Researchers Examine Effects of Dietary Magnesium on Type 2 Diabetes Risk

Abstract

EATING FOODS RICH IN MAGNESIUM such as whole grains, nuts, and leafy green vegetables may prove to be a cost-effective approach to reducing the risk of developing type 2 diabetes, according to two epidemiological studies with large enrollment numbers and long follow-up. The findings, published in the January issue of Diabetes Care, suggest a significant inverse association between dietary magnesium intake and diabetes risk, said the researchers from Harvard University’s Medical School and School of Public Health in Boston, Mass, who performed the two studies. The investigators said that research in animals had previously shown that an adequate magnesium intake may enhance peripheral insulin sensitivity and glucose metabolism. In addition, a randomized, double-blind placebocontrolled trial with 63 enrollees with type 2 diabetes and decreased serum magnesium had found that oral magnesium supplementation improved insulin sensitivity and metabolic control (Diabetes Care. 2003;26:11471152). Other prospective studies, such as the Iowa Women’s Health Study (Am J Clin Nutr. 2000;71:921-930) and the Honolulu Heart Program (Am J Cardiol. 2003;92:665-669), also showed an inverse correlation between magnesium intake and diabetes risk. But some other research findings have not been as encouraging, noted Jerry L. Nadler, MD, in accompanying editorial (Diabetes Care. 2004;27:270-271). For example, the Atherosclerosis Risk in Communities (ARIC) Study ( J Clin Epidemiol. 1995;48:927-940) found that magnesium intake had no significant effect on diabetes risk, he said. “Regarding the ARIC study, the intake of magnesium was not a key factor in predicting the changes in rates of diabetes—what it showed was that low serum levels of magnesium were associated with diabetes,” said Nadler, of the University of Virginia Health Science System and Diabetes and Endocrinol-