Health Benefits of Extra Virgin Olive Oil
On Extra Virgin Olive Oil
While it is well-known that the monounsaturated fats in olive oil are a key component of the Mediterranean diet, the rich mixture of antioxidant polyphenols is equally important.
Olive oil is the only vegetable oil that contains perceptible amounts of polyphenols, and the virgin olive oils are the only quality grades that contain considerable quantities – with Extra Virgin olive oils topping the charts. Generally, the lower, ordinary grades of olive oil contain 50 ppm or less of polyphenols, depending on their percentage of refined olive oil. Since imports to the U.S. are commonly labeled ‘Extra Virgin’ without meeting the international quality standards, the polyphenol content maybe anywhere up to, or within the typical range for Extra Virgins, which is about 100 to 250 ppm. The polyphenol content of some conventionally milled Extra Virgin olive oils maybe as high as 500 ppm, depending on factors such as the olive cultivar and degree of ripeness, as well as the production and extraction technologies employed, and the age of the oil.
Relative Polyphenol Ranges
Scientists in Spain and Italy are actively engaged in studying all aspects of these polyphenol compounds, including their health benefits and methods to increase the concentration in Extra Virgin olive oils. Several recent studies are cited here, each with a link to the scientific abstract:
Gallina-Toschi T, Cerretani L, Bendini A, Bonoli-Carbognin M, Lercker G.
Oxidative stability and phenolic content of virgin olive oil: an analytical approach by traditional and high resolution techniques.
J Sep Sci. 2005 Jun;28(9-10):859-70.
“The amount of phenolic compounds extracted during production is fundamental for the oxidative and nutritional quality of the oil. … the amount of phenolic compounds in virgin olive oil can be influenced by different factors including the olive cultivar and degree of ripeness, as well as by production and extraction technologies.”
Read the abstract on www.ncbi.nlm.nih.gov
Medina E, de Castro A, Romero C, Brenes M.
Comparison of the concentrations of phenolic compounds in olive oils and other plant oils: correlation with antimicrobial activity.
J Agric Food Chem. 2006 Jul 12;54(14):4954-61.
“The oils from olive fruits had a strong bactericidal action against a broad spectrum of microorganisms. … Most of the foodborne pathogens tested did not survive after 1 h of contact with olive oils. Results indicated that not all oils classified as “olive oil” had similar bactericidal effects and that this bioactivity depended on their content of certain phenolic compounds.”
Read the abstract on www.ncbi.nlm.nih.gov
Romero C, Medina E, Vargas J, Brenes M, Castro AD
In Vitro Activity of Olive Oil Polyphenols against Helicobacter pylori.
J Agric Food Chem. 2007 Feb 7;55(3):680-6
“H. pylori is linked to a majority of peptic ulcers and to some types of gastric cancer, and resistance of the microorganism to antibiotic treatment is now found worldwide. … These results open the possibility of considering virgin olive oil a chemopreventive agent for peptic ulcer or gastric cancer…”
Read the abstract on www.ncbi.nlm.nih.gov