USDA Nutrient-Dense Foods · Fruit
Rheum rhabarbarum (Rhubarb Stalk)
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Hermetica Superfood Encyclopedia
Rhubarb stalk (Rheum rhabarbarum) contains anthraquinone glycosides and tannins that demonstrate anti-inflammatory properties through cytokine modulation. Clinical evidence shows it may reduce inflammatory markers like IL-6 and TNF-α in sepsis patients when used as adjuvant therapy.
Rheum rhabarbarum, or garden rhubarb, is a perennial plant native to Asia whose stalks (petioles) and roots are used for their nutritional and medicinal properties. Its bioactive compounds, including anthraquinones and stilbenes, are isolated using solvent-based extraction methods to create standardized phytopharmaceutical preparations. The plant is a member of the Polygonaceae family.
Rhubarb's efficacy is supported by a meta-analysis of 15 randomized controlled trials (869 patients) which confirmed its ability to lower key inflammatory markers in sepsis. [3] Furthermore, a double-blind, placebo-controlled trial in 150 children demonstrated that rhubarb syrup significantly reduced the duration of fever and diarrhea in dysentery, [2] while a prospective study on 129 women validated a standardized extract (ERr 731) for managing menopausal symptoms. [5, 8]
Based on clinical trials, a standardized dried root extract (ERr 731) has been used at 4 mg daily for menopausal symptoms. For pediatric dysentery, a 5-day course of rhubarb syrup was administered, though the specific dose per administration was not detailed. Comprehensive dosage ranges for other preparations are not available in the provided research. Consult a healthcare provider before starting any new supplement.
Rhubarb stalk (raw, per 100g): Calories: 21 kcal; Carbohydrates: 4.5g (of which sugars: 1.1g); Dietary fiber: 1.8g; Protein: 0.9g; Fat: 0.2g. Key micronutrients: Vitamin K1 (phylloquinone): 29.3 mcg (24% DV) — notably high relative to caloric density; Vitamin C (ascorbic acid): 8.0 mg (9% DV); Calcium: 86 mg (9% DV) — bioavailability significantly reduced by high oxalic acid content (oxalate binds calcium, forming insoluble calcium oxalate, reducing net absorption by ~40-50%); Potassium: 288 mg (8% DV); Manganese: 0.196 mg (9% DV); Magnesium: 12 mg (3% DV); Phosphorus: 14 mg (1% DV); Folate: 7 mcg (2% DV); Vitamin A: 102 IU (2% DV). Bioactive compounds: Anthraquinones (primary pharmacologically active constituents): Rhein (most abundant, ~0.1-0.5% dry weight), Emodin (~0.05-0.3% dry weight), Aloe-emodin, Chrysophanol, Physcion — concentrated in roots but present in trace amounts in stalks; Stilbenes: Resveratrol and Rhapontigenin (glycosidic forms, ~0.01-0.05 mg/g dry weight in stalks); Tannins: Gallotannins and procyanidins (~0.5-2% dry weight), contributing astringent properties and antidiarrheal effects; Oxalic acid: 860 mg/100g raw stalk — significantly impairs calcium and iron bioavailability and contraindicated in kidney stone-prone individuals; Polyphenols: Total phenolic content ~200-400 mg gallic acid equivalents/100g fresh weight, including catechins and quercetin derivatives; Anthocyanins: Present in red-stalked varieties (~0.1-1.0 mg/g fresh weight), primarily cyanidin-3-glucoside and pelargonidin derivatives; Pectin: ~0.5-1.0g/100g, contributing to soluble fiber fraction and potential prebiotic effects. Bioavailability notes: Cooking (boiling, stewing) reduces oxalic acid by ~30-45% through leaching into cooking water; anthraquinone glycosides require colonic bacterial hydrolysis for activation; Vitamin K1 absorption enhanced by co-consumption with dietary fats (fat-soluble vitamin).
Rhubarb stalk's anthraquinone glycosides, particularly sennosides and rhein, modulate inflammatory pathways by inhibiting NF-κB activation and reducing pro-inflammatory cytokine production. These compounds also influence gut microbiota composition, which may contribute to systemic anti-inflammatory effects through the gut-immune axis.
A meta-analysis of 15 randomized controlled trials involving 869 sepsis patients demonstrated that adjuvant crude rhubarb treatment significantly reduced inflammatory markers IL-6 and TNF-α compared to standard care alone. The evidence quality is considered strong based on the consistency across multiple RCTs. However, most clinical research has focused on acute care settings rather than general wellness applications.
Rhubarb stalk is generally safe when consumed as food, but concentrated extracts may cause gastrointestinal upset including diarrhea and cramping due to anthraquinone content. It may interact with anticoagulant medications due to potential effects on blood clotting. Pregnant and breastfeeding women should avoid therapeutic doses, and individuals with kidney stones should exercise caution due to oxalate content. Long-term use of high doses may lead to electrolyte imbalances.
