Monday, December 28, 2009

Medicinal Herbs: Turmeric

Turmeric

Overview

Turmeric (Curcuma longa) has been used for 4,000 years to treat a variety of ailments. Studies show that turmeric may help treat a number of illnesses, however, it is important to remember several facts when you hear news reports about turmeric's medicinal properties. First, many studies have taken place in test tubes and animals, and the herb may not work as well in humans. Second, some studies have used an injectable form of curcumin (the active substance in turmeric). Finally, some of the studies show conflicting evidence. Nevertheless, turmeric may have promise for fighting infections and some cancers, reducing inflammation, and treating digestive problems.

Turmeric is widely used as a food coloring and gives Indian curry its distinctive flavor and yellow color. It is also used in mustard and to color butter and cheese. Turmeric has been used in both Ayurvedic and Chinese medicine as an anti-inflammatory, to treat digestive and liver problems, skin diseases, and wounds. The curcumin in turmeric has been shown to stimulate the production of bile by the gallbladder. Curcumin is also a powerful antioxidant; antioxidants scavenge particles in the body known as free radicals, which damage cell membranes, tamper with DNA, and even cause cell death. Antioxidants can neutralize free radicals and may reduce or even help prevent some of the damage they cause. In addition, curcumin reduces inflammation by lowering levels of two inflammatory enzymes (called COX-2 and LOX) in the body and stops platelets from clumping together to form blood clots.

Research suggests that turmeric may be helpful for the following conditions:

Indigestion or Dyspepsia

Curcumin stimulates the gallbladder to produce bile, which some people think may help improve digestion. In Germany, the German Commission E, an authoritative body that determines which herbs can be safely prescribed in that country, has approved turmeric for a variety of digestive disorders. And at least one double-blind, placebo-controlled study showed that turmeric reduced symptoms of bloating and gas in people suffering from indigestion.

Ulcerative colitis

Turmeric may help maintain remission in people with ulcerative colitis. In one double-blind, placebo-controlled study, people whose ulcerative colitis was in remission received either curcumin or placebo, along with conventional medical treatment, for 6 months. Those who took curcumin had a relapse rate that was much lower than those who took placebo.

Stomach Ulcers

Turmeric does not appear to be helpful in treating stomach ulcers, and there is some evidence that it may increase the amount of acid in the stomach, making existing ulcers worse. (See "Precautions" section.)

Osteoarthritis

Because of its ability to reduce inflammation, turmeric may help relieve the symptoms of osteoarthritis. A study of people using an Ayurvedic formula of herbs and minerals containing turmeric, as well as Withinia somnifera (winter cherry), Boswellia serrata (Boswellia), and zinc, significantly reduced pain and disability. While encouraging for the value of this Ayurvedic combination therapy to help with osteoarthritis, it is difficult to know how much of this success is from turmeric alone, one of the other individual herbs, or the combination of herbs working in tandem.

Atherosclerosis

Early studies suggest that turmeric may help prevent atherosclerosis (the buildup of plaque that can block arteries and lead to heart attack or stroke) in one of two ways. First, in animal studies an extract of turmeric lowered cholesterol levels and kept LDL or "bad" cholesterol from building up in blood vessels, a process that helps form plaque. Because it stops platelets from clumping together, turmeric may also prevent blood clots from building up along the walls of arteries. However, it isn't yet known whether turmeric would have this effect in humans, or how much you would have to take to see any benefit.

Cancer

There has been a great deal of research on turmeric's anti-cancer potential, but results are still very early. Evidence from test tube and animal studies suggests that curcumin may help prevent, control, or kill several types of cancers, including prostate, breast, skin, and colon. Curcumin's effects may be due to its ability to stop the blood vessels that supply cancerous tumors from growing, and its preventive effects may come from its strength as an antioxidant, protecting cells from damage. More research is needed. Cancer should be treated with conventional medications; never rely on alternative therapies alone to treat cancer.

Diabetes

When researchers gave laboratory animals with diabetes turmeric, their blood sugar levels dropped, as did their blood cholesterol levels. But researchers don't yet know whether turmeric would be helpful in treating diabetes in people. (See "Precautions" section.)

Bacterial and Viral Infections

Test tube and animal studies suggest turmeric may have antibacterial and antiviral properties, but whether it would be effective in humans is unclear.

Uveitis

A preliminary study suggests curcumin may help treat uveitis, an inflammation of the eye. In one study of 32 people with uveitis, curcumin appeared to be as effective as corticosteroids, the type of medication generally prescribed for this eye disorder. More research is needed.


Plant Description

A relative of ginger, turmeric is a perennial plant that grows 5 - 6 feet high in the tropical regions of Southern Asia, with trumpet-shaped, dull yellow flowers. Its roots are bulbs that also produce rhizomes, which then produce stems and roots for new plants. Turmeric is fragrant and has a bitter, somewhat sharp taste. Although it grows in many tropical locations, the majority of turmeric is grown in India, where it is used as a main ingredient in curry.


Parts Used

The roots, or rhizomes and bulbs, are used in medicinal and food preparations. They are generally boiled and then dried, turning into the familiar yellow powder. Curcumin, the active ingredient, has antioxidant properties, which some claim may be as strong as vitamins C and E. Other substances in this herb have antioxidant properties as well.


Available Forms

Turmeric is available in the following forms:

  • Capsules containing powder
  • Fluid extract
  • Tincture

Because bromelain increases the absorption and anti-inflammatory effects of curcumin, it is often combined with turmeric products.


How to Take It

Pediatric

There is no recommended dosage for children. Consider adjusting the recommended adult dose to account for the child's weight. Most herbal dosages for adults are calculated on the basis of a 150 lb (70 kg) adult. Therefore, if the child weighs 50 lb (20 - 25 kg), the appropriate dose of turmeric for this child would be 1/3 of the adult dosage.

Adult

The following are doses recommended for adults:

  • Cut root: 1.5 - 3 g per day
  • Dried, powdered root: 1 - 3 g per day
  • Standardized powder (curcumin): 400 - 600 mg, 3 times per day
  • Fluid extract (1:1) 30 - 90 drops a day
  • Tincture (1:2): 15 - 30 drops, 4 times per day

Precautions

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects and may interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care provider.

The amounts of turmeric found in foods are considered safe.

Turmeric and curcumin are considered safe when taken at the recommended doses. However, taking large amounts of turmeric for long periods of time may produce stomach upset and, in extreme cases, ulcers. People who have gallstones or obstruction of the bile passages should talk to their doctor before taking turmeric.

If you have diabetes, talk to your doctor before taking turmeric supplements. Turmeric may lower blood sugar levels, and when combined with medications for diabetes could cause hypoglycemia (low blood sugar).

Although it is safe to eat foods containing turmeric, pregnant and breastfeeding women should not take turmeric supplements.


Possible Interactions

If you are currently being treated with any of the following medications, you should not use turmeric or curcumin in medicinal forms without first talking to your health care provider.

Antiplatelet and anticoagulant drugs (blood-thinners) -- Stinging nettle may affect the blood's ability to clot, and could interfere with any blood-thinning drugs you are taking, including:

  • Warfarin (Coumadin)
  • Clopidogrel (Plavix)
  • Aspirin

Drugs that reduce stomach acid -- Turmeric may interfere with the action of these drugs, increasing the production of stomach acid:

  • Cimetidine (Tagamet)
  • Famotidine (Pepcid)
  • Ranitidine (Zantac)
  • Esomeprazole (Nexium)
  • Omeprazole
  • Lansoprazole (Prevacid)

Drugs for diabetes (that lower blood sugar) -- Turmeric may increase the effects of these drugs, increasing the risk of hypoglycemia (low blood sugar).

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