Colon cancer is the third most common kind in the U.S., and the second leading cause of cancer deaths.
When cancer spreads (metastasizes) to other organs, chances of survival shrink, so we urgently need ways to prevent or slow this process.
By showing that curcumin may slow colon cancer via a previously unknown pathway, new research supports this colorful turmeric extract's apparent anti-cancer potential.
Before we delve further into this very promising finding, let's take a close look at curcumin ... perhaps the most promising and extensively probed plant extract on the planet.
What is curcumin?
Curcumin (ker-cue-min) is the pigment that gives turmeric root its deep yellow-orange hues.
Turmeric is a key ingredient in most curry powders, whose characteristic colors come from its curcumin content.
This close cousin to ginger has long been prized in Asian medicine, where turmeric is traditionally used to treat inflammation, arthritis, and other ailments.
Curcumin is actually a trio of three polyphenol-class “antioxidants” that appear to support immune and brain health in uniquely powerful ways (see our sidebar, “The truth about ‘antioxidants' in plant foods”).
Unlike most herb extracts, curcumin has been explored extensively in hundreds of lab and preliminary clinical studies.
Overwhelmingly, the results suggest that curcumin possesses unusually strong potential to produce broad human health benefits.
Curcumin appears to exert “chemopreventive” effects … that is, it shows the potential to help reverse, suppress, or prevent some common cancers.
This doesn't mean that by itself, curcumin can cure or prevent cancer or any other condition … no food or nutrient can do that alone.
Cancer prevention and the slowing of tumor growth both rest in part on lifestyle and diet choices … and when it comes to colon cancer, turmeric and curcumin extract look like smart ones.
Until recently, the notably poor oral absorption of curcumin extracts has hindered research ... but new methods of delivering curcumin greatly increase its absorption and impact.
One highly effective tactic is to deliver curcumin along with the volatile oils in turmeric … as in the patented BCM-95 extract used in Vital Choice Curcumin in Wild Salmon Oil
, which is clinically proven to be absorbed about seven times better than standard curcumin extracts.
Lab study suggests that curcumin may slow colon cancer growth
A team led by University of Arizona scientists reports that curcumin blocks a key protein in colon tumors, called cortactin (Radhakrishnan VM et al. 2014).
Cortactin is essential for cell movement but is frequently “overexpressed” in colon cancer, which facilitates its spread (metastasis) to other organs.
The truth about “antioxidants” in plant foods
The polyphenol and carotenoid compounds in whole plant foods are commonly called “antioxidants” because they behave that way in test tube experiments.
But in general, these health allies do not exert direct antioxidant effects in the body… at least not to very substantial extents.
Instead, polyphenols appear to exert strong indirect effects on oxidation and inflammation via so-called “nutrigenomic” effects on gene switches (e.g., transcription factors) in our cells.
Polyphenols' nutrigenomic effects tend to moderate inflammation and stimulate the body's own antioxidant network … which includes enzymes, lipoic acid, CoQ10, melatonin, and vitamins C and E.
The richest known food source of polyphenols are raw (non-alkalized / non-“Dutched”) cocoa, berries, plums, curcumin (turmeric root), prunes, tea, coffee, extra virgin olive oil, beans, and whole grains.
Extra virgin olive oil is uniquely rich in tyrosol esters … a class of polyphenols with clinically documented vascular and brain benefits.
“What's novel about our research is that our study identified one of the mechanisms by which curcumin can prevent cancer cell metastasis in colon cancer,” said co-author Fayez K. Ghishan, M.D.
The research team discovered that the active part of the cortactin protein is hyper-activated in malignant colon tumors.
“We showed that the cortactin protein was hyper-activated due to a process called excessive phosphorylation,” added co-author Pawel Kiela.
Phosphorylation is responsible for turning proteins on and off, altering the protein's function and activity.
Excess cortactin, and its activation by phosphorylation, has been linked with cancer aggressiveness.
For their study, the University of Arizona team treated human colon cancer tumor cells with curcumin.
“We discovered that curcumin turns off the active form of cortactin,” said Vijay Radhakrishnan, who led the experiments in the lab (UA 2014).
“Thus, when cortactin is turned off, cancer cells lose the ability to move and can't metastasize to other parts of the body.”
Curcumin turned off cortactin by activating an enzyme (PTPN1) that removes phosphate groups from cortactin – a process known as “dephosphorylation.”
According to Dr. Kiela, “This [dephosphorylation] effect [is] correlated with reduced ability of colon cancer cells to migrate. This suggests that curcumin reduces cancer cells' ability to migrate, meaning the cancer can't metastasize.” (UA 2014)
“By identifying the mechanism of action … we believe that [curcumin-derived] chemopreventive drugs can be developed to target cortactin in cancer cells to prevent the cancer from metastasizing,” Dr. Radhakrishnan noted (UA 2014).
“Treatments aimed at the suppression of cancer metastasis remain an urgent therapeutic need,” Ghishan said. “Our findings have laid the foundation for future research to develop treatments using curcumin to prevent cancer's deadly spread to other organs.” (UA 2014)
Their research was funded by The National Institutes of Health.
- Dedes KJ, Lopez-Garcia MA, Geyer FC, Lambros MB, Savage K, Vatcheva R, Wilkerson P, Wetterskog D, Lacroix-Triki M, Natrajan R, Reis-Filho JS. Cortactin gene amplification and expression in breast cancer: a chromogenic in situ hybridisation and immunohistochemical study. Breast Cancer Res Treat. 2010 Dec;124(3):653-66. doi: 10.1007/s10549-010-0816-0. Epub 2010 Mar 6.
- MacGrath SM, Koleske AJ. Cortactin in cell migration and cancer at a glance. J Cell Sci. 2012 Apr 1;125(Pt 7):1621-6. doi: 10.1242/jcs.093781. Review.
- Radhakrishnan VM, Kojs P, Young G, Ramalingam R, Jagadish B, Mash EA, Martinez JD, Ghishan FK, Kiela PR. pTyr421 cortactin is overexpressed in colon cancer and is dephosphorylated by curcumin: involvement of non-receptor type 1 protein tyrosine phosphatase (PTPN1). PLoS One. 2014 Jan 22;9(1):e85796. doi: 10.1371/journal.pone.0085796. eCollection 2014.
- University of Arizona (UA). UA Discovery Shows Curcumin Blocks the Metastasis of Colon Cancer by a Novel Mechanism. August 25, 2014. Accessed at http://uanews.org/story/ua-discovery-shows-curcumin-blocks-the-metastasis-of-colon-cancer-by-a-novel-mechanism
- Zhu JW, Ma LL, Huang BY, Liu PG, Ru K, Cao X, Qian F. [A pivotal role of cortactin, a CTTN encoding protein, in endocytosis of human colon cancer]. Zhonghua Yi Xue Za Zhi. 2011 Feb 15;91(6):385-90. Chinese.