Introduction:
There are many studies which suggest that the occurrence of colorectal cancer is closely related to the dietary habits. It is known that a number of substances occurring in food can protect against the development of colon cancer. A procedure consisting of using natural or synthetic materials to prevent the progression of cancer is called chemoprevention.

Aim:
The aim of the paper is to present a number of substances having a chemopreventive effect in colorectal cancer.

Material and methods:
A method that was used for the creation of this article was to review the literature.

Discussion:
There are many substances having chemopreventive effect in colorectal cancer. During the many years of research, more than 200 potentially active ingredients have been detected, whose clinical relevance is constantly tested. These include epigallocatechin gallate, dietary fiber, probiotics, vitamin D, selenium, folic acid, methionine, anthocyanins, procyanidins, curcumin, resveratrol, antioxidant as vitamins A, C, E and b-carotene, genistein, allicin and others. These substances act by maintaining the balance between cell proliferation, differentiation and apoptosis of epithelial cells of the colon. Additionally, they have an ability to bind and degrade the potential carcinogens. What is more, they have a predisposition to slow down the cycle of colon cancer cells and to limit their ability of metastasis.

Conclusions:
There are many substances that have a potentially chemopreventive effect in colorectal cancer but currently chemoprevention is of limited use in the prevention of colon cancer. This is mainly due to the fact that there is a lack of clear evidence of preventive and therapeutic effects of chemopreventive substances.