Introduction to Medicinal Diet
Houttuynia and Mung Bean Soup is a traditional medicinal dish originating from the folk medicine of southwestern China, known for its dual effects of clearing moisture and removing turbidity. The core ingredient, Houttuynia cordata (fish mint), is recorded in the *Compendium of Materia Medica* as a substance that “disperses heat toxins, abscesses, and swellings.” Mung beans (*Vigna radiata*) have long been recognized as a common legume that clears summer-heat and resolves various toxins. When combined, the soup presents a clear, jade-green appearance with a slightly pungent yet sweet aftertaste. Drinking it in the height of summer can bring a remarkable sense of refreshment throughout the body. In recent years, this soup has transitioned from rural kitchens into modern urban health regimens, becoming a home remedy for coping with damp-heat climates and dietary indiscretions.
In the regions of Sichuan, Chongqing, Yunnan, and Guizhou, *Houttuynia cordata* (heartleaf houttuynia) is commonly known as “zhe’ergen.” It can be eaten raw in salads or simmered in soups, with its unique volatile oils imparting a subtle herbal fragrance to the broth. Mung beans (*Phaseolus radiatus*), after prolonged cooking, burst into a sandy texture, making the soup smooth and velvety. The pairing of these two ingredients is not accidental; it embodies the folk dietary wisdom of “clearing while tonifying, dispersing while nourishing.” This combination is especially suitable as a tea substitute or a pre-meal soup during muggy, damp summers.
The Origins and Regional Characteristics of Medicinal Diet
According to local gazetteers, the use of Houttuynia cordata (fish mint) in culinary practices can be traced back to the Tang dynasty, when the indigenous people of the southwestern borderlands already knew to decoct it in water to dispel miasmatic toxins from mountain forests. Mung bean (Phaseolus radiatus), a classic summer-heat-relieving ingredient, was discussed in the ancient dietary text *Shiliao Bencao* (Materia Medica for Food Therapy) as a substance that “harmonizes the five viscera and settles the spirit.” The combination of Houttuynia cordata and mung bean in a soup is believed to have originated during the Ming and Qing dynasties in the Bashu region (modern Sichuan and Chongqing). From there, it gradually spread to the Lingnan area (south of the Five Ridges) and the Jiangnan region (south of the Yangtze River), becoming a simple and effective folk remedy for summer-heat and dampness complicated by toxins.
Efficacy of Medicinal Diet
The most prominent effects of Houttuynia cordata and Mung Bean Soup are clearing Heat, resolving Dampness, detoxifying, and reducing swelling. The active constituents in Houttuynia cordata, such as houttuynin (decanoyl acetaldehyde) and quercetin, exhibit broad-spectrum antimicrobial activity against common pathogens including Staphylococcus aureus and influenza virus. Mung beans are rich in protein, B vitamins, and various minerals, which promote metabolism and accelerate the elimination of toxic substances. The synergistic action of these two ingredients effectively alleviates discomforts caused by summer Heat or Damp-Heat, such as sore throat, skin boils and carbuncles, and scanty dark urine.
Moreover, this soup can also assist in alleviating facial greasiness and recurrent acne breakouts. Houttuynia cordata (fish mint) clears heat from the Lung Meridian (LU), and Phaseolus radiatus (mung bean) resolves toxin from the Stomach (ST), thereby reducing abnormal sebum secretion from the inside out. It is suitable for young and middle-aged individuals with skin issues due to the pattern of “Heat Accumulated in the Lung and Stomach” (肺胃蕴热). Modern nutritional science has also found that polyphenols in mung beans and flavonoids in Houttuynia cordata both possess antioxidant activity, which helps reduce free radical damage to tissues.
Modern Interpretation of Detoxification Effect
Recent experimental studies have shown that the aqueous extract of *Houttuynia cordata* and mung bean soup exhibits complexation and precipitation effects on certain heavy metal ions, which can partially reduce the intestinal absorption of harmful elements such as lead and cadmium. Although this effect is not a substitute for clinical detoxification therapy, it serves as a supportive clearing and nourishing dietary measure, offering certain health benefits for individuals with long-term exposure to cooking fumes, dust, or unclean diet.
Functions of Traditional Chinese Medicine
From the perspective of TCM nature, flavor, and meridian tropism, *Houttuynia cordata* (fish mint) is slightly cold in nature and pungent in flavor, specifically entering the Lung Meridian (LU). It excels in clearing Heat and resolving Toxin, dispersing abscesses and expelling pus, and promoting urination and relieving strangury. It is a key herb for treating lung abscess with expectoration of pus and purulent, hot, toxic sores. *Vigna radiata* (mung bean) is cool in nature and sweet in flavor, entering the Heart (HT) and Stomach (ST) Meridians. Its functions include clearing Heat and resolving Toxin, dispelling summerheat and promoting urination, and it is commonly used for patterns of summerheat-heat with thirst, erysipelas, and poisoning from medications or foods. When these two herbs are used together, their cold and cool natures complement each other, simultaneously clearing the Lung and Stomach. This combination is especially adept at resolving pathogenic factors of intertwined summerheat, dampness, heat, and toxin.
From a deeper perspective, *Houttuynia cordata* (fish mint) opens the interstices (*cou li*) and vents stagnant heat through its acrid-dispersing nature, while *Vigna radiata* (mung bean) moistens dry earth and descends fire qi with its sweet-cool quality. In summer, the interstices become lax; when sweating is insufficient, damp-heat tends to stagnate. If one indulges in cold drinks and cooling at this time, it may instead cause cold-damp to close internally, creating a complex pattern of “external heat with internal cold.” The combination of *Houttuynia cordata* and mung bean soup employs the former’s “ventilating” property and the latter’s “clearing” property, enabling both the outward dissipation of stagnant heat from the muscular surface and the downward movement of accumulated heat from the intestines and stomach via urine—a synergistic effect of “resolving from both exterior and interior.” This pairing reflects the TCM therapeutic philosophy of “guiding pathogens according to their tendency, providing an outlet for evils,” rather than a purely antagonistic approach of using cold to overcome heat.
Indicated for
Those who are prone to developing acne, folliculitis, or eczema may benefit from regular consumption of this soup to help expel heat toxins and reduce inflammatory responses. These individuals typically have a yang-exuberant constitution or latent heat in the Lung and Stomach. *Houttuynia cordata* and mung bean soup can clear internal heat and accelerate the excretion of metabolic wastes through diuresis, gradually smoothing the skin. Especially for those whose facial oil production increases in summer with recurring comedones, noticeable improvement can often be observed after about one week of continuous drinking.
Long-term exposure to kitchen fumes and dust—common among chefs, traffic police, construction workers, and similar professionals—makes this an ideal daily lung-cleansing drink. Houttuynia cordata (heartleaf houttuynia) protects the respiratory mucosa, while Vigna radiata (mung bean) enhances hepatic detoxification enzyme activity; together they help mitigate chronic damage from environmental pollutants. Additionally, at the early stage of a mild wind-heat common cold, when symptoms such as a dry, slightly sore throat, cough with yellow phlegm appear, drinking this decoction promptly while still hot can often abort the progression of the illness and prevent worsening fever.
Contraindicated Groups
Individuals with a constitution of Spleen and Stomach Deficiency Cold should consume with caution. Both Houttuynia cordata (heartleaf houttuynia) and Vigna radiata (mung bean) are cold-natured substances. For those who typically present with epigastric cold pain, diarrhea upon exposure to cold, poor appetite, and other manifestations of “Middle Yang insufficiency,” excessive intake may further impair Spleen Yang, leading to dyspepsia or loose stools. If such individuals do need to take these herbs, it is recommended to add three slices of Zingiber officinale (ginger) and two Ziziphus jujuba (jujube) fruits to the decoction to moderate their cold nature, and the dosage should be limited to 100 ml per meal.
Pregnant and breastfeeding women should use under the guidance of a qualified professional. Certain volatile oil constituents in *Houttuynia cordata* (fish mint) have a slight stimulatory effect on uterine smooth muscle. Although the impact is minimal at conventional doses, to ensure safety, it is advisable to avoid arbitrary intake during pregnancy, especially in the first trimester. Additionally, it is not suitable for individuals with wind-cold cough (presenting with thin white sputum and clear nasal discharge) or cold extremities, so as not to allow cold pathogen to become deeply lodged and prolong recovery. Those who are currently taking warming and tonifying Chinese herbal medicines (e.g., *Panax ginseng* [ren shen], *Astragalus membranaceus* [huang qi], *Cervus elaphus antler* [lu rong]) should also stagger the administration time, allowing at least two hours between doses.
Food Ingredient Formula Proportions
Fresh Houttuynia cordata (heartleaf houttuynia) 100 g (or 15 g if using the dried herb), Vigna radiata (mung beans) 80 g, rock sugar 20 g (adjust to taste), and water 1500 mL. This serves 2–3 people as a single dose. If taken as a tea substitute in divided doses throughout the day, increase the water to 2000 mL, reduce the mung beans to 60 g, and retain the root fibers of the Houttuynia cordata to enhance its diuretic effect.
When selecting materials, note the following: Houttuynia cordata (fish mint) is best when the stems and leaves are intact, the root hairs are well-developed, and it has a strong herbal aroma—avoid wilted leaves or older plants that have already flowered. Vigna radiata (mung beans) should be plump, bright green in color, and free from insect damage; aged mung beans produce less starch when cooked and have an inferior texture. If a stronger detoxifying effect is desired, add 5g of Glycyrrhiza uralensis (licorice root) and 3g of Lonicera japonica (honeysuckle flower). If the goal is to enhance dampness-dispelling action, combine with 30g of Coix lacryma-jobi (Job’s tears/coix seed). All ingredients should be rinsed twice with clean water in advance; the mung beans are best soaked for two hours before cooking to reduce simmering time.
Cooking method
Step 1: Drain the soaked mung beans (Vigna radiata) and place them in a clay pot or ceramic casserole with 1500 ml of fresh water. Bring to a boil over high heat, then reduce to medium-low heat, maintaining a gentle simmer for about 30 minutes, until the mung beans begin to “bloom” (skins split open) and the broth turns slightly cloudy. Stir occasionally with a ladle to prevent the beans from sticking to the bottom of the pot.
Step 2: Cut fresh Houttuynia cordata (fish mint) into segments about 5 cm long, taking care to retain the white root parts. Rinse gently under running water and drain. When the mung beans (Phaseolus radiatus) are about 70–80% cooked, add all the Houttuynia segments to the pot along with rock sugar. Continue cooking over medium-low heat for 10–15 minutes. At this point, the distinctive aroma of Houttuynia will gradually infuse the soup, and the color will turn a light yellow-green.
Step three: After turning off the heat, cover and let it steep for 5 minutes to allow full extraction of the active constituents. Use a fine-mesh strainer to remove and discard the Houttuynia cordata (fish mint) residue (or keep it if texture is not a concern), retaining only the liquid and mung bean paste. Pour into a bowl and drink while hot, or allow it to cool to warm temperature before drinking. In summer, the decoction may be fully cooled and refrigerated to be consumed as a cooling summer drink; however, those with weak Spleen and Stomach constitution should still take it warm for best results.
Tips for Consumption
First, the optimal time for consumption is during the period of 3–5 PM, when the Bladder Meridian (BL) is dominant. At this time, the Foot Taiyang Bladder Meridian (BL) has the most vigorous qi and blood. Drinking Houttuynia cordata (heartleaf houttuynia) and Mung Bean (Vigna radiata) Decoction can leverage the body’s ascending yang qi to direct the medicinal effect to the water passages and the skin surface, enhancing the efficacy of clearing damp-heat. It can also be taken on an empty stomach in the morning, but those with a Cold constitution should first eat a small amount of warm food to line the stomach.
Second, continuous consumption should not exceed seven days. It is recommended to adopt a “three-two-one” rhythm: drink for three consecutive days, then pause for one day, then drink for two more days, then pause for one day, and finally drink for one additional day as a conclusion. This intermittent intake method can maintain the medicinal concentration while avoiding Cold-Damage to Stomach Qi. A single regulation cycle consists of seven to ten doses, and can be repeated after a one-month interval.
Third, flavor adjustment and contraindications: If the odor of Houttuynia cordata (fish mint) is too strong, add a few slices of lemon or a small handful of Mentha haplocalyx (peppermint) leaves two minutes before turning off the heat to harmonize the taste with their refreshing aroma. However, strictly avoid adding milk, honey, or other sweet and greasy substances, as they may react with the volatile oil components of Houttuynia cordata and affect the absorption of its active constituents. During consumption, reduce the intake of spicy, greasy, and seafood dishes to avoid increasing the gastrointestinal burden and diminishing the overall regulatory effect of this medicinal food.