Omega-3 Fatty Acids and Inflammation in Breast Cancer: A Research Review

This systematic review pulled together 67 studies (from lab, animal, and human research) looking at how EPA and DHA—the two main omega-3 fatty acids found in fish oil—interact with inflammation in breast cancer. Researchers wanted to understand whether omega-3s could influence the tumor’s surrounding environment and immune activity.

Across the studies, omega-3 exposure was linked to lower levels of inflammatory signaling molecules like IL-6, TNF-alpha, and CCL2/MCP-1, along with increases in molecules associated with a more balanced immune response, such as IL-10 and IL-2. Lab and animal studies also found reductions in inflammatory lipid compounds (prostaglandins) and the COX-2 enzyme that helps produce them, as well as decreased activity of NF-kB signaling and enzymes (MMP-2, MMP-9) involved in tissue breakdown and tumor spread.

Human clinical studies specifically noted that IL-6, a key inflammatory marker, dropped by roughly 50-70% with omega-3 treatment. However, the authors noted major differences in dosing, formulations, and study designs across the research, which made it hard to draw firm, consistent conclusions.