Magnesium Prevents Osteoporosis

Healthnotes Newswire (February 9, 2006)—Increasing magnesium intake may help prevent the bone loss that leads to osteoporosis, reports a study in the Journal of the American Geriatrics Society (2005;53:1875–80).

More than 10 million Americans have osteoporosis (thinning of the bones) and tens of millions more have a milder form of bone loss (osteopenia). At least 1.2 million fractures occur each year as a direct result of osteoporosis, and the annual cost of treating this disorder is $14 billion and climbing. Risk factors for osteoporosis include smoking, excessive alcohol consumption, high intake of carbonated beverages (especially colas), sedentary lifestyle, and a family history of the disease. Certain medical conditions, including diabetes, celiac disease, hyperthyroidism, and rheumatoid arthritis, are also associated with increased osteoporosis risk. Some medications accelerate bone loss; these include drugs used for epilepsy, steroid medications such as prednisone, and aluminum-containing antacids.

Magnesium plays an important role in bone-building by supporting the function of an enzyme involved in bone formation. In the new study, more than 2,000 elderly volunteers completed a questionnaire that assessed their intake of magnesium and other nutrients. In white, but not black, men and women, a higher magnesium intake was associated with greater whole-body bone mineral density, after adjusting for calcium and vitamin D intake, level of exercise, use of estrogen medication, and other factors known to be related to bone health. It is not clear why magnesium was protective only for whites, but blacks had higher levels of bone density than did whites at all levels of magnesium intake.

The study did not adjust for all potentially important dietary variables, which limits the usefulness of the findings. People who consumed more magnesium also ate more fruits and vegetables, compared with those who had lower magnesium intake. Fruits and vegetables contain many other nutrients besides magnesium, some of which have a beneficial effect on bone health. The study does, however, support previous research showing that magnesium supplementation prevents bone loss. In one of those studies, women in early menopause who were given 250 to 750 mg of magnesium per day for one year had an increase in bone mineral density in 71% of cases. Normally, bone density decreases by 3 to 8% per year in the early years of menopause, and increases during that time are unusual.

Good food sources of magnesium include whole grains, nuts, beans, dark green vegetables, fish, and meat. Other nutrients that have been shown to play a role in bone health include vitamin K, strontium, silicon, zinc, copper, vitamin B6, folic acid, manganese, and vitamin D.