Adzuki Bean and Carp Soup: TCM Recipe for Edema & Health

Introduction to Medicinal Diet

Adzuki Bean and Carp Soup is a classic TCM medicinal food therapy with a long history, first recorded in the Tang Dynasty *Shi Liao Ben Cao* (Dietary Materia Medica) and later in the *Ben Cao Gang Mu* (Compendium of Materia Medica). Following the principle of homology of medicine and food, this soup is made primarily from adzuki bean (*Vigna angularis*, Red Adzuki Bean) and carp (*Cyprinus carpio*, Common Carp). Adzuki bean is sweet and sour in flavor, neutral in nature, and enters the Heart and Small Intestine meridians; carp is sweet and neutral, entering the Spleen and Kidney meridians. Together, they promote urination to reduce edema, fortify the spleen, and dispel dampness. The soup is clear, the fish tender, and the bean aroma rich. It can be served as a daily soup with meals or as a restorative for conditions such as edema, beriberi (lower limb swelling), and difficult urination.

In the theory of Traditional Chinese Medicine (TCM) health preservation, water-dampness metabolism disorders often lead to symptoms such as edema and a sensation of heaviness. Adzuki Bean and Carp Soup (Chixiaodou Liyu Tang), through its principle of “promoting urination without damaging the upright (zheng qi) and reducing swelling without consuming qi,” has become a dietary therapy of choice for people during the transition from spring to summer, the rainy season (plum rain season), or those living long-term in damp environments. Its preparation is simple and the ingredients are readily available. For centuries, it has been widely circulated among the folk, representing the classic concept of “imbuing medicine into food” within the culture of medicinal cuisine (yaoshan).

Efficacy of Medicinal Diet

The primary effect of Adzuki Bean and Carp Soup (Chi Xiao Dou Li Yu Tang) is to promote urination and reduce edema. Adzuki bean (Phaseolus calcaratus) unblocks and regulates the water passages, allowing excess fluid to be expelled through urination, while carp (Cyprinus carpio) supplements the Spleen and Stomach, moves Qi, and promotes water metabolism. Together, they significantly improve edema caused by nephritis, cirrhotic ascites, malnutrition, or pregnancy. Clinical observations show that moderate consumption increases urine output, gradually alleviates swelling, and reduces body weight.

Secondly, this decoction has the effect of strengthening the Spleen and dispelling Dampness. The Spleen and Stomach are the acquired foundation, governing the transportation and transformation of water and dampness. Both Adzuki Bean (Vigna umbellata) and Common Carp (Cyprinus carpio) enter the Spleen Meridian (SP), able to invigorate Spleen Yang and transport and transform water and grains. This provides good regulation for conditions such as poor appetite, loose stools, and heavy limbs caused by Spleen Deficiency with Dampness Exuberance. Furthermore, Common Carp is rich in high-quality protein and various vitamins, while Adzuki Bean is rich in dietary fiber and minerals. Their combination also supplements nutrition and enhances physical strength, making it suitable for supporting healthy Qi in cases of post-illness weakness and postpartum insufficient lactation.

Auxiliary Lipid-Lowering and Detoxification

Modern research confirms that the saponins in Adzuki Bean (Semen Phaseoli) and the unsaturated fatty acids in Common Carp (Cyprinus carpio) help regulate blood lipids and lower cholesterol, offering auxiliary benefits for patients with hyperlipidemia. Additionally, Adzuki Bean clears heat and resolves toxins, drains pus and dissipates abscesses. For sores, abscesses, toxic swellings, and eczema with itching due to damp-heat accumulation (damp-heat pattern), regular consumption of this soup assists in clearing internal damp-heat toxins.

Role of Traditional Chinese Medicine

From the perspective of TCM nature, flavor, and meridian entry, Red Bean (Phaseolus calcaratus) is sweet and sour in flavor, neutral in nature, and enters the Heart (HT) and Small Intestine (SI) meridians. Its functions include promoting urination to eliminate dampness, detoxifying and expelling pus, reducing swelling, and stopping diarrhea. The *Shen Nong Ben Cao Jing* (Divine Farmer’s Materia Medica) classifies it as a superior herb, stating it “promotes the descent of water and drains abscesses, pus, and blood.” Carp (Cyprinus carpio) is sweet in flavor, neutral in nature, and enters the Spleen (SP) and Kidney (KI) meridians. It excels at promoting urination to reduce swelling, descending qi to promote lactation, and is particularly adept at moving water-dampness without harming the upright qi. When combined, these two ingredients work together—one promotes urination, the other moves water; one tonifies, the other drains—so that water-dampness is eliminated while the upright qi remains unabated.

In terms of formula compatibility, Red Bean and Carp Decoction (Chixiaodou Liyu Tang) subtly embodies the principle of “sour-sweet transforming yin, bland and light draining dampness.” Red bean (Phaseolus calcaratus, red bean) with its sour nature can astringe to prevent excessive diuresis from damaging yin fluids; carp (Cyprinus carpio) with its sweet and neutral quality tonifies and nourishes, providing the material basis for draining dampness. This formula is especially suitable for the pattern of yang deficiency with water flooding and impaired qi transformation (Yangxu Shuifan, Qihua Buli), such as in Water Qi disease (Shuiqi Bing) where swelling is more severe below the waist. The Tang dynasty physician Sun Simiao included a similar combination in his Essential Formulas for Emergencies Worth a Thousand Golden Pieces (Qianjin Yaofang), emphasizing its unique value in “treating abdominal water disease.”

Suitable For

This soup is primarily indicated for individuals with accumulation of water-dampness and spleen deficiency with impaired transportation. Specifically, it includes: ① Patients with various types of edema, such as nephrogenic edema (mild edema due to chronic nephritis), cardiogenic edema (lower extremity edema with shortness of breath), hepatogenic edema (during the regression phase of ascites in cirrhosis), and idiopathic edema; ② Pregnant women with edema of the lower legs and feet during the second or third trimester (to be consumed in moderation under medical supervision); ③ Individuals with obesity, heavy and sluggish body sensation, and a greasy white tongue coating due to spleen deficiency with exuberant dampness; ④ Patients with hyperlipidemia and arteriosclerosis, as an adjunct dietary therapy for lipid reduction; ⑤ Postpartum women with lactation obstruction or insufficient milk production accompanied by edema.

Additionally, office workers who frequently sit for long periods and lack exercise, leading to poor lower limb circulation and afternoon ankle edema, as well as those with summer damp-heat encumbering the Spleen and poor appetite, may also consume it 1–2 times per week to regulate their condition. Convalescent patients and the elderly with difficult urination or beriberi with edema may also use it as appropriate.

Contraindicated Populations

Red Bean and Carp Soup (Chìxiǎodòu Lǐyú Tāng), though generally mild in nature, still has contraindications. First, Semen Phaseoli (Adzuki Bean) has a strong diuretic effect; therefore, those with Fluid Deficiency pattern (e.g., dry mouth and tongue, dry skin, dry stool) should avoid overconsumption, as it may further damage Yin fluids. Second, patients with severe kidney disease presenting with oliguria or anuria (e.g., uremia stage) should be strictly prohibited, as impaired excretory function combined with indiscriminate diuresis may exacerbate electrolyte imbalances. Carp (Cyprinus carpio) is considered a “fa wu” (allergenic/triggering food). Those with fish allergy, severe skin disorders (e.g., acute urticaria or eczema), or non-healing sores with thin, clear discharge should avoid ingestion.

Additionally, patients with chronic gastritis or gastric ulcers accompanied by excessive stomach acid should avoid consuming large amounts of soup on an empty stomach (as Phaseolus calcaratus [adzuki bean] is slightly sour and may stimulate gastric acid secretion). Pregnant women must strictly control the dosage, especially avoiding its use during early pregnancy to prevent excessive diuresis from affecting the fetal vitality (Tai Yuan). In Traditional Chinese Medicine, it is stated that “prolonged consumption of Phaseolus calcaratus may cause dryness and depletion of body fluids,” therefore it is not advisable to consume it in large quantities continuously over a long period. It is recommended to take it intermittently as a tonic.

Ingredient Formula Proportions

Main Ingredients: 100 g adzuki bean (Vigna umbellata), 1 fresh common carp (Cyprinus carpio, approximately 500 g). Supplementary Ingredients: 3 slices ginger (Zingiber officinale, approximately 10 g), 2 sections scallion (Allium fistulosum, approximately 20 g), 10 ml cooking wine, 3 g salt, 1 g white pepper, 5 g cilantro (Coriandrum sativum, optional). Note: The ratio of adzuki bean to common carp should be 1:5 (by weight), and the dosage of adzuki bean should not exceed 150 g, otherwise the diuretic effect will be too strong. For postpartum lactation promotion, an additional 6 g of Tetrapanax papyriferus (Medulla Tetrapanacis) or 10 g of Vaccaria segetalis (Semen Vaccariae) may be added and cooked together.

Preparation Method

Step 1: Prepare the ingredients. Soak Phaseolus calcaratus (adzuki bean) in clean water for 4–6 hours in advance (shorten to 2 hours in summer) to allow full water absorption and expansion, thereby reducing cooking time. Scale the Cyprinus carpio (common carp), remove the gills and internal organs (note: retain the mucus beneath the scales; some regions have the custom of keeping the skin). Rinse the black membrane inside the abdominal cavity repeatedly with clean water, then drain thoroughly.

Step 2: Pretreatment. Make three diagonal cuts on each side of the fish, then rub a small amount of cooking wine and salt evenly over the fish and marinate for 10 minutes to remove any fishy odor and infuse a base flavor. Slice the ginger into thin pieces, and cut the scallion into sections. If using herbs such as Tetrapanax papyrifer (Rice Paper Pith), wrap them in a gauze bag and tie the opening tightly.

Step 3: Pan-fry the fish. Heat the wok, then add a small amount of cooking oil (approximately 15 ml). When the oil reaches about 70% hot (moderate heat), add the common carp. Pan-fry over low heat until both sides turn golden brown (about 2 minutes per side). Be careful not to burn it. Pan-frying the fish helps coagulate the protein, resulting in a milky white soup and reducing any fishy odor.

Step 4: Cook the soup. Place the fried fish in a clay pot (or soup pot), add the soaked red beans (Phaseoli Semen), ginger slices, scallion segments, and the herb bag (if any). Pour in enough boiling water (approximately 2000 ml). Bring to a boil over high heat, skim off any foam, then reduce to low heat, cover, and simmer gently for 40–50 minutes.

Step 5: Seasoning and Plating. Once the adzuki beans (Phaseoli semen) become soft and mushy and the fish broth turns white, remove the scallion segments, ginger slices, and herb packet. Add fine salt and white pepper powder to season, and optionally sprinkle with chopped cilantro to enhance aroma. Ladle into bowls for serving. The fish can be dipped in a small amount of light soy sauce as a condiment.

Tips for Consumption

1. Best time for consumption: 9–11 AM (Spleen Meridian time, SP) or 3–5 PM (Bladder Meridian time, BL). Drinking the soup at these times helps strengthen the Spleen to resolve Dampness and promote fluid metabolism. Avoid drinking large amounts shortly before bedtime to prevent frequent night urination.

2. Frequency of Consumption and Course of Treatment: For health maintenance, 2–3 times per week is sufficient. If used as an adjunctive treatment for edema, it can be consumed continuously for 3–5 days to observe symptom improvement. Typically, one week constitutes an observation cycle. If edema does not significantly subside or worsens, seek medical attention promptly.

3. Pairing and Contraindications: When consuming the soup, avoid simultaneously eating raw, cold, greasy, or strongly flavored foods (such as iced beverages, fatty meats) to prevent impairing the Spleen and causing dampness stagnation. During medication (especially diuretics and antihypertensives), consult a doctor to avoid drug synergy leading to dehydration or hypotension. Salt has already been added to the soup; individuals on a high-salt diet should correspondingly reduce the salt in other dishes.