Dietary fiber intake and colorectal cancer risk: Weighing the evidence from epidemiologic studies

The hypothesis is that fiber protects against colorectal cancer because of various biologic properties. Although several human studies have examined the relationship between fiber and colorectal carcinogenesis, the association remains unclear. This review evaluates key epidemiologic research in large populations conducted since 2003. With a combined analysis of 9 studies, results are mixed. Four studies show a statistically significant reduced risk of developing colorectal cancer with increased dietary fiber intake, and 5 studies show no association. On the basis of these equivocal findings, it cannot be concluded that a protective association exists between increased dietary fiber intake and reduced colorectal cancer risk.