Omega-3 fatty acids for the prevention of breast cancer: an update and state of the science.

The quantity and makeup of dietary fat intake are known to impact human health. Use of Omega-3 (ω-3) polyunsaturated fatty acid (PUFA) supplements has gained increasing attention for a variety of purported health benefits, including cancer prevention. Preclinical evidence has been encouraging and recent studies have expanded our understanding of the mechanisms by which ω-3 PUFAs may protect against breast cancer. However, epidemiologic studies have yielded mixed results. Recent population studies have attempted to delineate factors that may influence the effects of ω-3 PUFAs such as total fat intake and the ratio of ω-3 to ω-6 PUFA intake. Several clinical trials, including some currently ongoing, are investigating novel strategies that favorably alter endogenous fatty acid profiles in an effort to develop clinically feasible prevention methods. Identification of well-defined subpopulations that are most likely to benefit from a targeted prevention approach will likely be crucial in this effort.