Turmeric is a perennial plant botanically related to ginger and native to India, China, and Indonesia. It is a component of curry powder and prepared mustard and has been used for centuries in both traditional Chinese medicine and Indian Ayurvedic medicine. Traditionally, turmeric has been used for inflammatory conditions, digestive disturbances, menstrual discomfort, pain, and for supporting nervous system and cardiovascular health.
The biologically active compounds in turmeric are known as curcuminoids, which are concentrated in the rhizomes (root-like structures) of the plant. The major curcuminoids include curcumin, demethoxycurcumin, and bisdemethoxycurcumin. These compounds exhibit strong antioxidant and anti-inflammatory activity.
Research published in Arthritis & Rheumatism (2006;54[11]:3452–3464) found that a turmeric extract demonstrated significant anti-inflammatory effects in an animal model of arthritis. The authors noted that turmeric appeared to act through mechanisms similar to those targeted by newer anti-arthritis drugs under development, including suppression of cyclooxygenase-2 (COX-2), an enzyme involved in inflammation and pain signaling. While pharmaceutical COX-2 inhibitors have raised concerns regarding cardiovascular risk, curcumin has shown favorable effects on cardiovascular markers in other studies, including reductions in cholesterol and fibrinogen—both of which are involved in clot formation and atherosclerosis.
Curcumin has also been shown to protect cartilage and slow joint degeneration. Evidence for this comes from the Arthritis & Rheumatism study cited above, as well as research published in Annals of Anatomy (2005;187:487–497). Curcumin appears to reduce inflammation by suppressing leukotriene production and by moderating white blood cell responses involved in inflammatory signaling.
One of curcumin’s traditional uses has been for liver and gallbladder support. Research indicates that curcumin may protect against chemically induced liver damage in a manner similar to silymarin. It has also been shown to increase bile secretion, suggesting a possible role in supporting gallbladder function and reducing gallstone risk.
A substantial body of research has examined curcumin’s potential role in cancer biology. For example, studies published in Oncogene (2001;20[52]:7597–7609) demonstrated interference with prostate cancer cell survival. Research in Cancer Research (2002;62[19]:5451–5456) showed protection against chemically induced changes in oral epithelial cells. Animal studies published in Clinical Cancer Research (2005) suggested curcumin may reduce breast cancer metastasis to the lungs. Additional studies in Clinical Gastroenterology and Hepatology (2006;4:1035–1038) and the Korean Journal of Gastroenterology (2005;45[4]:277–284) reported inhibitory effects on colon cancer cell growth. Numerous other experimental and animal studies have explored similar pathways.
There is also interest in curcumin’s potential role in neurodegenerative disease. Epidemiologic observations suggest that Alzheimer’s disease is far less common in rural Indian populations than in Western countries. Some researchers have proposed that lifelong dietary exposure to turmeric may contribute to this difference. Experimental studies have shown that curcumin can reduce oxidative damage and interfere with the formation of amyloid plaques characteristic of Alzheimer’s disease. Dr. Sally Frautschy of UCLA presented related findings at the 2005 annual meeting of the Society for Neuroscience, demonstrating reduced amyloid pathology in an Alzheimer’s transgenic mouse model.
Curcumin has been used for centuries in traditional medicine systems and has been extensively studied for its antioxidant, anti-inflammatory, and cytoprotective properties. While much of the research remains preclinical, the growing body of evidence helps explain why turmeric has maintained such a prominent role in traditional herbal medicine.
