Omega (ω)-3 polyunsaturated fatty acids (PUFAs) are naturally occurring substances that are well tolerated and have been used extensively for the prevention of cardiovascular disease. More recently, ω-3 PUFAs have been recognised to have anticancer activity.

There is also evidence suggesting improved efficacy and/or tolerability of conventional cancer chemotherapy when administered with ω-3 PUFAs.

The purpose of this review is to
(i) describe the mechanisms by which ω-3 PUFAs are thought to have antineoplastic activity,
(ii) review published preclinical and clinical studies that support anti-colorectal cancer activity and (iii) summarise current clinical trials investigating the potential therapeutic role(s) of ω-3 PUFAs at different stages of colorectal carcinogenesis, from adenoma (polyp) prevention to treatment of established malignant disease and prevention of cancer recurrence.