Dandelion (Taraxacum officinale)

Dandelion (Taraxacum officinale)

Background

Dandelion is a member of the Asteraceae/Compositae family closely related to chicory. It is a perennial herb, native throughout the Northern hemisphere, found growing wild in meadows, pastures and waste grounds of temperate zones. Most commercial dandelion is cultivated in Bulgaria, Hungary, Poland, Romania and the United Kingdom.

Dandelion was commonly used in Native American medicine. The Iroquois, Ojibwe and Rappahannock prepared infusions and decoctions of the root and herb to treat kidney disease, dyspepsia, and heartburn. In traditional Arabian medicine, dandelion has been used to treat liver and spleen ailments. In traditional Chinese medicine (TCM), dandelion is combined with other herbs to treat hepatitis, to enhance immune response to upper respiratory tract infections, bronchitis or pneumonia, and as a topical compress for mastitis (breast inflammation).

Dandelion root and leaf are used widely in Europe for gastrointestinal ailments. The European Scientific Cooperative on Phytotherapy (ESCOP) recommends dandelion root for "restoration of hepatic and biliary function, dyspepsia [indigestion], and loss of appetite." The German Commission E authorizes the use of combination products containing dandelion root and herb for biliary abnormalities, appetite loss, dyspepsia, and for stimulation of diuresis (urine flow). Some modern naturopathic physicians assert that dandelion can detoxify the liver and gallbladder, reduce side effects of medications metabolized (processed) by the liver, and relieve symptoms associated with liver disease.

Dandelion is generally regarded as safe with rare side effects including contact dermatitis, diarrhea, and gastrointestinal upset. Traditionally, the herb is not recommended in patients with liver or gallbladder disease, based on the belief that dandelion stimulates bile secretion (an assertion not demonstrated in animal or human studies).

Dandelion is used as a salad ingredient, and the roasted root and its extracts are sometimes used as a coffee substitute.

Synonyms

Asteraceae (family) , Blowball, cankerwort, clock flower, common dandelion, Cichoroideae (sub-family), Compositae (family), dandelion herb, dent de lion, diente de lion, dudhal, dumble-dor, fairy clock, fortune teller, huang hua di ding (yellow flower earth nail), hokouei-kon, irish daisy, Leontodon taraxacum , lion's teeth, lion's tooth, Lowenzahn, Lowenzahnwurzel, maelkebotte, milk gowan, min-deul-rre, mok's head, mongoloid dandelion, pee in the bed, pissenlit, piss-in-bed, pries' crown, priest's crown, puffball, pu gong ying, pu kung ying, Radix taraxaci , swine snout, taraxaci herba, taraxacum, Taraxacum mongolicum , Taraxacum palustre , Taraxacum vulgare , telltime, white endive, wild endive, witch gowan, witches' milk, yellow flower earth nail.

Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidenceGrade*Anti-inflammatory
Research in laboratory animals suggests that dandelion root may possess anti-inflammatory properties (1). There are no well-conducted human studies in this area.

C

Antioxidant
Several laboratory studies report antioxidant properties of dandelion flower extract (2;3;4;5), although this research is preliminary, and effects in humans are not known.

C

Cancer
Limited animal research does not provide a clear assessment of the effects of dandelion on tumor growth (6;7). There are no well-conducted human studies in this area.

C

Colitis
There is a report in several patients that a combination herbal preparation containing dandelion improved chronic pain associated with colitis (8). Because multiple herbs were used, and this study is not well designed or reported, the effects of dandelion are not clear.

C

Diabetes
There is limited animal research of the effects of dandelion on blood sugar levels in animals. One study reports decreases in glucose levels in non-diabetic rabbits (9), while another notes no changes in mice (10). Effects in humans are not known.

C

Diuretic (increased urine flow)
Dandelion leaves have traditionally been used to increase urine production and excretion. Animal studies report mixed results, and there is no reliable human research in this area (11;12;13).

C

Hepatitis B
One human study reports improved liver function in people with hepatitis B after taking a combination herbal preparation containing dandelion root, called Jiedu Yanggan Gao (also including Artemisia capillaris, Taraxacum mongolicum, Plantago seed, Cephalanoplos segetum, Hedyotis diffusa, Flos chrysanthemi indici, Smilax glabra, Astragalus membranaceus, Salviae miltiorrhizae, Fructus polygonii orientalis, Radix paeoniae alba, Polygonatum sibiricum) (14). Because multiple herbs were used, and this study is not well designed or reported, the effects of dandelion are not clear.

C

* Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).

Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Abscess, acne, age spots, AIDS, alcohol withdrawal, allergies, analgesia, anemia, antibacterial, antifungal, antioxidant, antiviral, aphthous ulcers, appendicitis, appetite stimulant, arthritis, benign prostate hypertrophy, bile flow stimulation, bladder irritation, blood purifier, boils, breast augmentation, breast cancer, breast infection, breast inflammation, breast milk stimulation, bruises, cardiovascular disorders, chronic fatigue syndrome, circulation, clogged arteries, coffee substitute, congestive heart failure, dandruff, diarrhea, dropsy, eye problems, fertility, fever reduction, food uses, frequent urination, gallbladder disease, gallstones, gas, gout, headache, heartburn, high blood pressure, high cholesterol, immune stimulation, increased sweating, jaundice, kidney disease, kidney stones (), leukemia, liver disease, liver cleansing, menopause, menstrual period stimulation, muscle aches, nutrition, osteoarthritis, postpartum support, pregnancy, premenstrual syndrome, psoriasis, rheumatoid arthritis, skin conditions, skin toner, smoking cessation, stiff joints, stimulant, stomachache, urinary stimulant, urinary tract inflammation, warts, weight loss.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Standardization

Standardization involves measuring the amount of certain chemicals in products to try to make different preparations similar to each other. It is not always known if the chemicals being measured are the "active" ingredients. There are no standard or well-studied doses of dandelion, and many different doses are used traditionally. Safety of use beyond four months has not been evaluated.

Dandelion leaves are a source of vitamin A, containing up to 1400 IU per 100 grams.

Adults (18 years and older)

Dried root: Doses of two to eight grams taken by infusion or decoction have been used.

Leaf fluid extract: Doses of four to eight milliliters of a 1:1 extract in 25 percent alcohol have been used.

Root tincture: Doses of one or two teaspoons of a 1:5 tincture in 45 percent alcohol have been used.

Children (younger than 18 years)

There is not enough scientific research to recommend dandelion for use in children in amounts greater than found in food.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Dandelion should be avoided by individuals with known allergy to dandelion (16;17), honey (18), chamomile, chrysanthemums, yarrow, feverfew or any members of the Asteraceae / Compositae plant families (ragweed, sunflower, daisies) (19).

The most common type of allergy is dermatitis (skin inflammation) after direct skin contact with dandelion (20;21;22;23), which may include itching, rash, red/swollen or eczematous areas on the skin (24). Skin reactions are also reported in dogs (25). The main chemicals in dandelion responsible for allergic reactions are believed to be sesquiterpene lactones. Patch tests have been developed to assess for dandelion allergy (26;27;28).

Rhinoconjunctivitis and asthma have been reported after handling products such as birdfeed containing dandelion and other herbs, with reported positive skin tests for dandelion hypersensitivity (29).

Side Effects and Warnings

Dandelion has been well tolerated in a small number of available human studies. Safety of use beyond four months has not been evaluated.

The most common reported adverse effect is skin allergy, eczema, or increased sun sensitivity following direct contact (20;21;22;23;24).

According to traditional accounts, gastrointestinal symptoms may occur, including stomach discomfort, diarrhea and heartburn. There is a 1966 case of a patient who developed intestinal blockage from ingesting a large amount of dandelion greens three weeks after undergoing a stomach operation (30).

Parasitic infection due to ingestion of contaminated dandelion has been reported, affecting the liver and bile ducts, and characterized by fever, stomach upset, vomiting, loss of appetite, coughing and liver damage (31).

Dandelion may lower blood sugar levels based on one animal study (9), although another study notes no changes (10). Effects in humans are not known. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare provider, and medication adjustments may be necessary.

In theory, due to chemicals called coumarins found in dandelion leaf extracts, dandelion may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin, Advil) or naproxen (Naprosyn®, Aleve®).

Historically, dandelion is believed to possess diuretic (increased urination) properties and to lower blood potassium levels.

Dandelion may be prepared as a tincture containing high levels of alcohol. Tinctures should therefore be avoided during pregnancy or when driving or operating heavy machinery.

Pregnancy & Breastfeeding

Dandelion cannot be recommended during pregnancy and breast-feeding in amounts greater than found in foods, due to a lack of scientific information. Many tinctures contain high levels of alcohol and should be avoided during pregnancy.

References

1. Mascolo N, Autore G, Capasso F, et al. Biological screening of Italian medicinal plants for anti-inflammatory activity. Phytotherapy Res 1987;1(1):28-31.

2. Hu C, Kitts DD. Antioxidant, prooxidant, and cytotoxic activities of solvent-fractionated dandelion (Taraxacum officinale) flower extracts in vitro. J Agric Food Chem 2003;51(1):301-310.

3. Hagymasi K, Blazovics A, Feher J, et al. The in vitro effect of dandelions antioxidants on microsomal lipid peroxidation. Phytother Res 2000;14(1):43-44.

4. Kim HM, Oh CH, Chung CK. Activation of inducible nitric oxide synthase by Taraxacum officinale in mouse peritoneal macrophages. Gen Pharmacol 1999;32(6):683-688.

5. Kim HM, Lee EH, Shin TY, et al. Taraxacum officinale restores inhibition of nitric oxide production by cadmium in mouse peritoneal macrophages. Immunopharmacol Immunotoxicol 1998;20(2):283-297.

6. Baba K, Abe S, Mizuno D. [Antitumor activity of hot water extract of dandelion, Taraxacum officinale-correlation between antitumor activity and timing of administration (author's transl)]. Yakugaku Zasshi 1981;101(6):538-543.

7. Hata K, Ishikawa K, Hori K, et al. Differentiation-inducing activity of lupeol, a lupane-type triterpene from Chinese dandelion root (Hokouei-kon), on a mouse melanoma cell line. Biol Pharm Bull 2000;23(8):962-967.

8. Chakurski I, Matev M, Koichev A, et al. [Treatment of chronic colitis with an herbal combination of Taraxacum officinale, Hipericum perforatum, Melissa officinaliss, Calendula officinalis and Foeniculum vulgare]. Vutreshni bolesti 1981;20(6):51-54.

9. Akhtar MS, Khan QM, Khaliq T. Effects of Portulaca oleracae (Kulfa) and Taraxacum officinale (Dhudhal) in normoglycaemic and alloxan-treated hyperglycaemic rabbits. J Pak Med Assoc 1985;35(7):207-210.

10. Swanston-Flatt SK, Day C, Flatt PR, et al. Glycaemic effects of traditional European plant treatments for diabetes. Studies in normal and streptozotocin diabetic mice. Diabetes Res 1989;10(2):69-73.

11. Racz-Kotilla E, Racz G, Solomon A. The action of Taraxacum officinale extracts on the body weight and diuresis of laboratory animals. Planta Med 1974;26(3):212-217.

12. Hook I, McGee A, Henman M, et al. Evaluation of dandelion for diuretic activity and variation in potassium content. Int J Pharmacog 1993;31(1):29-34.

13. Tita B, Bello U, Faccendini P, et al. Taraxacum officinale W.: pharmacological effect of ethanol extract. Pharmacological Res 1993;27 (Suppl 1) :23-24.

14. Chen Z. [Clinical study of 96 cases with chronic hepatitis B treated with jiedu yanggan gao by a double-blind method]. Zhong Xi Yi Jie He Za Zhi 1990;10(2):71-4, 67.

15. Grases F, Melero G, Costa-Bauza A, et al. Urolithiasis and phytotherapy. Int Urol Nephrol 1994;26(5):507-511.

16. Cohen SH, Yunginger JW, Rosenberg N, et al. Acute allergic reaction after composite pollen ingestion. J Allergy Clin Immunol 1979;64(4):270-274.

17. Jovanovic M, Mimica-Dukic N, Poljacki M, et al. Erythema multiforme due to contact with weeds: a recurrence after patch testing. Contact Dermatitis 2003;48(1):17-25.

18. Helbling A, Peter C, Berchtold E, et al. Allergy to honey: relation to pollen and honey bee allergy. Allergy 1992;47(1):41-49.

19. Fernandez C, Martin-Esteban M, Fiandor A, et al. Analysis of cross-reactivity between sunflower pollen and other pollens of the Compositae family. J Allergy Clin Immunol 1993;92(5):660-667.

20. Ingber A. Seasonal allergic contact dermatitis from Taraxacum officinale (dandelion) in an Israeli florist. Contact Dermatitis 2000;43(1):49.

21. Dawe RS, Green CM, MacLeod TM, et al. Daisy, dandelion and thistle contact allergy in the photosensitivity dermatitis and actinic reticuloid syndrome. Contact Dermatitis 1996;35(2):109-110.

22. Wakelin SH, Marren P, Young E, et al. Compositae sensitivity and chronic hand dermatitis in a seven-year-old boy. Br J Dermatol 1997;137(2):289-291.

23. Guin JD, Skidmore G. Compositae dermatitis in childhood. Arch Dermatol 1987;123(4):500-502.

24. Davies MG, Kersey PJ. Contact allergy to yarrow and dandelion. Contact Dermatitis 1986;14(4):256-257.

25. Youn HY, Kang HS, Bhang DH, et al. Allergens causing atopic diseases in canine. J Vet Sci 2002;3(4):335-341.

26. Lovell CR, Rowan M. Dandelion dermatitis. Contact Derm 1991;25(3):185-188.

27. Goulden V, Wilkinson SM. Patch testing for Compositae allergy. Br J Dermatol 1998;138(6):1018-1021.

28. Mark KA, Brancaccio RR, Soter NA, et al. Allergic contact and photoallergic contact dermatitis to plant and pesticide allergens. Arch Dermatol 1999;135(1):67-70.

29. Rodriguez B, Rodriguez A, de Barrio M, et al. Asthma induced by canary food mix. Allergy Asthma Proc 2003;24(4):265-268.

30. Collins JM, Miller DR. Dandelion green bezoar following antrectomy and vagotomy - case report. J Kansas Med Soc 1966;67(6):303-304.

31. Merino AJ, Amerigo Garcia MJ, Alvarez RL, et al. [Human fascioliasis with atypical severe presentation. Treatment with triclabendazole]. Enferm Infecc Microbiol Clin 1998;16(1):28-30.

32. Zhu M, Wong PY, Li RC. Effects of taraxacum mongolicum on the bioavailability and disposition of ciprofloxacin in rats. J Pharm Sci 1999;88(6):632-634.

January 01, 2004