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. I think the con of “it’s too tasty” applies to all nut butters. Once I start eating any of them, I don’t ever want to stop. I actually feel this way about most food, so…

    Alexa wrote on May 28th, 2012
  2. What about brands like crazy richards where the ingredients are just, “peanuts”

    No added oils or salt or sugar

    Steve wrote on May 28th, 2012
  3. I used to be addicted to peanut butter. Then I made myself by only the light version because it really tastes weird comparatively. That worked for me. I wanted it less and less.

    Toni wrote on May 31st, 2012
  4. I gave up peanut butter almost 2 years ago. What I missed most was peanut butter and jelly sandwiches and I used to eat them on a regular basis. When I was asked by friends that routinely asked me “What do you miss most in your new diet?” I would always answer, “PB and J sandwiches”. So, about a month ago, my husband was eating some peanut butter (the best kind of course) and I thought I would just give it a taste test. I tried it and realized that I no longer like Peanut Butter. So, for all the addicts out there, just give it up for 2 years, maybe less, and then give it another try. You might find that you too no longer like it and can then give up the emotional addiction as well.

    Trace wrote on June 1st, 2012
  5. I’ve gone totally primal and I look and feel great. my card intake is consistently 50g a day or less. Once a week or so I will have a granny smith apple with like 2-3 tablespoons of whole foods brand peanut butter with crushed pieces of dark chocolate. I chop up the apple put in the peanut butter and the chocolate and heat the whole thing up a little… its a mouth-gasm!

    michael fleishcer wrote on June 6th, 2012
  6. I don’t see how eating peanut butter would be a problem for most people in terms of over-indulging. I’ve read about studies how great the “peanut butter diet” is for losing or maintaining weight: eating just a little peanut butter (or any other nuts, for that matter) produces satiety (feeling of fullness) for quite a long time, resulting in less eating overall. Peanut butter has been called “the poor man’s protein” with more plant protein than any other legume or nut. Peanut butter has been used as a very cheap, effective emergency food for starving children in Africa. Most studies show nut eaters have less heart disease and diabetes, but I haven’t seen studies that distinguish peanut butter eaters from those how eat other nuts, to see if peanut butter itself is not so good compared to other nuts in health impact. But since peanuts are overwhelmingly the most consumed nut, it would seem that the benefits accrued to nuts would be due in great part because of, not despite, peanuts. It would be great to see studies that isolate peanut butter eaters specifically, and perhaps there are some out there that I’m not aware of.

    Ed Sadowski wrote on June 14th, 2012
  7. I make my own pb from locally grown peanuts and have 2 tablespoons daily. I can’t imagine that this is a terrible thing to do.

    Denise wrote on June 29th, 2012
  8. Peanut butter was a major contribution to my weigh gain over the years. First thing when I got home from work it was the jar of peanut butter, a big spoon and a diet soda.

    Three weeks ago I made the switch to the paleo diet cold turkey…gave up grains, chips, pasta, sugar, all types of soda/juices, milk and processed foods. In 3 weeks I have lost 17 pounds and this includes one individual pack of Justin’s Natural PB (32g) with a small organic banana 4 to 5 times a week.

    I may consider giving it up in the future but that one small indulgence is getting me through the rest.

    Marc wrote on July 1st, 2012
  9. I’m a peace corps volunteer in africa. It’s so hard to be primal here and i probably eat too much crappy peanut butter. I miss almond and grass-fed butter, steaks, macadamia nuts, and weirdly, veggies like asparagus and brussels sprouts that can’t be found here. Still, i feel guilty complaining when there are malnourished kids around the corner who would love to have my peanut butter…

    Cait wrote on July 9th, 2012
  10. my grandmother would eat 8 to 10 tablespoons full of peanut butter since she was a little girl,she is 93 now and still loves her peanut butter…..

    eddie wrote on July 18th, 2012
  11. I eat a few spoonfuls and that’s it. I recently read a recipe of Bangkok Peanut Ice Cream, and decided to make a simplified version which has no flour, cheese and sugar, so it’s basically heavy cream, shredded coconut, peanut butter and ginger and cayenne to taste. 😀 Most of the time I abstain for financial reasons, peanut butter is not as widespread in Europe therefore costs more than my usual foods.

    Reka wrote on July 20th, 2012
  12. Marantha brand peanut butter is not to be trusted.. i refrigerate mine and it literally feels like fudge. that CANNOT be good!
    sure as hell tastes good but makes me feel like crap after eating two or three servings!

    Ana wrote on July 21st, 2012
  13. I’m currently eating almond butter instead but I do still have both. For me cost is a bit of an issue… peanut butter (even the good organic stuff) is very cheap for the nutrition you get. I also have issues stomaching the healthier alternatives. For me it’s a good stepping stone towards healthier nutrition.

    Ian Cannon wrote on August 6th, 2012
  14. I am not a big fan of peanut butter but do eat them now and then just out of pure cravings ( women and cravings, don’t ask!) but going on paleo recently meant I was desperate to get my hands on any kind of dips for veg and fruits etc
    got my hands on a few small packets of justins almond butter ( they are great for portion control or travelling ) tried it smeared on a few pieces of left over coconut flour pancakes,it was delicious! never going back to peanut butter again!

    Steph wrote on August 15th, 2012
  15. 16 grams of fat, 7 grams of protein, 8 grams of carbs (3 sugar, 2 fiber, 3?) in a 2 tablespoon serving and it tastes so good. I understand the part about wanting to eat the whole jar as an issue and that there may/may not be some other things wrong, but it will definitely remain one of my few vices!

    For all of you that say you used to like peanut butter but now don’t: I don’t believe you.

    David Sullivan wrote on August 17th, 2012
  16. Wow I never knew how bad peanut butter was for. I clearly love the fact where you suggested that peanut butter is too tasty. I see myself over-eating many times due to the fact that I just can’t stop eating.

    Btw I am a new reader to this blog and I am loving every post. I think very soon I am gonna go primal!

    Sid wrote on August 27th, 2012
  17. I have eaten a peanut butter sandwich with the proper whole wheat bread everyday for the last 5 months and have lost 40 pounds. From 190 to a fit 150. Of course I incorporate plenty of exercise and eat healthy the rest of the day. I also eat peanut butter once a day, 3 table spoons. So I eat it in moderation. I watch my fat intake the rest of the day and try not to eat more than 65 grams of fat a day. Nonetheless, though, I eat it every. Single. day. and have seen phenominal results.

    Taylor wrote on September 13th, 2012
  18. I literally only discovered the stuff about a week ago after my lady went on this silly “chemical breakdown diet” and bought lots of stuff such for it. I had a fingerful of it. “Hmm” I thought. Then I cracked a spoon from the draw, and had a little spoonful. That was it. Since them I’ve been having a few spoonfuls every other day, and the pot is about half empty since 2 weeks ago. But I’m afraid I’m getting addicted. I’m tempted to eat more right now. In fact I had a big spoonful 5 minutes ago after my lunch. I consider myself a healthy person. I do 60 minutes of cardio 3-4 days a week along with 30 mins of resistance training. Fairly balanced diet (I stay away from all that bad sugar and chocolate, pizza, processed food etc.) I suppose my case isn’t as bad as others’ but I want the pot to be empty so I never have to have a spoonful again. Especially when half the pot contains about 1000 calories and 100g of fat. I suppose the protein can help after coming back from the gym though…

    Sam wrote on September 14th, 2012
  19. I love PB, I don’t eat it in industrial quantities, maybe once or twice a week with an apple but I also enjoy almond butter. Good thing I don’t have an addiction to it though. I can stop at two tb, thankfully.

    Ivonne wrote on October 2nd, 2012
  20. my god, you’re all mad.
    i dont see any animals worrying about certain microscopic fungi they ingest, a fungi that is EVERYWHERE. eat healthyand excercise, eat what you’re SUPPOSED to eat, grains are natural?

    Jack wrote on October 3rd, 2012
  21. srry, that was insensitive me, whether i agree or not I should not have been so negative towards you, sorry about that

    Jack wrote on October 3rd, 2012
  22. I do eat peanut butter (the “natural” kind, with nothing but peanut). Is it THAT bad?

    As a student, my budget is limited (and I spend so much on veggies already), and peanut butter is a relatively cheap source of energy.

    Any suggestions?

    janus wrote on October 16th, 2012
  23. Has anyone here ever tried making their own? That way, you avoid any chemicals, sugars and other nasties. Having said that, once you are aware of what peanuts can do to your system, an occasional ‘treat’ of peanuts/peanut butter becomes less appealing. I love them, and have enjoyed my own home-made PB, but now I’ve started on Paleo/Primal don’t want to take the risk.

    heidifromoz wrote on October 16th, 2012
  24. I just recently heard about the negative effects of peanut butter, and while I was highly disappointed, I was not too concern. Don’t get me wrong, after reading this helpful article I will approach peanuts/peanut butter with even more prudence than before, but nevertheless, it is moderation ultimately which yields the most benefits in any decision. Economics and education are the 2 most relevant factors (i believe) to dictate what goes into our bodies. Ultimately, even purified water can hurt us or kill us, if consumed in excess. So I will enjoy away peanut butter, pork, beef, beer, etc and I shall approach it with the same awareness as raw veggies, fruits or any other healthy habit…

    Gabriel Mendez wrote on October 23rd, 2012
  25. Peanut Butter is definitely my guilty pleasure. I can’t resist it! I actually enjoy the taste of almond butter, though, as well. I mean, yes, it’s not PB but it’s still good. Almond butter has a plainer taste to it, whereas PB is just REALLY sweet. My taste buds have grown accustom to almond butter, but I still can NOT seem to shake my peanut butter habit. For some reason, we always have it stocked in the house. (Probably my husband buying it!) I can’t help getting up to go look for some, even if I think its not there. Actually, I’ve tried coconut butter, and it’s delicious to me. I love coconut anything, but thats just me. The thing is, Almond Butter is just SO expensive at the grocery store. My kids LOVE PB&J, and I try to buy almond butter as a sub for their sandwiches, but it gets sort of pricey at times!

    Keili J. wrote on October 30th, 2012
  26. I can eat pounds and pounds of smoked wild salmon (and I probably would keep eating as long as it was in front of me). Incidentally, this is also how I keep the O3:O6 ratio where it needs to be (after all the peanut butter I eat!)

    David Sullivan wrote on November 24th, 2012
  27. Americans eat over 700 million pounds of peanut butter; we do this because it helps replenishing some of the needed nutrients. Peanut butter has very good sources of polystutrated and monosturated fats. It can also help you lose weight by eating a spoonful of peanut butter it can curb your appetite. Peanut butter is also packed with nutrition that we lack in such as zinc, potassium, copper, and magnesium.

    Ryan wrote on December 4th, 2012
  28. What Mark says in this blog about peanut butter is true. I haven’t purchased peanut butter in two decades due to the reasons he has listed here. Additionally, I recommend to my patients to do the same. That said, I have tasted it here and there and my oh my it is good!

    Shellie wrote on January 13th, 2013
  29. I do not like almond butter AT ALL. It’s just too bland and thick. But I LOVE sunflower seed butter. Trader Joe’s has a one-pound container for $5. It’s creamy and rich! Despite at one point having a full-blown Whole Foods 365 brand peanut butter addiction a few years ago, I can’t even eat peanut butter anymore. Consuming too much peanut butter slowed my digestion to a halt. It got the point where I was expelling waste that literally looked just like peanut butter. It was unsettling, and a wake up call that maybe regular peanut butter consumption is a bad idea. But since I’ve found the reasonably-priced sunbutter, I don’t even want to go back, and my digestion is back to normal. It’s must closer to peanut butter in taste than almond or cashew butter.

    Hilary wrote on January 17th, 2013
  30. I think if you can have peanut butter in moderation, there really isn’t a big issue. I mean c’mon, there are worse things out there. It should be used as a treat instead of a habitual thing.

    Ann wrote on January 24th, 2013
  31. Hey everyone! So there’s an organic nut butter out there called “Nuttzo”, anybody else heard of it? It is a 7 nut/seed blend that even is infused with dark chocolate. However, the first ingredient is … Drum Roll … Peanuts!!

    So my question to you Mark or any of you primals is … Is this safe to eat? It claims it has a healthy amount of ALA omega 3 fatty acids as a disclaimer.

    I would love to hear your guys’ thoughts!

    To eat.. Or not to eat. Cheers!

    Bradley Wiskowski wrote on January 29th, 2013

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