A study by Northwestern University researchers published in the April 4, 2006, issue of Circulation: the Journal of the American Heart Association, found that a diet rich in magnesium appears to protect against metabolic syndrome, a combination of risk factors that can lead to diabetes and heart disease. Similar results, published in 2005 by researchers at Boston's Brigham and Women's Hospital, showed that women with the highest intake of magnesium had a 27 percent lower incidence of metabolic syndrome. Having three of the following abnormalities can indicate metabolic syndrome: high blood pressure, low HDL ("good") cholesterol, high triglycerides, high blood sugar and abdominal obesity.
The Northwestern study included 4,637 men and women who were between the ages of 18 and 30 when they were recruited. After following the group for 15 years, the research team found that about 600 had developed metabolic syndrome. When they looked at the participants' magnesium intake over the 15 years, they found that those whose magnesium intake was highest had a 31 percent lower risk of developing metabolic syndrome than participants whose magnesium intake was lowest.
It's easy to get magnesium from your diet - it is plentiful in whole grains, leafy green vegetables (spinach is a great source) as well as almonds, cashews and other nuts, avocados, beans, soybeans, halibut. You can also take supplemental magnesium. I recommend taking half the amount of magnesium as calcium. Look for magnesium citrate, chelate, or glycinate. Avoid magnesium oxide, which can be irritating. High doses will cause a laxative effect or diarrhea.
The Northwestern researchers noted that more studies will be needed to determine the optimal dosage of magnesium needed for people at risk of diabetes or heart disease.
While getting adequate magnesium is important, don't rely on it alone to protect against metabolic syndrome, diabetes and heart disease. To significantly lower risks, you should eat a healthy, balanced diet, exercise regularly, control your weight and avoid smoking.
Andrew Weil, M.D.