A study by ARS (Agriculture Research Service) physiologist Henry C. Lukaski and nutritionist Forrest H. Nielsen reveals important findings on the effects of depleted body magnesium levels on energy metabolism. Lukaski is assistant director of ARS’s Grand Forks Human Nutrition Research Center, Grand Forks, North Dakota. He and Nielsen, with the center’s clinical nutrition support staff, showed that inadequate magnesium is associated with a need for increased oxygen during exercise. They found that during moderate activity, those with low magnesium levels in muscle are likely to use more energy—and therefore to tire more quickly—than those with adequate levels.
The study’s first phase provided 10 postmenopausal women with a controlled diet adequate in magnesium for 35 days. In the next phase, a low-magnesium diet provided less than half the recommended daily intake for 93 days. The last phase provided a diet adequate in magnesium for 49 days. The volunteers were subjected to exercise tests at the end of each dietary phase, along with biochemical and physiological tests.
After consuming the low-magnesium diet, volunteers showed a significant overall loss of magnesium. They had lowered muscle levels of magnesium, and their red blood cells were at the low end of the normal range.
The data shows that during the low-magnesium-status phase, the volunteers used more oxygen during physical activity, and their heart rates increased by about 10 beats per minute. “When the volunteers were low in magnesium, they needed more energy and more oxygen to do low-level activities than when they were in adequate-magnesium status,” says Lukaski.
The study was published in the May 2002 issue of the Journal of Nutrition.
The body stores about half its magnesium inside the cells of tissues and organs. The other half is combined with calcium and phosphorus inside bones. A tiny amount—just 1 percent—of the body’s magnesium circulates within the blood at a constant level.
These findings are consistent with other studies showing that too little magnesium makes the body work harder. “The effects are likely to occur in individuals with low magnesium, regardless of whether the person is athletic or sedentary,” says Lukaski. “That means that athletes wouldn’t be able to work or train as long as they would if they had better magnesium levels. People need to eat adequate magnesium to make sure their hearts and muscles are healthy enough to meet the demands of daily living.”
Carolyn Dean, MD, ND – Expert Commentary:
Of the 700+ magnesium-dependent enzymes in the body, the most important enzyme reaction involves the creation of energy by activating adenosine triphosphate (ATP), the fundamental energy storage molecule of the body.
The mineral “Magnesium” is required for the body to produce and store energy. Without magnesium there is no energy.
Magnesium is my #1 metabolism revving nutrient because it activates hundreds of enzymes that control digestion, absorption, and the utilization of proteins, fats, and carbohydrates. Magnesium’s hundreds of activities in the human body can be divided into these essential categories:
1. Magnesium is a cofactor assisting enzymes in catalyzing most chemical reactions in the body, including temperature regulation.
2. Magnesium produces and transports energy.
3. Magnesium is necessary for the synthesis of protein.
4. Magnesium helps to transmit nerve signals.