Last Updated: 2002-10-21 13:00:18 -0400 (Reuters Health)

By Kathleen Doheny

SAN DIEGO (Reuters Health) - Paying more attention to magnesium intake could greatly improve the health of African Americans, making them less prone to high blood pressure, diabetes, heart and kidney problems, a New York researcher reported here Saturday at the annual meeting of the American Academy of Family Physicians.

Lower levels of magnesium, both from the diet and in the bloodstream, have been associated with an increased prevalence of high blood pressure, insulin resistance and diabetes--all of which are more common among African Americans than other ethnicities, according to Dr. Chester Fox, associate professor of clinical family medicine at the University at Buffalo.

Eating adequate amounts of magnesium--a mineral that helps maintain normal muscle and nerve function, regulate heart rhythm and keep bones strong--could help African Americans stay healthier, Fox told Reuters Health.

Fox reviewed more than 100 published studies on magnesium deficiency, including some on African Americans and magnesium deficiency, and found evidence that deficiency in the mineral is more common among blacks. Also, he noted, a national study found that the diet of African Americans is low in magnesium, as well as calcium and potassium.

And researchers have also linked a diet lacking in magnesium to insulin resistance among young black men and women. Insulin resistance, in which the body loses its ability to respond to this key blood-sugar-regulating hormone, is a precursor to diabetes and has also been linked to high blood pressure and atherosclerosis.

It is difficult to research magnesium deficiency, Fox said, because the vast majority of the body's magnesium is stored inside the cells of body tissues and within bone. Only a tiny amount is found in the blood.

"You can get a serum magnesium test, and if it is low you are deficient," he said. "If it is normal you may still be deficient."

Symptoms of deficiency include appetite loss, muscle cramps, confusion, abnormal heart rhythm and depression, according to the National Institutes of Health.

Fox suggests that African Americans, especially those who have high blood pressure or diabetes, should, with their doctor's approval, consider a diet plan called DASH (Dietary Approaches to Stop Hypertension), which has been shown to lower blood pressure and improve health.

"The DASH diet is high in potassium, magnesium and calcium, and low in sodium." The diet is described on the National Institutes of Health Web site.

The recommended dietary allowance (RDA) of magnesium varies by age and gender, with 420 milligrams a day recommended for men age 31 and older, and 320 milligrams a day for women 31 and older. Good sources of magnesium include avocados, leafy green vegetables, fruits and other foods.

Besides following the DASH diet, Fox advises people who want to reduce disease risk to exercise at least 30 minutes most days of the week.

He warns people not to self-dose with magnesium supplements, especially if they have kidney problems, but to consult their doctor first.

http://www.reutershealth.com/archiv...021elin015.html