Because beans are comparatively low in complete calcium, they’re likely to be only minor contributions to calcium intake. So, they are actually legumes. Kidney beans are full of protein. They are rich in anthocyanins which have very potent antioxidant properties. They are useful in detoxifying these free radicals and thus reduce the risk of cancer and many chronic diseases. Energy Booster Kidney beans have an abundance of iron, which can help increase your energy levels.