The stalk of the intensely flavored rhubarb plant has been used in European cooking since the 17th century. Prior to that, rhubarb species were utilized medicinally in Traditional Chinese Herbal Medicine. Traditional uses include treatment of constipation, diarrhea, fever, menstrual problems, jaundice, sores (when applied topically), ulcers, and burns.
Although there are many species of rhubarb, the one most studied is Rheum rhaponticum.
Rhubarb root contains lindleyin, a substance with estrogen-like properties.1 On this basis, extracts of rhubarb have been tried for control of menopausal symptoms. In a 12-week, double-blind, placebo-controlled trial of 109 women with menopause-related problems, use of a standardized Rheum rhaponticum. extract significantly improved symptoms as compared to placebo.2 Improvements were particularly seen in rate and severity of hot flashes. While this is meaningful supporting evidence, additional independent trials will be necessary to establish this rhubarb extract as a safe and effective treatment for menopause.
Other potential uses of rhubarb lack reliable supporting evidence.
One human trial purportedly found evidence that rhubarb could reduce the impairment of lung function that may occur when people with lung cancer receive radiation therapy.16 However, this study suffered from a number of significant flaws, and its results cannot be regarded as reliable.
Additional proposed uses of rhubarb are supported only by test tube studies. For example, various rhubarb species have shown hints of potential value for treatment of diabetes,4 kidney disease,5liver disease6,7, allergies8 and pancreatitis.9. The vast majority of effects seen in test tube studies do not pan out when human trials are conducted.
However, a review of 19 randomized trials did compare rhubarb and somatostatin to somatostatin alone in 1,161 patients with acute pancreatitis. The addition of rhubarb (given by gastric tube or retention enema) was associated with a reduced risk of complications, and shorter duration of abdominal pain, hospitalization, and time to first bowel movement. Rhubarb dosage ranged from 10-90 grams a day. Although the results were promising, all trials had biases that can affect the outcomes.17
A typical dosage of rhubarb root is ½ to l teaspoonful of the root boiled for 10 minutes in a cup of water, three times daily.
In the menopause study mentioned above, a standardized extract was used. Such extracts should be used according to label instructions.
As a widely consumed food, rhubarb is thought to be relatively safe if consumed in moderation. However, the plant contains high levels of oxalic acid, and rhubarb consumption can markedly increase oxalic acid levels in the urine.10-13 This could lead to increased risk of kidney stones, as well as other problems. Rhubarb leaf contains the highest oxalic acid content. The roots and stems contain less oxalic acid, but higher levels of anthraquinones, laxative substances similar to those found in senna or cascara. It is safest to use rhubarb standardized extracts processed to removed oxalic acid.
Very weak evidence hints that excessive consumption of rhubarb could increase risk of stomach and/or colon cancer.15
Maximum safe doses in pregnant or nursing women, young children, or people with severe liver or kidney disease have not been established.
1. Usui T, Ikeda Y, Tagami T, et al. The phytochemical lindleyin, isolated from Rhei rhizoma, mediates hormonal effects through estrogen receptors. J Endocrinol. 2002;175:289-96.
2. Heger M, Ventskovskiy BM, Borzenko I, et al. Efficacy and safety of a special extract of Rheum rhaponticum (ERr 731) in perimenopausal women with climacteric complaints: a 12-week randomized, double-blind, placebo-controlled trial. Menopause. 2006 Aug 4 [Epub ahead of print]
3. Saller R, Buechi S, Meyrat R, et al. Combined herbal preparation for topical treatment of Herpes labialis. Forsch Komplementarmed Klass Naturheilkd. 2002;8:373-382.
4. Choi SZ, Lee SO, Jang KU, et al. Antidiabetic stilbene and anthraquinone derivatives from Rheum undulatum. Arch Pharm Res. 2005;28:1027-1030.
5. Li X, Wang H. Chinese herbal medicine in the treatment of chronic kidney disease. Adv Chronic Kidney Dis. 2005;12:276-281.
6. Fan JG. Evaluating the efficacy and safety of Danning Pian in the short-term treatment of patients with non-alcoholic fatty liver disease: a multicenter clinical trial. Hepatobiliary Pancreat Dis Int. 2004;3:375-380.
7. Jin H, Sakaida I, Tsuchiya M, et al. Herbal medicine Rhei rhizome prevents liver fibrosis in rat liver cirrhosis induced by a choline-deficient L-amino acid-defined diet. Life Sci. 2005;76:2805-2816.
8. Matsuda H, Tewtrakul S, Morikawa T, et al. Anti-allergic activity of stilbenes from Korean rhubarb (Rheum undulatum L.): structure requirements for inhibition of antigen-induced degranulation and their effects on the release of TNF-alpha and IL-4. Bioorg Med Chem. 2004;12:4871-4876.
9. Zhao YQ, Liu XH, Ito T, et al. Protective effects of rhubarb on experimental severe acute pancreatitis. World J Gastroenterol. 2004;10:1005-1009.
10. Finch AM, Kasidas GP, Rose GA. Urine composition in normal subjects after oral ingestion of oxalate-rich foods. Clin Sci (Lond). 1981;60:411-418.
11. Vahlensieck EW, Bach D, Hesse A, et al. Epidemiology, Pathogenesis and diagnosis of calcium oxalate urolithiasis. Int Urol Nephrol. 1983;14:333-47.
12. Massey LK, Roman-Smith H, Sutton RA. Effect of dietary oxalate and calcium on urinary oxalate and risk of formation of calcium oxalate kidney stones. J Am Diet Assoc. 1993;93:901-906.
13. Hesse A, Siener R, Heynck H, et al. The influence of dietary factors on the risk of urinary stone formation. Scanning Microsc. 1994;7:1119-27; discussion 1127-1128.
14. Goel V, Ooraikul B, Basu TK. Effect of dietary rhubarb stalk fiber on the bioavailability of calcium in rats. Int J Food Sci Nutr. 1997;47:159-163.
15. Mantani N, Sekiya N, Sakai S, et al. Rhubarb use in patients treated with Kampo medicines--a risk for gastric cancer? Yakugaku Zasshi. 2002;122:403-405.
16. Yu HM, Liu YF, Cheng YF, et al. Effects of rhubarb extract on radiation induced lung toxicity via decreasing transforming growth factor-beta-1 and interleukin-6 in lung cancer patients treated with radiotherapy. Lung Cancer. 2008;59(2):219-226.
17. Zhou Y, Wang L, Huang X, Li H, Xiong Y. Add-on effect of crude rhubarb to somatostatin for acute pancreatitis: A meta-analysis of randomized controlled trials. J Ethnopharmacol. 201624;194:495-505.
Last reviewed December 2015 by EBSCO CAM Review Board Last Updated: 12/15/2016