Adzuki Bean and Snakehead Fish Soup: Benefits for Edema & Recovery

Introduction to Medicinal Diet

“Adzuki Bean and Snakehead Fish Soup” is a classic medicinal膳食 originating from the folk dietary therapy tradition of Lingnan (Southern China). It has gained widespread popularity due to its simple composition and notable efficacy. The snakehead fish (Channa argus), locally known as black fish or raw fish in Cantonese, is regarded in the Guangdong region as a nourishing tonic for post-surgical recovery and convalescence after illness. Adzuki bean (Semen Phaseoli / Vigna umbellata) is a commonly used ingredient in Traditional Chinese Medicine for promoting urination and resolving dampness. When combined, these two ingredients create a mild, balanced soup that effectively expels dampness and promotes diuresis without impairing the body’s upright Qi (vital energy).

The combination of this medicinal diet embodies the essence of TCM dietary therapy, “combining attack and supplementation.” The tender and delicious meat of the black carp (Mylopharyngodon piceus) is rich in high-quality protein and various amino acids, which can tonify the Spleen and boost Qi, as well as promote wound healing. Adzuki beans (Phaseolus calcaratus) guide excess water-dampness out of the body through urination. When simmered together, the soup is clear in color, blending the aroma of beans with the freshness of fish. This dish is not only a richly flavored home-style soup but also an effective remedy for regulating edema and dampness encumbrance, especially suitable for consumption during the damp spring and summer seasons or when the body experiences mild puffiness.

Efficacy of Medicinal Foods

The core effects of red bean (Semen Phaseoli) and snakehead fish (Channa argus) soup lie in “promoting diuresis to reduce edema” and “fortifying the spleen and nourishing blood.” For symptoms such as facial edema, pitting edema of the lower extremities upon pressure, scanty urination, and a heavy, sluggish body due to spleen deficiency with exuberant dampness, this soup leverages the draining property of red beans to expel excess fluid retained beneath the skin, while simultaneously utilizing the tonifying strength of snakehead fish to avoid depleting the right qi from excessive diuresis.

Additionally, the collagen protein in snakehead fish (Channa argus) synergizes with the dietary fiber in Phaseolus calcaratus (adzuki bean), offering auxiliary therapeutic value for improving malnutrition-related edema caused by hypoproteinemia. Modern research has also shown that the saponins in Phaseolus calcaratus promote the excretion of sodium ions, thereby alleviating water and sodium retention; the high-quality protein in snakehead fish helps increase plasma colloid osmotic pressure, fundamentally reducing edema occurrence. Regular consumption can also help purify the blood and enhance the body’s metabolic capacity.

The Role of Traditional Chinese Medicine

From the perspective of flavor, nature, and meridian tropism, the red bean (Vigna umbellata) has a sweet and sour flavor, neutral nature, and enters the Heart (HT) and Small Intestine (SI) meridians. It excels at “promoting urination to reduce edema, and removing toxins to expel pus,” with a particular skill in guiding the damp-heat of the Heart and Small Intestine meridians to move downward. The snakehead fish (Channa argus) has a sweet flavor, cool nature, and enters the Spleen (SP) and Stomach (ST) meridians. Its function is specifically to “tonify the Spleen and benefit the Stomach, promote urination and reduce edema,” offering a combined treatment for both root and branch when addressing deficiency-type edema caused by Spleen deficiency with water diffusion.

Combined, the Red Adzuki Bean (Semen Phaseoli) serves to “drain” while the Snakehead Fish (Channa argus) serves to “tonify.” Through this interplay of draining and tonifying, dampness is eliminated without injuring the Spleen, and edema is reduced without damaging the body’s right qi. Targeting the core pathogenesis of “Spleen deficiency with loss of transportation and transformation, leading to internal accumulation of water-dampness,” this medicinal food operates via two pathways simultaneously: on one hand, it directly promotes urination to relieve the manifestation; on the other hand, it tonifies the Spleen and Stomach, enhancing their transportation and transformation functions to treat the root cause. Additionally, the mucopolysaccharides abundant in the blood and flesh of Snakehead Fish, according to TCM theory, have the effect of “engendering flesh and constraining sores.” Thus, it is commonly used as an adjuvant therapy for chronic non-healing ulcerative sores or slow wound recovery after surgery.

Suitable Patients

For those presenting with Spleen deficiency and edema: characterized by puffy eyelids upon waking, pitting edema in the lower limbs, spirit fatigue and lassitude, poor appetite, and loose stools. This soup can strengthen the Spleen and drain Dampness, reduce edema without damaging Qi. It is especially suitable for office workers who sit for long periods with poor lower limb circulation, as well as individuals with a “false obesity” physique due to Dampness obstruction.

Post-surgery and post-illness recovery patients: Snakehead fish is rich in easily absorbable high-quality protein and trace elements such as zinc and selenium, which promote tissue repair and wound healing; red adzuki beans (Vigna umbellata) help prevent mild lower limb edema that may arise from prolonged bed rest after surgery. The soup combining these two ingredients is mild in nature, non-greasy, and not cloying, making it an ideal dietary choice during the recovery period.

For supportive care in chronic nephritis and nephrotic syndrome: For renal patients with low plasma protein levels and mild edema, this soup, when taken under medical guidance, may help increase serum albumin and reduce edema symptoms. However, strict salt restriction is necessary, and protein intake should be adjusted based on kidney function status.

For those with a damp-heat constitution, manifestations include skin prone to sores and ulcers, dark yellow urine, and a yellow greasy tongue coating. Vigna umbellata (adzuki bean), with its detoxifying and pus-draining effects, can help clear internal damp-heat toxins, while Channa argus (snakehead fish) supplements the qi and blood consumed by damp-heat.

Contraindicated Populations

Severe Renal Failure and Uremia Patients: In such patients, the kidneys’ excretory function is severely impaired, requiring strict control of protein, potassium, and phosphorus intake. Snakehead fish (Channa argus) is a high-protein food, and adzuki bean (Vigna umbellata) has a relatively high potassium content. Consumption may increase the burden on the kidneys, leading to elevated serum creatinine and potassium levels, potentially triggering dangerous complications. Therefore, these foods are absolutely contraindicated.

For patients during an acute gout flare: Snakehead fish is a food with moderate purine content. Consuming it during the acute phase of gout (when joints are red, swollen, hot, and painful) may further elevate serum uric acid and exacerbate symptoms. During the remission phase, a small amount may be consumed, discarding the soup and eating only the flesh, though caution is still required.

For individuals allergic to fish or legumes: Some people have a clear history of allergy to fish protein or legumes. Consumption may lead to skin rash, itching, diarrhea, or even anaphylactic shock. These substances should be strictly avoided.

For severe Spleen and Stomach Deficiency Cold: adzuki bean (Vigna umbellata) is neutral to slightly cool in nature, and snakehead fish (Channa argus) is also cool-natured. If the patient usually presents with epigastric cold pain, preference for warmth and pressure, and undigested grains in the stool, consuming this soup alone may aggravate the deficiency-cold symptoms. It is recommended to add 10 g of fresh ginger (Zingiber officinale rhizoma) and 5 g of tangerine peel (Citri Reticulatae Pericarpium) to the soup to counteract the cool nature.

Herbal formula ingredient proportions

Main ingredients: Fresh snakehead fish (Channa argus), approximately 500g (net meat about 350g after cleaning); Adzuki beans (Vigna angularis), 80g.

Supplementary ingredients: 15 grams of fresh ginger (Zingiber officinale, about 4–5 slices), 2 sections of scallion white (Allium fistulosum, each section about 5 cm long), 10 ml cooking wine (approximately 1 tablespoon), 2 grams of salt (for final seasoning, reduce to 1 gram or omit if severe edema), 1 gram white pepper powder (to remove fishy taste and enhance aroma), and 1500 ml water (about 6 bowls).

Key Ratio Explanation: The proportion of Adzuki Bean (Semen Phaseoli) to Snakehead Fish (Channa argus) is approximately 1:4 to 1:5. This ratio ensures that the diuretic effect of the Adzuki Bean is fully released without overwhelming the soup’s freshness due to an excess of beans. The addition of Fresh Ginger (Zingiber officinale Rhizoma recens) and Cooking Wine (Yellow Wine) serves to remove fishy odor, disperse Cold, and harmonize the Cool nature of Snakehead Fish.

Preparation Method

Step one: Ingredient preparation. Soak the adzuki beans (Semen Phaseoli) in clean water for at least 4 hours in advance—preferably overnight—to allow them to fully absorb water and swell, making them easier to cook until tender. After slaughtering the snakehead fish (Channa argus), remove the scales, gills, and internal organs (note: retain the liver, which is rich in nutrients), then repeatedly rinse the black membrane and blood stains inside the abdominal cavity with running clean water, and drain thoroughly. Cut the snakehead fish into sections of about 5 cm; take care not to cut them too small, to avoid them falling apart during simmering.

Step Two: Pan-frying the Fish to Remove Fishy Odor Take a clean wok (or directly use the clay pot intended for simmering the soup, but take care to prevent sticking). Place it on the stove over medium-low heat. Add about 15 ml of cooking oil. When the oil reaches about 60% heat (moderately hot), add ginger slices and scallion segments and stir-fry until fragrant. Then add the black fish (snakehead fish) segments. Pan-fry each side for about 2 minutes until the skin turns slightly golden and the flesh firms up. At this point, pour cooking wine along the edge of the wok, allowing the fishy odor to evaporate with the alcohol vapor.

Step 3: Simmer into soup. Directly pour the pre-soaked red beans (Phaseolus calcaratus) into the pot with the fried fish, then add 1500 ml (approximately 6 cups) of boiling water—note that boiling water must be used to achieve a rich, milky white broth. Bring to a boil over high heat, skim off any surface foam and oil, then reduce to low heat, cover, and gently simmer for 1 hour and 20 minutes.

Step 4: Season and Finish. Simmer until the Phaseolus calcaratus (red beans) are soft and mushy, the fish flesh is tender yet intact, and the soup turns milky white, then turn off the heat. Remove and discard the ginger slices and scallion segments. Season with salt and white pepper, stirring gently to combine. Ladle into soup bowls and garnish with a sprinkle of chopped scallions or cilantro to enhance aroma.

Drinking tips

1. Optimal drinking time: It is recommended to drink it warm between 9:00 a.m. and 11:00 a.m. (Spleen Meridian [SP] time) or between 3:00 p.m. and 5:00 p.m. (Bladder Meridian [BL] time). During these periods, the body’s yang qi ascends and the qi-transformation function is vigorous, which fully facilitates the diuretic effect of *Phaseolus calcaratus* (red bean) while avoiding interference with nighttime sleep.

2. Continuous Consumption Cycle and Contraindications: As an adjuvant therapy, it may be taken continuously for 3–5 days, followed by a 2-day pause to observe the body’s response. Once edema subsides, the dosage should be reduced or discontinued. Long-term daily use is not recommended, as excessive promotion of urination may lead to depletion of yin fluid, resulting in dry mouth and thirst.

3. Low-salt or even salt-free diet: When used as a dietary regimen for edema, salt intake must be strictly controlled, with total daily salt consumption not exceeding 2 grams. Excessive sodium intake will counteract the diuretic effect of Vigna umbellata (adzuki bean) and may even aggravate water and sodium retention. Natural spices such as Zingiber officinale (ginger), Allium fistulosum (scallion), and Coriandrum sativum (coriander) can be used to enhance the flavor profile of the soup.

4. Combining Fish Meat and Soup: Do not discard the fish meat and red adzuki beans (Phaseolus calcaratus) and consume only the soup, as most of the protein and dietary fiber remain in the solid components. The soup, beans, and meat should be eaten together to achieve the full therapeutic effect of this medicinal food. If chewing is difficult, the fish meat can be shredded and mixed into the soup for consumption.