Curcumin is the most plentiful of the curcuminoids (polyphenolic pigments) found in the turmeric. The term turmeric is used both to refer both to the turmeric pland and to the spice derived from the rhizomes of the plant. The major curcuminoids found in turmerica are curcumin, demethoxycurcumin and bisdemethoxycurcumin. These substances comprise 3 to 6% of the turmeric plant's total composition. Curcumin makes up 70 to 75% of the curcuminoids, demethoxycurcumin 15 to 20% and bisdemethoxycurcumin about 3%.

Curcuminoids are extracted from turmeric using a process that involves ethanol. Curcumin is the most studied of the curcuminoids. In pure form, it is an orange-yellow, crystalline powder that is insoluble in water.

The curcuminoids, such as Curcumin, may have anticarcinogenic, anti-atherosclerotic, anti-inflammatory (including anti-arthritic), antiviral, antifungal and immune-modulating effects. They appear to help detoxify some drugs and other chemicals. There is some evidence the curcuminoids may help prevent cataracts and ameliorate chronic anterior uveitis. They may also help speed wound healing. Because of their antioxidant and anti-inflammatory activities Curcumin and the other curcuminoids have been entered into Phase I clinical trials for cancer chemoprevention by the National Cancer Institute.

Additionally, it is believed that curcumin may help protect against atherosclerosis, reducing inflammation and symptoms such as pain and stiffness associated with rheumatoid arthritis and aid in digestion.

Dosage

Curcuminoid supplements are available that contain curcumin at 70 to 75%, demethoxycurcumin at 15 to 20% and bisdemethoxycurcumin at about 3%. Doses used range from 500 to 4000 milligrams daily, and they are taken with meals.