ABSTRACT
Colorectal cancer is one of the leading causes of death in both men and women in Western countries, being usually lethal when diagnosed at later stages of progression (Ferlay et al., 2007). Genetic predisposition is thought to account for about 15% of all colorectal cancer, notably hereditary nonpolyposis colorectal cancer and familial adenomatosis polyposis. Apart from these genetic factors, environmental aspects are thought to be involved in colon carcinogenesis, among which, dietary habits play a pivotal role. Mediterranean countries have lower rates of colorectal cancer compared with other Western countries (Trichopoulou et al., 2000). For example, colorectal cancer mortality in Greece is about 40% lower than in the United Kingdom (Ferlay et al., 2007). There is a 25-fold variation in the incidence rates of colorectal cancer between different countries in the world, which is highly suggestive of underlying environmental in uences in the etiology of this disease (Parkin et al., 1999). It has been suggested that these underlying environmental factors are predominantly dietary and that up to 80% of sporadic colorectal cancers are therefore potentially preventable (Cummings and Bingham, 1998).
