Although extra virgin olive oil may improve heart health and have other benefits
(partly due to their polyphenol content), there have been reports that some products are "fake" or adulterated with other types of oils. Fortunately, there are certain things you can look for on labels which help indicate a high quality oil, including seals from organizations which test olive oils for authenticity. While authenticity is very important, it is also useful to compare products in terms polyphenols (for potential "healthfulness"), which are not typically not included on labels or part of certification testing.
ConsumerLab.com purchased and tested 10 popular extra virgin olive oils, and tested their quality in the laboratory as well as subjecting them to sensory analysis (taste testing) by an expert olive oil tester. The results, which include CL's Top Picks
, are found in the Extra Virgin Olive Oils Review>>
Also see these related CL Answers:
What are the health benefits of olive oil? >>
Does cooking or frying with olive oil make it less healthy? >>