Soy intake is associated with a lower risk of developing type 2 diabetes. It isn’t clear whether soy can help control diabetes if you already have the condition. A recent analysis in The American Journal of Clinical Nutrition reviewed 24 studies on soy and diabetes. It found that whole soy foods were slightly more effective at lowering fasting blood glucose, a measure of diabetes control, than isolated soy products. (Isolated soy products are proteins separated from the rest of the soybean, then used as ingredients to make a variety of foods.) However, the overall amount of soy in the diet did not affect fasting glucose or insulin levels.