Dietary habits are recognized as an important modifiable environmental factor influencing cancer risk and tumor behavior. Estimates suggest that 30-70% of all cancer cases might be preventable by diet, depending on the dietary components and the specific type of cancer. An attractive possibility emerges that because of additive and synergistic interactions among various bioactive components, whole foods (either as single food products or food combinations) may be more efficacious in terms of cancer prevention than isolated individual compounds. A better understanding of the bioactive components present in food, the mechanism(s) of action of these dietary components towards cancer prevention, and physiologically important interactions among the components is needed before the merit of combining foods, as well as, which foods should be combined for maximum cancer prevention can be determined. This chapter focuses on important nutritional interactions for cancer prevention.