Turmeric

Other common name(s): jiang huang, haridra, Indian saffron

Scientific/medical name(s): Curcuma longa, Curcuma domestica

Description

Turmeric is a spice grown in India and other tropical regions of Asia. It has a long history of use in herbal remedies, particularly in China, India, and Indonesia. The root and rootstock, or rhizome, of the plant contain the active ingredient, curcumin. Curcumin is not related to cumin, which is a spice made from the seeds of a different plant.

Overview

Turmeric is a common food flavoring and coloring in Asian cooking. Animal and laboratory studies have found that curcumin, an antioxidant that is an active ingredient in turmeric, demonstrated some anticancer effects.

However, clinical research is needed to determine curcumin's role in cancer prevention and treatment in humans. Several types of cancer cells are inhibited by curcumin in the laboratory, and curcumin slows the spread of some cancers in some animal studies.

Curcumin is being studied to find out whether it helps other diseases such as arthritis, Alzheimer’s disease, and stomach ulcers. It is also being studied to see whether it can help lower “bad cholesterol” and improve outcome in kidney transplants. A few early studies have been done in humans, but more human research is still needed to find out it curcumin can be effective in these uses.

How is it promoted for use?

Some researchers believe turmeric may prevent and slow the growth of a number of types of cancer, particularly tumors of the esophagus, mouth, intestines, stomach, breast, and skin. One researcher reported that curcumin, the active ingredient in turmeric, inhibited the formation of cancer-causing enzymes in rodents.

Turmeric is promoted mainly as an anti-inflammatory herbal remedy and is said to produce fewer side effects than commonly used pain relievers. Some practitioners prescribe turmeric to relieve inflammation caused by arthritis, muscle sprains, swelling, and pain caused by injuries or surgical incisions. It is also promoted as a treatment for rheumatism and as an antiseptic for cleaning wounds.

Some proponents claim turmeric interferes with the actions of some viruses, including hepatitis and HIV.

Supporters also claim that turmeric protects against liver diseases, stimulates the gallbladder and circulatory systems, reduces cholesterol levels, dissolves blood clots, helps stop external and internal bleeding, and relieves painful menstruation and angina, chest pains that often occur with heart disease.

It is also used as a remedy for digestive problems such as irritable bowel syndrome, colitis, Crohn’s disease, and illnesses caused by toxins from parasites and bacteria.

What does it involve?

Turmeric root is on the Commission E (Germany’s regulatory agency for herbs) list of approved herbs, and it is available in powdered form as a spice in most grocery stores. It can also be made into a tea or purchased as a tincture, capsule, or tablet. Ointments or pastes made from turmeric can be applied to the skin. Although there is no standardized dose for turmeric, some practitioners recommend taking a teaspoon with each meal.

The dried root of turmeric normally contains from 3% to 5% curcumin. Today, many sellers market supplements that claim to be standardized to contain 95% curcumin compounds.

What is the history behind it?

The use of turmeric was described in traditional Chinese and Indian medicine as early as the seventh century AD. In various Asian folk medicine traditions, turmeric has been used to treat a long list of conditions, including diarrhea, fever, bronchitis, colds, parasitic worms, leprosy, and bladder and kidney inflammations.

Herbalists have applied turmeric salve to bruises, leech bites, festering eye infections, mouth inflammations, skin conditions, and infected wounds. Some people inhale smoke from burning turmeric to relieve chronic coughs. Turmeric mixed with hot water and sugar is considered by some herbalists to be a remedy for colds.

In India and Malaysia, there is a custom of making turmeric paste to apply directly onto the skin, a practice now under study for the possibility that it may prevent skin cancer. The bright red forehead mark worn by some Hindu women is created by mixing turmeric with lime juice. Chefs frequently add turmeric to their creations because of its rich flavor and deep yellow-orange color. The seasoning is an important ingredient in Indian curries. It is also used to add color to foods such as butter, margarine, cheese, and mustard; to tint cotton, silk, paper, wood, and cosmetics; as a food preservative; and to make pickles.

What is the evidence?

Curcumin, an active ingredient in turmeric, is an antioxidant. Antioxidants are compounds that can protect the body’s cells from damage caused by activated oxygen molecules known as free radicals. Laboratory studies have also shown that curcumin interferes with several important molecular pathways involved in cancer development, growth, and spread.

Recently, curcumin has received a great deal more attention in studies than turmeric as a whole herb. Researchers are studying curcumin to learn whether it is an effective anti-inflammatory agent and whether it holds any promise for cancer prevention or treatment.

A number of studies of curcumin have shown promising results. Curcumin can kill cancer cells in laboratory dishes and also reduces growth of surviving cells. Curcumin also has been found to reduce development of several forms of cancer in laboratory animals and to shrink animal tumors.

Human studies of curcumin in cancer prevention and treatment are in the very early stages. One study of 15 patients with colorectal cancer was done to find out how much curcumin they could safely take, and whether they could take a dose large enough to be detected in the blood.

The patients were able to take 3.6 grams of curcumin without noting ill effects. At this high dose, some curcumin and its products were found in the blood. Lower doses may work for the stomach and intestine. Even though it does not absorb well into the body, it has been shown to absorb into the colon lining and into any cancerous tissue in the colon. The researchers recommended that the high dose be used when curcumin is tested for effects outside the intestine.

Other small studies have found people were able to take up to 10 grams per day for a period of a few weeks without noting problems. Some researchers are currently working on ways to increase absorption of curcumin by combining it with other substances. Further clinical trials are needed to find out what role, if any, turmeric and curcumin may play in the prevention or treatment of cancer.

Curcumin is being studied to see whether it helps other diseases as well. One small study of curcumin and another antioxidant called quercetin was done in adults who had kidney transplants. Those who took the combination in high dosages had fewer transplant rejections than those who received lower doses or placebo. More studies are needed to find out whether this holds true.

Curcumin may also promote the emptying of the gallbladder, but again, more studies are needed.

Early studies showed promise that curcumin could correct the problem of cystic fibrosis, but later studies have been inconsistent and often showed no effect. Curcumin also seemed to help prevent stomach ulcers in rodents, although there are not good studies in humans to recommend it for this use.

Early research has suggested that curcumin may help lower "bad" cholesterol, reduce inflammation, and help with arthritis symptoms, although more reliable human studies are still needed.

Tests of curcumin in HIV disease have been mixed and have generally not shown it to be helpful. In studies of mice, curcumin appeared to help with blocking the plaques and proteins that cause problems in the brain during Alzheimer’s disease.

Although laboratory and animal tests look very promising, careful study is needed to find out whether curcumin will be useful for treating these conditions in humans. It is important to remember that extracted compounds such as curcumin are not the same as the whole herb, and study results would not be likely to show the same effects.

Are there any possible problems or complications?

This product is sold as a dietary supplement in the United States. Unlike companies that produce drugs (which must provide the FDA with results of detailed testing showing their product is safe and effective before the drug is approved for sale), the companies that make supplements do not have to show evidence of safety or health benefits to the FDA before selling their products. Supplement products without any reliable scientific evidence of health benefits may still be sold as long as the companies selling them do not claim the supplements can prevent, treat, or cure any specific disease. Some such products may not contain the amount of the herb or substance that is written on the label, and some may include other substances (contaminants). Though the FDA has written new rules to improve the quality of manufacturing processes for dietary supplements and the accurate listing of supplement ingredients, these rules do not take full effect until 2010. And, the new rules do not address the safety of supplement ingredients or their effects on health when proper manufacturing techniques are used.
Most such supplements have not been tested to find out if they interact with medicines, foods, or other herbs and supplements. Even though some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available. Because of these limitations, any information on ill effects and interactions below should be considered incomplete.

When used as a spice in foods, turmeric is considered safe. More research is needed to establish the safety of turmeric when used in herbal remedies. Little is known about the potential risks of taking the larger amounts used to treat illnesses.

Taking large amounts by mouth may result in stomach pain, gas, indigestion, and nausea. Skin rash and stomach ulcers have been reported after long-term use, and allergic reactions are possible. People who are allergic to ginger or yellow food colorings are more likely to be allergic to turmeric.

A recent safety study in humans suggested that curcumin changes metabolism of oxalate, a substance that can form kidney stones. The researchers urged caution in use of this supplement by people with other conditions that make them susceptible to kidney stones.

People taking blood-thinning medications, drugs that suppress the immune system, or non-steroidal pain relievers (such as ibuprofen) should avoid turmeric because of the risk of harmful drug interactions.

In animal and laboratory studies, turmeric made certain anti-cancer drugs less effective. Antioxidant supplements can interfere with the effectiveness of chemotherapy or radiation treatment. Patients who are in cancer treatment should talk to their doctor before taking vitamins, minerals, or other supplements.

In addition, other potential interactions between turmeric and other drugs and herbs should be considered. Always tell your doctor and pharmacist about any herbs or supplements you are taking.

People with bleeding disorders, obstructions of the bile duct, or a history of ulcers also should avoid turmeric. Women who are pregnant or breast-feeding should not use this herb. The amount of turmeric found in foods is thought to be safe for those who are not allergic to it.

Applying turmeric to the skin for long periods of time can cause a yellow discoloration of the skin that may be difficult to remove.

Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.

http://www.cancer.org/Treatment/TreatmentsandSideEffects/ComplementaryandAlternativeMedicine/HerbsVitaminsandMinerals/turmeric