While most people pursue fair skin, nutrition experts suggest that darker-colored foods deliver superior health benefits. Few people fully understand the advantages of black foods. Wang Xiaoqin, Director of the Nephrology Department at Hubei Provincial Hospital of Traditional Chinese Medicine, explains the core theory of traditional Chinese medicine: foods and medicinal herbs of different colors correspond to the five internal organs of the human body — red nourishes the heart, green the liver, yellow the spleen, white the lungs, and black the kidneys. Selecting food by color is a simple and practical dietary regimen, and specialists widely recognize black foods’ protective and tonic effects on the kidneys.

Wang Xiaoqin states that black foods are generally rich in trace elements and vitamins. The most representative category is the "Five Black Staples": black rice, black beans, black sesame seeds, black jujubes and walnuts, all exceptional kidney-tonifying ingredients.

A detailed nutritional breakdown reveals each of the Five Black Staples excels at nourishing kidney function:

1. Black rice, known as "black pearl", is a premium grain abundant in protein, amino acids, iron, calcium, manganese, zinc and other trace minerals. It stimulates appetite, tonifies the middle energizer, consolidates essence, invigorates the spleen and liver, and promotes blood circulation to relax tendons.

2. Ancient scholars named black beans "the grain of the kidneys". Sweet and neutral in nature, black beans resemble the shape of kidneys and reinforce renal strength, activate blood circulation to eliminate edema, detoxify, and moisturize the skin, making them ideal for those with kidney deficiency.

3. Black jujubes, dubbed a "nutrition warehouse", are warm and sweet. They tonify the middle burner, boost qi, nourish the kidneys, fortify the stomach and replenish blood.

4. Walnuts tonify the kidneys and secure essence, promote urination to expel urinary stones, lubricate intestines to relieve constipation, and warm the lungs to ease asthma. They are commonly used to improve lumbago from kidney deficiency and urinary calculi.

5. Black sesame seeds are neutral and sweet, tonifying the liver and kidneys and moisturizing all internal organs. They offer remarkable dietary relief for vertigo, premature gray hair, hair loss, soreness and weakness of the waist and knees, and dry intestinal constipation caused by insufficient liver and kidney essence and blood.

Cooking porridge with all five ingredients together creates an outstanding kidney-nourishing medicinal food.

Other nutrient-dense black foods beneficial to the kidneys include black fungus, plums, black-bone chicken, dark plums, laver, chestnuts, sea cucumber, shiitake mushrooms, kelp and black grapes.

People with impaired kidney function may try these simple kidney-tonifying recipes once a week: braised sea cucumber with green onions, stir-fried black fungus with shiitake mushrooms, or meat stew simmered with chestnuts.