Colorectal Cancer: Does It Matter if You Eat Your Fruits and Vegetables?

Epidemiologists have long regarded vegetables and fruits as key features of a diet associated with a reduced risk of colorectal cancer. In 1997, the American Institute for Cancer Research (1) assembled a panel of leading epidemiologists and basic scien-tists to review the literature covering the links between all as-pects of diet and the causation of all types of cancer. That panel gave its highest rating for degree of scientific certainty to veg-etables as a component of diet that would reduce risk of colo-rectal cancer. For fruits, the evidence is more limited—in fact, the American Institute for Cancer Research panel concluded that no judgment was possible. In this issue of the Journal, however, Michels et al. (2) report a thoroughly null association between both fruits and vegetables and colorectal cancer risk in a pair of large prospective cohort studies. Their study has several important strengths that make i