Q. Will taking magnesium help prevent diabetes?

A. Yes. Recent research suggests that magnesium keeps blood sugars from rising too high, thus staving off diabetes. According to the outcomes from a few large population studies—85,000 women in Harvard’s Nurses Health Study, 43,000 men in its Health Professionals Follow-Up Study, and 40,000 women in the Iowa Women’s Health Study—those who ate more magnesium-rich foods were less likely to develop type 2 diabetes. And those with diabetes tended to have lower magnesium stores and greater loss of magnesium in the urine, according to the studies.

These findings are crucial because diabetes is on the rise and the typical U.S. diet severely lacks this mineral. The Recommended Daily Value of magnesium is 400 mg, but research has shown that three-fourths of the population does not get nearly that much. Highly processed food is one of the culprits because it is stripped of magnesium. For example, a slice of white bread contains only 6 mg, whereas its unrefined counterpart—whole-wheat bread—has four times that amount, or 24 mg.

The expert consensus is that an overall healthy diet is the best prevention for diabetes because it ensures adequate intake of magnesium and other nutrients. To meet the daily requirement of magnesium, enjoy a variety of foods, such as fiber-rich whole grains, avocados, squash, nuts, fruits, and leafy greens.

Good sources of magnesium

1 cup baked acorn squash

105 mg

1/2 medium avocado

103 mg

1 ounce toasted wheat germ

90 mg

1 ounce dry roasted almonds (24 nuts)

86 mg

2 rectangular shredded-wheat biscuits

80 mg

1/2 cup cooked spinach

65 mg

1 stalk broccoli

59 mg

1 medium kiwi fruit

23 mg


This Ask the Expert was written by Victoria Shanta Retelny, RD, LD, who practices medical nutrition therapy at Northwestern Memorial Wellness Institute in Chicago, where one of her specialties is diabetes management.