Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
14 Aug

Is Your Olive Oil Really Olive Oil?

For thousands of years, humans have been picking, prizing, and pressing the fatty drupes found among the oblong leaves of the gnarled, twisted olive tree into rich, green-gold extra virgin olive oil. And for almost as many thousands of years, humans have been coming up with ways to fake it, to pass off cheaper, less delicious, less nutritious oils as the real thing. The earliest known written mention of olive oil – from Syria, 24 BC – describes how court-appointed inspectors would tour olive oil processing facilities to ensure quality, purity, and the absence of fraud. In ancient Rome, the vessels containing olive oil bore detailed information about the contents, including varietal of fruit used, place of origin, name of producer, the weight and quality of the oil, the name of the importer, plus the name of the official who inspected it and confirmed the previously mentioned data. Let’s just say they really, really liked their olive oil, and that olive oil adulteration has always been an issue.

It continues today, of course, and studies are bearing out the fact that extra virgin olive oil is often adulterated with cheaper, more refined, deodorized olive oils, oils from olives deemed unfit for human consumption, and/or random nut, seed, and vegetable oils spiked with chlorophyll and beta-carotene to replicate the authentic color. An Australian study found that over half the supermarket EVOO was anything but, even the supposedly legit stuff from the Mediterranean countries; New Zealand researchers had similar results with Mediterranean imports into their country. Last year, a University of California at Davis study (PDF) found that 69% of imported extra virgin olive oils failed to meet international standards, while 90% of California EVOO tested passed (the study was partially financed by major California olive oil producers, and producers of some of the failed imports are crying foul). Similar adulteration is taking place in China, where imported olive oil is mixed with cheap seed oils. In 2007, the New Yorker published a harrowing account of widespread and longstanding fraud in the Italian olive oil industry (“Profits were comparable to cocaine trafficking, with none of the risks”), and more recently, a study found that four out of five Italian olive oils were “debased.”

I’ve spent the last few years recommending that you eat extra virgin olive oil, and now it appears as if the fraud is pervasive enough to throw everything you thought you knew into a state of confusion. So what are you supposed to do? How do you know if your olive oil is actually olive oil?

The Fridge Test

By now, you’ve probably all heard about it: to test the legitimacy of a supposed olive oil, stick it in the fridge for a day or two. If it begins to solidify, you’ve got yourself a bottle of true extra virgin olive oil. Does it hold true?


Pure monounsaturated fat, also known as oleic acid, solidifies at 39 degrees F. Since olive oil is primarily oleic acid (about 70-85 percent, generally), sticking a bottle of real olive oil in the fridge should elicit solidification. The original olive oil adulterants, sunflower oil and safflower oil, were mostly polyunsaturated, so adulterating olive oil used to be easy to spot. Now, with high-oleic sunflower oil, high-oleic safflower oil, and high-oleic canola oil on the scene, adulterated olive oil can still solidify in the fridge. Thus, the fridge test is still a necessary, but not sufficient, test for the legitimacy of your extra virgin olive oil. It’s really a test for the degree of monounsaturation in the oils. It’s important (toss any oils that fail the test), but it’s not the full story.

The Taste Test

Good olive oil is often bitter, pungent, spicy, and slightly abrasive. It’s not always smooth and easy going. In fact, the “off-notes,” the intense flavors that make the uninitiated screw up their face actually indicate the presence of high levels of polyphenols, those antioxidant plant compounds which make olive oil so good for you. If the olive oil you taste burns the back of your throat and tastes funny to you, chances are you’ve been using and are used to adulterated (or at least non-virgin) oil.

To my knowledge, olive oil adulteration hasn’t progressed to the point where scammers are able to simulate the flavor of true EVOO. If they were to do it, I’d imagine they’d have to add polyphenols or olive extracts to the vegetable oils, and that can’t be cheap. And even if they did add olive extracts and synthetic polyphenols, it’d be better than having none at all.

Does It Matter?

Aside from being cheated out of your money for a disgustingly disappointing mix of soybean and canola oils, can any real health issues arise from consuming adulterated olive oils?

There are allergy concerns, of course, if the adulterant contains an allergen, like peanut oil. Owing to the similarity of its fatty acids to olive oil’s, hazelnut oil is another popular adulterant as well as a fairly common allergen, and one study even showed that people with hazelnut allergies could identify olive oil spiked with hazelnut oil because they suffered symptoms after eating it.

Another health issue that can arise from using adulterated olive oil is the one caused by excessive intake of omega-6 fats from the soybean, sunflower, safflower, canola, or any other cheap high-PUFA oil being added: generation of inflammatory eicosanoids, systemic inflammation, and oxidized blood lipids. Luckily, the fridge test is sufficient to ferret out PUFA-rich “olive oil” and prevent this from harming you.

Depending on the source and age of the adulterants (year old soybean oil, five month canola, etc), the once robust polyphenol profile of the starter extra virgin olive oil will have been severely diluted. And since the healthful, anti-inflammatory effects of olive oil can mostly be attributed to the polyphenols, olive oil adulterated with inferior, polyphenol-less oils will be less stable, more rancid, and more prone to oxidation. Oxidized oils are not very good for us; here’s why.

I’d say it does matter, and not just because of taste (as if “taste” isn’t reason enough). Here are my roughly recommended guidelines for choosing a good, real EVOO:

My best results have come with domestics – wherever I am. My favorite olive oil here in California is a California olive oil. The best Italian olive oil I ever had was in Italy. Same for Spanish olive oil. In all those studies referenced above, domestics seemed to win out. The NZ and Australian studies found that local oils bested the imports, just as the California study found that the top oils were from California. I’d imagine Italians like Italian olive oil and Spaniards like Spanish olive oil and so on and so forth because they’re not getting the imported, adulterated dregs.

You might have to spend a little money. Sure, I’ve made some good, affordable finds at Trader Joe’s in my day (including a $15 a liter bottle of spicy, unfiltered to the point of clogging the spout, lime green EVOO from Italy that appeared on the shelves for a month or two last year only to disappear before I could grab another bottle), but generally, I’ve gotten what I’ve paid for.

Do some tastings. Look for specialty shops or farmer’s market stands that allow and even encourage tastings of their olive oils. Take at least an ounce (the quarter teaspoon some places try to offer is way too meager to get an accurate reading), slurp it up, and swirl it around in your mouth like you’re trying to make a saliva-EVOO emulsification. Be obnoxious about it, even. But as you swallow the oil, relax and be ready to note the peppery polyphenol kick at the end, usually experienced at the back of your throat. Good EVOO should linger pleasantly in the mouth, even after it’s been swallowed.

Do the fridge test. Even though it won’t prove that your oil is pure, you’ll at least know that your EVOO wasn’t cut with PUFA-rich oils.

Avoid clear bottles. Although I’ve bought some fantastic olive oil from dedicated small-time producers that was stored in random glass jars, I usually opt for EVOO that comes in dark bottles or stainless steel containers. First reason being, light exposure oxidizes olive oil and degrades the polyphenol content. Second reason, most quality olive oil producers care about their product enough to ship it in suitable vessels.

Buy a winner. I always keep up with the latest winners of the Los Angeles International Extra Virgin Olive Oil Competition. Whenever I’ve tried one from the list of winners, I haven’t been disappointed. Here are some other lauded competitions.

Talk to people who know good olive oil. Talk to olive farmers at the farmers’ market who grow and pick and press and sell the stuff, talk to the mustachioed olive oil aficionado who owns the olive oil shop that you’ve never stopped in to see, talk to your friends who know about this sort of thing and splurge on olive oil all the time.

Ultimately, absent a team of sensory experts, access to gas chromatography equipment, and the ability to astrally project your soul backward through time to the time and place of the oil’s production, there’s no one way to tell, no grand, all knowing test. The closer you are to the proximate producer of the oil (buy “close to the mill”), the fewer times it changes hands before reaching yours, the “feeling” you get from sniffing the herbaceous fragrance, tasting the piquant fruitiness, the enjoyment you derive from it – this is how you determine the worth of your oil. It’s more art than science.

Thanks for reading, folks. Be sure to drop a link or reference to your personal favorite (or favorites) extra virgin olive oil, preferably one that’s widely available or available online, as well as your tips for finding a good brand.

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. 1. Whole Foods and Trader Joes need to build more stores in Southern Rhode Island. Preferrably near Westerly/Charlestown.

    2. Our corrupt society needs to make it 100% more difficult for us who like to eat real food to purchase our groceries. What the heck.

    We also mainly use coconut oil when cooking/baking, and olive oil for our salads. I also like a little olive oil on my sliced cukes and tomatoes for a “snack”
    Now to hunt for a better EVOO. 😉

    Mrs Awesome Pants

    Melody wrote on August 20th, 2012
  2. This is very interesting and good to know. Last year I started having health issues and was told my gallbladder was inflamed. My DR suggested I start taking a little EVOO first thing in the morning. It eliminated my problem but the big thing I noticed was that the olive oil I was using burned my throat. I’ve been so used to olive oil that didn’t burn, I thought something was wrong with that brand of oil (from California). I still use the brand that burns my throat. I’m glad I didn’t abandon it.

    Three West wrote on August 21st, 2012
  3. What alarming statistics!

    I would add that a true olive oil ought to cite the harvest date on the label. This is a commitment to quality and to the product’s freshness. Expiration dates are calculated from when the oil is bottled so the harvest date is a much more reliable indication of freshness.

    Disclaimer: I produce 900 bottles of IGP Toscano Extra Virgin Olive Oil every year…

    Laura wrote on August 30th, 2012
  4. Thought I’d add this here. For those of you who do buy EVOO from Trader Joe’s, this is a reply to an article on Food Renegade:

    Cynthia Calisch
    July 10, 2012 | 12:29 pm

    I wrote to Trader Joe’s about their olive oil and this was their reply which satisfies me:

    Hello Cynthia,

    Thank you for contacting us, and we do truly appreciate your interest in our Trader Joe’s olive oil products. We want to assure you that at Trader Joe’s we work very closely with our suppliers to assure that we are receiving only the highest quality products, and that our suppliers are meeting 100 percent of their claims (as stated on the product labeling).

    Every bottle of Extra Virgin Olive Oil at Trader Joe’s is from the first crush first press of the current crop. Our Olive Oil Buyer personally selects every olive oil blend on our shelves. She travels to Italy, Spain, Greece and Australia’s olive groves during the harvest season, meeting suppliers and taking part in the process of putting together each of our high quality olive oils. This is an integral part of how we buy our olive oil. By being involved at this level we can ensure the quality of our Olive Oils.

    In addition, we subject our olive oils to testing by an independent lab to ensure that their level of acidity equals that of Extra Virgin Olive Oil as Determined by the International Olive Oil Council Standards. Plus, We also do our own testing on a quarterly basis.

    At Trader Joe’s we require FDA regulated GMP (Good Manufacturing Practices) and HACCP (Hazard Analysis and Critical Control Point) program of our vendors. HACCP is a systematic approach to identifying, evaluating and controlling food safety hazards. In addition, our Quality Assurance Team audits our vendors on random and scheduled visits to monitor their facilities and practices on an ongoing basis.

    We believe that quality along with price is essential to the value of our products and we got to extreme measures to make sure we are bringing you the best of both.

    We hope this information adequately addresses your concerns, and we do appreciate you allowing us the opportunity to address this matter with you directly. We also thank you for shopping with us at Trader Joe’s.


    Trader Joe’s
    Customer Relations

    Here is a link to that article, which pretty much says the same thing MDA has written:

    Mary wrote on September 9th, 2012
  5. I’d hessitate to go by the fridge test alone, many referigerators are lousy at holding temp and have warmer zones internal depending on the compressor. It is exciting to see so many comments on this blog, most people just stick the stuff in a pan and crank up the heat to fry veggies & meats.
    Do you buy your expensive wine with out tasting, I don’t think so, you need to taste your Olive Oil & Balsamic before purchasing. That’s why I would recommend an expereinced olive oil tasting bar like

    I’d also recommend reading and following Tom Mueller’s website

    Oil Man Ken wrote on January 10th, 2013
  6. Its a freaking shame that we have to go to these lengths to know whet we are eating!! No wonder our country is so overweight and unhealthy! When those of us that really care about our health and are willing to pay extra money for quality are getting screwed that’s a disgrace!! So now even the honest companies that do make quality olive oil are going to suffer because no one is going to trust/ buy their product! What a shame! What are freaking disgrace!

    katrina wrote on February 12th, 2013
    • You could not be more right, but this is no different than any other “food” Look at chicken, beef or fish. Find a small business you can trust.

      Tony Kasandrinos wrote on May 18th, 2013
  7. I guess I am a little late to the party – but I can confirm all the info Mark has posted about the UC Davis study (which they have updated with more current info) and Australian study. I have also found something interesting. Veronica Foods is the major supplier to most of the specialty olive oil shops in the nation. Take a look at the Truth In Olive Oil website and they list all the shops that VF (Veronica Foods) supplies. VF is a big proponent of proper chemical testing and the owner said to me that they only trust the lab in Australia to verify the purity of the oil that they sell to the retail shops. Unfortunately, the specialty shops in my area supplied by VF are charging approx. $60 per liter which is just too expensive for every day use. (I cook with exclusively EVOO). But at least all the shops that VF supplies are instructed in how to interpret the chemical test results and they are encouraged to post the info online or in store. So I have been on a quest to find high quality EVOO at better prices, but it’s been a real struggle. If anyone has a suggestion, please let me know. Thanks!

    Tony wrote on March 8th, 2013
  8. I found myself a Greek fellow who immigrated long ago and he imports some stuff from Greece, in fact half the label is Greek. When you take a spoonful it actually BURNS your throat after. It’s the real deal! I’ve never had olive oil like this. I actually have to add a squirt of lemon juice to take it as “medicine” like the Greek fellow suggested. 16 dollar a bottle…it’s well worth the money! The store bought stuff Star, Bertolli, etc are crap…LOL.

    Kate wrote on March 24th, 2013
  9. As for the USC study……follow the money

    We are grateful to Corto Olive, California Olive Ranch, and the California Olive Oil Council for their financial support of this research. We value the leadership of Dr. Richard Cantrill, technical director of the American Oil Chemists’ Society (AOCS); the advice of the AOCS Expert Panel on Olive Oil (particularly Bruce Golino, member of the board of directors of the California Olive Oil Council and Paul Miller, president of the Australian Olive Association)

    Tony Kasandrinos wrote on May 18th, 2013
  10. My favorite olive oil by far is the La Boella Arbosana!

    Beth Jackson wrote on July 18th, 2013
  11. the link below dismays the myth that evoo shoukd be solid in fridge. i left my oil in the fridge for 2 days and it was liquid , however i bought my olive oil from a small farm locally sourced company who have won many awards!
    i had to be sure that it was right as i was doin a liver flush where by i had to drink alot of this stuff.. sure enough i called the small company and they reassured me telling me they also get tested for awards every few months… this implys that the fridge test may be untrue.. plus it tastes fruity!!

    shosh wrote on September 17th, 2013

Leave a Reply

If you'd like to add an avatar to all of your comments click here!

© 2016 Mark's Daily Apple

Subscribe to the Newsletter and Get a Free Copy
of Mark Sisson's Fitness eBook and more!