ABSTRACT
Colorectal cancer (CRC) is one of the most aggressive malignant solid tumors which remain a rampant killer across the world. Toxic drugs have failed to reduce the morbidity and mortality rate of CRC patients. In addition, adoption of cancer-causing behaviors has increased the globule burden of CRC. Inappropriate lifestyle such as, smoking, obesity, physical inactivity, alcohol consumption and poor dietary components, all of which have been reported to aggravate the CRC incidence worldwide. In this regard, there is a growing awareness and increasing interest in cancer prevention approaches focusing on environmental and behavioral interventions, where specific carcinogenic factors implicated in cancer initiation, promotion, and progression may be triggered. In this communication, we report the role of lifestyle patterns and nutritional components in the modulation of CRC, and discuss the possible biological mechanism which involves in CRC pathogenesis. The findings indicate that smoking and alcohol consumption release a wide range of carcinogenic compounds such as, polynuclear aromatic hydrocarbons and acetaldehyde which can cause DNA damage and alter the function of tumor suppressor genes. Moreover, the link between obesity and CRC has been detected in several studies, whereby obesity induces insulin resistance and hyperglycemia, resulted in NF-κB and IGF-1 activation. In contrast, an inverse association between physical activity and cancer incidence has been constantly observed; the risk of CRC has been reduced 10-60% in the regular physical activity. With respect to nutritional components, compelling evidence indicates that avoidance of high intake of processed red meat, highly refined grains, starches, sugar and salt, and replacing them with poultry, fish, unrefined grains, legumes, vegetables, and fruits are strongly associated with lower risks of CRC.