Quick Summary
Which are the best and worst extra virgin olive oils?
Only eight of the 11 popular extra virgin olive oils selected for review by ConsumerLab.com were determined to be extra virgin based on flavor and aroma testing by a panel of experts. The other three products were deemed to be lower-quality oils due to perceived defects, such as having a “rancid” flavor. This is despite finding that each product met the minimum chemical requirements of extra virgin olive oil. 
Even among olive oils considered extra virgin, only four had oleic acid levels of at least 70%, further qualifying them for a “reduced risk of coronary heart disease” claim. Some products were also much higher in antioxidant polyphenols than others (levels ranged from 200.3 mg/kg to 472.8 mg/kg).
Across products, higher cost did not reflect higher quality, with the least expensive being among the best and the most expensive being among the worst. The cost per tablespoon ranged from 16 cents to 61 cents.
Among the products of highest quality, CL selected three as its Top Picks for extra virgin olive oil -- one that is mild (more fruity than pungent), one that is medium (balanced), and one that is robust (more pungent). (See What CL Found to compare the test results, taste descriptions, prices, and other features. Also see How Products Were Evaluated).
Products tested include extra virgin olive oils by Atlas Olive Oils, Bertolli, Bragg, California Olive Ranch (Everyday and Global Blend), Graza (Drizzle and Sizzle), Kirkland/Costco (Italian and Organic), and Terra Delyssa (Premium). The oils are labeled as originating from California, Greece, Italy, and Morocco, Spain, and Tunisia, with blends also listing Argentina, Australia, Chile, Peru, and Portugal, and Turkey.
Is olive oil sold in a “bag-in-box” as good as that in a bottle?
To answer this question, we tested the same California Olive Ranch Everyday extra virgin olive oil sold in a glass bottle and in a plastic bag in a box, What we found was encouraging but also surprising.
What does extra virgin olive oil do?
In addition to a pleasurable, pungent and somewhat fruity taste, extra virgin olive oil has potential health benefits including reduced risk of coronary heart disease, reduced risk of breast and colorectal cancers, and improved blood sugar control (see What It Does). Some of these benefits are associated with higher amounts of polyphenols in extra virgin olive oils, as well as higher concentrations of oleic acid.
How much olive oil should I take?
Health benefits with extra virgin olive oil have been associated with intakes of about 2 to 4 tablespoons per day when this replaces saturated fats in the diet (as opposed to being taken as a supplement) (see What It Does).
How to buy, use, and store olive oil?
Buy olive oil in a dark-colored bottle to protect it from light (and/or store it in a dark cabinet), and don't worry about the color of the oil — it's not a reliable indicator of quality or flavor. If cooking with olive oil, limit use to later stages of cooking, keeping heating time to a minimum (see ConsumerTips™).
Safety and side effects of olive oil
Olive oil is generally safe and well-tolerated, but it may interact with certain medications (see Concerns and Cautions).
