Olive oil and health effects: from epidemiological studies to the molecular mechanisms of phenolic fraction

Olive oil is a key component of the Mediterranean diet which is recognized to contribute to its health benefits. Recent prospective studies point towards a protective effect from an olive oil-rich diet in relation to the incidence of cardiovascular diseases and an improvement of cardiometabolic markers such as blood pressure, glycaemia and dyslipidemia, notably by reducing LDL cholesterol and LDL oxidation. The role of minor phenolic fraction was evidenced in intervention trials where lipid profiles showed greater improvement in participants receiving olive oil with higher phenolic content. The phenolic fraction of olive oil is composed of simple phenols (hydroxytyrosol), phenolic secoiridoids (oleuropein aglycone), lignans (pinoresinol), flavonoids and hydroxyisochromans. All these compounds have diverse biological activities that are described in the present review, supporting the protective effects of olive oil against degenerative diseases found in large cohorts monitored in Southern European countries