Oleacein is natural food preservative agents, possess the strongest antimicrobial activity even compared with Hydroxytyrosol. Oleacein is a secoiridoid (a subclass of iridoids resulting by the breaking of a bond on cyclopentane ring), one of the main “polyphenols” presents in extra virgin olive oil (secoiridoids are a group of compounds present in the Oleacee family and in particular in olive trees –Olea europaea- ). In vitro tests showed antinflammatory, antiatherosclerotic and antihypertensive properties of Oleacein, this last one by the inihibition of the angiotensin conversion enzyme, moreover, Oleacein is an inhibitor of the mammalian/mechanistic target of rapamycin (mTOR), an important metabolism and cellular growth regulation mechanism related to lifespan and aging. New data, that are being accumulating, indicates Oleacein as the main responsible of the positive effects of olive oil on cardiovascular system. Oleacein results, also, to be an inhibitor of MTOR pathway, an important methabolism and cellular growth regulation mechanism. Oleacein is mainly absorbed and enters the human systemic circulation in reduced forms as glucuronides, but it appears that it is released from glucuronides by the lysosomal Beta glucuronidase secreted by inflammatory macrophages at the site of inflammatory activity.