Turmeric

Turmeric is a perennial plant belonging to the ginger family (Zingiberaceae); its biological names are Curcuma longa, Curcuma aromatica, and Curcuma domestica. C. longa is native to India and Southeast Asia. It requires warm temperatures (between 68 and 86°F) and abundant rainfall to thrive. The turmeric plant is harvested for its rhizomes (underground stems) each year; some rhizomes are used to propagate new plants, whereas others are used either fresh or prepared by boiling and drying to make turmeric powder. As of 2018, about 80% of the turmeric used worldwide comes from India.

Other names for turmeric outside North America include halada, haldi, haridra, Indian saffron, nisha, pian jiang huang, rajani, safran bourbon, safran de batallita, safran des Indes, turmeric root, and yu jin.

Turmeric has a wide range of historic and contemporary uses:

Turmeric is available in the United States, Canada, and the European Union as a dried root or powdered spice for use in cooking and in various packaged forms as a dietary supplement. Supplements are available as capsules, chewables, tablets, liquids, tonics, tinctures, booster powders, softgels, teas, and extracts. In the United States, there is no standardization in the content of these supplements; for example, turmeric capsules are sold in 300 mg, 400 mg, 475 mg, 500 mg, 800 mg, and 1000 mg doses. In addition, turmeric is sometimes sold in combination with either bromelain, an enzyme derived from pineapple, or boswellia, a resin historically used to make frankincense. Although boswellia has some anti-inflammatory properties, bromelain has no known medical uses.

Turmeric may be regulated as an import, as an agricultural product, as a food additive, or as a dietary supplement.

No standard dosage has been established for turmeric dietary supplements because of the many forms in which the plant can be prepared for oral administration. In general, extracts and tinctures are stronger than tablets and capsules, which in turn are stronger than teas. Dosages also vary depending on whether the turmeric is being used in Ayurveda, TCM, naturopathy, or under the supervision of a mainstream healthcare provider. Some detailed recommendations for adults are provided in Health Canada and European Medicines Agency statements.

Some general recommendations for American consumers interested in turmeric as a dietary supplement are as follows:

Although turmeric has been touted by practitioners of alternative medicine for years as an effective remedy for osteoarthritis, rheumatoid arthritis, skin rashes, cancer, metabolic syndrome, prediabetes, stomach ulcers, inflammatory bowel disease, Alzheimer's disease, eczema, dental plaque, and others, no studies as of 2018 has shown conclusively that it is effective in treating any of these conditions. One reason for its relative ineffectiveness is its low bioavailability; curcumin, the active compound in turmeric, is unstable and readily broken down in the stomach; thus very little (about 1% at most) reaches the systemic circulation. Curcumin's other disadvantages for drug development include its potential for toxicity, its limited distribution in body tissue, and its insolubility in water.

Turmeric supplements are not recommended for children. Women who are pregnant or lactating can safely use turmeric as a spice in cooking, but they should not take turmeric supplements because of the risk of bleeding.

People with any of the following conditions or disorders should not take turmeric as a dietary supplement:

In addition, because turmeric affects blood clotting, people should discontinue using it at least two weeks before surgery or dental work.

Turmeric should be used only in its topical or oral forms; it should never be administered as an injection. In March 2017, a 30-year-old woman seeking treatment for eczema was given intravenous curcumin by a naturopath in San Diego; she died of a heart attack shortly after the infusion.

Turmeric used in small quantities to color or season foods has not been associated with side effects. In skin creams and other topical formulations, turmeric may cause skin rashes and irritation in some people.

Turmeric taken as a dietary supplement has been reported to cause the following side effects:

Turmeric interacts with a wide variety of prescription drugs, including:

Turmeric also interacts with other herbs and supplements, including those that affect blood clotting (angelica, capsicum, clove, dandelion, danshen, evening primrose, garlic, ginger, gingko, horse chestnut, ginseng, poplar, red clover, saw palmetto, and willow) and those that lower blood sugar levels (chromium, damiana, devil's claw, fenugreek, garlic, guar gum, horse chestnut, psyllium, and Siberian ginseng). It should not be used in combination with any of these.

See also Detoxification diets ; Dietary supplements ; Food additives .