When choosing your olive oil, the highest level of polyphenols should not be your primary concern. The beneficial effect may be obtained with the consumption of 20ml of an olive oil containing a total of 250mg/kg polyphenols. An olive oil carrying above 750mg/kg is considered by scientists to be a medical-grade olive oil. It typically contains a high level of oleuropein, hydroxytyrosol, and their derivatives; and it only takes 10ml for the beneficial effect to take place. These compounds are powerful antioxidants displaying anti-oxidant, anti-angiogenic and anti-inflammatory properties. Another point to watch out for is chemical free or organic products, which practically means that you won't be consuming any chemical compounds that may cause oxidative damage. An organic high phenolic olive oil is the true definition of functional foods.