Dear Mark: Olive Oil Followup

For today’s edition of Dear Mark, I’m answering questions from last week’s olive oil post. First, is there a way to identify real olive oil and distinguish it from fraudulent olive oil? Second, should EVOO be used when grilling food? Third, how can we know if our canned seafood is packed in real, actual olive oil and not some industrial seed swill? Fourth, is algae oil worth eating? And fifth, what about just eating whole olives? Finally, why not just eat beef fat, which is also relatively high in MUFA?

Let’s go:

I’ve read that some “olive oil” has canola or other oils mixed in, fraudulently. Is that still an issue, and is there any way to be sure (reliable brands or sources) that what you are buying is pure and authentic?

It’s still an issue.

It all started after a raid by Italian police discovered that many olive oil producers were adding chlorophyll to sunflower and soybean oil and passing it off as EVOO. Later, UC Davis conducted a study on popular brands of imported EVOO, finding that about 70% were adulterated with seed oils. Other studies have found similar results.

Find a brand you trust. Research a maker, whether it’s a local market or a specialty brand you find at the store.

There’s this master list of olive oils certified by the North American Olive Oil Association for quality and authenticity. Many are commonly available in grocery stores.

I like it drizzled over cottage cheese for lunch or brunch, topped with cracked pepper, yum!

Finally someone agrees! This is indeed the best way to consume cottage cheese, for those who don’t know. Use at least a teaspoon of pepper, as much as you can handle.

I typically use an EVOO spray on meats before searing on the grill. Could this be harmful with the flame on high?

I wouldn’t recommend EVOO for high heat or direct flame. Personally, I use an oil made for high heat cooking in that kind of situation.

How can one be assured that they’re packed in genuine EVOO? Is there some source/website that lists those that have been tested and verified? Call me a skeptic. If I’m Crown Prince, King Oscar, Starkist, or whoever, I’m buying massive quantities of olive oil for my fish packing operation. And the cheaper price gets my business. I’m not sending samples off to a lab to test if it’s authentic EVOO.

Good question. I can’t attest to any particular brand. It’s possible some adulterated oil could slip in, and I was unable to find any mention of it in the online literature.

If you’re concerned, drain the oil. Even if a half gram of omega-6 PUFA were to slip by, the actual fish in the can is rich enough in omega-3s that I wouldn’t worry.

For what it’s worth, I doubt something like Wild Planet sardines (what I generally buy) uses fake olive oil. Unless I’m including it specifically for a recipe, I usually pour the oil into a bowl for my dog to eat, since it’s good for her, too. (You can imagine how much she enjoys it….)  Her fur shows the benefit as well.

Terrific info, thank you!
Can you do the same breakdown and analysis of algae oil? Please. I’m using ‘thrive’ brand. Thanks!

Algae oil is a good source of long chain omega-3s and has been shown to improve omega-3:omega-6 ratio in people and animals, a strong indication it “works.” Algae represents the “source” of DHA for most of the seafood we eat, in fact. Great way for vegans and vegetarians to get them.

Don’t use it for cooking. Omega-3 fats are very fragile in the presence of heat, unless protected by the

To what extent do you get the same benefits from just eating olives? I’m usually more inclined to do that… wondering if there’s any research on the health benefits?

Yep, olives are great. Love them. There isn’t really any research into olive consumption, and you’d have to get about two dozen olives to get a tablespoon worth of EVOO, but they’re bound to be good for you. Just account for the sodium intake.

Every time I see these claims about EVVO, I think:
1. EVOO is rich in MUFAs; so is BEEF FAT.
2. BEEF FAT is rich in SFAs; so is EVOO.
3. EVOO is rich in polyphenols. Does polyphenols show some improvement in healthspan and longevity in humans in a prospective study?
4. EVOO is a liquid fat. There are some studies showing that liquid fats increases intestinal permeability.
OBS.: yes, I´m doing carnivore.

1. Agreed. Beef fat is rich in MUFAs, just like EVOO.

2. Beef fat is rich in SFA, but it’s a particular type of SFA (stearic acid) that turns into MUFA in the body. EVOO isn’t really rich in SFA, though it’s rich in the MUFA that stearic acid becomes.

3. Plant phytonutrients actually do have consistent inverse associations with mortality in humans. More phytonutrients, longer lifespan. However, this isn’t measuring cause and effect. It’s very possible that people who eat more polyphenols also do other types of healthy behaviors, like exercise regularly and avoid smoking, that definitely improve longevity.

4. If anything, MUFAs (the primary fat in liquid EVOO) along with omega-3s are protective against intestinal permeability. And let’s not forget that less intestinal permeability isn’t necessarily a good thing. Increased intestinal permeability can be physiological, or it can be pathogenic.

I get the carnivore thing. I’m not against it. Beef fat is great, too. But the evidence in favor of EVOO is quite robust. Definitely robust enough for my taste.

Thanks for reading, writing, and asking, everyone. Take care and be sure to comment down below if you have any more questions!


Kim Y, Je Y. Flavonoid intake and mortality from cardiovascular disease and all causes: A meta-analysis of prospective cohort studies. Clin Nutr ESPEN. 2017;20:68-77.

Cândido FG, Valente FX, Grze?kowiak ?M, Moreira APB, Rocha DMUP, Alfenas RCG. Impact of dietary fat on gut microbiota and low-grade systemic inflammation: mechanisms and clinical implications on obesity. Int J Food Sci Nutr. 2018;69(2):125-143.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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17 thoughts on “Dear Mark: Olive Oil Followup”

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  1. Would it be safe to say that any EVOO labeled as USDA Organic would go through enough of a vetting process that you wouldn’t have to worry about other oils being mixed in?

  2. Last year I contacted Wild Planet asking about their source of olive oil. Though the person replying to me wouldn’t tell me exact details, she said the CEO of the company travels to Europe to personally select their olive oils for their canned fish products. I felt better, but I wasn’t 100 percent convinced. I’m just suspicious when they won’t say what the actual source for the oil is, and how old it is.

  3. Great info, thanks! I drain the tuna and salmon cans for my cats, they love it (the liquid/oil that is)! I eat the fish (oh OK, I share that as well). Can’t quite get sardines down yet. Working on it. The bones are so good for you. I can do herring, YUM!

  4. Referring to the question regarding how can you tell if your buying 100% EVOO. We own dressed by an Olive, we are a Olive Oil & Vinegar tasting room/store. Our exclusive supplier Millpress Imports works closely with Paul Vossen and Richard Cantrill both are well respected individuals in the Olive Oil world. To ensure quality the Olive is 3rd party lab tested 2x to ensure that the olive oil has not been compromised or adulterated with “seed oils”. We give our customers the crush date, Country of Origin and chemistry peroxide, FFA, Oleic Acid and the polyphenols are measured.. Sample before you buy and ask for the 3 C’s when buying EVOO.
    ** Consumer beware there a lot of copycats out there!

  5. I noticed this on the evoo list: “Primal Kitchen Organic Extra Virgin Olive Oil*
    (Since 2019)”

    Are you coming out with one? Or is the search on Primal Kitchen’s site not responding to “olive oil”?

    That would be exciting news.

    1. Angelica, you’ve got a keen eye. I’ll have more news on that in the coming weeks…. And for being the first to notice, how about I send you a free bottle when the time comes? Our editor will get in touch. Best — M

  6. Interesting that Kirkland/Costco isn’t on the certified list, as I’m sure they are a huge player in the US EVOO space.

  7. After you’re done eating peppered EVOO and cottage cheese, save those cottage cheese boxes! America’s Test Kitchen ranks them second place as freezer boxes, behind a spendy European gadget. If you freeze food, you can’t do better than a cottage cheese box. And if you’re growing muskmelons, an upturned cottage cheese box under each green melon will keep them off the soil and keep the pillbugs from burrowing into them as they ripen.

    1. This is interesting! Where I live, cottage cheese does not come in boxes, it comes in plastic tubs with a plastic snap on lid. Could you please tell me more about these boxes? Thanks!

      1. That’s wast I’m referring to: plastic cartons. If you’re making extra food to freeze for later, those cartons are the best thing to freeze in.

  8. Hi Mark,
    I think the Thrive brand of algae oil in the question above is a different product than an Omega3-rich fish oil.
    Here is the product link:
    It actually contains < 2% Omega3, and is ~90% MUFAs.
    Might be a good oil for those individuals that want to stay away from seed oil PUFAs and have lower SFA, but still want an higher heat oil (comapred to EVOO).

  9. What about the harvest date? Isn’t it important to make sure you get a recent harvest?

  10. What gets me is the absence of olive oil acidity disclosure on bottles Something that is mandated overseas. It’s best to aim for olive of with 0.5 acidity and under.