Although you probably think of dandelion (Tarazacum officinale) as a weed, the plant is also medicinal and has been used as a traditional herbal remedy for centuries. Native Americans boiled the plant and used it to treat skin problems, while Chinese herbalists recommend dandelion for stomach problems and to promote milk flow during breast-feeding. Modern science suggests that dandelion leaves and tea brewed from the leaves may have significant health benefits.
In traditional medicine, dandelion leaves are often used to promote urine formation and to support kidney health. Research suggests that the leaves contain diuretic compounds that increase the amount of urine the kidneys make. A clinical study published in the August 2009 issue of the "Journal of Alternative and Complementary Medicine" tested the effect of dandelion leaf extract on urination in 17 healthy subjects and found that consuming several doses over 24 hours resulted in increased frequency of urination during the five-hour period after the first dose and increased urine volume by the second dose. The exact component of dandelion responsible for this effect remains unidentified, but experts at the Memorial Sloan-Kettering Cancer Center suggest that dandelion's high content of potassium -- 218 milligrams per cup of leaves -- might be responsible for increased urine production.
Research summarized on the Cancer Center website suggests that compounds in dandelion leaves have significant anti-cancer properties, at least in a laboratory setting. For example, a study published in the November 2002 issue of the ''Biological and Pharmacological Bulletin" found that a compound called taraxinic acid in dandelion stopped the growth of cultured leukemia cells and caused them to mature into a non-cancerous cell type. Another study in the January 2004 issue of "Life Sciences" found that dandelion extract caused cultured liver cancer cells to produce compounds that decreased their own survival. These findings are promising but still need further exploration in clinical trials with human subjects.
Dandelion leaves also contain several antioxidant compounds, such as luteolin, caffeic acid and chlorogenic acid, that help your body rid itself of potentially harmful free radicals. Free radicals form as byproducts of digestion, in your skin when you're in sunlight or if you're exposed to toxins. Over time, they can damage cellular membranes and DNA, raising the risk of cancer and other disorders. A study published in 2012 in the "Journal of Medicinal Food" found that animals fed dandelion leaf extract along with acetaminophen in high doses were protected from liver damage, compared to a placebo group. The researchers attributed this effect to the antioxidant properties of dandelion. More research into this potential benefit of dandelion compounds is still needed, but these findings are promising.
Dried or fresh dandelion leaves suitable for tea are available at some health-food stores. To make tea, pour hot water onto about 1 teaspoon dried leaves or one-quarter cup fresh leaves and allow to steep for five to 10 minutes before drinking. You can also purchase dandelion leaf extract, either as powder or as an alcohol-based tincture; add about 500 milligrams of powder or 30 to 60 drops of tincture to hot water to make a tea. Dandelion tea is generally considered safe to drink up to three times daily, but avoid it if you experience an allergic skin reaction when you contact dandelion plants. The tea could interact with certain medicines, including diuretics and diabetes drugs, so discuss its use with your doctor to decide if it's appropriate for you. Ask your doctor before drinking it, too, if you have kidney or gall bladder problems.