- Findings from a small UK study suggest that taking a folate supplement daily could help ward off colon cancer in people at risk of the disease. Previous research has suggested that taking folate supplements, or eating a folate-rich diet, could help reduce the risk of this type of cancer. While folate, a B vitamin also known as folic acid, is found in fruit and green, leafy vegetables and frequently added to grains including bread and cereal, it can also be taken in supplement form. Colon cancer is one of the most common cancers and often develops over several years from small growths called polyps. In the current investigation, lead author K. Khosraviani of Royal Victoria Hospital in Belfast, Northern Ireland, and colleagues evaluated the effects of a 2-milligram supplement of folate, taken each day for 3 months, in six people with recurrent colon polyps. They were compared with five people who also had recurrent polyps but took an inactive placebo instead. All of the men and women in the study had tissue samples from their rectums analyzed before, during and after the study period. The researchers evaluated these samples to determine whether or not cells from the lining of the rectum were actively dividing and multiplying--an indication that polyps and possibly cancer may be more likely to develop. While all of the patients showed similar rates of cell growth before taking the folate supplements, after the study began there was a reduction of cell proliferation in those taking folate. And 6 weeks after the study's end, when patients were no longer taking folate, tissue samples from the two groups again showed a similar rate of cell proliferation. "This study has demonstrated that folate supplementation modulates the state of proliferative cells in the rectal mucosa," the authors write in the August issue of the journal Gut. The finding suggests that folate may hamper polyp growth, which could ultimately reduce the risk of developing colon cancer. However, the authors warn that consuming too much folate may be harmful, especially for individuals with vitamin B-12 deficiency, those who have advanced cancer or people who are taking medication forepilepsy. Khosraviani and colleagues call for more research on the subject. SOURCE: Gut 2002;51:195-199. (juli 2002)