A major difficulty in conducting studies of single foods or nutrients in relation to colorectal cancer is the high degree of correlation among dietary constituents. In this situation, isolating the particular effects of a single food or nutrient becomes a serious methodological problem. Moreover, the assumption that single foods or nutrients have isolated effects may not be valid; foods and nutrients more likely act in synergy such that the joint effects of the foods and nutrients work in something other than a simple additive fashion (7,8). Recognition of these facts has led several investigators to propose a diet patterns approach as an alternative to the reductionist, single-food or single-nutrient focus of many studies of diet and chronic disease (7,9,10). A diet patterns approach could, it is hoped, capture the totality of dietary experience, including all the nutrient interactions, in a manner that studies of single nutrients or individual foods can not.