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

How Bad is Peanut Butter, Really?

Man, you guys really love your peanut butter.

I get at least one email a week from a devoted reader of the blog who just can’t shake the desire (that feels like a need) to eat peanut butter on a regular basis. They’re on board with everything else. They’ve ditched grains and vegetable oils. They’re walking more and getting better sleep. They’re getting sun and eating more vegetables than ever before. They’ve switched to grass-fed beef (sometimes liver, too!) and wild-caught fish. They’ve even happily dumped all the other legumes, except for that persistent, palatable peanut. The more dedicated among them may be soaking, sprouting, roasting, and grinding their own peanuts into peanut butter, but they’re still eating peanut butter – a “forbidden” food on the Primal eating plan.

I’m talking questions like this:

Dear Mark,

I have been following MDA for about a year now and last I week I finally went primal.  So far I have not had any issues with giving up grains (no cravings), except I cannot shake my peanut butter addiction! I eat a small bowl full of peanut butter with banana slices for a snack and I know it is awful for me! I eat very healthy foods for the rest of the day (eggs for breakfast, salad for lunch, meat and veggies for dinner) but the peanut butter is probably preventing progress! Help!


I don’t want people to feel deprived, nor do I enjoy stripping from them the ability to enjoy their favorite foods, but I also want people to make the best and healthiest food choices possible. To do that, we need to examine the evidence. We need to give peanut butter the rice and oat treatment. We need to figure out whether or not peanut butter is really all that bad. Let’s go, shall we?

First, The Good.

What’s good about peanut butter? Why would we ever want to eat it?

It’s tasty.

I’ll admit it: peanut butter is quite delicious. I’ve never much cared for actual peanuts – they were okay, but not something I sought out – but I’d always grab a spoon or dip a finger for some peanut butter.

It contains nutrients.

It’s food, so of course it has something to it. But what?

Peanut butter is a decent source of thiamin, niacin, folate, and magnesium. It’s actually fairly rich in polyphenols, particularly when roasted (which increases the coumaric acid content considerably). Peanuts also contain small amounts of CoQ10 and resveratrol, though I’d much rather get those from beef heart, sardines, and red wine, personally.

Now, The Bad.

Why should we avoid it? What’s not to like about peanut butter? I’m not even going to discuss the soybean oil and sugar-laden garbage that passes for peanut butter, because my readers definitely aren’t asking about that stuff. They’re doing natural butter with peanuts (and salt) as likely the only ingredient.

It generally contains aflatoxins.

Aflatoxins are naturally occurring fungal toxins, or mycotoxins, produced by certain members of Aspergillus, a type of fungus found pretty much everywhere throughout the world. Aspergillus tends to colonize any monosaccharide and polysaccharide it comes across, as long as the conditions are right, but peanuts are particularly susceptible. Most crops are colonized after harvest and during storage, but since Aspergillus is found in the soil (among other places) and peanuts grow underground, peanut colonization often occurs well before harvest. The result is that peanuts are among the most contaminated crops, along with corn and cottonseed.

I wrote about the negative effects in a previous post, which I’ll sum up for you:

Aflatoxin, being a toxin, is metabolized by the liver. Large enough doses of aflatoxin are a liver carcinogen in high doses (it’s actually what T. Colin Campbell used to induce liver cancer in mice during his China Study crusade to indict animal protein). Early exposure and elevated bloods level of aflatoxin are associated with stunted growth in children.

Interestingly, it seems that the peanut butter-making process dramatically reduces the aflatoxin content of the initial peanuts, by around 89% (PDF). In the study, roasting at 160 degrees C reduced aflatoxin by 51%. Blanching, or skin removal, reduced it by 27%. Finally, grinding the peanuts into butter removed another 11% of the aflatoxin, probably because of the heat (not the actual grinding). So if you’re going to eat peanuts, stick with a good butter.

It contains peanut agglutinin.

As of now, the harmful effects of peanut agglutinin, a peanut lectin, are mostly speculative, but still compelling:

  • In isolated human colon cancer cells, peanut lectin is a mitogen, or growth-promoter. You generally don’t want cancer cells to divide and increase in number.
  • Altered glycosylation may be at the heart of inflammatory bowel disease-related cancers, like colon cancer.
  • Peanut agglutinin causes colon cancer cell proliferation via altered glycosylation, in an in vitro study.

That said, those are just in vitro studies. They don’t tell us what happens when peanuts are eaten. However, in real live human subjects who ate real peanuts, peanut agglutinin has been shown to make it through the gut lining to end up in the blood stream. That’s a little worrisome, don’t you think?

I want to reiterate, though: eating peanut butter has never been causally linked to the development of colon cancer. In fact, one epidemiological study found that frequent intake of peanuts and peanut products was linked to a lowered incidence of colorectal cancer in Taiwanese women.

It might contain a uniquely atherogenic oil. 

Yeah, peanut oil has a good amount of monounsaturated fat, about 46.8% of the total fatty acid content, which has earned it a solid reputation for heart health in the conventional health world. But it’s also got a significant amount of PUFAs, too. 33% of the total fat is omega-6 linoleic acid, with an essentially nonexistent omega-3 ALA content. You could say that about a lot of nuts, though, and I don’t think the PUFA content is the big determinant here. It doesn’t help, but it’s not a deal breaker on its own. Let’s dig a little deeper.

Peanut oil has favorable effects on standard lipid panels. LDL drops, total drops, total:HDL ratio drops. The jury is out on how much that all matters, but eating peanut oil will probably make your cardiologist happy. Awesome, right? Maybe, but peanut fat appears to be uniquely atherogenic despite the lipid effects. For decades, it’s been used by scientists to induce atherosclerosis in cholesterol-fed rats, rabbits, and primates. Some researchers think that peanut lectins, present in the oil, are the cause of the atherogenicity. Reduction of the lectin content of peanut oil, through “vigorous washing,” also reduces the atherosclerosis it causes (although not completely).

You know what else reduces the peanut lectin content? Not eating any peanut butter.

It’s a little too tasty.

There’s something about the combination of fat, salt, protein, and smooth scoopability of peanut butter that promotes overeating. I wasn’t able to bring up any concrete studies on the pro-bingeing effects of peanut butter in humans (though if you run a Google search for “peanut butter addiction,” you’ll get a bevy of testimonials from all sorts of people claiming to be addicted to the stuff), I believe it. And I bet obesity researchers who typically work with rodents would believe it, too, since peanut butter is often used in these studies as a high-reward, obesogenic comfort food that rats and mice will readily and consistently overeat.

Ultimately, to feverishly scoop in a ravenous frenzy or not to feverishly scoop in a ravenous frenzy is a choice you have to make. I wouldn’t recommend eating peanut butter very regularly, and I know I won’t for the reasons mentioned above, but that doesn’t mean you have to follow suit. The inclusion – or exclusion – of peanut butter (or peanuts in general) will not make or break your Primal cred. There are a lot of things you want to have under control before obsessing over peanut butter, like grains, omega-6 oils, sleep, exercise, play, daily low level activity level, quality of meat, etc. You get those under control and then start thinking about some peanut butter as a treat every now and then, if ever.

As I see it, the easy answer is to just not eat it, because I don’t see anything at which it particularly excels (besides inducing people to eat the entire jar in a single sitting). You can get your polyphenols and your minerals from fruits and vegetables, your monounsaturated fat from meat, olive oilmac nuts, and avocados, and your smooth pulverized salty nutty fix from almond butter, mac nut butter, coconut butter, or any other nut butter – without the peanut lectin, the weirdly atherogenic fat, the aflatoxin load, or the insatiable desire to eat more and more and more until it’s all gone and your forearm is sticky.

Of course, it’s easy for me to say: I don’t have a peanut butter habit.

Anyway, let’s hear from you guys. Do you eat peanut butter? Are you addicted? Are you able to stop with just a bite or two? And most importantly, has your peanut butter habit negatively affected your results? Let me know in the comment section!

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. D: No peanut butter? For real?

    This is going to have to be my one regular non-Primal indulgence. Grok can’t take my precious peanut butter, haha! 😛

    Cassidy wrote on February 28th, 2013
  2. Two years ago, started having a breakfast of green tea with a bowl of oatmeal, buckwheat or 10 grain hot cereal for breakfast, with a generous scoop of peanut butter, and added cinnamon, turmeric, pepper, olive oil, raisins and berries, and some almond or soy milk. Currently weigh about 33 pounds less than two years ago and have maintained that weight. Also eat peanut butter during the day on sandwiches, snack on walnuts and pistachios..

    About a year and a half ago, I read an article on a triple play way of cutting body fat, where there were three classes of foods that eaten together were 10 times more effective at reducing body fat that each one separately. Peanuts were one type, oatmeal was in a second group, green tea was in the third group. Turns out the morning bowl of hot cereal combined the major fat blasting foods in the right proportions.

    I also do interval training using a soccer ball, or martial arts, or walking up and down hills, which do doubt is responsible for some of the weight loss and control.

    My old weight (220) was due, in part, to eating peanut butter out of the jar on a spoon, and a just before bedtime peanut butter sandwich. Stopped eating PB out of the jar, and cut down on the late night PB sandwiches.

    Your article is a bit scary to someone who eats a lot of the stuff. Maybe I should reduce the PB substantially. Some health experts say eat all the nuts and seeds you want. My total LDL/HDL is about 170, which may not be especially good.

    larry Bee wrote on April 2nd, 2013
  3. Well, peanut butter contains a lot of zinc and protein. Try it a couple of hours before an exam or some deadline, better than chocolate, you will be working non-stop for hours. All that zinc.

    I think if it is organic and from toasted peanuts, small amounts of peanut butter once a week should be ok. Chewing it carefully before swallowing will reduce its carbs load. Keeping it in the fridge will reduce mold as well.

    No nuts should be consumed in large quantities, Too moldy.

    A.T. wrote on April 5th, 2013
  4. aflatoxin is generally only a problem in high humidity areas like south africa and the like. in canada, the states and uk, peanuts below our standard (higher potential for contamination) are actually shipped to other poor countries. i don’t think aflatoxin is a huge worry here, especially if youre grinding it up yourself into a tasty pasty!

    humanemeat wrote on April 12th, 2013
  5. I absolutely LOVE peanut butter, and have no control once the jar is open – which isn’t a good thing for me or my kids. So we stick with cashew butter and mac nut butter, on an occasional basis.

    Ellen Smith wrote on April 16th, 2013
  6. I prefer sunflower butter now; used to love peanut butter but felt the potential for bingeing was indeed more enhanced than other foods. Also, my body doesn’t handle peanut butter (or most nuts and nut based foods) well. Enjoyed reading your article!!

    C wrote on May 12th, 2013
  7. W100% Almond Spread

    Gabi Pasqualon wrote on May 21st, 2013
  8. Wholemeal bread, 100% almond spread, slices of banana and a very small drizzle of honey…. PERFECT!

    Teach your kids from an early age!

    Thanks for the article.

    Gabi Pasqualon wrote on May 21st, 2013
    • Wholemeal bread ?

      We don’t eat no stinkin bread here.

      samc wrote on May 27th, 2013
  9. I do put peanuts in my homemade lara bars and a little dairy dairy free chocolate but I keep these in the freezer for treats (i.e. once a week) so I think that kind of cheat is acceptable especially if it keeps me away from a bigger cheat.

    llong wrote on June 2nd, 2013
  10. I buy peanut butter to bait mouse traps with. It’s perfect for that. But, probably almond butter would catch mice too, and I would feel better about eating the rest of the jar.

    shannon wrote on June 4th, 2013
  11. I eat tons of organic peanut butter. I go through about a jar every 3 days or so. I put it on apples, and hence go through about 9 or more apples a day. I cut the apples into slices and put the peanut butter on them. I’m thoroughly addicted to this. Been doing it every day for probably the last 4 months. I don’t know how many jars of peanut butter that adds up to lol..

    matt wrote on June 5th, 2013
  12. Unless there is a serious allergy involved, it is insane to suggest that peanut butter be completely eliminated from the diet. Use common sense, moderation, etc. In other words, be human. All or nothing is a false choice.

    joel weinberg wrote on June 20th, 2013
  13. I go through a bottle of peanut butter per week. Good stuff. What you wrote is interesting speculation but it doesn’t contain any compelling evidence to avoid peanut butter. You can similarly critique just about any food. Vegetables contain pesticide residue and we all know how bad that stuff is for you. Even organic veggies can’t escape it. There’s practically no absolutely safe or healthy food out there now.

    Richard wrote on June 27th, 2013
    • Agreed. I normally agree with Mark’s arguments, but his reasoning why peanut butter should be avoided is not persuasive. I enjoy Smart Balance Peanut Butter with omega 3 from flax oil. Not only is this cheaper and easier to find than most almond butters, but it also has a better omega 3:6 ratio. I see no reason to choose almond butter over omega 3 peanut butter.

      grant wrote on October 1st, 2013
  14. I’ve been gradually trying to avoid processed foods and eat healthier. I’m a vegetarian who typically eats a natural peanut butter and jelly sandwich for breakfast. Though I eat it regularly, I don’t find myself craving or over-eating it. I’m currently looking for eggs from pastured chickens as I will not eat them otherwise. Pretty sure in comparison to your regular repliers, my diet is pretty darn awful. For example, I eat Post Raisin Brand with almond milk. I don’t have a nearby source where I can get good dairy or meat products (and I really cannot afford them currently). I really like beans of all varieties and will make various soups or stews with beans, vegetables and spices. Anyway, I’m probably a hopeless case in your eyes, but thought I’d post anyway. Though it is naïve, I have to think in comparison to all the processed foods that have umpteen ingredients I’ve never heard of that eating peanut butter, which only has one ingredient, daily but not in excess cannot comparatively be that bad for me. Oh and I eat cheeseless pizzas with xtra sauce and a lot of veggies on them. (You’re probably doing a face palm now.) Cheers!

    Jeff Wissman wrote on July 6th, 2013
  15. I came across your article today while doing weight-loss research. It started while reading a comment from Jim Karas who slated peanut butter as being a forbidden food to eat.
    I’ll be honest, I had the iLap Band surgically done on 3/1/13; while preparing to have this surgery, the doctor told me to load up on proteins because proteins help heal the body faster after the surgical work has been done. I have gained 2 pounds since then with no other news to report! The surgeon and Dietician have been at odds as to why I have been not losing the weight post-op the Lapband and folding of my stomach. During a recent dietician visit, I professed the LOVE and consumption for Silk Jiff PB. I eat it practically EVERY day; not only do I eat multiple pre-packed containers on a daily basis, I have even gone to the “whipped” version that states it has 100 less calories per serving–that just makes me think that I can eat more!! Subconsciously, maybe I turned addict because the PB goes down smooth and it never gets hung in the band area; it is a trusty food of sorts!
    I AM ADDICTED TO SILK JIFF PB! I can’t stop and this worries me. I eat one cup, and then I jump right into the next! The smooth, creamy, sweet/salty combo draws me in every time.
    Now after reading the woes of PB from various standpoints of those who are struggling in losing weight, the answer is quite clear- STOP EATING THE STUFF! I am so sad…really, it’s like losing a best friend and not knowing who will be your new best buddy. But since the proof is in the pudding…I mean peanut butter…I better take the hint and leave the contemptuous habit in my past if I want to be slim and trim!

    Parthena Freeman wrote on July 7th, 2013
  16. fresh grind almond butter at whole foods is way better than jarred almond butter. don’t know why but that stuff is rank… i agree ive tossed that shit too.

    OR grind your own in a food processor at home. takes some time but it’s sooo good!

    jasmine wrote on July 7th, 2013
  17. Peanut butter is an issue for me too. I enjoy it as a protein pairing with carbs for a snack (i.e.. peanut butter and apple, or banana, etc.). It actually makes me feel not hungry and since I’m trying to go more primal with my diet, I have been feeling kind of weak and hungry. Granted it has been two days but I am not looking to go VLC or be in ketosis. I’ve had kidney stone issues in the past, have thyroid issues and have no interest in possibly screwing things up further. So I am trying to keep carbs at 120-150. Problem is I need a protein pairing to prevent insulin spike. Anyway, I can’t do almond butter, it’s gross and I am sometimes sensitive to almonds. I also have a major sunflower allergy and my son has a cashew allergy so as you see, my nut butter substitutes are not great.

    Jeanne wrote on July 22nd, 2013
  18. wow I have been eating peanutbutter from childhood,
    I’m a NYer so peanutbutter & marshmellow is a way of life lol
    how ever I live in Australia now and got away from some of my oldies, but I still like peanutbutter. as far as being hook on it? no
    the only things you get hook on is the things you want to. I have stopped a few things that I found were not good for me and walk away from them, but only when I found they were not what I needed. I like my peanut butter but I don’t eat a lot of it. and no one has been able to show me that it is not good for me so I keep eating it and yes I still have my NY ACC after beening here for 13 years. thanks have a great life.

    Rick Jeffers wrote on July 26th, 2013
  19. Buy me some peanuts and Cracker Jacks I don’t care if I never get back! For its root root root for the Dodgers if they don’t win its ashame,for its 1-2-3 strikes you’re out at the old ballgame!
    I enjoy a bag of peanuts at the baseball game.It is part of the National pastime!

    Laurie Ackerman wrote on August 10th, 2013
  20. i read, i understand, i take to heart your statements on PB.

    but what about cultures that rely on peanuts fairly heavily for taste and protein–like the Thai and other southeast Asian cultures, as well some African cultures?
    I believe their heart disease rates are very low–probably for many reasons–but peanuts don’t have an effect here?
    I wonder about what might need to be COMBINED with PB to cause atherosclerosis? perhaps PB in the right combination of foods doesn’t have so many negative effects, and in fact could be a positive food? i do think that peanuts is always cooked in these cultures–perhaps the way peanuts are cooked and used matters..?
    anyway, interesting topic..i actually prefer cashew butter and even almond butter over PB, so i’m not too drowned by its exclusion from my food life. but it interesting to understand plant and animal effects on their consumers.

    jo wrote on August 24th, 2013
  21. My conclusion from reading this article is: don’t eat peanut butter because it’s good for you!

    wyndham wrote on August 26th, 2013
  22. I don’t love peanut butter, but I do switch between almond butter and natural peanut butter as the almond butter is over twice as expensive. I also switched to gluten-free oat bread and rice pasta as a realistic starting point instead of ditching pasta and bread altogether.

    I continue to eat beans as I do not and will never eat meat in the future (personal choice). I avoid all dairy products from the regular grocery stores and have pretty much eliminated soy and wheat from my diet. Currently I am eating 4 eggs a day (a “free-range” Amish farm is the best I can get right now…looking for pasture-raised ones) usually with veggies sautéed in butter. I drink almond milk and as a rule do not eat cottage cheese, sour cream, cream cheese, etc.

    As an example, I used to eat peanut butter and jelly on wheat bread. Now I eat this open-face with one slice of gluten-free bread, preserves made with pure cane sugar instead of corn syrup and almond or natural peanut butter.

    I don’t eat any fast food, but still do eat pizza about once a week or two.

    I realize this is likely considered a terrible diet from your perspective, but my goal is to include paleoesque features into a vegetarian diet by eliminating most processed foods and all fast/junk foods. Were it not for the occasional pizza with light cheese and daily eggs, I would be eating mostly a vegan diet (btw I do not care for their ideology).

    I also drink Green Goodness and 100% carrot juice from Bolthouse farms and supplement with a multi-vitamin, B12, C, calcium/magnesium and iron.

    As I’m going for an individual hybrid diet please feel free to throw any critique or suggestions at me you would like to. Anything will be welcome (short of eating meat).


    Jeff Wissman wrote on August 26th, 2013
  23. güzelbirsite herkese tafsiye ederim bu siteyi teþekkürler.

    d wrote on September 12th, 2013
  24. Not eating peanut butter was fairly easy for me.
    “Oh what? There’s a million other nut butters in the world! Variety, yay!”
    There’s this great brand where I live called ‘Nuts To You Nut Butter’
    and they make cashew butters, macadamia butters, almond butters, combo nut butters (almond/cashew, macadamia/almond etc)…

    I love love love it. I have an apple with nut butter smothered all over the slices almost every day.

    Kate wrote on September 16th, 2013
  25. I use P/B to bait my mouse traps,my mentor said it was George Washington Carvers revenge against white people.I love me some Cheezy Poofs!

    scott bleyle wrote on September 23rd, 2013
  26. No added sugar or salt peanut butter is what I buy now.

    Regularly on bread ,sometimes dipped in coffee or tea.

    My pain from statin drugs has dissappeared!

    Roger wrote on October 7th, 2013
  27. I think that peanut butter is a gray area food, under Paleo. Is it a legume? Yes. Can peanuts be eaten raw? Yes. Is this something that a primitive culture would have eaten if given the chance? Probably. Peanuts are a ground nut that can be dug out with bare hands, sticks, rocks, or any other primitive digging tools. A knowledgeable primitive culture would most likely have soaked the nuts in salt water and roasted them in a fire pit in order to remove the antinutrients if they had to survive on them for any extended period of time. As for myself, I seem to be ok healthwise eating natural peanut butter as an indulgence (2 tablespoons worth) on a couple pieces of dark chocolate, within the 80/20 principle.

    James wrote on October 11th, 2013
  28. I love peanut butter and will eat it from a spoon, drizzled with honey. Best combination ever. Good thing I can’t eat more than a spoon at a time. I don’t know why, but it’s a lot like meat. Very tasty and satisfying but it makes me feel “done” with it after a small amount.

    Miryem wrote on November 15th, 2013

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