Sex, Fiber, and Cancer

Research into the effect of fiber on colon cancer has shown first that more fiber in your diet protects you from colon cancer, then other studies seem to show that it doesn't. Researchers in Arizona (Am J Clin Nutr 2006;83:343-349) recently combined and analyzed the results of two studies to find that the effects of fiber intake appears to be gender-specific (bet you thought the headline was about something else!).

All 3,209 subjects who participated in the two trials had previously had a colorectal adenoma (a benign polyp that can be a precursor to cancer) removed. Subjects received varying levels of fiber supplementation, either with or without additional dietary changes, and at the end of the study, all subjects had another colonoscopy to assess whether a colorectal adenoma had recurred.

The outcome? Men who had the highest fiber intake had the lowest rate of recurrence compared to other men, while fiber intake did not seem to have any significant effect on recurrence in women (although, interestingly, women who were on Hormone Replacement Therapy seemed to fare better than women who were not). The researchers wisely note that colon cancer locations tend to differ between men and women and that further study should not only look at the effect of fiber on tumor location but also that colon cancer studies should more generally be differentiated by sex as well.

What this means for you

Whether or not fiber will protect you from colon cancer, it’s still part of a heart-healthy diet!

First posted: May 23, 2006