Oleacein is one of the most abundant polyphenols in extra virgin olive oil . This phenolic compound has antioxidant, anti-inflammatory, anti-proliferative, antimicrobial activity, and it seems to decrease the progression of atherosclerosis. Also, a new clinical trial about chronic lymphocytic leukemia provided more insight. Olive oil with a high oleocanthal and oleacein content decreased cancerous white blood cells. It also caused an increase in the specialized death of cancer cells. Nine out of ten patients experienced these results.