In a long-term study at the Harvard School of Public Health in Boston, researchers examined a possible link between low magnesium intake and increased risk of type 2 diabetes. They monitored the health and diet of 85,060 women and 42,872 men with no history of diabetes, heart disease or cancer, for 18 years (women) or 12 years (men).

After adjusting for factors such as weight, exercise and family history, they were able to establish that low magnesium intake was linked with increased risk of type 2 diabetes. The results, they said, support recommendations to increase regular intake of magnesium-rich foods such as whole grains, nuts and green leafy vegetables.

Magnesium may also help those with existing diabetes improve cholesterol levels. At Lady Hardinge Medical College in New Delhi, India, researchers studied the effects of magnesium supplements on cholesterol and blood sugar levels of diabetic patients. First, they took baseline measurements of 40 patients with type 2 diabetes and 54 non-diabetic controls. They found the diabetic patients had significantly lower baseline levels of magnesium than the controls. Then, they gave the diabetic patients 600 mg of magnesium daily for 12 weeks and did follow-up every four weeks. Only four weeks into supplementation, the patients experienced a significant drop in total cholesterol, LDL (or bad) cholesterol and triglycerides, and a rise in HDL (or good) cholesterol levels. This benefit continued throughout the trial. Blood sugar levels were not altered during the 12 weeks of magnesium supplementation.

Sources: Diabetes Care. 2004 Jan;27(1):134-40; J Assoc Physicians India. 2003 Jan;51:37-42