Omega-3 fatty acids as cancer chemopreventive agents.

There is both epidemiologic and experimental evidence that the long-chain omega-3 fatty acids (FAs), which occur at high levels in some fish oils, exert protective effects against some common cancers, notably those of breast, colon, and, perhaps, prostate. Multiple mechanisms are involved in this chemopreventive activity, including suppression of neoplastic transformation, cell growth inhibition and enhanced apoptosis, and antiangiogenicity; however, a common feature of most of these biological effects is the inhibition of eicosanoid production from omega-6 FA precursors. Several of the known risk factors for breast, and colon cancer may be favorably modified by dietary omega-3 FA supplementation, and the implementation of clinical chemoprevention trials is now feasible.