Heart, Brain, Energy & Bones
Just try getting by without magnesium.
More than 300 of your body’s biochemical mechanisms require magnesium, a mineral that helps heart muscle cells relax, reduces blood pressure, and even lowers homocysteine levels. No surprise then that magnesium deficiency has been linked to elevated heart disease risk.
But heart health is just one good reason to make sure your intake of magnesium is up to snuff. Today we’ll look at three more reasons.
1) Good for the brain – A laboratory study from the Massachusetts Institute of Technology (MIT) reveals that an adequate amount of magnesium is necessary to maintain the “plasticity” of synapses – the connectors that move information from neuron to neuron in the brain. In this case, plasticity refers to the ability to change. When synapses are flexible to change, learning and memory are enhanced.
According to a report released by the MIT News Office, the researchers believe their results confirm that cognitive function is stunted when magnesium is deficient, but clearly improved when magnesium intake is abundant.
Other conditions that have been associated with a magnesium deficiency include depression, anxiety and attention deficit disorder.
2) Good for energy- Researchers with the USDA Agricultural Research Service recruited 10 postmenopausal women to participate in a three-phase diet and exercise study. During phase one (35 days), the women followed a controlled diet that delivered an adequate amount of magnesium. (The current Recommended Dietary Allowance (RDA) for women is 320 mg daily. For men; 420 mg daily.)
In the second phase (93 days), each subject consumed a diet that contained less than half the RDA for magnesium. In the final phase (49 days) the subjects returned to a diet with adequate magnesium. At the end of each phase, subjects took exercise tests, as well as physiological and biochemical tests.
Results showed that when magnesium intake was low, exercise increased heart rate and required more oxygen compared to exercising when magnesium intake was adequate. Also, when magnesium levels in muscles were low, more energy was required and subjects tired more easily compared to subjects with adequate magnesium levels.
3) Good for bones –Scientists already know that magnesium increases bone density in postmenopausal women, so researchers at Tel-Aviv University in Israel used an animal study to test magnesium as an osteoporosis preventive agent.
A group of female rats were divided into two groups to receive either a diet with adequate magnesium or a magnesium deficient diet. Over a one-year period, urine samples were collected every three months and a blood sample was taken from each rat at the end of the year. Bone samples from the thighs and vertebrae of each rat were also analyzed for bone density.
Results showed that bone density was significantly higher in the rats that received adequate magnesium in their diets. Microscopic examination of the bones revealed signs of osteoporosis in only the rats that received inadequate magnesium. Also, less force was required to break the bones of these rats compared to the bones of the rats that received proper amounts of magnesium.
The “go to” foods
About half of all Americans don’t get an adequate intake of magnesium, and studies show this is especially true among older adults. To complicate the situation, many factors contribute to magnesium depletion. High stress and menstruation can take their toll on magnesium levels, while a heavy intake of starches, alcohol, diuretics and some prescription drugs (such as antibiotics) can increase urinary excretion of magnesium.
Sohow do you make sure your magnesium intake is sufficient? You can start by eating.
Magnesium is naturally present in green leafy vegetables, avocados, nuts and seeds, and whole grains, but usually only in small amounts so you’d need to eat a wide variety of these foods regularly to get all the magnesium you need.
In the e-Alert “Mind Over Matter” (5/27/05), HSI Panelist Allan Spreen, M.D., offered these guidelines on magnesium supplementation: “I’ve always recommended 500 mg/day, since absorption of most forms isn’t that great.
“My limit for oral magnesium is that which causes any loosening of the stools, and there’s always a distinct dose that will do it. I’m careful to warn people not to go over that limit for the simple reason that food is moved through the GI tract too quickly with too much magnesium, and that cuts down on absorption of nutrients (both from foods and supplements). However, that amount is usually between 400 and 1500 mg/day.
“Now, bear in mind that that’s ELEMENTAL magnesium. In a supplement, such as magnesium oxide, the tablet that is sold as a 400 mg tablet only has 241.3 mg of elemental magnesium. So, when you take a ‘400 mg’ tablet, you aren’t getting 400 mg of magnesium anyway. Plus, even the label says you can take 2/day, or 800 mg.”
Sources:
“MIT: Magnesium May Reverse Middle-Age Memory Loss” Medical News Today, 12/1/04, medicalnewstoday.com
“Dietary Magnesium Depletion Affects Metabolic Responses During Submaximal Exercise in Postmenopausal Women” Journal of Nutrition, Vol. 132, No. 5, May 2002, nutrition.org
“Lack Energy? Maybe It’s Your Magnesium Level” Science Daily, 5/10/04, sciencedaily.com
“Prolonged Magnesium Deficiency Causes Osteoporosis in the Rat” Journal of the American College of Nutrition” Vol. 23, No. 6, December 2004
“Magnesium Deficiency Linked to Osteoporosis” Natural Products Insider, 1/10/05, naturalproductsinsider.com
