A researcher at Massachusetts Institute of Technology (MIT) grew curious about magnesium's role in memory after a lab study found that, in rats fed high levels of the mineral, communication between brain cells was activated like a fully engaged orchestra.

The researcher, Guosong Liu, an associate professor of biophysical neuroscience at MIT's Neuroscience Research Center, said the finding indicates magnesium makes the mature brain open for growth and change.

"The animal studies are telling us something very important about magnesium," he said. His findings are published in the latest issue of the journal Neuron.

Magnesium in the American diet has declined since the Industrial Revolution, he said. Additionally, high fat content of the modern diet prevents magnesium from being absorbed.

In his experiment, he fed lab rats the equivalent of a human dose of 400mg of magnesium a day. The result, he said, was that the mineral increased the activity of receptors that control learning and memory. Specifically, it enhanced the activity at the synapse, the gap between two neurons, or brain cells.

He said the results were most impressive in female rats. Women typically have lower magnesium levels than men, he said, and he is studying whether that may play a role in why women are at greater risk for Alzheimer's. He said federal studies in nursing homes indicate that virtually all residents have magnesium deficiency.

According to the National Institutes of Health, magnesium is needed for more than 300 biochemical reactions, including maintenance of normal muscle and nerve function, strong bones and steady heart rhythm. It is also involved in energy metabolism and protein synthesis. Magnesium is present in small amounts in many foods, one reason a varied diet rich in fruits and vegetables is recommended.