Houttuynia and Mung Bean Soup: Clear Heat, Detox, and Recipe

Introduction to a Traditional Dietary Approach

Houttuynia and Mung Bean Soup is a traditional dish originating from the folk practices of southwestern China, valued for its ability to support the body’s natural moisture balance. The core ingredient, Houttuynia cordata (fish mint), has been used in historical texts to describe its role in promoting comfort from heat-related discomforts. Mung beans (Vigna radiata) have long been recognized as a common legume that helps maintain a sense of coolness and supports overall wellness. 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 popular choice for supporting the body during humid and warm climates.

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 “supporting while nourishing, promoting while comforting.” This combination is especially suitable as a tea substitute or a pre-meal soup during muggy, damp summers.

The Origins and Regional Characteristics of This Dietary Tradition

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 support the body’s natural defenses against environmental influences. Mung bean (Phaseolus radiatus), a classic ingredient for promoting a cooling sensation, was discussed in the ancient dietary text Shiliao Bencao (Materia Medica for Food Therapy) as a substance that “harmonizes and nourishes the body’s systems.” 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 approach for supporting comfort during warm, humid seasons.

Benefits of This Dietary Approach

The most prominent benefits of Houttuynia cordata and Mung Bean Soup are supporting the body’s natural cooling processes, maintaining moisture balance, promoting a sense of cleansing, and soothing occasional swelling. The active constituents in Houttuynia cordata, such as houttuynin (decanoyl acetaldehyde) and quercetin, are known to support the body’s normal response to common environmental challenges. Mung beans are rich in protein, B vitamins, and various minerals, which help support normal metabolism and the body’s natural elimination processes. The synergistic action of these two ingredients helps maintain comfort from occasional heat-related discomforts, such as mild throat irritation, skin bumps, and occasional urinary changes.

Moreover, this soup may also help maintain a healthy complexion by supporting balanced oil production. Houttuynia cordata (fish mint) supports the respiratory system’s natural function, and Phaseolus radiatus (mung bean) supports digestive comfort, thereby helping to maintain normal skin appearance from the inside out. It is suitable for young and middle-aged individuals who seek to support skin health. 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 Understanding of the Cleansing 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 may help support the body’s natural elimination of unwanted elements such as lead and cadmium. Although this effect is not a substitute for medical interventions, it serves as a supportive dietary measure for individuals with long-term exposure to cooking fumes, dust, or occasional dietary imbalances, offering certain health benefits.

Functions from a Traditional Perspective

From a traditional perspective, Houttuynia cordata (fish mint) is considered slightly cooling in nature and pungent in flavor, associated with supporting the respiratory system. It is traditionally used to promote comfort from occasional heat and to support the body’s natural cleansing processes. Vigna radiata (mung bean) is considered cooling in nature and sweet in flavor, associated with supporting the digestive and cardiovascular systems. Its traditional functions include promoting a cooling sensation and supporting urinary health. When these two herbs are used together, their cooling natures complement each other, simultaneously supporting respiratory and digestive comfort. This combination is especially suited for promoting comfort during warm, humid seasons.

From a deeper perspective, Houttuynia cordata (fish mint) helps open the body’s surface and promote the release of trapped heat through its pungent-dispersing nature, while Vigna radiata (mung bean) helps moisten and cool the digestive system with its sweet-cool quality. In summer, when the body’s surface becomes relaxed and sweating is sometimes insufficient, occasional damp-heat sensations may occur. If one indulges in cold drinks and cooling at this time, it may instead create a feeling of internal coolness. 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 temporary heat from the skin and the downward movement of accumulated heat from the intestines and stomach via urine—a synergistic effect of “supporting from both exterior and interior.” This pairing reflects the traditional therapeutic philosophy of “guiding excess according to its tendency, providing an outlet for disturbances,” rather than a purely antagonistic approach.

Suitable For

Those who are prone to occasional skin bumps, minor redness, or temporary skin irritation may benefit from regular consumption of this soup to help promote a clear complexion and support the skin’s natural comfort. These individuals typically have a constitution that tends toward warmth or occasional heat sensations. Houttuynia cordata and mung bean soup can help maintain internal coolness and support the body’s natural elimination of metabolic wastes through normal urinary function, gradually promoting smooth skin. Especially for those whose facial oil production increases in summer with occasional skin concerns, noticeable improvement in skin appearance 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 drink to support respiratory and overall wellness. Houttuynia cordata (heartleaf houttuynia) helps maintain respiratory mucosa comfort, while Vigna radiata (mung bean) supports the body’s natural detoxification processes; together they help mitigate the effects of occasional environmental exposure. Additionally, at the early stage of a mild seasonal discomfort, when symptoms such as a dry, slightly scratchy throat or occasional cough appear, drinking this decoction promptly while still hot may help support the body’s natural defenses and promote comfort.

Considerations for Use

Individuals with a naturally cool or weak digestive system should consume with caution. Both Houttuynia cordata (heartleaf houttuynia) and Vigna radiata (mung bean) are considered cooling in nature. For those who typically experience occasional stomach discomfort, loose stools upon exposure to cool foods, or poor appetite, excessive intake may further affect digestive comfort, leading to occasional digestive upset. 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 its cooling 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) may have a mild 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 who feel cold or have occasional chills, so as not to interfere with the body’s natural warmth. Those who are currently taking warming herbal supplements (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 support its natural urinary function.

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 cleansing effect is desired, add 5 g of Glycyrrhiza uralensis (licorice root) and 3 g of Lonicera japonica (honeysuckle flower). If the goal is to support moisture balance, combine with 30 g 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 3: After turning off the heat, cover and let it steep for 5 minutes to allow full extraction of the beneficial 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 a naturally cool or weak digestive system 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 certain bodily rhythms support urinary and skin functions. At this time, drinking Houttuynia cordata (heartleaf houttuynia) and Mung Bean (Vigna radiata) Decoction can leverage the body’s natural energy to direct the beneficial effects to the water passages and the skin surface, supporting the overall sense of comfort. It can also be taken on an empty stomach in the morning, but those with a naturally cool constitution should first eat a small amount of warm food to prepare 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 beneficial concentration while avoiding overexposure to cooling ingredients. A single cycle consists of seven to ten doses, and can be repeated after a one-month interval.

Third, flavor adjustment and considerations: 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 heavy substances, as they may interact with the volatile oil components of Houttuynia cordata and affect the absorption of its beneficial constituents. During consumption, reduce the intake of spicy, greasy, and heavy dishes to avoid overburdening the digestive system and diminishing the overall supportive effect of this food.