The darker the food, the more it benefits Yin of the body. This is what keeps you calm, grounded, cool, and collected. At the same time each organ needs a balance of Yin and Yang. Black beans are great for tonifying the Kidneys, just by looking at beans, their shape gives us a clue as to which organ they tonify. Black beans are good for relieving lower back pain due to aging, or premature greying of hair, reducing night sweats, and reducing premature ejaculation. A great addition to meals, or soups as the Kidneys in TCM always need nourishment as they are being consumed throughout life.