In a review of three studies of over 85,000 women and 42,000 men, individuals who consumed the most magnesium lowered their risk of developing diabetes by more than 30 percent during the next 12 to 18 years compared to those who consumed the least amount. The studies suggest that magnesium influences the action of insulin in the body. A lack of magnesium may worsen insulin resistance, triggering the onset of diabetes.