Lifelong n-3 PUFA Consumption Reduces HER2+ Mammary Tumour Growth and Alters Immune Markers Compared to Safflower- or Corn Oil-Based Sources of n-6 PUFA

These findings indicate that the presence of dietary <i>n</i>-3 PUFA plays a key role in modulating mammary tumour development, which may be further influenced by the underlying <i>n</i>-6 PUFA background. The associated changes in immune markers suggest that <i>n</i>-3 PUFA exert anticancer effects in part by shifting the tumour immune microenvironment toward an anti-tumour phenotype and modulating cannabinoid receptor signalling. Collectively, this work informs future human studies investigating the role of dietary fat composition in breast cancer risk.