Olive oil, an oil rich in monounsaturated fatty acids (MUFCs) and minor constituents including phenolic compounds, is a major component of the Mediterranean diet. The potential health benefits of the Mediterranean diet were highlighted by the seminal Seven Countries Study, and more contemporary research has identified olive oil as a major element responsible for these effects. It is emerging that the phenolic compounds are the most likely candidates accounting for the cardioprotective effects of extra virgin olive oil (EVOO). In particular, the phenolic compound, hydroxytyrosol has been identified as one of the most potent antioxidants found in olive oil.
Reference: Mechanisms of Action of Phenolic Compounds in Olive