Folic acid doesn't cut risk of colon polyps: study

Taking extra folic acid and other B-vitamin supplements may not help protect against colon polyps, according to a U.S. study that contradicts observational studies suggesting people who get more of the vitamins are less likely to get colon cancer.

The study, led by Yiqing Song from Brigham and Women's Hospital in Boston and published in the Journal of the National Cancer Institute, followed 1,470 women with an average initial age of 62.

The women were randomly assigned to take daily folic acid and vitamins B6 and B12, or a vitamin-free placebo pill, and then followed them to see who developed colon polyps.

Women in the "active" treatment group took 2.5 milligrams of folic acid, 50 mg of vitamin B6 and 1 mg of vitamin B12 each day.

All participants had a colonoscopy or sigmoidoscopy to check for colon polyps, which can develop into cancer if not removed, sometime before mid-2007. According to their medical records, 355 had a confirmed polyp.

What is a colon polyp? A colon polyp is a benign tumor or growth which arises on the inner surface of the colon. Amazingly, from mouth to rectum, the human intestinal tract averages about 30 feet in length. The last six feet is called the colon, or large intestine. Like a piece of pipe, the colon is hollow and the inner surface is normally smooth. For unknown reasons, some individuals grow polyps, or small lumps of tissue, on the inner wall of the colon. There may be single or multiple polyps. The cause is not known, but the incidence of polyps increases with age.

What is a tumor?

All tissues of the body are made up of millions of tiny individual cells. In health, there is a delicate balance. Old cells are constantly dying and are replaced by new healthy cells. If too many new cells form, they create a lump or mass which is called a tumor. Tumors can be benign or malignant. Benign tumors are not cancer. They can usually be removed and, in most cases, they do not grow back. Cells from benign tumors do not spread to other parts of the body. Most important, benign tumors are rarely a threat to life. Malignant tumors are cancer. Cells in these tumors are abnormal and they continue to divide uncontrollably. Without treatment, they can invade and spread to nearby tissues and organs.

What does a polyp look like?

Colon polyps are found in one of two shapes. Polyps on stems or stalks look like mushrooms and are called pedunculated. When they grow directly onto the inner wall of the colon like spilled paint, they are called sessile and are much more difficult to remove.

Why remove polyps if they are benign?

Colon polyps are important, since some may turn into colon cancer over time. While not every colon polyp turns to cancer, it is felt that almost every colon cancer begins as a small non-cancerous polyp. Fortunately, during colonoscopy. these polyps can be identified and removed or destroyed - thus preventing a possible colon cancer. If a polyp is large enough, tissue can be retrieved and sent for biopsy to determine the exact type of polyp.