions suffered in the modern world.
It’s quite possible that a low-magnesium diet combined with high calcium intake will promote calcification of soft tissues and create an environment for osteoporosis to begin. Interestingly, the research also shows that increasing magnesium intake improves rather than interferes with calcium utilization. Magnesium regulates active calcium transport, crucial to bone metabolism. Plentiful magnesium is calcium-sparing, reducing the need for calcium.
Is Magnesium Crucial for Bones?
There are hundreds of studies showing the crucial role that magnesium (Mg) plays in the health of the bones. For example, although severe Mg deficiency has long been known to be a risk factor, what happens with just a moderate Mg deficiency? Rats fed 0.04% of the nutrient requirement (NR) for Mg (severe Mg deficiency) get osteoporosis.
A more moderate dietary Mg restriction, 10% of NR, was then tested for six months. After just two months, bone Mg content was reduced 51%. Increased release of substance P and TNF-alpha were noted by the end of the study and bone loss. J Nutr. 2004 Jan;134(1):79-85.
Then 25% of NR was tested, and again decreased bone volume occurred. “These data demonstrate that Mg intake of 25% NR in the rat causes lower bone mass which may be related to increased release of substance P and TNFalpha.” Bone. 2005 Aug;37(2):211-9.
Recently a very moderate reduction of dietary magnesium (50% NR) was tested. As found in more severe Mg restriction, bone magnesium content was reduced at the 3- and 6-month time points, as was bone volume. Osteoporos Int. 2006;17(7):1022-32. Epub 2006 Apr 7. Other studies confirm a similar role for magnesium in humans.
Rats given half their needed magnesium suffered bone loss in 6 months. How many millions of human beings are subject to chronic, long-term 50% (or less) intake of optimal magnesium? Why are we surprised at the near-epidemic of osteoporosis?