In April 2000, researchers shot down the notion that a high-fiber diet could protect the colon against polyps, and thus potentially decrease colon cancer. But some experts questioned these findings -- saying that the participants' diets, already higher in fiber than the average population, may have interfered with the findings of the study.
But a new study, published in the Nov. 6 issue of the Journal of the National Cancer Institute, confirms that -- in spite of all the good that fiber can do -- it does not prevent colon polyps from recurring.
Lead researcher Elizabeth T. Jacobs, PhD, of the Arizona Cancer Center in Tucson, separated the participants in the previous study based on their amount of fiber consumption. Again, they found that the amount of fiber had no bearing on the risk of new colon polyps.
The researchers also looked at the effects from specific sources of fiber -- fruits, breads, cereals and crackers, and vegetables. They found no protective effect for any specific type of fiber.
These polyps are growths on the inner wall of the colon or rectum. About 5% to 10% of polyps will become cancerous. In the first three years after being diagnosed with a polyp, people have as much as a 50% risk of developing more.