What’s Your Magnesium Level?

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What's Your Magnesium Level?

 

http://www.life-enhancement.com/article_template.asp?ID=1765

 

 

Magnesium May Improve Muscle

Strength in the Elderly

Serum levels correlate with grip strength,

leg-muscle power, and knee and ankle strength

By Will Block

ere's a scenario for you guys: imagine that you're here in Petaluma,

California, home of the annual World's Armwrestling Championship,

where intimidation and brute force rule (all in good fun, of course).

By dint of enormous effort and a little luck, you've made it to the

finals, with only one match left—and your opponent is Arnold

Schwarzenegger! And you beat him! (Daht's fahntahstic, ja?) OK, maybe

it doesn't compute in this universe, but where's the harm in doing a

Walter Mitty now and then?

 

When we were " 97-pound weaklings, " we boys pored over the Charles

Atlas ads in popular magazines, dreaming of becoming musclemen who

would put the sand-kicking beach bullies in their place while the

girls swooned over us. Some of us even scraped together the money to

send away for Atlas's " Dynamic Tension " muscle-building program (now

known as isometric exercises). Darned few of us, though—OK,

technically only one of us—grew up to be Arnold Schwarzenegger.

Still, we did the best we could, and we've gotten through life

reasonably well with the muscles we developed.

 

It's Never Too Late for Muscle Building

 

The question is, do we still have those muscles, and how strong are

they? The answer will not please you. You probably already know it

anyway: with aging comes a gradual loss of muscle mass and strength

(this applies to the ladies as well as the men). It's called

sarcopenia, and it seems to be inevitable—although not necessarily to

the degree that we commonly see in our society. As with every other

aspect of our health, it all depends on how we have lived our lives

thus far, in terms of diet, exercise, and other lifestyle choices—not

to mention our genetic makeup and other aspects of pure luck.

 

We cannot, of course, turn the clock back and relive our lives the

way Charles Atlas lived his (not that we'd want to, necessarily—he

died of heart failure at age 80), but we can always do better from

here on out, because it's never too late to start building and

strengthening muscles that may have fallen into disuse. You've

probably seen or heard stories about folks in their seventies,

eighties, or even nineties who took up exercise of one form or

another (yoga, for example) and benefited greatly from it, in both

physical and psychological terms. Sometimes the improvements,

especially in those with arthritis, are truly amazing.

 

Connecting the Magnesium Dots

 

Exercising is vitally important for good health in general and

physical fitness in particular, and it can make you feel great if you

do it right. But other things are important too, such as diet—which,

of course, includes the vitamins and minerals your body needs for

optimal performance. It could be that the element magnesium plays an

important role in muscle performance in the elderly. Here are half a

dozen relevant facts to consider:1

 

Magnesium is intimately involved in cellular energy metabolism in the

mitochondria, and abundant chemical energy is required for physical

exertion.

Magnesium depletion is associated with structural damage to muscle

cells in athletes.

Magnesium supplementation has been shown to increase muscle strength

in young adults.

Magnesium seems to be necessary for maintaining optimal muscle

performance and exercise tolerance in postmenopausal women.

Inadequate magnesium intake is common, especially in older persons.

Sarcopenia is prevalent in older persons and is a strong, independent

risk factor for disability and mortality.

Can we connect the dots? A team of researchers from Italy and the

United States tried to do that by investigating whether there is a

measurable association between serum magnesium levels and muscle

performance in the elderly.1 That's much easier said than done,

however. Part of the challenge was to correct for, and thus rule out,

numerous factors in the study population that might confound the

results—factors such as age, sex, body mass index, calf-muscle area

and density, several biological indexes (serum levels of calcium,

albumin, hemoglobin, glucose, creatinine, and vitamin D), the

presence of self-reported or medically diagnosed diseases, and levels

of physical activity in the year before recruitment.

 

Magnesium Benefited Men and Women Equally

 

The researchers analyzed recorded data on 1138 men and women, average

age 67, from an existing epidemiological study in Italy that was

aimed at identifying risk factors for mobility-related disability in

older adults, in whom poor muscle strength is a major cause of

disability. The study was called InCHIANTI, short for Invecchiare in

Chianti, which means Aging in Chianti (the region, not the wine—

although aging in wine sounds like fun, doesn't it?).

 

The men and women had been given four tests of muscular performance

under controlled conditions: handgrip strength, knee-extension

torque, maximum lower-extremity muscle power, and ankle-extension

strength. The details of how these measurements were made need not

concern us here. What matters is the results: in all four tests, the

data showed a modest but measurable increase in muscle performance

with increasing serum magnesium level. The relationships were

statistically significant in all but the test for maximum lower-

extremity muscle power, and the results were essentially the same for

men and women.*

 

 

 

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*Here's an irony: gymnasts and weightlifters often use magnesium

carbonate powder on their hands to improve their grip on the bars.

 

 

 

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The More Magnesium, the Better

 

To see whether the relationships were being driven by the data from

individuals whose serum magnesium levels were below or above the

normal range, the researchers reanalyzed the data, using only those

individuals who were within the normal range. The results were the

same, indicating that the relationships hold across the full spectrum

of serum magnesium levels: the more you have, the stronger you're

likely to be.

 

The researchers suggested three possible explanations for their

results:

 

Low magnesium levels may impair cellular energy production and cause

structural and functional damage to proteins, which would limit

muscle performance.

Low magnesium levels may cause structural damage to muscle cells

through increased oxidative stress and impaired calcium homeostasis

(maintenance of calcium equilibrium).

Low magnesium levels may induce an inflammatory status by enhancing

the production of certain proinflammatory compounds. (A state of

chronic, low-grade inflammation has been proposed as one of the main

causes of frailty in the elderly.)

Eat Your Spinach!

 

It's not possible to say, from the results of this study, whether

supplementation with magnesium would be likely to improve any

individual's muscle performance. Based on a large body of existing

knowledge, however, one can say that maintaining healthy magnesium

levels is a very good idea. It's important for helping to prevent

hypertension, cardiovascular disease, type 2 diabetes, osteoporosis,

migraines, and immune-system disorders.

 

Magnesium deficiencies in healthy adults with a good diet are rare

because the element is so readily available in plant and animal foods—

especially green leafy vegetables (the chlorophyll molecule contains

a magnesium ion at its center). Probably the best vegetable source of

magnesium is spinach (preferably without E. coli).* Bran and

unrefined grains are also excellent sources of magnesium, as are

legumes and nuts.

 

 

 

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*Contrary to the Popeye legend, spinach is not a rich source of iron.

The myth arose because of a misplaced decimal point in an 1870

nutritional publication that ascribed to spinach 10 times more iron

than it actually has. The error wasn't discovered until 1937, by

which time Popeye ruled. Either way, though, the story was bogus,

because dietary iron does not make you strong.

 

 

 

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The primary risk for magnesium deficiency is age, because many older

people simply don't consume enough good, healthy food (this, of

course, leads to other deficiencies as well). Also, however, there is

an age-related tendency for magnesium absorption by the gut to

decrease and for urinary excretion of magnesium to increase—a double

whammy that increases the risk for deficiency. Severe deficiency can

cause depressed calcium levels and disruptions of electrolyte

metabolism, as well as muscle spasms, tremor, loss of appetite,

nausea, vomiting, cardiac arrhythmias, and personality changes, among

others.

 

 

 

Versatile Magnesium

Magnesium—as magnesium ions, Mg2+—is one of the four most important

metals in human physiology, the other three being sodium, potassium,

and calcium. Each of us has about 25 grams (0.9 ounce) of magnesium.

Over 60% is found in the skeleton, about 27% in the muscles, 6–7% in

other cells, and less than 1% in the blood and extracellular fluid.

 

Numerous inorganic and organic salts of magnesium are used in

medicine and as home remedies. For example, milk of magnesia (a water

suspension of magnesium hydroxide) is a mild base that acts as an

antacid and laxative, and Epsom salts (hydrated magnesium sulfate)

acts as a cathartic and anti-inflammatory agent. Other magnesium

salts are used as analgesics, antipyretics, anticonvulsants, and

lubricants. The form in which magnesium is usually provided as a

nutritional supplement is the organic salt magnesium aspartate.

 

Magnesium's role in the physiology of all living things is pervasive.

In humans, it's involved in over 300 essential metabolic reactions.

Most prominent is its role in cellular respiration, or energy

metabolism—it exists primarily as a complex with ATP (adenosine

triphosphate), the body's master energy molecule. Without magnesium,

there would be no biochemical energy production, hence no life.

 

Magnesium is also required for synthesis of nucleic acids and the

proteins they code for. It's required as a cofactor for a number of

enzymes involved in the synthesis of carbohydrates and lipids.

Glutathione, the body's premier antioxidant, could not be produced

without it. It plays a structural role in bones, cell membranes, and

chromosomes. It's required for the active transport of other metal

ions across cell membranes, thus affecting nerve transmission, muscle

contraction, and heart rhythm. And it's required for many cell-

signaling functions (the conveyance of chemical messages within and

between cells).

 

 

 

© iStockphoto.com/

Fredrik Holm

All four of the metals mentioned above, by the way, were discovered

in 1807–1808 by the great English chemist Sir Humphry Davy. Elemental

magnesium, which is not found in nature (it's too reactive), was

first produced in quantity in the mid-nineteenth century by the

German chemist Robert Wilhelm Bunsen (of Bunsen burner fame), who

showed how it could be burned to produce an extremely bright light;

this proved invaluable to early photographers and provides much of

the dazzle in fireworks.

The primary industrial application for magnesium is as an alloying

agent to make tough, strong, aluminum-magnesium alloys that are used

in beverage cans, automotive and aircraft components (if you're the

sporty type, perhaps your car has " mag wheels " ), and consumer

electronic devices, such as laptop computers, cell phones, and

cameras.

 

 

Deficiency Bad — Supplementation Good

 

For adults aged 31 or older, the Food and Nutrition Board of the

Institute of Medicine has set the Recommended Dietary Allowance (RDA)

for magnesium at 420 mg/day for men and 320 mg/day for women (for

adults aged 19–30, the figures are 400 and 310, respectively). In the

United States, however, the average daily magnesium intake is about

320 mg for men and about 230 mg for women, or 24% and 28%,

respectively, below the RDAs.2 A recent study showed that elderly

American men and women consume only about 225 and 166 mg/day of

magnesium, respectively, or 46% and 48% below the RDAs.3

 

 

 

© iStockphoto.com/

Lisa Kyle Young

This deplorable situation is an indictment of our generally poor

diet, which we seem to favor despite all the health experts'

admonitions about fruits and veggies. Fortunately, however, the

problem is easily solved through supplementation. As always, amounts

matter. Just as it's potentially harmful to ingest too little

magnesium, it's also inadvisable to take too much, especially for

those with impaired kidney function, which afflicts many elderly

people. (If you have a kidney disorder, consult your physician before

taking any magnesium supplement, including magnesium-based antacids

or laxatives.)

For all generally healthy adolescents and adults, the Tolerable Upper

Intake Level (UL) for supplemental magnesium (all supplements

combined), set by the Food and Nutrition Board of the Institute of

Medicine, is a very conservative 350 mg/day. This represents the

level of daily supplemental magnesium intake beyond which there is

some risk of diarrhea or other gastrointestinal disturbances in some

people; the risk increases with increasing intake and is easily

reduced by scaling back if necessary. Highly excessive intakes (many

grams or more per day) could, ironically, lead to muscle weakness, or

worse.

 

Indulge Your Fantasies

 

OK, you can go back to Walter Mitty mode now, if you wish. Whether

your fantasy is being brawnier than Arnold Schwarzenegger, brainier

than Stephen Hawking, or something too private to discuss, there's

one thing you can fantasize about that probably will come true: being

healthier as a result of taking judiciously selected nutritional

supplements, such as magnesium.

 

References

 

Dominguez LJ, Barbagallo M, Lauretani F, Bandinelli S, Bos A, Corsi

AM, Simonsick EM, Ferrucci L. Magnesium and muscle performance in

older persons: the InCHIANTI study. Am J Clin Nutr 2006;84:419-26.

Food and Nutrition Board, Institute of Medicine. Dietary Reference

Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride.

National Academy Press, Washington DC, 1997.

Ford ES, Mokdad AH. Dietary magnesium intake in a national sample of

U.S. adults. J Nutr 2003;133:2879-82.

 

 

 

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Will Block is the publisher and editorial director of Life

Enhancement magazine.