Olive Tree: A Source of Functional Bioactive Components

Abstract

The olive tree (Olea europaea L.) is an iconic symbol of the Mediterranean region since ancient times and products derived from its fruit and leaves have been used both as a food and as traditional medicine. Phytochemical studies have demonstrated olive oil, olives and processed olives as a rich source of phenolic compounds which are the most important components of the polar fraction of olive fruit, oil leaves and bark, owing to their health properties as natural antioxidants. The role of high content of antioxidative compounds is related to human health. Olive oil provides protection against heart disease by controlling low density lipoprotein (LDL) while raising high density lipoprotein (HDL) cholesterol levels. Compounds such as hydroxytyrosol and oleuropein are antioxidants that demonstrate some health effects in the prevention of certain diseases and ageing. The major phenolics include hydroxytyrosol, tyrosol, and oleuropein which are believed to be responsible for a number of biological activities. This paper summarizes current knowledge on the physiological effects of phenolics present in different parts of olive tree, on human health. Studies (human, animal and in vitro) have shown that olive oil phenolics have positive effects on certain physiological parameters, such as plasma lipoproteins, oxidative damage, inflammatory markers, platelet and cellular function, and antimicrobial activity. Apparently, regular consumption of virgin olive oil containing phenolic compounds manifests in health benefits.