Turmeric

Turmeric (Curcuma longa) is a plant of the ginger family whose underground stems (rhizomes) give a bright yellow spice and dye. It is a domesticated plant, not known in the wild, widely grown throughout the tropics.

Type

Plant

Botanical name

Curcuma longa

Other names

Indian saffron

Plant

Turmeric is an upright herb with large, oblong leaves, dark green above and pale green below. Its yellow-white flowers grow on a spike-like stalk. It reproduces only through its rhizome, which is thick and ringed with the bases of old leaves.

Spice

To make the spice, the rhizomes are boiled, dried, peeled and ground to a powder, which has a warm, bitter flavour like black pepper and an earthy, mustard-like aroma. Turmeric is the main ingredient of curry powder and an important yellow food dye in many Indian foods, such as curries, pickles and rice; in Europe and the United States it also colours processed foods, sauces and sweets. India is the world's largest producer, consumer and exporter of turmeric, and people there have used it for at least 2,500 years.

Traditional and supplement use

Curcumin, a major component of turmeric, gives the spice its yellow colour. Turmeric has been used in Chinese, Indian (Ayurvedic), Islamic and Thai traditional medicine for conditions such as indigestion, colds, skin infections and arthritis. Today it is also used in dietary supplements, but it is not known whether turmeric or curcumin is beneficial for any health purpose.

A 1999 monograph of the World Health Organization (WHO) is more positive about one use. It names the treatment of indigestion (dyspepsia) with acidity, wind or a sluggish stomach as the rhizome's main use supported by clinical data. Pharmacopoeias and traditional medicine, it notes, also use turmeric for peptic ulcers, rheumatoid arthritis pain, period pain and skin diseases. Folk uses, such as for asthma, coughs or insect bites, are not supported by data.

Safety

Turmeric or curcumin in ordinary formulations is likely safe in the recommended amounts for up to 2 or 3 months. Taken by mouth, it can cause nausea, vomiting, acid reflux, stomach upset, diarrhoea or constipation. Liver damage has been reported in some people who took curcumin products made to be better absorbed. Signs of liver damage include tiredness, nausea, poor appetite, dark urine and jaundice. Anyone who notices them should stop turmeric or curcumin products at once and see a doctor.

Turmeric supplements may be unsafe in pregnancy, and little is known about the safety of amounts larger than those in food while breastfeeding. As a medicine, turmeric should not be used when the bile ducts are blocked, and with gallstones only after consulting a doctor.

Products containing it

• Curcumin with oleuropein capsules (D 210)