Turmeric is a spice that is made by grinding up the rootstocks of the Curcuma longa plant. Turmeric has a distinctive bright-yellow color caused by the presence of yellow pigments known as curcuminoids. The most abundant pigment in turmeric is curcumin, a polyphenolic compound with potent anti-inflammatory and antioxidant properties. Recent research as of March 2011 has investigated the use of turmeric in preventing and treating cancers. Although the preliminary findings are encouraging, additional research is needed to establish definitive results. As with any health supplement, you should consult your doctor before attempting to treat cancer or other diseases with turmeric.
Cancer Prevention
Only a few studies have investigated using turmeric to prevent cancer. One small clinical trial found promising results in preventing stomach, oral, cervical and skin cancers using supplements of purified curcumin, the active ingredient in turmeric. In this study, curcumin reduced the progression from precancerous lesions into full-blown tumors in a small percentage of patients, as reported in the July-August 2001 issue of "Anticancer Research." However, full cancer did develop in some of the other patients. Additional large-scale trials are needed to fully understand the ability of turmeric to prevent cancer.
Dosing
Many studies use very large doses of turmeric or purified curcumin, up to 12 g per day. The small amounts of turmeric used to flavor food are unlikely to significantly raise levels of curcumin in the blood, explains the Linus Pauling Institute. If you are interested in preventing cancer, using more turmeric to flavor your food is unlikely to raise the amount of curcumin in your blood to protective levels. Doses of more than 3.6 g per day of purified curcumin are needed to significantly alter blood levels of curcumin.
Treating Cancer
Turmeric and curcumin have also been investigated as a cancer treatment, particularly for colorectal, pancreatic and skin cancers. Similar to cancer prevention, the early small-scale human trials have demonstrated promising results in treating cancer, such as a study published in the July 2008 issue of "Clinical Cancer Research." However, additional large-scale studies are needed to confirm these results.
Mechanism
Researchers are still trying to understand why turmeric may be able to treat or prevent cancers. The protective effect is likely due to curcumin, which has antioxidant properties and is able to protect cells from the damage caused by oxidizing free radicals. Curcumin is also able to trigger human cancer cells to self-destruct, explains the Linus Pauling Institute. Another possible mechanism is the ability of curcumin to prevent tumors from recruiting blood vessels, which is necessary to allow tumors to grow larger.
References
- Linus Pauling Institute, Oregon State University: Curcumin
- MedlinePlus: Turmeric
- University of Maryland Medical Center: Turmeric
- "Anticancer Research"; Phase I Clinical Trial of Curcumin, a Chemopreventive Agent, in Patients with High-Risk or Pre-Malignant Lesions; A.L. Cheng, et al.; July-August 2001
- "Clinical Cancer Research"; Phase II Trial of Curcumin in Patients with Advanced Pancreatic Cancer; N. Dhillon, et al.; July 15, 2008
