Dietary phytochemicals and their role in cancer chemoprevention.

Epidemiological studies suggest a close association between diet and cancer initiation, which provides evidence that the dietary components may be effectively developed as chemopreventive agents[1]. These pieces of evidence are further supported by several case-control and cohort studies, which overwhelmingly support a converse association between the intake of phytochemicals and cancer risk[2,3]. A number of clinical studies have been conducted demonstrating that dietary phytochemicals have the ability to inhibit tumorigenesis[4]. Components present in fruit and vegetables termed “bioactive” phytochemicals belong to several classes of micronutrients, including flavonoids,