Many people may know that eating a diet rich in whole grains can reduce one’s risk for developing type 2 diabetes, and now researchers may have found another clue as to why this is. Whole grains are a good source of magnesium, which the new study has linked to a significantly reduced risk of developing type 2 diabetes.

Those who consumed the most magnesium in their diets (200 mg for every 1,000 calories consumed) were almost 50% less likely to develop diabetes than people who ate the least (100 mg/1,000 calories).

The research team at UNC, Chapel Hill followed almost 4,500 people, aged 18-30 years old for a period of 20 years. None of the participants had diabetes at the study’s outset, and researchers tracked how many developed the disease over the follow-up period. They also calculated how much magnesium the participants consumed in their diets.

Over the 20-year follow-up, 330 people developed diabetes. Those who consumed the most magnesium in their diets (200 mg for every 1,000 calories consumed) were almost 50% less likely to develop diabetes than people who ate the least (100 mg/1,000 calories).

The authors say that reduced inflammation is probably what’s behind the magnesium effect. Certain key inflammatory markers in the blood, like c-reactive protein, interleukin-6, and fibrinogen were lower in people who consumed the most magnesium, compared to those who ate the least. Higher magnesium levels were also linked to less insulin resistance, which is the red flag in the development of diabetes.

Magnesium is found in halibut, cashews, almonds, soybeans, spinach, and whole grains, as well as many other foods. See the NIH’s factsheet for more information on the magnesium and magnesium-rich foods.