Turmeric is an Indian spice derived from the plant Curcuma longa, a relative of ginger. The yellow color of turmeric results from the presence of compounds called curcuminoids, a group of polyphenolic, antioxidant molecules. The main curcuminoid found in turmeric is curcumin. Turmeric has a long history as a traditional medicine used to treat a variety of ailments, including diarrhea, heartburn, headaches and colds. Recently, researchers have investigated turmeric and curcumin for treating cancer, especially colorectal cancer. Although the preliminary results are promising, additional research is needed before definitive conclusions can be drawn.
Treating Cancer
Several human clinical trials have investigated the anti-cancer properties of curcumin. Most completed trials have focused on the safety of using large doses of curcumin; it's been found that doses of up to 8,000 mg per day are safely tolerated. In these trials, treatment with curcumin showed promising evidence of reducing cancer in patients with colorectal cancer, reports a review article published in October 2007 in the journal "Cancer Letters." More large-scale trials specifically tested to measure the effectiveness of curcumin are needed to confirm these preliminary findings.
Killing Cancer Cells
Several studies have investigated how curcumin reduces cancer. In laboratory and animal models, curcumin has been shown to induce cell death, or apoptosis, in cancer cells. Several studies have found that curcumin activates many intracellular signaling cascades that trigger self-destruction in cancer cells, reports a review article published in October 2007 in the journal "Cancer Letters." These studies have included experiments involving cells lines grown from human cancer cells, suggesting curcumin may be able to kill cancer cells in humans.
Slowing Cancer Growth
In addition to activating self-destruction signals, curcumin also inhibits several pathways involved in cell growth. Because rapid cell growth is one of the hallmarks of cancer, this ability to slow down cell growth may also contribute to curcumin's effect in reducing cancer. Curcumin also reduces the ability of cancer cells to recruit new blood vessels and clear away surrounding tissue, both of which are necessary for the growth of tumors.
Safety Concerns
Although large doses of curcumin are generally safely tolerated, side effects including nausea and diarrhea may develop in some individuals. In addition, because curcumin inhibits so many biological signaling pathways in human cells, some researchers think the long-term effects of curcumin requires additional study to ensure safety, reports the article published in "Cancer Letters."
