Magnesium Research

One Mineral Can Make Or Break Your Heart's Rhythm

March 7, 2002

A new study reveals that low blood levels of an important mineral can significantly affect the way your heart pumps blood throughout your body. And even if you think you're living a healthy lifestyle, you may not be getting enough of it.

I'm talking about magnesium, a mineral that is naturally present in water and foods in varying amounts. The U.S. RDA for magnesium is about 320 mg per day for women and more than 400 mg per day for men - yet studies show that most people regularly take in about half of that. And now new research reveals that this lack of magnesium may put your heart - and your health - at significant risk.

More evidence that magnesium is key to heart health

In this study, published in the latest issue of the American Journal of Clinical Nutrition, researchers from the U.S. Department of Agriculture tracked the effects of a magnesium-deficient diet on 22 healthy postmenopausal women between the ages of 47 and 78. The women all ate the same meals for six months as they lived together under close supervision, taking in about 130 mg of dietary magnesium each day. But half the women also took in another 280 mg of magnesium in supplement form for the first 81 days while the other half took placebo; for the second half of the study period, the groups crossed over to the other treatment category.

The researchers assessed magnesium levels in urine and blood regularly throughout the study period. They also assessed heartbeat patterns through regular electrocardiograms. And here's what they found: not surprisingly, serum and urine concentrations of magnesium were substantially lower on the controlled diet. But they also discovered that heart rhythms were significantly affected by magnesium deficiency - specifically, a lack of magnesium made the heart beat more frequently than usual.

Scientists have long known that magnesium is a critical player in cell metabolism, helping to transport other minerals across cell membranes and affecting cell mechanisms that control the activity of muscle and nerve cells. But as the authors note, their research suggests "cardiac muscle seems to be more sensitive to [magnesium] intake than skeletal muscle."

How to assess your risk for magnesium deficiency

This throws additional weight behind the developing theory that magnesium can help prevent many of the processes that lead to heart disease. In previous research, scientists found several important connections between magnesium deficiency and the development of heart disease; in fact, one study found that the risk of heart disease is higher in areas with "soft" water compared to those with "hard" water. (Hard water contains much more magnesium than soft.)

But there's more to magnesium intake than the water. You may also be at increased risk for magnesium deficiency if you regularly consume alcohol or diuretics, because both can increase urinary excretion of the mineral. Prescription medications, like the antibiotics Gentamicin, Amphotericin, and Cyclosporin, and the cancer drug Cisplatin, can increase magnesium excretion as well. Diabetics are also at increased risk of magnesium deficiency, as are those with Crohn's disease or other chronic gastrointestinal problems.

If you're concerned, ask your doctor to test your blood for magnesium levels. A normal range is anywhere between .66 and 1.23 mmol/L. Fortunately, it's easy to get more magnesium. The mineral is naturally present in green leafy vegetables, avocados, nuts and seeds, and whole grains, but usually in small amounts; you need to eat a wide variety of these foods regularly to get all you need. To make sure you're getting enough of this important mineral, you can also take magnesium supplements - they are readily available at health food stores and vitamin suppliers.

All of us could probably benefit from increasing our magnesium intake. But there is such a thing as too much. The tolerable upper intake level for supplemental magnesium is 350 mg per day for adults. That means that you shouldn't take any more than that in supplement form; more than that amount, in addition to the magnesium you get from food and water, could cause problems. At very high levels, the mineral can be toxic, causing kidney failure. But within reasonable limits, magnesium is an important part of a complete supplement program - and as this study shows, an important tool in your heart-health regimen.

To Your Good Health,

Jenny Thompson
Health Sciences Institute
Source: American Journal of Clinical Nutrition 2002; 75:550-554

MAGNESIUM: Miracle in Minutes

Source for a portion of Part One:

http://www.bodyandfitness.com/Information/Health/Research/magnesium1.htm

DID YOU KNOW?

Very few people are aware of the enormous role magnesium plays in our bodies. After oxygen, water, and basic food, magnesium may be the most important element needed by our bodies. So vitally important, yet hardly known. Magnesium is by far the most important mineral in the body, activating over 300 different biochemical reactions in your body, all necessary for your body to function properly.

Magnesium is more important than calcium, potassium or sodium and regulates all three of them. When we get too low on oxygen, water or food, the consequences are serious. Yet, we often don't realize the consequences of magnesium deficiency. The improper use of magnesium among health professionals and the population in general, is deeply responsible for many of the failures encountered daily in treating chronic health conditions nationwide.

What are the symptoms of a magnesium deficiency? Millions suffer daily from:

Over 90% of the population is deficient, including many of those who already supplement it. Why? Due to the misleading information presented in common magnesium texts. As a result, magnesium remains largely misunderstood, largely misused and the problem goes on undetected.

CALCIUM WARNING

The use of magnesium today is often incorrect, resulting in frequent failure to improve common conditions and complaints. One reason is this: Calcium needs magnesium in order to assimilate into the body. However, when too much calcium is consumed, it will pull magnesium out of the body parts in order to assimilate. This creates a magnesium deficiency and the person will get worse and feel accordingly.

"Contrary to common belief, magnesium deficiency is very common even amongst those who supplement it regularly"

Excess calcium (in the wrong form/size for proper assimilation) in the body results in calcium deposits on joints (often called arthritis). All of these have been known to disappear after taking extra magnesium especially the drink form.

BECOME AN EXPERT

After reading this data you will become your own expert on how to handle a magnesium deficiency, which strikes most of our unknowing population. This data is vital for everybody to know. It has changed the lives of many. It may change your own as well.

The fact remains that many of us suffer for months and years from chronic conditions, for which no one seems to detect the source (not even the experts). With all the myriad of solutions we try, only a lucky handful amongst us realize that the true source of these conditions lies with a mineral deficiency. Many of these conditions listed above are caused primarily by magnesium deficiency.

This information may bring new hope to those who have already grown hopeless about improving their condition. Over 90% of the population is magnesium deficient, and many of them have thought that regular magnesium supplements will fix this deficiency. Unfortunately, this isn't the case. Read on to understand this in full, and why water-soluble magnesium (angstrom in size) is the answer.

To understand the importance of magnesium let's consider this:

Magnesium is the most important mineral in the body, activating over 300 different processes in your body; Among these functions are digestion, energy production, muscle function, bone formation, creation of new cells, activation of B vitamins, relaxation of muscles, the functioning of your heart, kidneys, adrenals, brain, as well as the nervous system.

Part Two

The Mineral That Could Have Saved 4 Million Women

by Bill Sardi

Modern medicine has made a remarkable admission. Its failure to utilize a simple, inexpensive intravenous mineral drip might have saved the lives millions of women over the past century. Modern medicine knew about the cure since 1906. [New England Journal Medicine 333: 201-05, 1995]

Around 210 million women become pregnant annually around the world and every minute a woman dies in pregnancy or childbirth, with a quarter of these deaths due to a condition called pre-eclampsia which can lead to the more severe and mortal condition called eclampsia. Women may develop high blood pressure during pregnancy (pre-eclampsia) and during or prior to birth may experience life-threatening seizures (eclampsia). About 5-10 percent of women in their first pregnancy develop pre-eclampsia.

Over the past century, drugs rather than minerals have been employed to treat eclampsia, Diazepam (Valium) since 1968 and then phenytoin (Dilantin) since 1987. During the period from 1905 to 1987 an estimated 42 million women may have undergone eclamptic convulsion and possibly 4 million died. The modern therapy for eclampsia now includes calcium-blocking drugs and a host of anti-hypertensive agents. Drugs may reduce the risk of severe high blood pressure, but not the overall rate of hypertension or the risk of eclampsia. [The Cochrane Library, Issue 2, 2002]

Yet the anticonvulsant drugs continue to be employed with little reliable evidence that they work. Finally, a just-released study of 10,141 women in 33 countries has shown beyond a "reasonable doubt" that intravenous magnesium reduces the risks of eclampsia among women with pre-eclampsia. The relative risk of eclampsia was reduced by 58 percent and the mortality rate nearly cut in half among women receiving magnesium ...compared to those who receive a saline drip. The authors of the study concluded: "magnesium sulfate is remarkably effective at reducing the risk of eclampsia." [The Lancet 359: 1877-90, June 1, 2002]

Not The First Time

This wasn't the first study to conclusively show magnesium sulfate is a remedy for eclampsia. In a 1995, a study heralded as the most important obstetric trial of the 20th century, magnesium sulfate was found to be the most effective approach to controlling convulsions during childbirth. [British Medical Journal 311: 702-03, 1995]

By 1998 data from numerous studies had been analyzed and it was known that magnesium was superior to any anticonvulsant drugs. [Cochrane Review 2002] This evidence still didn't convince most obstetrical doctors.

Seven years after the report showing magnesium reduces the risk of mortality from eclampsia, a report endorsed by the World Health Organization (WHO), UNICEF and the World Bank, magnesium sulfate is still not available to millions of women worldwide. British medical researchers are pleading with the World Bank and WHO to fund and disseminate treatment kits. [The Lancet 359: June 1, 2002]

Clues Were There

It wasn't as if physicians had no clues as to the cause of eclampsia. The worldwide mortality rates from eclampsia vary widely from country to country. The mortality rate from eclampsia ranges from 0 to 13.9 percent. [European Society Cardiology 21st Annual Congress, Sept. 1, 1999]

So there are obviously some modifiable factors involved in the development of eclampsia among pregnant females. Pre-eclampsia and eclampsia are the most important causes of death during pregnancy in the United Kingdom, USA and Nordic countries, nations that consume the most calcium-rich dairy products. Calcium and magnesium must be maintained in a proper ratio to maintain proper muscle tone and prevent convulsive muscle spasms. Furthermore, estrogen and progesterone levels, which increase as a pregnancy advances, elevate the body's demand for magnesium. [Journal American College of Nutrition 12: 442-58, 1993]

Magnesium is a natural calcium blocker. [American Journal Medicine 96: 63-76, 1994]

Magnesium Shunned For Heart Disease Too

This isn't the first time magnesium has been shunned in favor of prescription drugs. In the 1990s a preliminary report showed that intravenous magnesium reduced mortality rates following a heart attack. This was apparently perceived as a threat to the sale of calcium-blocking drugs used for the same purpose. Medical researchers, financially backed by a pharmaceutical company that produces calcium-blocker drugs, deliberately chose to use an excessive dose of intravenous magnesium to prove it was of no value during the post-heart attack period. [Townsend Letter for Doctors, October 1998]

The sale of calcium-blockers never faltered. There are more than 64 million annual prescriptions for calcium blocking drugs (Procardia, Cardizem, Norvasc, Verpamil, Adalat, Dilacor, Verelan, Calan), with sales exceeding $2.5 billion. [American Druggist 1997]

Magnesium May Prevent Sudden-Death Heart Attacks

Magnesium is not limited to treating heart disease after a heart attack. A shortage of dietary magnesium has been repeatedly shown to be associated with an increased risk of sudden-death heart attack. Unequivocally, a shortage of magnesium from the American diet, in particular the absence or shortage of magnesium in drinking water, is directly related to sudden-death heart attack. [Epidemiology 10: 31-36, 1999; Heart 82: 455-60, 1999; American Journal Epidemiology 143: 456-62, 1996] Out of 750,000 heart attacks in the USA annually, an estimated 340,000 deaths occur within one hour of a heart attack. [Journal Nutrition Health Aging 5: 173-78, 2001]

One study showed the relative risk of sudden-death heart attack is more than 1.5 times higher among adults who consume on average 105 milligrams of magnesium a day compared to adults who consume 233 milligrams a day. [Magnesium Trace Element Research 9: 143-51, 1990]

Recently researchers reported on the effects of slowly withdrawing magnesium from the diet of postmenopausal women. Women began to exhibit abnormal heart rhythms as circulating magnesium levels declined. [American Journal Clinical Nutrition 75: 550-54, 2002]

Of the minerals removed during water softening, magnesium is the only mineral found to be deficient in the heart muscle of sudden-death heart attack victims. [Science 208: 198-200, 1980]

In an animal experiment, no rodents experienced a sudden-death heart attack when magnesium levels were adequate, whereas 4 of 11 rodents with low magnesium levels experienced a sudden lethal heart muscle spasm. [Journal American Collage Cardiology 27: 1771-76, 1996]

For comparison, there are about 50,000 tobacco-related deaths per year in the USA and consequently massive smoking-cessation efforts are undertaken. There are more than 200,000 to 300,000 avoidable sudden-death heart attacks that could be prevented by the provision of an inexpensive mineral, yet public health authorities do nothing to stop the problem. This amounts to over 500 needless deaths per day in the USA. The current approach to cardiovascular disease is to reduce circulating cholesterol levels, which has been shown to reduce the incidence of heart attacks, but has not reduced mortality rates. Sudden fatal heart failure may be related to magnesium deficiency rather than high cholesterol levels. [Medical Hypotheses 43: 187-92, 1994]

Widespread Dietary Deficiency

A 1994 Gallup poll found that 72 percent of Americans don't consume sufficient amounts of magnesium. The widespread consumption of processed foods has led to a progressive decline in dietary magnesium. While nuts and green leafy vegetables are good sources of magnesium, the shortage of magnesium in the American diet, about 200-300 milligrams per day, is not likely to be made up through foods alone.

Progressive decline of dietary magnesium consumption

[Magnesium Trace Elements 10: 162-28, 1997]

Supplementation Advised

Only universal magnesium supplementation is likely to make up for such a widespread mineral deficiency. Foods cannot easily be fortified with magnesium because it is a bulky mineral that would alter the consistency and taste of flour and foods. Magnesium cannot be added to tap water because it would erode piping. Either magnesium pills or magnesium added to bottled water would make up for this mineral deficiency. Currently, only 5 major brands of bottled water provide a desirable measure of more than 75 milligrams of magnesium per liter and only one brand has a ratio of magnesium that exceeds that of calcium.

Blood tests for magnesium are notoriously inaccurate. Only 1 percent of the total body magnesium pool exists outside of living cells. So blood serum levels are notoriously inaccurate. [Clin Chem Lab Med 37: 1011-33, 1999]

Only red-blood cell magnesium levels accurately determine the risk for pre-eclampsia and/or magnesium deficiency, but this test is not commonly performed in laboratories. [American Journal Hypertension 13: 765-69, 2000]

A bias against the use of intravenous magnesium sulfate by modern medicine has taken a terrible toll on humankind. Magnesium sulfate, also known as Epsom salt, is not absorbed orally and attracts water in the colon and would thus act as a laxative. So Epsom salts are not recommended orally. Magnesium pills are recommended (200-400 milligrams per day). Magnesium has been called the "The Forgotten Mineral" and the "5-Cent Miracle Tablet" by medical researchers. Numerous researchers have reported that the provision of this mineral in the population at large would greatly diminish the incidence of kidney stones (1 in 11 Americans), calcified mitral heart valve (1 in 12 Americans), premenstrual tension, constipation, miscarriages, stillbirths, strokes, diabetes, thyroid failure, asthma, chronic eyelid twitch (blepharospasm), brittle bones, chronic migraines, muscle spasms and anxiety reactions. [Pediatric Asthma, Allergy Immunology 5: 273-79; Journal Bone Mineral Research 13: 749-58, 1998; Magnesium 5: 1-8, 1986; Medical Hypotheses 43: 187-92, 1994]

That's a lot of health benefits for a nickel. Sufficient provision of magnesium in the American population would likely reduce health care costs by billions of dollars.

Part Three, source http://www.billsardi.com/sdm.asp?pg=news&specific=49

Too much calcium, not enough magnesium

HEART BECOME IRRITABLE WHEN DEPRIVED OF MAGNESIUM

The Human Nutrition Research Center in Grand Forks, North Dakota has released an alarming report that reveals when humans are deprived of magnesium they may begin to experience abnormal heartbeats. [American Journal Clinical Nutrition 75: 550-54, March 2002]

The heart muscle of people who experience sudden-death heart attack has been found to be low in magnesium. Areas of the world where drinking water is low in magnesium (soft water areas) have higher rates of heart attacks. Magnesium is a muscle relaxant, while calcium is a muscle constrictor. Low magnesium intake is associated with muscle spasm, tremors and convulsions.

Most Americans, particularly women, have been advised to consume 1200-1500 milligrams of calcium daily. Virtually none of these women have been told that calcium in single doses that exceed 500 milligrams are not absorbed and that they only need an additional 400-600 milligrams of supplemental calcium since their diet already provides about 800 milligrams of this mineral.

Since 99 percent of magnesium resides inside living cells, blood serum levels are not a good indicator of magnesium deficiency. In other words, your doctor can't easily tell you by a blood test if your magnesium levels are low. Most Americans, 8 in 10, do not consume enough magnesium.

The countries that have the highest mortality rates in the world are the Scandinavian countries and New Zealand where more calcium is consumed from dairy products, while for comparison the lowest mortality rates in the world are in Portugal and Japan where calcium-rich dairy products are not consumed regularly. Americans consume about 800 milligrams of calcium daily (milk drinkers may get 1200-1500 mgs from their diet alone), but only consume about 275 milligrams of magnesium. Thus the dominance of calcium over magnesium produces symptoms of muscle spasm. Migraines, eyelid twitch, heart flutters, backaches, premenstrual tension, leg cramps and constipation are all linked to calcium overload. Excessive calcium may also result in kidney stones (1 in 11 Americans) and heart valve calcifications (mitral valve, 1 in 12 Americans).

A significant percentage of American adults consume more than 2000 milligrams of daily calcium, the point where side effects of overdosage begin to be reported. More than 300,000 sudden-death heart attacks are reported annually in the US (more than 80 per day), which are believed to be related to excessive calcium and a shortage of magnesium.

Modern medicine's answer to the problem is to prescribe billions of dollars of calcium-blocker drugs. Magnesium is a natural calcium blocker, but this goes unrecognized by most physicians. Researchers warn that adults who consume excessive amounts of caffeine or alcohol, or who take water pills (diuretics), are prone to experience irregular heartbeats and should consume more magnesium. The same is true for diabetics and people with low thyroid. Most Americans consume tap water that has been softened (sodium added) which worsens the problem. American adults need to supplement their diet with 200-400 milligrams of magnesium. The only side effect of too much magnesium is loose stool. Reducing dosage resolves this problem.

Copyright Knowledge of Health, Inc., 2002, Written By: Bill Sardi, See our Top News here.

Source: SunToads Health News 204: Magnesium Is Vital, June 8, 2002

SunToads Health News (formerly named Health Matters) is a newsletter. We write very little of the materials you receive. We do not use a web site. This newsletter is for those who want to know more about: 1. Current serious health threats even though you may not be sick now.
2. Suppressed cures.
3. Sources of info so you can do further research.
4. Controversial health information.
5. Alternatives. Bits and pieces.

Our Archives list can be emailed to you. Email a request to: jfeb@yucca.net In the body of your email, write: SunToads Health News archives requested.

Please send us similar health info you are aware of and include references, if possible, so others can do further research. Since our staff volunteers its time and we do not charge you for our efforts, we are therefore unable to pay money to writers. Feel free to forward this material to those who may have an interest in better health.

SunToads Health News emailings are on no particular schedule. We don't claim to be experts or doctors, we just search for suppressed and little known information. Any statements made by SunToads are solely our opinions and in no way constitute medical advice. All information is for educational purposes only and is not intended to diagnose, treat, or cure any disease. For clarification and/or professional advice, you should seek the opinion of an appropriate licensed professional.

To SUBSCRIBE write in the body area of your email:
Subscribe SunToads Health News. Include your complete email address. Email this to jfeb@yucca.net

Similar information can be found in the True Health Newsletter by Carotec, Inc.

One Mineral Can Make Or Break Your Heart's Rhythm

Health Sciences Institute e-Alert, March 7, 2002

Dear Member,

A new study reveals that low blood levels of an important mineral can significantly affect the way your heart pumps blood throughout your body. And even if you think you're living a healthy lifestyle, you may not be getting enough of it.

I'm talking about magnesium, a mineral that is naturally present in water and foods in varying amounts. The U.S. RDA for magnesium is about 320 mg per day for women and more than 400 mg per day for men - yet studies show that most people regularly take in about half of that. And now new research reveals that this lack of magnesium may put your heart - and your health - at significant risk.

More evidence that magnesium is key to heart health

In this study, published in the latest issue of the American Journal of Clinical Nutrition, researchers from the U.S. Department of Agriculture tracked the effects of a magnesium-deficient diet on 22 healthy postmenopausal women between the ages of 47 and 78. The women all ate the same meals for six months as they lived together under close supervision, taking in about 130 mg of dietary magnesium each day. But half the women also took in another 280 mg of magnesium in supplement form for the first 81 days while the other half took placebo; for the second half of the study period, the groups crossed over to the other treatment category.

The researchers assessed magnesium levels in urine and blood regularly throughout the study period. They also assessed heartbeat patterns through regular electrocardiograms. And here's what they found: not surprisingly, serum and urine concentrations of magnesium were substantially lower on the controlled diet. But they also discovered that heart rhythms were significantly affected by magnesium deficiency - specifically, a lack of magnesium made the heart beat more frequently than usual.

Scientists have long known that magnesium is a critical player in cell metabolism, helping to transport other minerals across cell membranes and affecting cell mechanisms that control the activity of muscle and nerve cells. But as the authors note, their research suggests "cardiac muscle seems to be more sensitive to [magnesium] intake than skeletal muscle."

How to assess your risk for magnesium deficiency

This throws additional weight behind the developing theory that magnesium can help prevent many of the processes that lead to heart disease. In previous research, scientists found several important connections between magnesium deficiency and the development of heart disease; in fact, one study found that the risk of heart disease is higher in areas with "soft" water compared to those with "hard" water. (Hard water contains much more magnesium than soft.)

But there's more to magnesium intake than the water. You may also be at increased risk for magnesium deficiency if you regularly consume alcohol or diuretics, because both can increase urinary excretion of the mineral. Prescription medications, like the antibiotics Gentamicin, Amphotericin, and Cyclosporin, and the cancer drug Cisplatin, can increase magnesium excretion as well. Diabetics are also at increased risk of magnesium deficiency, as are those with Crohn's disease or other chronic gastrointestinal problems.

If you're concerned, ask your doctor to test your blood for magnesium levels. A normal range is anywhere between .66 and 1.23 mmol/L. Fortunately, it's easy to get more magnesium. The mineral is naturally present in green leafy vegetables, avocados, nuts and seeds, and whole grains, but usually in small amounts; you need to eat a wide variety of these foods regularly to get all you need. To make sure you're getting enough of this important mineral, you can also take magnesium supplements - they are readily available at health food stores and vitamin suppliers.

All of us could probably benefit from increasing our magnesium intake. But there is such a thing as too much. The tolerable upper intake level for supplemental magnesium is 350 mg per day for adults. That means that you shouldn't take any more than that in supplement form; more than that amount, in addition to the magnesium you get from food and water, could cause problems. At very high levels, the mineral can be toxic, causing kidney failure. But within reasonable limits, magnesium is an important part of a complete supplement program - and as this study shows, an important tool in your heart-health regimen.

To Your Good Health,

Jenny Thompson, Health Sciences Institute

Source: American Journal of Clinical Nutrition 2002; 75:550-554

Source: Case Western Reserve University(http://www.cwru.edu/)
Date Posted: Monday, August 26, 2002
Web Address: http://www.sciencedaily.com/releases/2002/08/020826071458.htm

Case Western Scientists Reveal How Magnesium Works
On Ion Channels Important For Regulating Blood Pressure

CLEVELAND -- Researchers at Case Western Reserve University report in the August 22 issue of Nature how magnesium activates microscopic ion channels in the membrane of a cell. These particular ion channels are important in controlling blood pressure. Scientists, the researchers say, can use this new finding in the quest to understand how magnesium helps to decrease blood pressure and also treat heart failure and stroke.

Calcium activated potassium channels are important microscopic pathways in the cell membrane that relax the smooth muscle in a blood vessel, according to the researchers. They also modify electrical impulses, which travel in nerve cells throughout the brain.

"Research of this kind may help to understand why some therapies such as magnesium supplements are important in the prevention and management of hypertension or heart failure," said Jianmin Cui, the lead researcher and assistant professor in the department of biomedical engineering at CWRU. "Along with some other groups, we have discovered that when magnesium is applied to calcium-activated potassium channels, these channels will open. We know from literature that the opening of these channels can reduce blood pressure."

The Nature article ("Mechanism of magnesium activation of calcium activated potassium channels") was written by Jianmin Cui, the principal researcher, who was assisted by Jingyi Shi, senior researcher in the department of biomedical engineering; Gayathri Krishnamoorty and Lei Hu, graduate students in the department of biomedical engineering; and Neha Chaturvedi and Dina Harilal, undergraduates students. The team is collaborating with Yanwu Yang and Jun Qin, structural biologists at the Cleveland Clinic Foundation. The research is supported by a $1 million grant from the National Institutes of Health, Heart Lung and Blood Institute.

"The completion of stage one of the project is due to the combination of state-of-the-art bioelectric facilities and advanced structural biology results," Cui said. "The collaboration between the department of biomedical engineering and The Cleveland Clinic Foundation was key."

CWRU researchers used cloned ion channel DNA to express the ion channels in frog eggs. The ion channels are proteins made of various amino acids; the researchers mutated some of these amino acids and recorded functional change that resulted from the mutations.

Hypertension, Cui explained, results from the contraction of blood vessels, which causes an increase in blood pressure. "The diameter of blood vessels is controlled by smooth muscle cells around them," he said. "When magnesium reaches these potassium channels, the channels open causing blood vessels to dilate and therefore reduce hypertension."

According to the National Health and Nutrition Examination Survey conducted between 1988 and 1994 by The National High Blood Pressure Education Program, an estimated 42.3 million people in the U.S had hypertension. Doctors had told an additional 7.7 million on two or more occasions that they had hypertension, which gives a total of 50 million hypertensives.

"Our research is basic science, however, we hope that the results can help to explain why some treatments would work and provide rationale for development of new drugs for hypertension," Cui said.

Author: Maureen Haggerty

Definition

A mineral found in the fluid that surrounds cells, magnesium (Mg) is an essential component of more than 300 enzymes that regulate many body functions. Imbalances occur when the blood contains more or less magnesium than it should.

Description

Magnesium is necessary for the formation and functioning of healthy bones, teeth, muscles, and nerves. It converts food into energy, builds proteins, and is instrumental in maintaining adequate levels of calcium in the blood. Magnesium helps prevent cardiovascular disease and irregular heartbeat, reduces the risk of bone loss (osteoporosis), and increases an individual's chance of surviving a heart attack. It may also help prevent stroke and lessen the effects of existing osteoporosis.

Fish, dairy products, leafy green vegetables, legumes, nuts, seeds, and grains are especially good sources of magnesium, but varying amounts of this mineral are found in all foods. Some is stored in the kidneys, and excess amounts are excreted in the urine or stools.

Magnesium deficiency (hypomagnesemia) or excess (hypermagnesemia) is rare, but either condition can be serious.

Causes & symptoms

Hypomagnesemia

Magnesium deficiency most often occurs in people who have been fed intravenously for a long time, whose diet doesn't contain enough magnesium, or who are unable to absorb and excrete the mineral properly.

Secreting too much aldosterone (the hormone that regulates the body's salt-fluid balance), ADH (a hormone that inhibits urine production), or thyroid hormone can cause hypomagnesemia.

Other factors associated with hypomagnesemia include:

• Loss of body fluids as a result of stomach suctioning or chronic diarrhea

• Cisplatin (a chemotherapy drug)

• Long-term diuretic therapy

• Hypercalcemia (abnormally high levels of calcium in the blood)

• Diabetic acidosis (a condition in which the body's tissues have a higher-than-normal acid content)

• Complications of bowel surgery

• Chronic alcoholism

• Malnutrition

• Starvation

• Severe dehydration.

People who have hypomagnesemia usually experience loss of weight and appetite, bloating, and muscle pain, and they pass stools that have a high fat content. Also, they may be listless, disoriented, confused, and very irritable. Other symptoms of hypomagnesemia are:

• Nausea

• Vomiting

• Muscle weakness

• Tremor

• Irregular heart beat

• Delusions and hallucinations

• Leg and foot cramps

• Muscle twitches

• Changes in blood pressure.

Severe magnesium deficiency can cause seizures, especially in children.

Neonatal hypomagnesemia can occur in premature babies and in infants who have genetic parathyroid disorders or who have had blood transfusions. This condition also occurs in babies born to magnesium-deficient mothers or to women who have:

• Diabetes mellitus.

• Hyperparathyroidism (overactive parathyroid glands)

• Toxemia (a pregnancy-related condition characterized by high blood pressure and fluid retention).

Hypermagnesemia

Hypermagnesemia is most common in patients whose kidneys cannot excrete the magnesium they derive from food or take as medication. This condition can also develop in patients who take magnesium salts, or in healthy people who use large quantities of magnesium-containing antacids, laxatives, or analgesics (pain relievers).

Magnesium poisoning can cause severe diarrhea in young people, and mask the symptoms of other illnesses. Very high overdoses can lead to coma. The risk of complications of magnesium poisoning is greatest for:

• Elderly people with inefficient kidney function

• Patients with kidney problems or intestinal disorders

• People who use antihistamines, muscle relaxants, or narcotics.

Severe dehydration or an overdose of supplements taken to counteract hypomagnesemia can also cause this condition.

People who have hypermagnesemia may feel flushed and drowsy, perspire heavily, and have diarrhea. Breathing becomes shallow, reflexes diminish, and the patient becomes unresponsive. Muscle weakness and hallucinations are common. The patient's heart beat slows dramatically and blood pressure plummets. Extreme toxicity, which can lead to coma and cardiac arrest, can be fatal.

Diagnosis

Blood tests are used to measure magnesium levels.

Treatment

The goal of treatment is to identify and correct the cause of the imbalance. Oral magnesium supplements or injections are usually prescribed to correct mild magnesium deficiency. If the deficiency is more severe or does not respond to treatment, magnesium sulfate or magnesium chloride may be administered intravenously.

Doctors usually prescribe diuretics (urine-producing drugs) for patients with hypermagnesemia and advise them to drink more fluids to flush the excess mineral from the body. Patients whose magnesium levels are extremely high may need mechanical support to breathe and to circulate blood throughout their bodies.

Intravenously administered calcium gluconate may reverse damage caused by excess magnesium. Intravenous furosemide (Lasix) or ethacrynic acid (Edecrin) can increase magnesium excretion in patients who get enough fluids and whose kidneys are functioning properly.

In an emergency, dialysis can provide temporary relief for patients whose kidney function is poor or who are unable to excrete excess minerals.

Prognosis

Because imbalances may recur if the underlying condition is not eliminated, monitoring of magnesium levels should continue after treatment has been completed.

Prevention

Most people consume adequate amounts of magnesium in the food they eat. Dietary supplements can be used safely, but should only be used under a doctor's supervision.

Key Terms

Hypermagnesemia

An abnormally high concentration of magnesium in the blood.

Hypomagnesemia

An abnormally low concentration of magnesium in the blood.

Gale Encyclopedia of Medicine. Gale Research, 1999.

Oral Magnesium Inhibits Acute PDT

Author: Richard Sadovsky
Issue: Jan 15, 2000

Magnesium is an important intracellular cation and cofactor for many human enzymes. Intravenous magnesium therapy has been shown to be useful in reducing mortality in thombolysis-ineligible patients with acute myocardial infarction. Magnesium also has been shown to suppress platelet activation. Schechter and associates evaluated the effectiveness of oral magnesium treatment on potential mediators of acute thrombus formation in patients with coronary artery disease (CAD).

Patients with stable, documented CAD were eligible for the double-blind, crossover, placebo controlled study if they did not have concomitant unstable angina, congestive heart failure or other serious medical problems. Those who met the inclusion criteria were randomized to receive magnesium oxide tablets in a dosage of 800 to 1,200 mg per day or placebo for three months, followed by a four-week washout period, and then the alternate treatment for an additional three months. All other regular medications were continued throughout the study. All patients underwent a physical examination, blood tests for measurement of platelet-dependent thrombosis (PDT), platelet aggregation and other laboratory tests before and after each phase of the study.

A total of 36 patients completed the study. After three months of oral magnesium treatment, median PDT decreased by 35 percent. This change was not related to the presence of other risk factors such as hypertension, diabetes or smoking. Magnesium treatment appeared to have no effect on platelet aggregation, serum lipid levels, fibrinogen or apolipoprotein A-I and B. In addition, no serious adverse effects associated with the study medication were apparent.

The authors conclude that oral magnesium therapy reduced acute PDT, possibly because of its antiplatelet adhesion effects. The antithrombotic effect of magnesium treatment occurred despite 100 percent use of aspirin therapy. The clinical relevance of this observation needs further confirmation with a larger cohort of patients before any specific recommendation can be made.

Shechter M, et al. Oral magnesium supplementation inhibits platelet- dependent thrombosis in patients with coronary artery disease. Am J Cardiol July 15, 1999;84: 152-6.

editor's note: Hypomagnesemia has been shown to selectively impair the release of nitric oxide from the coronary endothelium. Because nitric oxide is a vasodilator and inhibitor of platelet aggregation and adhesion, hypomagnesemia may stimulate vasoconstriction and possibly even coronary thrombosis. This suggests that low magnesium levels may even contribute to the development of coronary atherosclerosis. Recently, intravenous infusions of magnesium have been used in an attempt to decrease infarct size in the immediate post-myocardial infarction period. Magnesium seems to have an important beneficial coronary vascular effect. More study is needed to determine how to actually harness magnesium's positive effects and whether its benefit will be generalizable.-r.s.

COPYRIGHT 2000 American Academy of Family Physicians

http://www.findarticles.com/cf_0/m3225/2_61/59486897/p1/article.jhtml?term=magnesium

Too little magnesium affects the postmenopausal heart

(Altmed Watch).(Brief Article)

Author/s: Paul L. Cerrato
Issue: April, 2002

A low magnesium diet puts postmenopausal women at risk for supraventricular ectopy suggests this new clinical trial. In a recent metabolic ward study, 22 women were blindly fed a diet containing less than half the RDA for magnesium or more than the RDA (320 mg/day). Those on the low magnesium regimen were more inclined toward arrhythmias, despite the fact that the diet did not cause hypomagnesemia, the usual marker that clinicians use to diagnose magnesium deficiency. Their research is consistent with previous animal and human data that have shown that magnesium deficiency causes adverse neuromuscular effects like spasm, tremor, tetany, and convulsions.

Klevay LM, Milne DB. Low dietary magnesium increases supraventricular ectopy. Am J Clin Nutr. 2002;75:550-554.

Department editor Paul L. Cerrato, MA, Managing Editor of Contemporary OB/GYN is a guest lecturer at the Institute of Human Nutrition, Columbia University College of Physicians and Surgeons, New York, N.Y.

COPYRIGHT 2002 A Thomson Healthcare Company

http://www.findarticles.com/cf_0/m0BGG/4_47/86060287/p1/article.jhtml?term=magnesium

MAGNESIUM - nutritional aspects

(includes related articles)

Author/s: David Schardt
Issue: Dec, 1998

You can't take a breath, move a muscle, or think a thought if you don't have enough magnesium in your cells. But according to dietary surveys, many Americans may not be getting enough from their food. And research suggests that a shortage of magnesium may put you at increased risk of diabetes, high blood pressure, heart disease, osteoporosis, and maybe migraines.

Many Americans don't take in enough magnesium to replace what they lose every day. One reason: it's most plentiful in foods like green leafy vegetables, whole grains, beans, and nuts--not exactly staples in most households.

The National Academy of Sciences (NAS) recommends that women over 30 consume 320 mg of magnesium a day. Yet half of all women aged 31 to 70 get 230 mg or less. Half of all women over 70 get 205 mg or less.

(Those are probably underestimates, because people typically don't report everything they eat.)

The story's the same with men. Most should consume 420 mg a day. But half of all men aged 31 to 50 get less than 330 mg. Half of all men over 70 get less than 275 mg a day.

What's wrong with losing a little magnesium each day?

"Many of us in magnesium research feel that there are harmful consequences to getting less than the requirement--like diabetes, high blood pressure, osteoporosis, and atherosclerosis," says Robert Rude of the University of Southern California in Los Angeles. "But we haven't been able to prove any of that yet."

Rude served as the magnesium expert on the NAS panel that recommended higher magnesium intakes last year.

Others take a more skeptical view. "We don't know which is the cart and which is the horse," says Stephanie Atkinson of McMaster University in Hamilton, Canada, who chaired the panel.

"There is mounting evidence that people with a number of diseases have lower blood magnesium levels, as measured by the only readily available method. But we don't know if that is a result of the disease or a possible cause."

Here's some of that evidence.

Diabetes

Magnesium and insulin need each other. Without magnesium, your pancreas won't secrete enough insulin--or the insulin it secretes won't be efficient enough--to control your blood sugar. And without insulin, magnesium doesn't get transported from your blood into your cells, where it does most of its work.

When Jerry Nadler of the Gonda Diabetes Center at the City of Hope Medical Center in Duarte, California, and his colleagues placed 16 healthy people on magnesium-deficient diets, their insulin became less effective at getting sugar from their blood into their cells, where it's burned or stored as fuel.(1) In other words, they became less insulin sensitive. And that's a step on the road to diabetes.

Two large population studies also found that people who eat less magnesium have a higher risk of type 2, or adult-onset, diabetes. In a study of 65,000 nurses, those who consumed about 220 mg a day were about one-third more likely to develop diabetes over the next six years than those who consumed about 340 mg a day.(2) A study of 43,000 male health professionals turned up similar results.(3)

And last year, the Atherosclerosis Risk in Communities Study (ARIC) weighed in. It has been following about 14,000 middle-aged people for up to seven years.

"We have found that those men and women with the lowest levels of magnesium in their blood at the start of ARIC were twice as likely to be diagnosed later with diabetes as those with the highest levels of magnesium," says Frederick Brancati, an epidemiologist at the Johns Hopkins School of Medicine in Baltimore.(4)

What about people who already have diabetes?

"A high percentage of type 2 diabetics have a deficiency of magnesium inside their cells," says Nadler. But no one knows which came first--the diabetes or the magnesium deficiency.

And it's not clear whether magnesium supplements can help diabetics. Nine small studies have tested 360 mg to 390 mg a day for one to five months. Six found that it didn't lower blood sugar, while three found that it improved insulin sensitivity.

That's what you would expect, says Nadler. "Magnesium is not likely to change blood sugar very much because there are so many factors that influence glucose levels. But it may improve insulin sensitivity," he adds, and that would improve your long-term prospects of avoiding a heart attack or stroke.

High Blood Pressure

Magnesium helps signal muscles to contract and relax. And when the muscles that line the major blood vessels contract, your blood pressure rises.

When researchers studied the diets of 40,000 nurses and 30,000 male health professionals, they found lower blood pressures in people who ate more magnesium.(5,6)

And in the ARIC study, "women with lower levels of magnesium in their blood were more likely to develop high blood pressure over the next few years than women with higher levels," says Aaron Folsom of the University of Minnesota in Minneapolis. That was not true for men, though researchers don't know why.

What about people whose blood pressure is already high? Could magnesium supplements help them?

Since 1985, at least 16 trials have given magnesium to people with high or high-normal blood pressure. The two largest compared 360 mg a day to a (look-alike but magnesium-free) placebo in 285 people for six months.(7,8)

"Magnesium had no effect in either," says Frank Sacks of the Harvard School of Public Health in Boston, who headed one of the two studies.

Still, some smaller studies have found that magnesium lowered blood pressure modestly. In the latest, from Japan, 360 mg a day for eight weeks lowered blood pressure by an average of 3 points over 1 point in 60 men and women who started with high-normal blood pressures (they averaged 134/81).(9)

"Extra magnesium is not a definitive treatment for high blood pressure," says Marvin Moser, a hypertension expert at Yale University. "Eating magnesium-rich foods or taking magnesium supplements might result in some decrease in pressure. But the vast majority of people with high blood pressure will still need medication."

Heart Disease & Stroke

Since the 1960s, researchers have known that people who live in areas where the water is "hard" often have lower rates of heart disease and stroke. ("Hard" water contains more calcium, magnesium, and other minerals than "soft" water.)

But the amount of magnesium in hard water is typically no more than 3 mg to 20 mg per liter--less than ten percent of what people get from a day's food.

"It's hard to imagine how such a small amount could have such a big effect on preventing heart disease," says epidemiologist Raymond Neutra of the California Department of Health Services.

"Still, there's enough suggestive evidence out there that it needs to be seriously looked at."

In fact, there's some evidence that magnesium may be harmful. In what Neutra calls a "sobering" Dutch study from the early 1990s, more than 450 men and women with heart disease who were given 360 mg a day of magnesium for a year were more likely to suffer a second heart attack, need a bypass, or die a sudden death than heart disease victims who were given a placebo.(10)

"That could be due to chance," says Neutra. Another possibility, according to USC's Robert Rude: People with more severe heart disease may have inadvertently ended up in the group given magnesium.

Other Diseases

* Migraines. "Some people who suffer from migraine headaches may be deficient in magnesium," says Alexander Mauskop of the New York Headache Clinic.

In one of two small studies, 40 migraine patients who took 600 mg of magnesium a day for 12 weeks went from three attacks per month to two. Patients taking a placebo had no fewer attacks. There was no difference in the severity of the headaches, though.(11)

* Osteoporosis. "There are hints out there in human and animal research that magnesium is important for good quality bones," says Purdue University's Connie Weaver. "But the evidence that magnesium supplements can prevent osteoporosis in humans is pretty skimpy."

(1) Hypertension 21 (6 Pt 2): 1024, 1993.
(2) J. Amer. Med. Assoc. 277: 472, 1997.
(3) Diabetes Care 20(4): 545, 1997.
(4) Diabetes 46 (Suppl 1): 20A.
(5) Hypertension 27: 1065, 1996.
(6) Circulation 86: 1475, 1992.
(7) Annals of Epidemiology 5: 96, 1995.
(8) Hypertension 31 (Part 1): 131, 1998.
(9) Hypertension 32: 260, 1998.
(10) British Medical Journal 307: 585, 1993.
(11) Cephalalgia 16: 257, 1996.

RELATED ARTICLE: GETTING ENOUGH?

Last year, the National Academy of Sciences announced new recommended intakes for magnesium. Women need 310 mg a day (ages 19 through 30) or 320 mg (over 30). Men need 400 mg (19 through 30) or 420 mg (over 30).

How much magnesium are you getting? And is it enough to keep you from running short?

"Unfortunately, there isn't a reliable test of magnesium deficiency that's widely available," says the University of Southern California's Robert Rude. "About all a primary care physician can do is measure the level of magnesium in the blood. But that doesn't tell you if the level of magnesium is adequate within the cells, which is where it's critically important."

"I think that magnesium should be obtained from the diet, if possible," says Jerry Nadler of the City of Hope Medical Center in Duarte, California. "That's because many magnesium-rich foods are the healthier foods to eat." But if someone can't get enough from food (see "Magnesium Counts," p. II), "then taking a magnesium supplement clearly is better than nothing."

Multivitamin and mineral supplements seldom contain a day's recommended dose of magnesium, simply because the 300 or 400 mg necessary won't fit into a pill small enough for most people to swallow. So if you want more than 25 percent or so of a day's supply from a supplement, you'll probably need to buy it separately.

Don't worry about how the magnesium is bundled--whether it comes in an oxide, chloride, or any other form. "There's no convincing evidence that one is better-absorbed than another," says Connie Weaver of Purdue University. And don't be afraid to get your calcium and your magnesium in a single supplement. "Calcium doesn't interfere with magnesium absorption, as some people believe," says Weaver.

But not all magnesium supplements are equal. Dolomite (a naturally occurring calcium-magnesium combination) is more likely to contain lead than other kinds of magnesium.

Can you get too much magnesium? "Taking too much from magnesium-confining antacids or drugs causes diarrhea," says magnesium expert Mildred Seelig. "So most people find out quickly when they've exceeded a safe dose."

No cases of magnesium toxicity from food have ever been reported, says the National Academy of Sciences. As for supplements, the NAS recommends a ceiling of 350 mg a day as a Tolerable Upper Intake Level (UL).

RELATED ARTICLE: MAGNESIUM COUNTS

Food                                                    Magnesium
                                                             (mg)
All-Bran (1/2 cup)                                            120
Black or navy beans (1 cup cooked)                        105-120
Great Northern or pinto beans (1 cup cooked)                90-95
Brown rice (1 cup cooked)                                      85
Almonds or cashews (3 Tbs.)                                 75-85
Garbanzos (chickpeas) or lima beans (1 cup cooked)             80
Kellogg's Raisin Bran (1 cup)                                  80
Spinach (1/2 cup cooked)                                       75
Lentils (1 cup cooked)                                         70
Grape-Nuts (1/2 cup)                                           60
Multi-Bran Chex or Wheat Chex (1 cup)                          60
Baked potato, with skin (1-7 oz.)                              55
Seafood (4 oz. cooked)                                      35-55
Peanuts (1/5 cup) or peanut butter (2 Tbs.)                    50
Whole wheat bread (2 slices--2 oz.)                            50
Acorn squash (1/2 cup cooked)                                  45
Yogurt (1 cup)                                              35-45
Banana (1)                                                     35
Peas (1/2 cup cooked)                                          35
Watermelon (2 cups)                                            35
Chocolate, semisweet or sweet (1 oz.)                       30-35
Milk (1 cup)                                                30-35
Grapefruit, orange, or prune juice (1 cup)                  25-35
Beef, pork, or poultry (4 oz. cooked)                       20-35
Butternut squash (1/2 cup cooked)                              30
Cheerios or Wheaties (1 cup)                                   30
Broccoli (1/2 cup cooked)                                      20
White rice (1 cup cooked)                                      20
White bread (2 slices--2 oz.)                                  15
Kellogg's Corn Flakes (1 cup) or Frosted Flakes (3/4 cup)       0

Chart compiled by Ingrid VanTuinen.

Sources: USDA and manufacturers.

RELATED ARTICLE: THE BOTTOM LINE

* The average American gets too little magnesium from food. The richest sources are legumes, nuts, whole grains and whole-grain breads and cereals, and some vegetables.

* Too little magnesium in the diet could increase the risk of diabetes, high blood pressure, heart disease, and stroke, but the evidence isn't conclusive.

* With the possible exception of treating migraines, there's no good evidence that getting more than the recommended levels of magnesium (see "Getting Enough?") - from food or supplements - provides any additional benefits.

COPYRIGHT 1998 Center for Science in the Public Interest

COPYRIGHT 2000 Gale Group

http://www.findarticles.com/cf_0/m0813/10_25/53389622/p1/article.jhtml?term=magnesium+chloride+MgCl