Food, nutrition, diet, and cancer are teems that encompass a very broad subject area, and the already vast accumulation of literature on the interrelationship of these factors is growing rapidly. Thus, the committee began its work by developing a preliminary map of its territory. Having initially interpreted its charge to mean that no part should be arbitrarily excluded, the committee came to recognize that it would be wasteful to duplicate effort, especially when certain subjects have recently been evaluated in detailed reviews. After careful consideration, the decision was made to refer the reader to these comprehensive reviews and to concentrate in this report on the relationship between diet and its nutritional components and cancer in a narrower sense. The committee is aware that several aspects of its charge are matters of controversy, either within the scientific and medical com- munity or among the general population.
Controversies are inevitable when data are neither clear-cut nor complete.
Interpretations then depend on the criteria selected for evaluation and are influenced by individual or collective judgment. The committee has attempted to present the evidence as objectively as possible and to indicate the range of scientifically acceptable interpretation. It hopes that the results will be useful to all interested parties. The charge to the committee also included a request for dietary recommendations that could be used in the formulation of public policy. All three types of studies provide useful in- formation, especially when data derived from all sources point in the same direction.