Dear Mark: French Press Coffee, Mid-Oleic Sunflower Oil, Peanuts, and a Keto Success Story

For today’s edition of Dear Mark, I’m answering three questions and sharing a quick, but awesome story from a reader. First, are French press, Turkish, and other unfiltered boiled coffee preparations unhealthy due to the presence of coffee oils in the finished product? They may raise LDL, which gets the conventional health experts hot and bothered, but there are other effects, too. Second, high-oleic sunflower oil was given the go-ahead in a previous post. What’s the story with mid-oleic sunflower oil? Third, with the recent study indicating that peanut/tree nut eaters enjoy improved mortality from all causes, should we take peanuts and most importantly peanut butter off the “no-go” list? And finally, a long term keto success story briefly mentioned in last week’s post writes in.

Let’s go:

Hi Mark,

I have read in the past that the oils in coffee are healthful, and brewing methods that don’t use paper filters are best. But I recently read (on CNN and a few other sites) that coffee oils contain a compound called “cafestol” which apparently is very effective at raising LDL cholesterol. The articles said it was healthier from a cholesterol standpoint to brew using paper filters, rather than using methods like french press (my favourite). Now I’m confused! Since many of us really enjoy coffee, would it be possible for you to shed some light on this? Thanks so much!


I use a French press every morning, so my stance on cafestol — that it’s okay and likely beneficial — might be biased. Either way, I haven’t seen anything in my bloodwork to worry about. If you’re interested in researching the health of effects of French press coffee, search the literature for “boiled coffee.” That phrase refers to Turkish coffee, Greek coffee, French press, and all other methods that don’t use paper filters and thus allow passage of the oil-bound diterpenes (like cafestol) into the cup. I’ll use “boiled coffee” from here on out.

73 mg of purified cafestol a day for six weeks can increase cholesterol by a worrisome 66 mg/dL, but since the average cup of French press coffee contains between 3-6 mg, this isn’t a normal physiological dose. When you look at actual boiled coffee consumption, rather than isolated cafestol, cholesterol levels rise by about 8-10%. Yes, still potentially problematic, particularly if LDL particle number also increases. But except for an older study in middle aged men and women in Norway (where coffee is typically boiled) that found 9 cups of boiled coffee or more per day increased the relative (not absolute) risk of heart disease mortality, concrete links between French press (or other boiled coffee preparation methods) consumption and actual heart disease or heart attacks simply don’t exist.

And one of the ways cafestol affects cholesterol homeostasis is by acting as a natural agonist to the liver’s farnesoid X receptor. What does that mean? Without getting too deep into the biochemistry, other farnesoid X receptor agonists have been shown to reduce atherosclerosis, prevent the uptake of cholesterol by macrophages, and inhibit the formation of atherosclerotic lesions — so cafestol may have an overall beneficial effect on heart health.

Get your LDL particle number checked out to see if you should worry. If your LDL-P is going up dramatically, try switching to paper filtered coffee some of the time. But other than that, cafestol is off the hook. And there’s considerable evidence that it does really good things for us, too.

Liver enzyme levels drop when you consume boiled coffee. And when you inject rats with a known liver toxin, boiled coffee protects them against the expected rise in liver enzymes. Most evidence suggests that coffee, whether boiled or filtered, is protective against liver cancer, liver disease, and mortality from chronic liver disease.

The more boiled coffee a man drinks, the lower his chance of prostate cancer. This inverse relationship was not present for filtered coffee. Cafestol (and a related coffee deterpene, kawheol) may also trigger cell death in certain cancer cells.

Cafestol can increase glutathione activity in the body, which aids in detoxification of aflatoxins (a mold toxin commonly found in coffee beans, so it kinda works out) and may be responsible for its anti-carcinogenicity.

However, much of the benefit stems from cafestol’s ability to activate the Nrf2 pathway, the “hormesis gene” I mentioned in last week’s ketogenic diet post. And like fasting, exercise, and any other hormetic stressor with proven health benefits acting via the Nrf2 pathway, the benefits of cafestol may disappear or turn negative at higher doses.

If you’re really worried about cafestol but don’t want to give up the unfiltered coffee, a 2012 study examined the factors that determine the amounts of cafestol that ends up in your cup when making it:

  • Light roasts give the most cafestol.
  • Dark roasts give the least.
  • Both French press and boiled coffee (literally boiling the grounds in a pot of water, or cowboy coffee) produce the most cafestol.
  • Moka pot and Turkish coffee produce the least cafestol.

Overall? I wouldn’t give up the French press, but I also wouldn’t ignore any massive spikes in LDL-P. If cafestol is a poison, it’s all in the dose. Two to three cups? I wouldn’t worry and it’s probably helping. But it’s entirely possible that 6 cups of strong French press coffee every day introduce an excessive dose of cafestol, surpassing and reversing the benefits to liver health, antioxidant activity, and cancer resistance.

I can only find mid-oleic cold pressed sunflower oil (verified by the manufacturers) in local stores, i.e. Trader Joe’s and Wal-Mart. I know you said high-oleic sunflower is paleo, but was wondering if mid-oleic could be also.


High-oleic runs around 82% MUFA, which is awesome and makes for a stable, healthy fat, but at about 69%, mid-oleic sunflower oil is still far higher in monounsaturated fats (MUFAs) than regular sunflower oil and thus far more stable. For what it’s worth, avocado oil sports a similar fatty acid profile, coming in at 70% MUFA, albeit with less PUFA and more SFA than the mid-oleic sunflower oil. I’m a big fan of avocado oil (obviously), and I’m okay with the fatty acid profile of this one, too.

There’s not a ton of research on mid-oleic sunflower oil (boy, do I feel like I’m typing that a lot), but what exists is reassuring:

  • A double-blind controlled trial in men and women with high cholesterol found that mid-oleic and olive oil had similar effects on lipid oxidation, i.e. none. The slightly higher PUFA levels in the sunflower oil weren’t enough to increase oxidative damage to blood lipids.
  • A hamster study found that while high-oleic sunflower is best, mid-oleic sunflower oil is still way better than high-PUFA oils for reducing oxidative stress.

Go for it. I wouldn’t rely on it exclusively, but you could certainly keep some around.

Hi Mark,

What do you think of the latest study on peanuts and health?

Study: Peanut Eaters May Live Longer

Can I go back to regularly eating peanut butter instead of all the ok-but-just-not-the-same other nut butters? 😉

Thanks for you always informative blog.


First of all, this is an observational study that can’t establish causation. It’s reassuring, but it’s not the final word.

There is some evidence that peanut lectins are atherogenic (peanut lectin is often used in animal studies to reliably initiate atherosclerosis) and can make it through the gut lining into the blood intact. Peanut lectin can induce cancer in colorectal cells, and cancer patients probably shouldn’t regularly consume peanuts because peanut agglutinin promotes metastasis. Peanuts are also typically contaminated with aflatoxins, which can contribute to liver disease.

On the other hand, peanut skins contain polyphenols that are both bioavailable to humans and improve blood lipids. And despite the in vitro colorectal cancer studies, people who eat peanuts have lower rates of colorectal cancer. Then there’s the study you mentioned, although it appears as if tree nuts were lumped in with peanuts.

The biggest problem with peanut butter, as I see it, is how good it tastes. Let’s be honest, folks: real nut butters don’t really compare to peanut butter. Entire tubs of crunchy salted peanut butter disappear in minutes if one isn’t careful.

Moderate amounts of peanut butter in the context of an overall solid diet, lifestyle, and exercise program won’t matter much. If I had to hazard a guess, I’d say a tablespoon of peanut butter each day alongside a Primal lifestyle will reduce optimal health by 0.5%, increase risk of early heart mortality by 0.7% (that’s relative risk, BTW), knock 500 milligrams of eliteness off your weekly capacity, and increase the number of still-crusty-after-a-turn-in-the-dishwasher spoons by 0.8/day.

Kidding aside, I’m still leery of the uniquely-atherosclerotic qualities of peanuts, peanut oil, and peanut lectin, the ability of the lectin to appear in the blood of those who eat peanuts, the aflatoxin contamination concerns, and the addictiveness of peanut butter. A handful of peanuts or a spoonful of peanut butter every once in a while is probably fine, but don’t go crazy. If peanut butter is a “trigger” food for you that initiates massive binges, lay off it.

Hi Mark,

I’ve never written you, or shared my success story, even though your website has been instrumental in changing my life for the better. Today, you wrote an article on long-term ketogenic diets, and shared a link to the case study that Dr. El-Mallakh wrote about me a few years back (I am one of the women for whom a ketogenic diet has relieved symptoms of bipolar). Since the case study was published, I have had two healthy babies, breastfed the first for 14-months and am currently breastfeeding the second – something I never would have thought possible before the keto diet eliminated my symptoms of bipolar. I was out of ketosis during my pregnancies (mostly primal), but returned to ketosis about 8 weeks post-partum. My babies have thrived on my milk (after I had the blessing of my pediatrician), which seems unaffected by my diet. Anyway, I felt (anonymously) famous today that my case study made it all the way to your blog, and I sincerely appreciate you sharing.

I hope that this dietary intervention gains recognition in the medical community and that others benefit as much as I have.

Thank you!


Hallie, that’s awesome! Thanks so much for writing in. I’m glad to hear you and your kids have thrived.

If I may ask, have you weaned your kids at all yet? If so, what kind of food are they eating? Just out of curiosity.

Thanks again.

That’s it for today, everyone. Thanks for reading and be sure to leave a comment if you have anything to add!

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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32 thoughts on “Dear Mark: French Press Coffee, Mid-Oleic Sunflower Oil, Peanuts, and a Keto Success Story”

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  1. PB is something I don’t keep in the house only because of my lack of control with it! As you said it’s way too easy to eat far too much of it at once. In my height of marathon training it wasn’t unusual for me to polish off a jar in 4 days.

    1. I’m also a PB addict, I had to give it up completely because I can’t say no to it and I’m aware of that in me. There are just some foods you have to put aside for safety’s sake.

  2. Thank god for food allergies–peanut butter gives me a rapid pulse, so i quit eating it. But I am a glutton when it comes to sun butter, so I have learned to limit my consumption to 2 celery sticks dunked in a jar of the stuff (still more than I probably need, but less than before).

    At least I no longer lick the inside of the lid clean! 🙂

    1. I had to stop buying almond butter completely, as I could polish off a jar in a sitting. I’m sure why holding back on these nut butter is so hard!

  3. Trader Joes Dark Chocolate Peanut Butter Cups.
    What a treat!
    I’m not going to pretend their primal, but they’re an awfully nice dessert if I’m in the mood for one. 🙂

  4. Trader Joes Dark Chocolate Peanut Butter Cups.
    What a treat!
    I’m not going to pretend they are primal, but they’re an awfully nice dessert if I’m in the mood for one. 🙂

    1. Ha, for me it’s Justin’s dark chocolate peanut butter cups? Paleo? Nope. A delicious treat eery now and again? Oh heck, yeah.

      I use a table spoon of peanut butter in a banana pancake recipe I make that could be paleo if it was almond butter instead. My problem is I am very allergic to almonds. And sunflower. Other tree nuts makes my ears suspiciously itchy since having my kids as well. However, I am perfectly fine with peanut butter. So I do eat it. I consider it part of my 80/20. Otherwise I’m looking at no nut butters which is doable but harsh.

  5. Hello Mark, I love starting my day with a shot of espresso or Turkish Coffee. I only wonder, why in your opinion Turkish coffee produce less cafestol then boiled coffee (cowboy coffee)? Since true Turkish coffee must be boiled 1st or one risk stomach ache (it also contains cardamon…) . On the other hand, I came across a research that one must exceed 5 cups a day in order to be negatively effected by it. Also, the media where I am, got excited over the proclamation that peanuts are healthy (basically, so the local manufacture can promote it’s inferior peanut flavored snack). But the “health” community, forgot to mention that the conclusion was derived from observational study. No surprise there. Now, I do love unsalted roasted peanuts, so once or twice a year I eat around 50-100 grams and forget about it. And besides, coconut butter is so much tastier and healthier.

  6. It is possible to add a paper filter to a French press. Simply place it under the metal press unit and wrap the sides up. Might make it harder to press but it still works.

  7. Hi Mark – thanks for posting my story. To answer your question, my toddler eats a really varied, mostly primal, diet. Lots of eggs, full-fat dairy, grass-fed meats, fruits, veggies etc. Her favorites are olives, fried Brussels sprouts, broccoli. She does eat some wheat (bread, cereals) when we are out with other kids, and she eats birthday cake and celebratory foods – I believe the social aspects of inclusion are good for her, and she doesn’t show adverse affects to small doses. My little one is just starting solids – we are following “Super Nutrition for Your Babies” – so far she’s had egg yolks, sweet potato mashed with bone broth, bone marrow, avocado and bananas, plus some full-fat yogurt. Eating this way has changed my life – I wish I’d discovered it sooner – so I am eager to share it with my girls and have them reap the benefits as well.

    1. I have bipolar as well, was thrilled to read your story. I started Primal for diabetes control and weight loss, but have found my moods to be so much more in control it is amazing. I’m not ready or willing to come off mood stabalizing meds at this point, I just do not feel it is the right time. I do however feel there might be a time, which I never thought possible. Are you totally off meds at this point? I’d love to hear more about how it works for you with your bi polar. could you email me ?

  8. I gave up my French press a year ago for an Areopress (uses a small paper disk filter) and I’m not planning on going back. I have a cup of coffee made in under 5 minutes and that includes hand grinding the beans, boiling the water, and cleaning up. I don’t know what that means for my health but it makes the best cup of coffee, ever.

    1. Joe,
      I use an Aeropress too, and don’t plan on ever changing. Great coffee, doesn’t take up much counter space, and easy to use. Travels well too.

    2. The Aeropress is great, and you can buy a stainless steel filter for it which provides a material improvement in flavor.

  9. if you miss peanut butter, check out barney butter. its expensive, but it tastes so close to the real thing.. there’s nothing else like it.

      1. It’s a brand of almond butter (they may have other nut butters, too?). It is very thick, but has sugar and oil of some sort. It doesn’t require any stirring.

  10. Hallie Fox, is there a more detailed account of your ketodiet experience? I would love to read about it in detail.

    I have two sisters who have been struggling with bipolar disorder, plus we have generational Type II diabetes that runs in our family. In many ways, a ketodiet seems like an extension of a diabetic diet. Recently, I’ve been rapidly gaining weight, following the family pattern, after a lifetime of being thin and still active. Restricting carbs to 80g or less appears to be the only way to manage the weight gain for me.

    I would love to know what you eat and how you maintain a ketogenic state! So, hopefully you will see this comment. Congratulations on your success!


  11. Sunbutter (sunflower seed butter) is my preference in nut/seed butters. I think it’s even better than peanut butter. It also has the added benefit that the odd peanut allergy-sufferer near me won’t drop dead the instant I open the jar.

    1. You are like my polar opposite. I have a deadly sunflower allergy but am just fine with peanut butter. I loved sunflower seeds once, life can be very cruel.

  12. What’s the verdict on cold brew coffee? Beans sit in cold water overnight, then poured through filter for use in cold or hot coffee.

  13. On peanut butter…we found out the hard way that my oldest daughter has a severe peanut allergy. Reading some studies linking delayed introduction to allergies, I wondered if her entirely Primal gestation and first two years of life helped cause or exacerbate the allergy. She didn’t have her first peanut butter until she was 2, and since even I avoid it she didn’t get any through breastmilk.

    Her little sister just turned 10 months and on the advice of her Paleo supportive pediatrician, I gave her some peanut butter and she had no reaction. This could be a total coincidence, but I do think there may be something to delaying introduction of foods too long. I’m wondering if I should give her a little gluten too for the same reason.

    I’m glad the occasional PB we will now have isnt that bad. We won’t make it a regular thing but I sure do enjoy it!!

  14. I’m curious as to how you’re differentiating between Turkish / Greek coffee, and what you call “cowboy coffee”, since both of these types of coffee are prepared by boiling coffee grounds directly in the water?

  15. I can’t quit peanut butter, but fortunately I don’t consider it a “trigger” food either. I usually buy the natural, unsalted stuff, so that cuts down on how much you’d really want to eat straight from the spoon. My most common use of peanut butter is to make a Thai-style dip for vegetables (or dilute to make a stir fry sauce). Peanut butter, coconut aminos, sriracha, ginger powder, minced garlic, rice vinegar – combined until I like the way it tastes.

    I used to make french press coffee, but the annoying clean up process was giving me cortisol spikes. Not primal. :p

  16. The only thing bettor than peanut butter on toast is peanut butter and bacon on toast, lots of bacon! From a primal standpoint I figure all that bacon counteracts any perceived negative impacts of whatever might be in peanut butter.

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