Submitted to: Journal of the American College of Nutrition
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/21/2005
Publication Date: 12/1/2006
Citation: Rumawas, M.E., Mckeown, N.M., Rogers, G., Meigs, J.B., Wilson, P.W., Jacques, P.F. 2006. Magnesium intake is related to improved insulin homeostasis in the framingham offspring cohort. Journal of the American College of Nutrition. 25(6): 486-492. Interpretive Summary: Magnesium is an important nutrient that is found in a wide range of foods including whole grains, green leafy vegetables, nuts and legumes. Diets rich in magnesium have been found to have important health benefits, such as reduced risk of type 2 diabetes mellitus. One mechanism whereby diets rich in magnesium may reduce type 2 diabetes is by improving blood glucose and insulin levels. We undertook the present study to determine if people whose diets contained more magnesium had lower glucose and insulin levels compared to people whose diets contained less magnesium. Our findings indicated that people with the highest dietary magnesium intake had better insulin sensitivity compared to people with the lowest magnesium intake. The findings in this study suggest that dietary magnesium improves insulin sensitivity, a key risk factor for type 2 diabetes mellitus.
Technical Abstract: Higher dietary intake of magnesium may protect against development of type 2 diabetes. The aim of this study was to examine the association between dietary magnesium intake and metabolic risk factors for diabetes. We examined cross-sectional associations between magnesium intake and fasting glucose and insulin, 2-hour post-challenge plasma glucose and insulin, and the homeostasis model assessment - insulin resistance [HOMA-IR] in 1342 men and 1615 women without diagnosed diabetes from the Framingham Offspring cohort. Magnesium intake was assessed by a food frequency questionnaire and categorized by quintiles. Geometric mean insulin and glucose concentrations were adjusted for several potential confounding factors, including age, sex, BMI, smoking status, alcohol intake, physical activity score, and total energy intake. After adjustment for potential confounding factors, magnesium intake was inversely associated with fasting insulin (mean: 29.5 vs 26.3 microU/mL in the lowest vs highest quintiles of magnesium intake; P trend<0.001), post-glucose challenge plasma insulin (84 vs 70 microU/mL; P trend<0.001), and HOMA-IR (6.98 vs 6.21; P trend<0.001). No association was found between magnesium intake and fasting glucose or 2-hour post challenge glucose. Improved insulin sensitivity may be one mechanism by which higher dietary magnesium intake may reduce the risk of developing type 2 DM.