225 articles related to primary or secondary prevention of CRC were retrieved. Of these 145 were considered valid on meta-analysis: 12 on epidemiology, 56 on diet and lifestyle, and over 77 different screenings for early detection of CRC. Cancer is a worldwide problem as it will affect one in three men and one in four women during their lifetime. There is no doubt whatsoever which environmental factors, probably diet, may account for these cancer rates. Excessive alcohol consumption and cholesterol-rich diet are associated with a high risk of colon cancer. A diet poor in folic acid and vitamin B6 is also associated with a higher risk of developing colon cancer with an overexpression of p53. Eating pulses at least three times a week lowers the risk of developing colon cancer by 33%, after eating less meat, while eating brown rice at least once a week cuts the risk of CRC by 40%. These associations suggest a dose-response effect. Frequently eating cooked green vegetables, nuts, dried fruit, pulses, and brown rice has been associated with a lower risk of colorectal polyps. High calcium intake offers a protector effect against distal colon and rectal tumors as compared with the proximal colon. Higher intake of dairy products and calcium reduces the risk of colon cancer. Taking an aspirin (ASA) regularly after being diagnosed with colon cancer is associated with less risk of dying from this cancer, especially among people who have tumors with COX-2 overexpression.16 Nonetheless, these data do not contradict the data obtained on a possible genetic predisposition, even in sporadic or non-hereditary CRC. CRC is susceptible to screening because it is a serious health problem given its high incidence and its associated high morbidity/mortality.