Do the health benefits of EVOO decline as an oil ages?
The health benefits of EVOO are associated with its fatty acids profile (oleic acid) and minor components such as phenols. As an oil ages (past its expiration date), its antioxidant nutrients decline, but there is no change in the fatty acid profile. So from the point of view of antioxidant nutrients, the health benefits of EVOO may decrease, but its overall benefits do not disappear altogether. It’s important to remember that cooking with EVOO increases the bio-availability of ingested bio-active compounds in other foods. This beneficial effect probably persists, even as the oil ages. More research is needed to answer this very thoughtful question.