Can Omega-3 prevent colon cancer?

The omega-3 fatty acids know as EPA and DHA are increasingly being identified as nutrients with powerful health-promoting properties. A recent British study indicates that EPA (eicosapentaenoic acid) can have a pronounced protective effect on precancerous growths in the colon.

UK study

Based on laboratory experiments which had indicated that EPA has anti-colorectal cancer activity, a research team in London tested if EPA is capable of preventing the formation of rectal polyps in human subjects who have a genetic tendency to develop bowel cancer. Such individuals suffer from a condition called familial adenomatous polyposis (FAP) which predisposes them to develop bowel polyps or precancerous growths in the bowel. These polyps have a tendency to develop into colon or rectal cancer (West et al, 2010).

A group of 55 patients who had already undergone surgery to remove precancerous rectal growths or polyps, were randomly divided into two groups. The one group was given 2 gram of EPA on a daily basis for 6 months, while the other group (the control group) received a placebo (dummy pill).

Endoscopies were performed on all the subjects before and after the 6 months of treatment to determine if any changes had occurred in their tendency to develop colorectal polyps. Samples of bowel tissue were also analysed for omega-3 content (West et al, 2010).


The patients receiving the EPA supplement on a daily basis experienced a dramatic reduction of 22.4% in the number of new polyps that had developed over 6 months and a 30% reduction in the size of their colorectal polyps.

In contrast, the condition of the patients in the group receiving placebo, had deteriorated with an increase in both the number and size of the colorectal polyps.

In the treatment group, the EPA supplementation also caused a positive 2.6-fold increase in the EPA-levels in bowel tissue compared to the placebo-treated group (West et al, 2010).

Because a new form of concentrated EPA in what is called "an enteric-coated formulation" was used for this study (i.e. tablets coated in such as way that they are only digested in the intestine and not in the stomach), the patients found that they did not experience indigestion which is often associated with taking omega-3 supplements (Med Chronicle, 2010).


West and coauthors (2010), concluded that EPA is as efficient in preventing precancerous growths in patients with FAP as the anti-inflammatories which are usually used to control progression of this genetic condition. The problem with anti-inflammatories such as cyclo-oxygenase-2 inhibitors, is that these so-called Cox-2 inhibitors often cause negative cardiovascular side-effects particularly in older patients.

In contrast, the omega-3 fatty acids EPA and DHA, are know to have positive, heart-protective functions, which makes them even more suitable for the treatment of patients with a tendency to form colorectal polyps.

The researchers suggest that this new formulation of EPA can be used to prevent and treat patients with precancerous growths in the colon and rectum. It is possible that EPA may also play a role in preventing the development of bowel polyps in individuals who do not have a genetic predisposition and thus have a double health benefit by preventing both colon and rectal cancer and cardiovascular disease (Med Chronicle, 2010).


If you suffer from FAP or have a family history of bowel polyps and/or bowel cancer, then it may be a good idea to discuss the use of omega-3 fatty acids in general, and EPA in particular with the doctor who is monitoring or treating your condition. You may be able to avoid taking Cox-2-inhibitors provided you take omega-3 supplements.

Ask at your chemist or health shop if the new enteric-coated, high-dose EPA is available in South Africa, and eat foods containing omega-3 fatty acids regularly. 

The following foods are rich sources of omega-3 fatty acids:

  • Fish, particularly oily fish like tuna, sardines, or mackerel
  • Omega-3-enriched eggs, bread and milk which can be found in most larger supermarkets

Hopefully these new research findings concerning the protective effect of EPA will help to prevent colon cancer in genetically predisposed individuals and other persons who develop bowel polyps.

 - (Dr IV van Heerden, DietDoc, May 2010)

Any questions? Ask DietDoc


(Medical Chronicle (2010). Omega 3 curbs precancerous growths in patients prone to bowel cancer - Study. Medical Chronicle May 2010, p 70; West NJ et al (2010). Eicosapentaenoic acid reduces rectal polyp number and size in familial adenomatous polyposis. Gut, March 26 2010)

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All about Colon Cancer

Statins won't lower colon cancer risk

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