Kidney beans are a very good source of cholesterol-lowering fiber, as are most other beans. In addition to lowering cholesterol, kidney beans' high fiber content prevents blood sugar levels from rising too rapidly after a meal, making these beans an especially good choice for individuals with diabetes, insulin resistance or hypoglycemia. When combined with whole grains such as rice, kidney beans provide virtually fat-free high quality protein. But this is far from all kidney beans have to offer. Kidney beans are an excellent source of the trace mineral, molybdenum, an integral component of the enzyme sulfite oxidase, which is responsible for detoxifying sulfites.