Lu Dou
StarVigna radiata
Synonyms: Azukia radiata, Phaseolus radiatus
Traditionally used for
- Urinary & fluids
- Mood & calm
- Energy & fatigue
Cautions & contraindications
- Allergy risk
- Toxic — professional use only
☯ TCM Properties
Resolves Summerheat and relieves thirst; Clears Heat and relieves toxins; Antidote for herbal poisoning (e.g., Aconite)
Traditional Chinese Uses
Lu Dou (mung bean) is a cool, sweet, food-grade herb widely consumed across East Asia for its Heat-clearing and detoxifying properties. It clears Summerheat, relieves thirst and irritability during hot weather, and counteracts the toxicity of certain herbs and heavy metals. Its gentle nature makes it safe for daily consumption, and it is commonly eaten as a cooling porridge or soup in summer. As a staple food in Chinese dietary therapy, it embodies the principle of preventive medicine through everyday nourishment.
Western Herbalism Properties
Relationships
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Gallery
Botanical Description
Vigna radiata is an annual legume growing 30-100 cm tall, with erect to slightly twining stems. Leaves are trifoliate with ovate to rhomboid leaflets 6-15 cm long. Yellow flowers are borne in axillary racemes. Pods are slender, cylindrical, 6-10 cm long, containing 10-15 small, oval, green seeds (mung beans). The seeds turn pale when dried. The whole plant is pubescent with brown hairs.
Cultivated in tropical, subtropical, and warm temperate regions worldwide; grown in well-drained soils and warm climates throughout South and Southeast Asia.
Vigna radiata is a cultivated crop with origins in South Asia. It is an important food crop grown extensively throughout Asia, Africa, and Australia. No conservation concerns for the cultivated form.
Active Constituents
Vitexin
Flavone C-glycoside (apigenin-8-C-glucoside)Concentration: roughly 0.12-3.0 mg/g of the whole seed depending on variety; far higher in the isolated seed coat
With isovitexin, the principal flavonoid of the mung bean and the constituent most of the modern pharmacology attributes activity to. It inhibits formation of advanced glycation end products and shows hypoglycaemic activity in vitro. Because it concentrates in the seed coat, the separate Chinese drug Lu Dou Yi (mung bean hull) is far richer in it than the whole bean.
Isovitexin
Flavone C-glycoside (apigenin-6-C-glucoside)Concentration: roughly 0.03-1.2 mg/g of the whole seed depending on variety; far higher in the isolated seed coat
The 6-C isomer of vitexin, co-occurring with it throughout the seed. C-glycosides of this type resist gut hydrolysis, so they are absorbed poorly and largely intact, which limits systemic exposure from an ordinary dietary portion.
Seed storage protein (8S globulin and albumins)
Storage proteinConcentration: commonly reported at roughly 20-30% of the dry seed
The fraction on which the only human trials of this species were done: isolated mung bean protein, not whole bean or decoction, improved glucose and lipid measures in the published trials. Practitioners should not read those results across to a traditional Lu Dou decoction, which delivers a different and much smaller protein load.
⚠ Drug Interactions
Warming and tonifying Chinese herbs (Ren Shen, Huang Qi, Fu Zi, Rou Gui, Ding Xiang)
This claim deserves to be recorded accurately rather than repeated or dismissed. Its origin is the classical reputation of Lu Dou as a general antidote: the Ben Cao Gang Mu praises its detoxifying power as exceeding that of the other beans and credits it with countering poisoning by Fu Zi (aconite), Ba Dou (croton) and pi shuang (arsenic). From that antidotal reputation the materia medica generalised a rule that a cold, detoxifying food would oppose warm, tonifying medicines, and in practice this has hardened into the folk instruction to avoid mung bean while taking any herbal prescription. There is no pharmacokinetic or pharmacodynamic study showing that mung bean reduces the absorption, plasma exposure or effect of ginseng, astragalus, aconite or any other named herb or drug. It is a doctrinal contraindication with no measured basis, and the broad version of it - that mung bean cancels all herbal medicine - overstates even the classical claim, which is specific to poisons and to warming agents.
Clinical note: Not a reason to withhold a prescription or to stop a patient eating mung bean as a food. Reasonable practice is to keep a large medicinal dose of Lu Dou away from a course of warming tonics, and to consider it as one candidate explanation if a warming formula unexpectedly underperforms in a patient who eats a lot of mung bean.
Aconitum preparations (Fu Zi, Chuan Wu, Cao Wu) in overdose
Lu Dou, usually as a decoction of up to 120 g combined with Gan Cao, is the classical first-aid measure for aconite and croton poisoning, recorded from the Ben Cao Gang Mu onward and repeated in modern Chinese manuals for lead, arsenic, alcohol and aconite poisoning. No controlled study has shown that mung bean alters aconitine absorption, distribution or cardiotoxicity. Aconitine poisoning is a genuine emergency: it produces ventricular arrhythmias that can be fatal within hours, and the treatment is cardiac monitoring, antiarrhythmic therapy and supportive care.
Clinical note: The clinically important point is the negative one. Do not treat mung bean as a reason to manage suspected aconite poisoning at home. Suspected aconitine toxicity - perioral numbness, tingling, vomiting, palpitations after a Fu Zi or Chuan Wu containing formula - goes to hospital immediately.
Antidiabetic drugs (metformin, sulfonylureas, insulin)
Isolated mung bean protein improved glucose and lipid measures in human trials in the USA and Canada, and mung bean noodles produce low glycaemic and insulin responses in healthy volunteers. The vitexin and isovitexin of the seed are hypoglycaemic in vitro. The effect sizes are modest and were obtained with concentrated protein isolate or with mung bean as a staple carbohydrate, not with a medicinal decoction.
Clinical note: No adjustment is normally needed. In a patient on insulin or a sulfonylurea who takes mung bean products in substantial daily quantity, ordinary glucose self-monitoring is sufficient to pick up any change.
Legume allergens (soy, peanut, lentil, chickpea)
Mung bean is a Vigna legume and its storage proteins belong to the same vicilin and legumin families that carry the major allergens of other legumes, so cross-reactivity in an already legume-sensitised patient is chemically plausible. The published allergy literature on mung bean specifically is thin and the clinical rate of cross-reaction is not established.
Clinical note: Ask about legume allergy before prescribing Lu Dou medicinally, particularly at the large antidotal doses of 60 to 120 g, and avoid it in a patient with known reactions to soy or peanut until tolerance is known.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 15-30 g | daily | — | adult | Bensky, Clavey & Stöger, Chinese Herbal Medicine: Materia Medica, 3rd ed. (2004): 15–30 g. Up to 60–120 g used as an antidote for herbal/food poisoning; cook whole beans for clearing heat, use lightly cooked for relieving Summerheat. |
Evidence Tier
Moderate evidence · 2 studiesRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
2
0 verified · 2 unverified
Show 2 studies
- Mung Bean Functional Protein Enhances Endothelial Function via Antioxidant Activity and Inflammation Modulation in Middle-Aged Adults: A Randomized Double-Blind Trial
- Improvement of glucose and lipid metabolism via mung bean protein consumption: clinical trials of GLUCODIA™ isolated mung bean protein in the USA and Canada
Other clinical trial
0
Observational / case report
0
In vitro / animal
0
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Mung Bean Functional Protein Enhances Endothelial Function via Antioxidant Activity and Inflammation Modulation in Middle-Aged Adults: A Randomized Double-Blind Trial
A three-arm randomised, double-blind, placebo-controlled trial in adults aged 45 to 60 who took a drink containing 10 or 15 g of mung bean protein daily for six weeks. Endothelial function improved alongside changes in antioxidant enzyme activity and inflammatory markers. The intervention was an isolated protein preparation, not the culinary bean or a Lu Dou decoction.
Improvement of glucose and lipid metabolism via mung bean protein consumption: clinical trials of GLUCODIA™ isolated mung bean protein in the USA and Canada
Reports human trials of a proprietary isolated mung bean protein in the USA and Canada, with improvement in glucose and lipid metabolism measures. Together with the endothelial function trial this is essentially the whole human evidence base for the species, and it concerns a protein isolate used as a food ingredient rather than the TCM drug.
Historical Texts
Ben Cao Gang Mu
Ming dynastyReferences
- Dianzhi Hou, Laraib Yousaf, Yong Xue, Jinrong Hu, Jihong Wu, Xiaosong Hu, Naihong Feng, Qun Shen. Mung Bean (Vigna radiata L.): Bioactive Polyphenols, Polysaccharides, Peptides, and Health Benefits . Nutrients (2019) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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