MAGNESIUM FINDS ITS WAY INTO NUTRITIONAL LIMELIGHT

                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: TUESDAY, January 28, 1992                   TAG: 9201280100
SECTION: EXTRA                    PAGE: E-3   EDITION: METRO 
SOURCE: Jane Brody
DATELINE:                                 LENGTH: Long
MAGNESIUM FINDS ITS WAY INTO NUTRITIONAL LIMELIGHT
Magnesium, an essential mineral in the human diet, has been all but ignored by nutrition enthusiasts who tout an alphabet-soup of supplements to correct purported deficiencies, to counter various ailments and to enhance overall health.
Unlike calcium, which few Americans get enough of to sustain healthy bones throughout life, or selenium, which may help to prevent cancer, magnesium was not considered to play a major role in nutritional problems nor was it regarded as a "sexy" nutrient.
But recent research may soon change magnesium's image and JANE BRODY
thrust it into the nutritional limelight. The findings indicate that magnesium deficiencies can play an important role in several major health problems, including heart disease, high blood pressure and diabetes, as well as some less-threatening problems like premenstrual disturbances and chronic fatigue syndrome.
Researchers also have found that magnesium deficiencies may be far more common than doctors realize. Many doctors are unfamiliar with the effects of magnesium deficiency and few patients are ever tested for it.
When they are, the tests nearly always measure magnesium levels in blood and may not reflect the amounts found in muscle cells, bone and other tissues in which the mineral plays crucial roles.
While many adults have at least heard of milk of magnesia, the antacid magnesium hydroxide, and while some people know that epsom salts is the laxative magnesium sulfate, very few know which foods supply the nutrient and even fewer can name even one of magnesium's functions in the body.
Magnesium is contained in many foods, but it is found in the largest amounts in raw leafy green vegetables, in nuts, especially almonds and cashews, in dried beans, like soybeans, in seeds and in whole grains and seafood. Some magnesium in foods is washed away when they are cooked.
The recommended daily intake of magnesium is 350 milligrams for men age 19 and older and 300 milligrams for women, with an extra 150 milligrams for women who are pregnant or nursing. National food consumption studies have shown that most Americans, with the exception of preschool children, do not consume the recommended amount.
Magnesium plays a role in the synthesis of proteins and this makes the mineral important for the health of tissues throughout the body. Sixty percent of the magnesium found in the body is in bones, where about a third is part of the structure and the remainder serves as a magnesium bank for the rest of the body. The remaining 40 percent is found in muscle and other soft tissues.
Magnesium helps to release energy for cell functions and eases muscle contractions and the conduction of nerve impulses. It also helps to regulate body temperature and to maintain a normal metabolic rate. In teeth, the mineral interacts with calcium to maintain tooth enamel.
Symptoms of magnesium deficiency include weakness in the muscles, twitches and tremors, irregular heart beat, insomnia, cramps in the leg and foot and shaky hands. Deficiencies are most common among people with prolonged cases of diarrhea, kidney disease, diabetes, epilepsy or alcoholism and in people who take diuretics to lower the blood pressure, for example, or digitalis. These conditions and medications put people at risk for developing magnesium deficiencies.
Dr. Robert Whang, of the University of Oklahoma Health Sciences Center, who studied more than 1,000 hospitalized patients tested for abnormalities in blood chemicals, found that 487 had abnormally low blood levels of magnesium. But only about 10 percent of these abnormalities were detected by tests ordered by the patients' doctors.
In general, Whang has reported, 7 percent to 11 percent of hospitalized patients would prove to have a magnesium deficiency. He also warned that a normal level of magnesium could be found in blood even when there is a deficiency in other body tissues.
Such shortages can compromise a patient's chances for survival. For example, in a study of 199 people with congestive heart failure, researchers in New York and Baltimore reported that the nearly one in five patients who had low magnesium levels were found to be more likely to have irregular heart rhythms and much less likely to survive for one year than patients with normal levels.
In another study, among 193 patients in the intensive care unit after surgery, 61 percent had low magnesium levels in the blood, and the deficiency was severe in 17 patients. The post-operative death rate was three times higher, 41 percent, among those with severe magnesium deficiencies even though they were no sicker than the remaining patients.
In people with insulin-dependent diabetes, low levels of magnesium in the blood were associated with an increased risk of developing diabetic retinopathy.
Other studies have indicated that insulin injections these patients require may account for their abnormally low levels of circulating magnesium. In addition, low levels of magnesium were found in the cells of people with high blood pressure, and this could result in an impairment in the contraction of muscle cells that help to control blood pressure.
A combined deficiency of potassium and magnesium can be particularly dangerous, seriously impairing the function of heart muscles.
Jane Brody writes about health issues for The New York Times.

NOTE: Some of this text did not appear in the newspaper due to technical difficulties.

by Archana Subramaniam by CNB