DIJON, France--In a study published in the Oct. 14 issue of The Lancet (356:1300-1306, 2000), researchers found that fiber (in particular, ispaghula husk, which is similar to psyllium) may promote the recurrence of colon cancer.
For three years, scientists at the University of Bourgogne here followed 552 patients between the ages of 35 and 75 with a history of colorectal adenoma. Separated into three groups, patients were given daily doses of 2 g of calcium gluconolactate and carbonate, 3 to 5 g of ispaghula husk, or a placebo. Participants had a colonoscopy at the end of three years, and adenoma recurrence was used as the primary measurement for efficacy.
The most recurrences occurred in the fiber group: 58 of 198 patients (29 percent) developed at least one adenoma. In the calcium group, 28 of 176 patients (16 percent) developed adenomas, as did 36 out of 178 patients (20 percent) in the placebo group. There were no significant differences between the three groups' results in terms of age or sex.
Even though the researchers did not design the study to see calcium's effect on fiber, it was found that ispaghula husk had adverse effects on colorectal adenoma recurrence in patients with a high dietary calcium intake. It was also noted that calcium supplementation was associated with a modest, but not significant, reduction in the risk of adenoma recurrence.
Despite the finding, the researchers concluded that people should not be dissuaded from eating a diet high in vegetables, fruits and cereals because of fiber's potential benefits on chronic diseases such as coronary heart disease. For a copy of the study, visit www.thelancet.com.
