Before the development of type 2 diabetes or metabolic syndrome, most individuals pass through a stage of glucose intolerance, a condition characterized by impaired glucose handling and rising blood sugar levels (hyperglycemia).
A consistent body of research links low magnesium status with impaired glucose metabolism and insulin resistance. In a large population study published in Clinical Laboratory (2008;54(5–6):169–172), investigators examined magnesium levels in more than 7,600 adults over age 35. Individuals with fasting glucose levels above 7 mmol/L were significantly more likely to have low magnesium levels compared with those with normal glucose values.
Similar findings were reported in an observational study published in the Journal of the American College of Nutrition (2006;25(6):486–492), which included 1,223 men and 1,485 women without diabetes. Dietary magnesium intake was inversely associated with fasting insulin levels and post–glucose challenge insulin responses, suggesting better insulin sensitivity with higher magnesium intake.
Intervention data support these observations. A study published in the American Journal of Clinical Nutrition (1992;55:1161–1167) found that subjects receiving approximately 360 mg of magnesium per day had higher erythrocyte magnesium levels and improved glucose tolerance compared to controls. Individuals with insulin resistance and low magnesium status showed improved glucose handling following supplementation. The authors concluded that increasing magnesium intake may reduce the risk of developing type 2 diabetes.
