Can Curry and Onions Really Prevent Colon Cancer?

Updated September 10, 2014.

Researchers at Johns Hopkins University found that curcumin and quercetin (substances present in curry and onions) can significantly reduce the number and size of polyps. But has the media overblown this a bit? I think so.

The findings have been reported with titles like "Spice Fights Colon Cancer" and "Curry and Onions Prevent Colon Cancer." That's jumping the gun a bit. Yes, the findings were interesting: a regimen of curcumin and quercetin decreased the number of polyps by 60% and the size of polyps by 50%.

That's good news since in general, the more polyps you have and the bigger they are, the greater your chances of developing colon cancer.

But...

There are a couple of important caveats to consider. First, most of the reporting refers to the research as a "small clinical trial." Know how small? Five people. Most studies involve at least a hundred people because the greater the sample size, the more statistically significant the results. You can't really put too much stock in a sample size of five people.

Also, study participants were asked to take a pill containing 480 mg of curcumin and 20 mg of quercetin, three times a day. You could probably eat that much quercetin in a day, but most people won't be able to get that much curcumin via their diet. This will likely open the door to unscrupulous individuals out to make a quick buck with "concentrated curry" supplements mass-marketed to anyone concerned about colon health.

Bottom Line

This research is definitely interesting, but it isn't definitive.

If you're concerned about polyp formation (especially if you have FAP, HNPCC, or juvenile polyposis), you may want to discuss this research with your doctor. He/she should be able to provide a balanced view of the potential benefits and risks associated with curcumin supplementation.

_Sources:_{Cruz-Correa M. and Shoskes, D.A. "Combination Treatment with Curcumin and Quercetin of Adenomas in Familial Adenomatous Polyposis." Clinical Gastroenterology and Hepatology 4.8 (Aug. 2006): 1035-1038. PubMed. 9 Aug. 2006 [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed].
Curry, Onions Can Prevent Colon Cancer. Hindustan Times. 1 Aug. 2006. 9 Aug. 2006 [http://www.hindustantimes.com/news/181_1758404,001100020006.htm].
Daniells, Stephen. Curry and Onion Extracts Could Protect Against Colon Cancer. NUTRAingredients.com. 2 Aug. 2006. 9 Aug. 2006 [http://www.nutraingredients-usa.com/news/ng.asp?n=69573-curcumin-quercetin-colon-cancer].
Spice Fights Colon Cancer. Ivanhoe Newswire. 3 Aug. 2006. 9 Aug. 2006 [http://www.ivanhoe.com/channels/p_channelstory.cfm?storyid=14245].
Warner, Jennifer. Curry May Cut Down Colon Cancer. CBS News. 2 Aug. 2006. 9 Aug. 2006 [http://www.cbsnews.com/stories/2006/08/02/health/webmd/main1860248.shtml].}
Researchers at Johns Hopkins University found that curcumin and quercetin (substances present in curry and onions) can significantly reduce the number and size of polyps. But has the media overblown this a bit? I think so.

The findings have been reported with titles like "Spice Fights Colon Cancer" and "Curry and Onions Prevent Colon Cancer." That's jumping the gun a bit. Yes, the findings were interesting: a regimen of curcumin and quercetin decreased the number of polyps by 60% and the size of polyps by 50%. That's good news since in general, the more polyps you have and the bigger they are, the greater your chances of developing colon cancer.