The dietary fibre debate: more food for thought.

Comments on two papers in the same issue of 'The Lancet' that associate high intake of dietary fiber with a decreased risk of colonic adenomas or colorectal cancer. Study done by the Prostate, Lung, Colorectal, and Ovarian Cancer Screening project team (PLCO) in the U.S.; Different approach used by the European Prospective Investigation into Cancer and Nutrition (EPIC) consortium; Comparison of the findings in these two studies with three others that found no protective effects of dietary-fiber intake on the development of colonic adenomas or colorectal cancer; Findings of the U.S. Nurses Health Study; Possible reasons why the studies gave such different results, including differences in the number of participants studied and the amounts of dietary fiber consumed; Effects of contrasting preferences in food in different population groups.