Low magnesium may mean weaker muscles

NEW YORK (Reuters Health) - Older adults with higher levels of magnesium in the blood have stronger muscles, a new study shows.

Further research on whether magnesium supplements will help boost muscle function is needed, the authors conclude, given the high risk of injury and disability among older adults.

Magnesium plays a number of key roles in body function, including energy metabolism, and adequate levels are essential for optimum athletic performance, Dr. Ligia J. Dominguez of the University of Palermo in Italy and colleagues point out in a report in the American Journal of Clinical Nutrition.

To investigate whether loss of magnesium might contribute to the loss of muscle mass, or sarcopenia, often seen in older people, Dominguez and colleagues measured serum levels of magnesium and performed a number of tests of muscle strength and function in 1,138 men and women with an average age of about 67 years.

The researchers found a strong relationship between magnesium levels and muscle function that remained even after they adjusted for factors that could affect both muscle strength and magnesium metabolism.

Individuals with higher magnesium levels had a stronger handgrip, more power in their lower leg muscles, and were able to extend their knees and ankles with more force.

Even people in wealthy Western nations may not get enough magnesium, Dominguez and colleagues note; 68 percent of US adults get less than the recommended daily allowance of this mineral. Older people and those with chronic disease are at particularly high risk of magnesium deficiency.

"The importance of elucidating the role of low magnesium status on the development of sarcopenia cannot be overlooked, because the aging population at risk of related disability continues to grow and contribute to extensive health care costs," the team concludes.

SOURCE: American Journal of Clinical Nutrition, August 2006.