Black beans are a terrific source of dietary fiber, which has shown to help lower cholesterol. In addition, the high fiber of black beans helps to prevent blood sugar from rising too rapidly after a meal, which is beneficial for people with diabetes or other similar diseases. In addition, black beans are especially high in insoluble fiber, which helps keep your digestive tract healthy and helps fight against problems stemming from constipation and bowel problems. Most importantly, black beans are a high source of protein with virtually no fat. Recent research has also found that black beans are rich in antioxidants, the highest level of antioxidants among other beans. These antioxidants, known as anthocyanins, found in black beans help destroy free radicals in the body, which can help fight against heart disease, cancer and aging.