Purified omega-3 fatty acid may help fight bowel cancer

Omega 3, the so-called "good fat," is found naturally in certain fish and nut oils. Taking capsules of purified fish oil regularly could slow or prevent bowel cancer for people with a genetic condition called familial adenomatous polyposis, or FAP, which make them prone to this type of cancer, the study said.

Rare genetic condition FAP
FAP, the condition which runs in families, puts people at an increased risk of bowel cancer. People with this genetic condition get lots of small, fleshy growths (called polyps) on the inner surface of their bowel. If left untreated, these growths are likely to turn into tumor.

The rare genetic condition FAP is thought to be responsible for about one in every 100 bowel cancers.

Study details
Now, doctors from three UK hospitals and one Italian hospital have come out with the findings that a purified form of omega 3 (eicosapentaenoic acid or EPA) can reduce dangerous polyps among people who are vulnerable to bowel cancer.

To reach their findings, the investigators looked at fifty five patients from St Mark's Hospital in London. In the beginning, all patients were diagnosed with the inherited genetic mutation FAP that prompts the development of polyps--the precancerous growths in the bowel that often develop into tumors requiring removal of large sections of intestine.

In order to prevent the side effects that some people get from taking large amounts of fish oil, the capsules used in the study were given a coating to make sure they would break down in the gut and not in the stomach

The team of investigators, led by Professor Mark Hull from the University of Leeds, gave 28 patients two-grams daily dose of highly purified formulation of the omega-3 polyunsaturated fatty acid EPA (called Alfa), while the rest 27 were administered a placebo.

Study’s findings
After six months of follow-up, Pro. Hull and colleagues found that the patients treated with the capsules had fewer polyps at the end of the study than at the start. They also observed a significant reduction in the size of polyps in this group, whilst the patients who received dummy treatment showed an increase in polyp number and size over the same period.

More precisely, the number of polyps had fallen by 12 percent for those taking the omega 3 capsules, but risen by almost 10 percent among the placebo group, representing a difference of more than 22 percent.

Likewise, polyp size fell by more than 12.5 percent in those taking the EPA capsules, but increased by more than 17 percent among those treated with placebo, a difference of just fewer than 30 percent.

Specially designed capsules used in the study
In order to prevent the side effects that some people get from taking large amounts of fish oil, the capsules used in the study were given a coating to make sure they would break down in the gut and not in the stomach.

The side effects that some people get from taking large amounts of fish oil include feeling sick, a fishy taste in the mouth, and heartburn.

"The particular preparation of EPA that we used delivers approximately four times as much beneficial polyunsaturated fatty acid per day as is derived from eating two to three portions of fish a week. The drug is also designed to be released into the small intestine, minimising nausea and halitosis often associated with taking over-the-counter fish oil supplements," said Professor Hull.

Larger studies required for concrete results
The research team said the results seen in those taking the fish oil supplements are similar to a drug called celecoxib, which is used to inhibit polyps among genetically vulnerable patients.

Celecoxib, marketed as Celebrex, has been associated with harmful cardiovascular side effects in older patients. In contrast, the omega 3 supplement was "very well tolerated," and has even been shown to be good for heart health, say the doctors.

However, the researchers say longer-term studies are now required to find out whether the improvements would continue over time, and whether they translate into fewer bowel cancers in future.

The findings are published online by Gut, a journal of the British Medical Association (BMA).