Olive oil contains oleic acid, the monounsaturated fatty acid (MUFA).
It is richer in polyphenols (a class of phytochemicals: chemicals that evolved in plants to protect them from predators), which have anti-inflammatory and antioxidant properties.
It is the oxidized form of LDL cholesterol that gets into the arterial wall and spurs plaque formation, and
plaques with more inflammation are more likely to rupture and cause heart attacks. In addition, oxidized LDL cholesterol impairs the ability of arteries to relax and dilate. Stiffer arteries lead to increased blood pressure.
So polyphenols found in olive oil inhibit the process of oxidation, lending a protective effect.
10 grams of extra-virgin olive oil has as many as 5 milligrams of antioxidant polyphenols.
MUFA-rich olive oil can lower blood pressure. This blood-pressurelowering effect of the main fat in the Mediterranean diet is one explanation for its ability to combat congestive heart disease.