Rhubarb means two different things depending on which part of the plant — and which tradition — you’re asking about. In North American and European kitchens, it’s the tart, pink-to-green stalk that goes into pie, jam, and crumble. In traditional Chinese medicine, it’s the dried root, used for centuries as a stimulant laxative. Most searches for rhubarb plant benefits blend both of these together, so it’s worth separating the food from the herb before deciding whether either one belongs in your routine.
The plant’s medicinal reputation is genuinely old. Root preparations appear in writings credited to Shen-Nung, a legendary Chinese emperor said to have catalogued hundreds of herbs around 2695 B.C. (Toxipedia, Shen Nung). Centuries later, the Greek physician Pedanius Dioscorides described similar root preparations in De materia medica, the pharmacology text that shaped Western medicine for roughly 1,500 years (Encyclopaedia Britannica, Pedanius Dioscorides). That history explains why rhubarb root still shows up in herbal laxative blends today. It doesn’t mean every traditional claim made about it holds up, and the plant carries a real, well-documented risk that has nothing to do with dosing: its leaves.
What the Rhubarb Plant Actually Is
Rhubarb (genus Rheum) belongs to the Polygonaceae, or knotweed, family, the same family as buckwheat and sorrel (Wikipedia, Polygonaceae). Two groups matter for this article:
- Garden or culinary rhubarb (Rheum rhabarbarum, also sold as Rheum x hybridum) is the plant grown for its edible stalks. Only the stalk is food; the leaf blade is not.
- Chinese, Turkish, or “turkey” rhubarb (Rheum palmatum and Rheum officinale) is grown for its root and rhizome, which is dried and used in traditional Chinese medicine and in some Western herbal laxative products (Memorial Sloan Kettering Cancer Center, Rhubarb).
A perennial plant with large, broad leaves and thick, celery-like stalks, rhubarb needs a cold winter to grow well, which is why it’s a spring crop across the northern U.S., Canada, and northern Europe (USDA SNAP-Ed, Rhubarb).
Rhubarb Stalk Nutrition, By the Numbers
Rhubarb stalks are low in calories and carry a modest but real nutritional profile — most notably vitamin K1, some fiber, and a small amount of vitamin C. The numbers below come from USDA and Healthline’s reporting of USDA FoodData Central figures; cooked rhubarb is almost always prepared with added sugar, which changes the calorie and carbohydrate count substantially.
| Nutrient | Raw stalk, 1 stalk / 51 g (USDA) | Cooked with added sugar, per 100 g (Healthline/USDA FDC) |
| Calories | 21 | 116 |
| Carbohydrates | 4.5 g | 31.2 g |
| Dietary fiber | 1.8 g | 2 g |
| Protein | 0.9 g | 0.4 g |
| Vitamin C | 5 mg | ~4% of Daily Value |
| Vitamin K1 | 29.3 mcg | ~18–24% of Daily Value |
| Calcium | 3 mg | ~11% of Daily Value (mostly as calcium oxalate, poorly absorbed) |
Sources: USDA SNAP-Ed, Rhubarb; Healthline, Rhubarb: Nutrition, Benefits, and More.
Potential Health Benefits — Graded by Evidence
Most of what gets called a rhubarb “benefit” falls into one of two buckets: reasonably solid nutrition facts about the stalk as a food, or early-stage or traditional claims about the root as an herb. Here’s how the evidence actually breaks down.
Antioxidants
Rhubarb stalks contain anthocyanins (the pigments behind the red color) and proanthocyanidins, a type of condensed tannin. Healthline notes one 2012 study suggesting rhubarb’s total polyphenol content may exceed kale’s — a single lab analysis, not a health-outcome trial, so treat it as a reason rhubarb could contribute antioxidants to a varied diet rather than as a stand-alone health claim (Healthline, Rhubarb: Nutrition, Benefits, and More).
Cholesterol and heart health (limited evidence)
Compounds in rhubarb — including resveratrol and emodin — have been studied for a role in lipid metabolism, and rhubarb’s fiber content may modestly support healthy cholesterol the way fiber from many other vegetables does. This is limited, largely preclinical evidence, not proof that eating rhubarb lowers cholesterol in people (Healthline, Rhubarb: Nutrition, Benefits, and More).
Digestive and laxative use of the root (traditional, with some clinical interest)
This is where rhubarb’s reputation as medicine actually comes from, and it’s specific to the root, not the stalk you’d put in a pie. Memorial Sloan Kettering Cancer Center’s clinician-reviewed herb monograph describes rhubarb as a stimulant laxative, and notes that small human studies suggest it can improve feeding tolerance and gastrointestinal function in critically ill patients, and may help with recurrent mouth ulcers or reduce some radiation side effects in lung cancer patients — all described as preliminary, with more research needed.
The same source is direct on the point that matters most for anyone who’s encountered rhubarb through unproven cancer-cure products like Essiac tea: rhubarb has not been shown to treat or prevent cancer (Memorial Sloan Kettering Cancer Center, Rhubarb).
Traditional herbal medicine also credited low-dose rhubarb root with a mild choleretic effect — the idea that it stimulates bile flow and relieves a “congested” liver. That’s an older traditional claim rather than one with modern clinical backing, so treat it the way you’d treat most folk-remedy claims: plausible, not proven. If you’re looking for liver-supportive foods with more current sourcing behind them, our guide to 10 Best Foods for The Liver is a better starting point than rhubarb root.
How Rhubarb Root Traditionally Works — and Why Dosing Isn’t a DIY Decision
Rhubarb root’s effects genuinely do shift with the amount taken, and this isn’t just folk theory. According to MSKCC’s clinical summary, the tannins in rhubarb have an astringent, constipating effect at lower intake, while at higher intake the hydrolyzed anthraquinone compounds (emodin and sennidin, among others) stimulate the gut and produce a laxative effect instead (Memorial Sloan Kettering Cancer Center, Rhubarb). That’s a real, dose-dependent pharmacological pattern.
What this article won’t do is hand you specific gram doses. Older herbal references (including the print encyclopedia this article previously cited) list exact numbers for root powder and infusions, but that source can’t be verified with live tools, and giving precise doses for a stimulant laxative with real kidney and colon risks isn’t something to do on the strength of an unconfirmed print citation. If you’re considering a rhubarb root product, follow the dose on that specific product’s label and check with a pharmacist, doctor, or qualified herbalist first — particularly because rhubarb interacts with several medications (below).
If your actual goal is just keeping things regular rather than using a stimulant laxative, it’s worth trying gentler options first. Apples, for example, regulate bowel movements through soluble fiber rather than a stimulant mechanism, and are generally considered fine for regular, everyday use in a way rhubarb root isn’t. Our guide to 10 Top Foods for The Intestines covers other non-stimulant ways to support regularity.
Safety, Side Effects, and Who Should Avoid Rhubarb
The leaves are genuinely toxic
Only the stalk is food. Rhubarb leaves contain oxalic acid and possibly an anthraquinone-related compound, and eating them can cause mouth and throat burning, blistering, excess salivation, nausea and vomiting, diarrhea, and in serious cases seizures, breathing difficulty, or kidney failure (MedlinePlus Medical Encyclopedia, Rhubarb leaves poisoning). The USDA’s produce guide states this plainly: rhubarb leaves, cooked or raw, contain toxins and should not be eaten (USDA SNAP-Ed, Rhubarb). If someone eats rhubarb leaves and develops these symptoms, call Poison Control (1-800-222-1222 in the U.S.) or go to an emergency room — don’t wait to see if it passes.
Oxalate and kidney stones
Rhubarb stalks are also high in oxalate, most of it bound as calcium oxalate that the body can’t absorb well (Healthline, Rhubarb: Nutrition, Benefits, and More). The National Institute of Diabetes and Digestive and Kidney Diseases lists rhubarb by name among the foods people with calcium oxalate kidney stones are typically advised to limit, alongside spinach and wheat bran (NIDDK, Eating, Diet, & Nutrition for Kidney Stones).
MSKCC’s monograph also notes case reports of acute kidney injury following unusually large intakes of rhubarb, including a case involving several weeks of heavy rhubarb stew consumption (Memorial Sloan Kettering Cancer Center, Rhubarb). Ordinary servings of rhubarb in a pie or crumble are not the same risk as those case reports, but if you’ve had calcium oxalate stones, this is a food worth discussing with your doctor or a dietitian — our guide to Foods That Cause Kidney Stones covers the fuller list of what else to watch.
Chronic laxative use and melanosis coli
Rhubarb root belongs to the same family of plant-based stimulant laxatives as senna, cascara, and aloe. Long-term use of any of these can cause melanosis coli, a harmless but visible dark pigmentation of the colon lining that shows up on colonoscopy and typically resolves within months of stopping the laxative (StatPearls, Melanosis Coli). MSKCC’s monograph documents one such case tied specifically to a long-term fiber supplement containing rhubarb. Melanosis coli itself isn’t linked to a higher risk of colon cancer, but its presence is a signal that a laxative has been used long enough that it’s worth a conversation with a clinician about why, and about non-stimulant alternatives.
Medication interactions
MSKCC’s clinician-facing summary flags several interactions worth knowing about before using rhubarb root products:
- Digoxin: rhubarb’s laxative effect can lower potassium, which raises the risk of digoxin side effects.
- CYP450-metabolized drugs: in animal and lab studies, rhubarb affected several liver enzymes that process many prescription medications; clinical significance in people isn’t established.
- Melatonin, cyclosporine, and methotrexate: lab studies suggest rhubarb can alter how the body handles each of these; again, real-world significance is unclear.
Because a stimulant laxative can also speed transit time and reduce absorption of other oral medications generally, tell your doctor or pharmacist about any rhubarb root product you’re taking, especially alongside prescription drugs (Memorial Sloan Kettering Cancer Center, Rhubarb).
Pregnancy and breastfeeding
Safety data here is thin rather than reassuring. The NIH’s LactMed database notes that rhubarb has no specific role in lactation, and that two old, small studies found no detectable laxative effect in breastfed infants after mothers took rhubarb syrup — but most current reviewers still advise against using rhubarb root while breastfeeding because of its cathartic potential (Drugs and Lactation Database (LactMed), Rhubarb).
Well-controlled safety data for rhubarb root use during pregnancy is limited; the most defensible approach is to treat rhubarb root preparations as something to avoid in pregnancy unless a doctor specifically advises otherwise. Garden rhubarb eaten as food, in ordinary amounts, is a different and lower-concern category, but anyone pregnant with a history of kidney stones should still mind the oxalate content.
| Health Disclaimer This article is for educational purposes only and is not medical advice. It does not diagnose, treat, or cure any condition. Rhubarb root preparations, high-oxalate eating patterns, and any change to a laxative or supplement routine should be discussed with a doctor, pharmacist, or registered dietitian first — especially if you are pregnant, breastfeeding, have kidney disease or a history of kidney stones, or take prescription medication. If you experience mouth or throat burning, severe stomach pain, vomiting, or blood in your urine after eating rhubarb leaves or a large amount of rhubarb, treat it as a poisoning emergency and call Poison Control at 1-800-222-1222 (U.S.) or seek emergency care right away. |
Frequently Asked Questions
Is rhubarb actually good for you?
The stalk, eaten as food, is a low-calorie source of fiber, vitamin K, and some antioxidants — reasonable to include in a varied diet, though not a superfood by itself. The root, used as an herbal laxative, has real traditional and some preliminary clinical support for short-term digestive use, but hasn’t been shown to treat or prevent disease.
Can you eat rhubarb leaves if you cook them?
No. Cooking does not make rhubarb leaves safe. The USDA and MedlinePlus both specify that rhubarb leaves, cooked or raw, contain toxins and should be discarded, not eaten.
Does rhubarb cause kidney stones?
Rhubarb doesn’t cause stones in everyone, but it’s high in oxalate, and the NIDDK specifically names it as a food to limit if you’ve had calcium oxalate stones. If you have no history of stones, ordinary servings are unlikely to be a major concern, but very large or frequent intake is a different story.
Is it safe to take rhubarb root as a laxative regularly?
Regular, long-term use of any anthraquinone-based laxative, including rhubarb root, is associated with melanosis coli and isn’t generally recommended without medical supervision. Short-term, occasional use under a clinician’s guidance is a very different situation than daily long-term use.
Can I eat rhubarb while pregnant?
Rhubarb stalk as food, in normal amounts, isn’t flagged as a specific pregnancy danger, but rhubarb root preparations lack solid pregnancy safety data and are best avoided unless a doctor advises otherwise.
References
- Toxipedia (asmalldoseoftoxicology.org). “Shen Nung.” Steve Gilbert/Toxipedia. https://www.asmalldoseoftoxicology.org/shen-nung
- Encyclopaedia Britannica. “Pedanius Dioscorides.” Britannica Editors. https://www.britannica.com/biography/Pedanius-Dioscorides
- Wikipedia. “Polygonaceae.” https://en.wikipedia.org/wiki/Polygonaceae
- Memorial Sloan Kettering Cancer Center. “Rhubarb.” About Herbs, Botanicals & Other Products. Last updated November 8, 2022. https://www.mskcc.org/cancer-care/integrative-medicine/herbs/rhubarb
- National Institute of Child Health and Human Development / NCBI Bookshelf. “Rhubarb.” Drugs and Lactation Database (LactMed). Last revision February 15, 2025. PMID 30000922. https://www.ncbi.nlm.nih.gov/books/NBK501862/
- MedlinePlus Medical Encyclopedia (National Library of Medicine). “Rhubarb leaves poisoning.” Reviewed October 14, 2025. https://medlineplus.gov/ency/article/002876.htm
- Healthline. “Is Rhubarb Good for You? All You Need to Know.” Atli Arnarson, medically reviewed by Katherine Marengo LDN, R.D. Updated July 15, 2024. https://www.healthline.com/nutrition/rhubarb
- USDA, SNAP-Ed Connection. “Rhubarb.” Seasonal Produce Guide. https://snaped.fns.usda.gov/resources/nutrition-education-materials/seasonal-produce-guide/rhubarb
- Tian C, Al Nasser Y. “Melanosis Coli.” StatPearls [Internet]. Updated April 30, 2025. PMID 29630198. https://www.ncbi.nlm.nih.gov/books/NBK493146/
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). “Eating, Diet, & Nutrition for Kidney Stones.” Last reviewed May 2017. https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones/eating-diet-nutrition
