Parents have long spread the message to their kids: drink lots of calcium-rich milk and you’ll grow up with strong bones.
Doctors, too, stress the importance of calcium to their older patients trying to avoid bone loss and osteoporosis. But a physician at the Keck School of Medicine of USC is looking one rung beyond calcium in the periodic table of the elements: magnesium.
Magnesium seems to play a role in keeping bones healthy, said Robert Rude, USC professor of medicine.
Epidemiological studies looking at bone health and diet have found that the more magnesium people consume in their food, the denser their bones, Rude said.
But scientists need more proof before they know for certain that magnesium directly boosts bone strength, so Rude has been investigating the effects of poor magnesium consumption in mice through a recently completed study funded by the National Institute on Aging.
“In these studies, we and others have found that magnesium depletion will result in bone loss and osteoporosis,” Rude said. “There seems to be both less bone growth and increased bone loss.”
Rude has applied for another NIH grant that would further the studies in rats.
Magnesium seems to play a less obvious part in bone health than calcium, he explains. Calcium is the most plentiful metallic element in the human body, and about 99 percent of the body’s calcium is found in bones and teeth. But bones do not form a repository of magnesium that element is found within cells.
“Magnesium is important for many enzymes,” Rude said. “Over 300 enzymes in the body need it to form reactions. Many hormones needed for growth depend on magnesium.”
When the body does not get enough magnesium, cytokines certain inflammatory proteins known to affect bone health–are released into the blood stream, he said. The body also secretes less parathyroid hormone, which regulates calcium in the blood and formation of vitamin D in the kidneys (two more important factors in bone health).
People who drink a lot of alcohol or take diuretics and those with diabetes are especially at risk for magnesium depletion. Acute deficiencies can cause cramps, seizures and serious heart problems.
So should people take magnesium pills to protect against osteoporosis and its associated risk of broken bones? Rude cautions that scientists need to learn more before suggesting supplements. But simple changes in diet could go far in helping more people reach the recommended daily allowance, or RDA, of magnesium (350 milligrams). Green leafy vegetables and unprocessed grains and nuts are excellent sources.