Olive oil contains oleuropein, a potent antioxidant compound, for which previous researchers have identified the capacity to inhibit cell proliferation of breast and urinary cancers, as well, as to decrease breast cancer cell viability.   ZK Hassan, from King Saud University (Saudi Arabia), and colleagues investigated the effect of oleuropein on the metastatic and anti-metastatic gene expression in the MDA human breast cancer cell line. The team observed that oleuropein initially down-regulated matrix Metalloproteinase (MMP) genes – thought to be overexpressed in tumor cells; and oleuropein promoted the tissue inhibitors of metalloproteinases (TIMPS) – with which cell-death inducing properties are associated. The study authors submit that: “oleuropein plays an important role in regulating MDA cell metastasis by suppressing the expression of MMP-2 and MMP-9 genes and upregulating the expression of TIMP1 and TIMP4 genes in breast cancer cells therefore it can help in tailoring new anti-metastatic cancer therapy.”