• Your life and health are your own responsibility.
• Your decisions to act (or not act) based on information or advice anyone provides you—including me—are your own responsibility.


Anti-Nutritionism, L-Canavanine, And The Limitations of N=1 Self-Experimentation

What Is Nutritionism?

While I disagree with Gyorgy Scrinis (and the popularizer of the concept, Michael Pollan) on their proposed solution, I believe Scrinis’ concept of “nutritionism” as an error in dietary thinking has merit—and I doubt anyone in the paleo community would disagree.

Reducing food to its nutrient components could be called “nutritionism”, and it has probably become the dominant way of thinking about food and health, and of constructing healthy diets.

The nutrition industry has implicitly, if not explicitly, promoted nutritionism by continually framing most research studies and dietary advice in terms of these chemical-nutrient categories.

The rise of nutritionism is clear in one of the well-known sayings promoted by the food industry and some nutritionists: “There is no such thing as good and bad foods, only good and bad diets.” According to this argument, all types of foods, including junk food, have a place in a “balanced” diet.

Marketing foods and diets on the basis of their nutritional composition tends to take attention away from the quality and the type of foods being promoted.

Processed foods, for example, are often fortified with vitamins and minerals, or stripped of some of their fat, to enable such nutrient-content claims to be made. Nutrient claims on the labels of processed foods and drinks conceal the fact these foods are typically high in added fat, sugar, salt, chemical additives and reconstituted ingredients, and have often been stripped of a range of beneficial micro-nutrients and food components.”

High in protein, low in fat and too good to be true, Gyorgy Scrinis, Sydney Morning Herald, April 7, 2006

Nutritionism makes several unspoken assumptions:

  • We already know all the important nutrients and their functions.
  • The function of an isolated nutrient (even in a synthetic form not occurring in nature, e.g. folic acid) is exactly the same as its function in food, because…
  • There are no competitive or synergistic effects between the thousands of chemical compounds found in one bite of real food.
  • The effect of a food on health is reducible to its effects on the numbers obtained from cheap, easy tests like “BMI” and “total cholesterol”.
  • Therefore, so long as our diet contains the proper “nutrients”, we will be healthy and happy.

I doubt anyone in the paleo community disagrees with Scrinis (and Pollan) that nutritionism, in its modern form, is bunk. A diet of chicken nuggets, Twinkies, and Diet Coke is not nutritionally equivalent to a diet of fresh meat, fruits, and vegetables no matter how many supplements we take.

What Is Anti-Nutritionism?

Unfortunately it’s possible to fall into an analogous trap when pursuing a paleo way of life…a trap I call “anti-nutritionism”. Anti-nutritionism also makes several unspoken assumptions:

  • We already know all the important anti-nutrients and their functions.
  • The function of an isolated anti-nutrient is exactly the same as its function in food, because…
  • There are no competitive or synergistic effects between the thousands of chemical compounds found in one seed, sprout, fruit, or bite of plant or animal tissue.
  • Herbivorous, seed-eating mice—especially genetic knockout mice—are metabolically and biochemically the same as humans, and are excellent models for human digestion and metabolism.
  • Therefore, if I eat a food for six months and I don’t get any fatter or suffer obvious health problems, I can recommend it to others as healthy—and perhaps even paleo-compatible.

Food Doesn’t Want To Be Eaten

It’s tempting to believe that if a food we like doesn’t contain gluten, excessive omega-6 fats, or excessive fructose, that it’s fine to eat. However, all food has defenses against being eaten—because any plant or animal that was eaten before it reproduced failed to leave descendants!

This leads us to a tautological but astonishing conclusion. Every living thing on this Earth is the descendant of millions of generations of successful ancestors—not a single one of which was eaten, trampled, gored, poisoned, burned, drowned, starved, fell from a tree, killed by parasites or infection, or otherwise died before it managed to reproduce at least once.

“Being eaten” certainly qualifies as a reproduction-limiting event. Animals can hide, run away, or counter-attack—but plants cannot. Therefore, we might expect their defenses to involve being disgusting, poisonous, or indigestible—particularly for seeds, their agents of reproduction.

Fruit is the exception to the rule, but there’s an unspoken bargain involved: “eat this delicious, sweet fruit, but don’t digest the seeds…poop them out somewhere else.” As we’d expect, the seeds of most sweet fruits range from bitter to frankly poisonous.

Many books, websites, and scientific papers explore the biochemistry of anti-nutrients like gluten and gliadin (found in wheat and its relatives) and lectins (found in just about every plant seed), and I won’t rehash the biochemistry here. But just as our knowledge of the nutrients in food and their function is incomplete, our knowledge of anti-nutrients is, if anything, far more incomplete.

A Partial List Of Plant Toxins

Lectins, trypsin inhibitors, antigenic proteins, cyanogens, tannins, quinolizidine alkaloids, glucosinolates, saponins, phytoestrogens, non-protein amino acids…

Today’s Unsung Anti-Nutrient: L-Canavanine

To illustrate the limitations of the paleo community’s understanding of anti-nutrients, here’s an example I’ve never seen mentioned by any paleo source: L-canavanine.

(Update: Though it makes no appearance in the literature, apparently Dr. Loren Cordain has indeed been discussing L-canavanine in his speeches and presentations. Thanks to Pedro Bastos for the correction.)

“L-canavanine is a common non-protein amino acid found naturally in alfalfa sprouts, broad beans [also known as “fava beans”], jack beans, and a number of other legume foods [including sword beans] and animal feed ingredients [1] at up to 2.4% of food dry matter. This analog of arginine (Figure 1.) can also block NO synthesis [2-5], interfere with normal ammonia disposal [6,7], charge tRNAarg, cause the synthesis of canavanyl proteins [8], as well as prevent normal reproduction in arthropods [9] and rodents [10].

Canavanine has also been reported to induce a condition that mimics systemic lupus erythematosus (SLE) in primates [11,12], to increase antibodies to nuclear components and promote SLE-like lesions in auto immune-susceptible (e.g., (NZB X NZW)F1) mice [13].” (Brown 2005)

Stated plainly: canavanine “looks” like arginine, and is incorporated into our tissues like arginine…but the resulting proteins don’t function properly. And did I hear someone say “lupus”?

Arthritis Rheum. 1985 Jan;28(1):52-7.
Effects of L-canavanine on T cells may explain the induction of systemic lupus erythematosus by alfalfa.
Alcocer-Varela J, Iglesias A, Llorente L, Alarcón-Segovia D.

Alfalfa sprouts can induce systemic lupus erythematosus (SLE) in monkeys. This property of alfalfa sprouts has been attributed to their non-protein amino acid constituent, L-canavanine. Occurrence of autoimmune hemolytic anemia and exacerbation of SLE have been linked to ingestion of alfalfa tablets containing L-canavanine. In this report we show that L-canavanine has dose-related effects in vitro on human immunoregulatory cells, which could explain its lupus-inducing potential.

Rheum Dis Clin North Am. 1991 May;17(2):323-32.
Dietary amino acid-induced systemic lupus erythematosus.
Montanaro A, Bardana EJ Jr.
“In this article, we detail our experience with a human subject who developed autoimmune hemolytic anemia while participating in a research study that required the ingestion of alfalfa seeds. Subsequent experimental studies in primates ingesting alfalfa sprout seeds and L-canavanine (a prominent amino acid constituent of alfalfa) is presented. The results of these studies indicate a potential toxic and immunoregulatory role of L-canavanine in the induction of a systemic lupus-like disease in primates.”

L-canavanine, being an amino acid, is not deactivated by heat or cooking. So when we hear statements like “Beans are fine so long as you soak or sprout them”, it’s worth reminding ourselves that this isn’t even true according to the tiny fraction of legume biochemistry we understand—let alone the overwhelming majority we don’t.

Further Reading

J. Agric. Food Chem. 2003, 51, 2854−2865
Nonprotein Amino Acids of Plants: Significance in Medicine, Nutrition, and Agriculture
E. Arthur Bell

“Much more needs to be learned of the biological activity, the relative toxicities of these compounds to different organisms, and their nutritional value if we are to make the best use of them and the plants in which they are synthesized.”

Autoimmun Rev. 2006 Jul;5(6):429-35. Epub 2005 Dec 29.
Role of non-protein amino acid L-canavanine in autoimmunity.
Akaogi J, Barker T, Kuroda Y, Nacionales DC, Yamasaki Y, Stevens BR, Reeves WH, Satoh M.

Am J Clin Nutr November 1995 vol. 62 no. 5 1027-1028
Reply to NR Farnsworth
Victor Herbert

Also note that you’ll find a much-copied reference on the Internet claiming that canavanine toxicity is irrelevant to humans. Don’t be misled: it’s an article from a 1995 vegetarian journal which makes a host of blatantly false claims, such as “There is NO canavanine at all in other legumes that are commonly used as human food.”

Favism: A Postscript to the Fava Bean/Broad Bean Issue

Canavanine toxicity is distinct from vicine toxicity. Vicine (and its analogs covicin and isouramil) is a poison in fava beans that causes hemolytic anemia in susceptible people—a sometimes-fatal condition known as favism. Favism is caused by G6PDH deficiencies, common X-linked mutations which affect over 400 million people worldwide, mostly in Africa, the Middle East, and southern Asia.


The Limitations Of Self-Experimentation and N=1

Self-experimentation is very important, and we can learn much that is useful from it. For instance, trying to dial in carbohydrate intake can be a balancing act between weight loss, mood, and physical performance. People have found solutions to their own individual health issues via anything from egg yolks to beef liver to coconut oil to magnesium supplementation. And just coming up with a new repertoire of healthy, paleo-compatible foods to replace the pantry full of junk we used to eat involves extensive N=1 with new recipes—with immediate success not guaranteed.

However, there are limits to the knowledge we can accumulate. Stated plainly:

N=1 self-experimentation can tell us what works best for ourselves—within the limits of healthy eating, as defined by biochemistry and evolutionary context.

However, self-experimentation alone cannot tell us which foods are healthy to eat, because even a dramatic increase in lifetime risk is vanishingly unlikely to manifest itself during a few months of self-experimentation.

For instance, here’s a seemingly reasonable statement:

1. “I ate corn for six months, and I didn’t gain weight or feel worse. Therefore corn is healthy to eat.”

It’s certainly tempting to make these sorts of statements—but I find that temptation is best resisted. To illustrate why, here’s an equivalent statement that we can all agree isn’t reasonable:

2. “I started smoking six months ago, and I feel fine. Therefore smoking is healthy.”

Permit me to drive the point home with force:

3. “I started eating strontium-90 six months ago, and I haven’t got cancer yet. Therefore radiation exposure is healthy.”
4. “I started shooting heroin six months ago. It’s solved all my anxiety issues, and I’ve lost twenty pounds! Therefore shooting heroin is healthy.”
5. “I started having unprotected sex with Tanzanian hookers six months ago, and I feel great! Therefore unprotected sex with high-risk strangers is healthy.”

The reason we can identify the second through fifth statements as false is because we don’t trust the results of our own self-experimentation. We know that long-term observations show that smoking greatly increases our risk of several forms of cancer and heart disease; each Sievert of radiation exposure causes a 5-10% increase in cancer deaths (Strom 2003); heroin addiction is almost never a controllable vice; and HIV infection takes longer than six months to produce symptoms of AIDS—no matter how we feel in the short term.

No, I’m not directly comparing eating corn to smoking or unprotected sex with high-risk strangers! I’m demonstrating that even a substantial increase in lifetime risk is vanishingly unlikely to manifest itself within any period of self-experimentation. This is why anecdotes are useless when evaluating risk.

For example, my grandfather smoked two packs of cigarettes a day for over sixty years, dying in his 80s of a non-smoking-related illness…but that doesn’t change the fact that smokers contract lung cancer 15-20x more often than non-smokers (Thun et.al. 2008), and also suffer from all types of heart disease, many other cancers, renal damage, and impotence at a far greater rate than non-smokers. And while I’ve spent plenty of time making fun of weak associations extracted from known-bad data, I do find the evidence for negative health effects from regular smoking reasonably convincing—though perhaps of smaller magnitude than claimed by typical sound-bites.

In conclusion, it’s clear that anti-nutritionism makes it easy to fall into the trap of extrapolating N=1 beyond its limits. By assuming that we already know all the important anti-nutrients, we can easily convince ourselves that a clearly Neolithic food is healthy (or, at least, harmless) just because we don’t feel any obvious harmful effects from consuming it in the short term.

To answer such questions, we need to apply science, not N=1…

…and it is very likely that the answer will not be authoritative. Scientific answers are much more likely to be of the form “There are a lot of potential toxins, but we don’t know how bad they are for humans, either singly or in combination” or “It’s analogous to something that quickly causes pancreatic cancer in rats—at 10 times a realistic dietary dose.”

That’s where evolutionary context comes in, and where I use my general rule of thumb, previously seen here:

Eat foods you could pick, dig, or spear. Mostly spear.

The Takeaways: Now What?

My intent is not to encourage anyone to become overly fearful about eating the occasional bowl of ice cream or tarka dal! I understand that even functional paleo can feel somewhat limiting at times, and that nothing will make a fresh, hot Krispy Kreme not taste delicious.

What I’m doing is cautioning my readers that no interesting or useful information comes from arguments about whose N=1 is more authoritative; I’m reiterating my own commitment to careful, rational inquiry; and, most importantly, I’m hoping to communicate my own respect, humility, and awe as one infinitesimal part of our huge, beautiful and dizzyingly complex world and the multi-billion year history of life upon it. As I said nearly a year ago:

“There is an important difference between “We don’t know all the answers yet” and “Do what feels right, man.” These questions have answers, because humans have biochemistry, and we should do our best to find them and live by the results.”

The Paleo Identity Crisis: What Is The Paleo Diet, Anyway?

Meanwhile, I will continue to do my best to find interesting and useful information at the intersection of biochemistry and evolutionary context, and I will continue to explain it as best I can to you, my readers, here at gnolls.org.

And since I like to leave my readers with a few practical takeaways, here are some useful thoughts for when you start finding even functional paleo limiting or monotonous.

  • Consider what you’ve gained, not just what you’ve lost. Sure, you can’t just binge on half a dozen crullers anymore…but you can eat all the prime rib you want without any form of guilt. How cool is that?
  • If you’re stuck in a rut of monotonous food, try some new recipes. Yes, it’ll take some time and several tries to find and perfect a new dish you like as much as your current favorites. Here’s an endless source to get you started.
  • Cheat proudly. For the most part, the dose makes the poison…so unless cheating will start you on a binge, it’s better to say “I am going to eat these street tacos because they’re delicious and I want some” than to try to convince yourself that corn is paleo.
  • Cheat intelligently. Think of a cheat as dessert: once you’ve satisfied yourself with a complete meal, you can think about a Coke or a Reese’s. Otherwise you run the risk of your cheat replacing an entire meal—and once you’ve been paleo for a while, 1200 calories worth of Krispy Kremes will most likely make you feel like you’ve contracted Ebola Zaire.
  • Live in your body. The pleasure of junk food lasts until it slides down your throat: the pleasure of good health manifests itself 24/7 in better sleep, less pain, greater mental clarity and capacity, and greater physical ability. The strong, sleek, healthy body of an apex predator is a great place to be. Instead of medicating it into passivity or becoming a sessile peripheral to your computer and television, go outside. Climb a tree, kick balls, shoot baskets. Learn a new skill. Explore somewhere you’ve never been.

    There’s a big, bright, beautiful world out there: what are you waiting for?

Atop a Sierra peak that shall remain nameless

Live in freedom, live in beauty.


Yes, this one turned into another epic! Spread it like pollen with the new social clicky-popup-thing…and please support my continued efforts by making your Amazon purchases through my referral link. Did I mention that T-shirts are back in stock, in all sizes?


Permalink: Anti-Nutritionism, L-Canavanine, And The Limitations of N=1 Self-Experimentation
  • Samantha Moore

    Outstanding! Thank you—

  • Asclepius

    A great post as always.

    You’ve addressed much of my frustrations with Paleohacks! People are chasing numbers, not health. Many are complicating things in pursuit of a prescription/formula they can follow.

  • Those last five points are exactly where I am now and while reading would have made those very points here in the comments.

    Recently, I have taken to saying things like, “I love haggis more than I love paleo, so there!” or “I love whisky more than I love paleo”. These are things outside of paleo, potentially bad for me but things I love enough to risk it, so to speak. I don’t eat them frequently but when I do, I thoroughly enjoy them.

    Certain neolithic foods that I dearly love are off the table because they now make me feel ill (Yorkshire Pudding, processed cheese and most beers, sadly, by way of a few examples), others do not (yet … Haggis, whisky, Guinness, for example). That’s not n=1 at work, that is simply a list of neolithic things that I will still happily eat that (a) do, and (b) do not make me ill – they’re never going to be paleo, but does that matter? Absolutely not!

    I won’t call them cheats, because I am not cheating! Yes, I’m not sticking rigidly to a paleo diet by consuming these things, but so what? I’m not Paleo Man! I’m a simple human being who hopes he’s getting it right. Following as closely to how our ancestors have done for thousands of generations is a pretty sure bet, so long as we can get our foods from as close to the ground as we can.

    I love how you keep coming back to “or, as much as we know about xyz at the moment”. You’ve said it before – we’re on the first page of a huge book called ‘Understanding Nutrition’ and even modern biochemistry will not tell us the answers; certainly not when the absractions (nutritionalism) are combined together in an organism we use as food.

    Noting Asclepius’ comment above, I said it in one of my own recent blog entries – optimal is not necessarily advantageous, or desirable: http://paleo.pjgh.co.uk/2011/12/coming-in-from-cold.html

    For my next step in paleo, I’m going back to seasonal and local eating – the difficulty is getting seasonal and local food! Read that back … what I mean is, if something is seasonal for me, where I live, that product in a shop might not have been grown anywhere near where I live or even grown seasonally, perhaps grown in a warehouse all year round. Taking time to buy produce in farm shops, noting down the growers, farmers and butchers, then researching them to build up a list of local growers, farmers and butchers is worthwhile.

    Solid article, J! This is one I will read over again and again – it is very much where I am at the moment and I think where many people are. Funnily enough, ancestral lifestyle authors seem to be going one way while the community quite another way. These concepts can very happily draw paleo back on track and proud.

    Take care, pal.

    Right, time to get me a T-shirt …

  • Dave Sill

    “Every living thing on this Earth is the descendant of millions of generations of successful ancestors—not a single one of which was eaten, trampled, gored, poisoned, burned, drowned, starved, fell from a tree, killed by parasites or infection, or otherwise died before it managed to reproduce at least once.”

    Beautiful. Thanks.

  • Dan Brown

    Great read. Sign me up!

  • eddie watts

    i’m glad you’re tackling nutritionism as it is getting frustrating seeing it everywhere.

    i will also share this specifically with some friends who are sufferers of Lupus in particular, as well as with my whole facebook.
    (i now know that some people do read my links as a friend shared a link i put on there before from a different blog. also i normally get comments on my sharing of your work too)

  • Stacy

    If we have evolved with plants from the beginning, why haven’t we evolved the means to eat them? Like we have with meat and fish, tubers and fruit? Not a scientist here, so be nice!

  • Pedro

    Very Nice post. Congrats.
    Just one small repply to your statement that nobody in the Paleo community has ever talked about l-canavanine:
    Since 2008, Prof Loren Cordain has talked about L-canavanine many times in his lectures on autoimmunity.
    Keep up the good work

  • […] you any good either. Along those lines, I want you to take a good read at this post by J. Stanton: “what is nutritionism?” It takes a look at some of the more important anti-nutrients, and asks some really hard questions. […]

  • Marilyn

    “Every living thing on this Earth is the descendant of millions of generations of successful ancestors—not a single one of which was eaten, trampled, gored, poisoned, burned, drowned, starved, fell from a tree, killed by parasites or infection, or otherwise died before it managed to reproduce at least once.” Or as the genealogist said, “None of my ancestors died as infants.” 🙂

    Thank you for this post. I have long known that fava beans could be a problem, though I didn’t have much information beyond that, and had read some reassurances that cooking them solved the problem. But I don’t eat them anyway. It’s good to know about the alfalfa sprouts, since it would be easy to consider them a perfect low-carb food.

  • Samantha:

    I'm glad you find it helpful!


    There's definitely some chasing numbers on Paleohacks, and there's definitely some denial…”please, someone tell me my favorite junk food is paleo or that I can make a paleo version of it”.  It's a useful resource when used correctly — but remember, what it's really telling you is “Here's the result of a popularity contest between what a bunch of random people on the Internet said.”  

    In other words, Paleohacks is great for presenting you with options you may not have previously considered — but it's still your responsibility to investigate them, and the popularity of an answer doesn't necessarily predict its truth or usefulness.


    I believe yours is a much more healthy attitude than orthorexia or guilt.  The stress caused by “no, I can never touch that again, ever” or “oh no, I'm a failure, I drank a Red Bull” is most likely more damaging than the Red Bull itself!

    That being said, there's a difference between cheating and giving up entirely.  At some point we're not 90/10 or even 80/20…we're just using “paleo” as an excuse to put more processed meat on a pizza.  But your metric of “close to the ground” is a good one: the closer we can get to the source of our food, which is the Earth, the more nutritious it's likely to be (all other things being equal).


    Thank you!  I'm reasonably sure it's a paraphrase or summary of something Richard Dawkins said, though I don't remember from where.


    Glad you enjoyed it!  If you checked the “Subscribe” box, make sure to click the link in the subscription email.  If you didn't get one, check your junk or spam folders.


    Though I doubt that alfalfa supplements or sprouts, or fava beans, are statistically a major contributor to lupus incidence, it's certainly worth avoiding foods that could easily exacerbate the problem — especially when there's no reason to consume any of them in the first place!  (Even if you're too poor to afford meat, there are far less toxic beans than the fava.)

    More soon!


  • Paul Verizzo

    I think N=1 can be valuable, vs. controlled studies, in that if many individuals report roughly the same outcomes from a specific action, it certainly may indicate an advantage.

    “Hmmmm…..many diabetics switching to a very low carb diet can reduce or even eliminate insulin, maybe there is a cause/effect relationship!”

    I think Sisson talked about this once.

    I think controlled studies in diet and nutrition are almost impossible. Thousands of variables with both short and long term outcomes. For this reason, I think N=1 is a good jumping off point.

  • Pete Ray

    As always, J., yours is the voice of reason, in the face of PhD researchers using “scientific consensus” as an argument in favour of their incomprehensible theories.

  • Alex

    Great stuff! You’re in my top 10 fav blogs now!

  • Stacy:

    “If we have evolved with plants from the beginning, why haven't we evolved the means to eat them? Like we have with meat and fish, tubers and fruit?”

    That's a great question, and the answer is: we have, to some extent.

    For instance, avocados contain the fungicidal toxin persin, which is harmful or toxic to many animals (especially birds) but apparently harmless to humans in reasonable quantities.  Aspirin is toxic to cats, but a very effective pain reliever for us: it's very closely related to salicylic acid, a phenolic compound found in willow bark.  And so on throughout the plant kingdom: cruciferous vegetables are chock-full of glucosinolates which give them their bitter taste, and which we are reasonably well equipped to deal with (although large quantities do become goitrogenic).

    The way to think about it is an arms race.  Each generation, the plants which aren't too bitter or poisonous to eat get eaten, and the survivors produce more plants.  Yet the animals that can eat those plants without being poisoned also survive…and the cycle continues.  

    Every plant is full of anti-bacterial, anti-fungal, insecticidal, and digestion-inhibiting compounds!  The difference is that some animals eat that plant often enough to be competitive in the arms race with the plant, and some don't.  For instance, cats lost the ability to neutralize salicylic acid, because it's been tens of millions of years since their ancestors ate anything that contained salicylates.

    The problem for humans is that there are plenty of plant toxins we can eat and still manage to reproduce…but they still shorten our lifespan or decrease our quality of life.

    Yes, it's a complicated issue with no easy answers!


    Thanks for the correction: I'll make a note of that in the article.

    Note that I deliberately used the phrasing “…an example I've never seen mentioned” for exactly this reason.  Even if it doesn't appear in the paleo literature, I suspected I wasn't the only one to encounter L-canavanine and its leguminous relatives — whether from Bell 2003 or elsewhere.

    I greatly appreciate the vote of support!  It means a lot to know I've earned the respect of professionals such as yourself.


    Alfalfa sprouts are basically an object of religious devotion: anyone hardcore enough to choke them down is viewed somewhat akin to a saint of nutrition.  No, there is absolutely no reason to do so, and there are several good reasons not to.  I stick to baby greens.


    Add together thousands of N=1 and you get N=1000, which is a bit more interesting.

    Far more importantly, though, the progress of diabetes is something that can be quantified and accurately measured, at home, with a blood glucose meter.  In that case, the data isn't “I feel fine”, it's “My post-prandial blood sugar is no longer 280, it's 140.”

    Pete Ray:

    I'm glad my work isn't going unnoticed!  

    And no, you're not the only one who noticed that particular appeal to (imagined) authority.  Perhaps it's easier than getting the science right.


    I'll take that as a compliment, even though I don't know what the other nine are 🙂


    I'm caught up (for now), so now it's time to catch up on sleep.  Thank you all for helping keep gnolls.org a civil, information-rich place!


  • pam

    “cheat intelligently & proudly” , i like it.

    these days the cheat food has to be really enticing for me to be worth it,


  • DancinPete

    You can solve some of the limitations of N=1 if you get yourself a bunch of clones that you keep locked up in the basement and fed various experimental and control diets. However, you still have issues with the long gestation rates of various diseases – not to mention the cost of housing and feeding those good for nothing layabouts.

  • Lauren

    In fact there IS something that will make a Krispy Kreme not delicious: intellectual aversion based entirely on the ‘do you know what’s IN that!?’ or ‘have you seen who eats those?’ method. (like the famous bread on PH: http://paleohacks.com/questions/51685/do-you-have-any-great-images-that-show-your-worldview#axzz1rCabU0Uj) I can’t look at a cruller without shuddering. Oh, my mouth knows how it would taste/feel, but my brain immediately says stop right there, starts in on a rant about rancild oils, and my stomach closes the drawbridge and that’s that.
    That’s the only contradiction I’ll offer here; I think this is a great post and a sign of both the way and the times.

  • Pete Ray

    I second Lauren’s comment. It often happens now that I take a bit of a doughnut or pastry and can actually taste the “vegetable” fats that have gone into it. It’s most probably my mind playing tricks on me, but hey, it gets me to put that doughnut down, doesn’t it?

    Regarding herbivorous, seed-eating mice, John, have you read this (rather long) article: http://www.slate.com/articles/health_and_science/the_mouse_trap/2011/11/lab_mice_are_they_limiting_our_understanding_of_human_disease_.html? I posted this in a comment on Dr. Scientific Consensus’ blog, but he simply brushed it off.

  • EF

    J. Stanton,

    Long time reader, first time commenter.

    I just ordered The Gnoll Credo and am looking forward to devour it. Your blog is spectacular.


  • EF

    Typos be damned….”devouring”

  • pam:

    Absolutely.  The longer I eat paleo, the less tempted I am to cheat.  Like you, my standards for cheating have increased.


    What you need is a simulation that runs faster than real time, so you can see the long-term effects of various dietary and life changes on your simulated clones.


    Foresight is a big help: “yes, that'll taste delicious, and I'll feel terrible for the rest of the day”.  It is also possible for cultural conditioning to instill an aversion (Muslims and Jews with pork, for instance).

    Pete Ray:

    I'd seen that article before but forgotten about it.  Thanks for reminding me!  Imagine if the “control diet” for humans was to lock them in a room for weeks on end with a water fountain, a toilet, and a vending machine.

    The proverb “When all you have is a hammer, everything looks like a nail” is instructive: people tend to explain things based on what they know.  So for a neuroscientist fresh out of school, well, it's easy to give everything a brain-centered explanation whether it fits or not.


    Thank you!  I'm doing my best to keep gnolls.org both information-dense and drama-free.


  • Beowulf

    I think N=1 experiments are most useful when the effects can be noticed in the short-term. For example, I can see quite clearly that I get almost zero acne when I’m sticking to the “pick, dig, or spear” mantra, and that that acne will reappear within a few days of eating neolithic junk. Therefore, I think I can clearly state that paleo eating is better for my skin.

    On the other hand, being only in my early 30s, I can’t really judge paleo as being “heart healthy” from a personal perspective any more than I could say that being a vegetarian for seven years was good for my heart. I had/have no signs of heart disease on either diet.

    Long term effects where solid research and analysis comes into play along with a heavy dose of common sense (rare as it may be) on top.

  • Beowulf:

    Absolutely true: N=1 is great for short-term effects that we have some way to measure directly (e.g. acne, blood sugar).  The longer-term the effects, the less information N=1 can give us.

    Unfortunately there are no easy answers.  Much science is biased and/or unhelpful, and our scientific knowledge is very, very far from complete…so we must do our best to make evolutionary context, science, the historical record, and N=1 all meet in the middle.


  • […] part 2, part 3 Another record year for half-marathons Are we underestimating how fat Americans are? Anti-nutritionism, L-Canavanine, and the limitations of N=1 self-experimentation Better shrimp cocktail / Fire-roasted […]

  • Jeffrey of Troy

    I think that signaling (nutrigenomics)is the basis-in-reality of the old concept of some foods having a “vital force” that other foods don’t. The foods of agriculture lack this signaling benefit for us, because they are too new.

    I expand on the idea here

  • […] for me, while I was cogitating this series, J. Stanton of Gnolls.org beat me to the punch and posted on nutritionism. So if you’re looking for a smarter, more […]

  • Jeffrey:

    Abstractions like “vital force” make me uncomfortable because I don't know what they mean.  But since substances as basic as salt affect gene expression (discussed briefly here), it's not a stretch to assume that other foods affect it even more profoundly.


  • Miki Ben-Dor

    As you know I have written a post on the value of anecdotes. Reading your post here it strikes me that your examples are of non-valid positive personal experiences and mine are of negative personal experiences being valuable.

  • Miki:

    That's a good distinction.  Said another way: it only takes N=1 to disprove (“I tried it and it produced an entirely different effect than expected/desired”), but it takes far more than N=1 to prove.  And when we're talking about accounts of other cultures, that's far more than N=1.

    (Note to readers!  Miki is too modest to link his own article, so here it is: Can anecdotes and history match science in guiding Paleo nutrition?)


  • Jesse

    Thanks for this. My favorite post of yours so far, though it could just be the timing….

    This will be my goto link to forward to people instead of trying to give my feeble explanation of what a robust diet is, I mean it in terms of “not going to fail in light of innaccurate or insufficient information”.

  • After 'Eat Like a Predator', I think this is my favourite post, too.

    I would just like to drop something in about the idea of anecdotes, N=1, experimentation, or whatever we call is versus cold/hard science …

    What about “old wive's tales”? What about passed on generational wisdom? There's truth in them, there tales, you know …

    Some may be familiar with the DIKW construct – data, information, knowledge and wisdom, the development from data to wisdom.

    I am not at all stating an opinion contrary to Miki because I found that article very sound and very much full of straight down the line good sense, but I hope my thoughts perhaps soften the edges and maybe give it some depth.

    We are on “page one of a huge book called 'Human Nutrition'”, a J often says. We also have millennia of human history showing us what is right to eat. Very recently, in evolutionary terms, we have science. Science provides us with the data. An applied scientist could turn that into information. A well read person could translate that into knowledge, but it takes generations of anecdotes, experimentation and N=1 to produce wisdom.

  • Jesse:

    I'm glad it resonates for you!


    I'm not discounting the value of anecdotal evidence: if it weren't for historical and cultural knowledge, we would know very little about nutrition!  What I'm demonstrating is that N=1 personal experimentation can't tell us whether a Neolithic food is bad for us in the long term, or not — and such pronouncements, even if they're made by a paleo “authority”, are worthless.

    I may write a complementary article sometime about what we can learn from personal, anecdotal, cultural, and historical evidence!


  • Simon

    Great article as ever!

    One thing however – On the topic of “Food Doesn’t Want to Be Eaten”

    It is not necessarily the case that being less desirable as a food leads to increased reproductive success. On the contrary, take corn and chicken for example. Both of these species are highly successful because we like eating them.

    Though an individual chicken or corn plant may not “want” to be eaten, it is because their DNA have been selected to code for attributes that make them appealing to humans as food choices that they have become so successful in evolutionary terms.

  • J. Stanton said:


    I'm not discounting the value of anecdotal evidence: if it weren't for historical and cultural knowledge, we would know very little about nutrition!  What I'm demonstrating is that N=1 personal experimentation can't tell us whether a Neolithic food is bad for us in the long term, or not — and such pronouncements, even if they're made by a paleo “authority”, are worthless.

    I may write a complementary article sometime about what we can learn from personal, anecdotal, cultural, and historical evidence!


    Absolutely, J – I am certain that we're saying the very same thing, perhaps missing the subtlety of how each of us use our common language.

    We simply have not had anything like long enough to make pronouncements about neolithic food.

    I talk a lot about principles. Our ancestors would have lived by principles to guide them when they encountered new potential foods – can it be eaten raw is one which is very simple and works well within nature. This pushes grains and beans out. We can observably and even biochemically eat these once processed, but even then, who can say about long term use?

  • Simon:

    You're correct that domestication is a special case, and you're correct that domestication has had great survival value for a few species.  (At the price of great suffering — but natural selection doesn't care if you're happy.)

    In the case of animals, domestication makes them more defenseless — slower, fatter, and more tame.  However, the plant case is less clear.  Certainly we breed plants to be less bitter, bigger, and tastier, decreasing their toxicity…but, at the same time, we breed them for traits like insect and fungus resistance, which increases their toxicity.  (For instance, corn gluten meal is used as an herbicide.)

    I'm glad you enjoy my work!


    We're trying to make laboratory science, biochemistry, evolutionary biology, and anthropology meet on some sort of common ground.  It's a hard problem!


  • Kenneth Shonk

    Here is an example of science counter indicating traditional folk wisdom. Aristolochic acid (AA), a derivative of te Aristolochia plant and an ingredinet used in Asian botanical remedies for weight loss, joint pain, stomach aliments, gout, and childbirth has now been found to be a potent carcinogen – it carries serious risks of causing kidney disease and urinary cancers. It is thought to be responsible for 50% of such cancers in Taiwan. The latest research found it can interact with a person’s DNA and form unique biomarkers of exposure, as well as creating signals within tumor suppressing genes that indicate the carcinogen has been ingested. In Taiwan, where previous research has shown about one-third of the population has taken AA in recent years, rates of urinary tract and kidney cancer are about four times higher than in Western countries where use is less common. After being ingested, AA forms a unique kind of lesion in the renal cortex, and also gives rise to a particular mutational signature in the TP53 tumor suppressing gene, said the study. The herb is known in Europe by the name birthwort because it was often given to women during childbirth. from Newsmax Health e-mail 4/10/12 – http://www.newsmaxhealth.com/health_stories/cancer…. Proof ancient wisdom is not always so wise.

  • Kenneth:

    That's a great example of exactly the point I'm trying to communicate.  Thank you for bringing it up!


  • Stefani Ruper

    Hey JS! This reminds me of a post I read over at Evolvify, in which Andrew discusses how plant miRNAs insert themselves into human genes. Creepy.


  • Stefani:

    I remember that!  It takes “you are what you eat” to a whole new level.  Not only are our bodies made out of food, food directly alters our gene expression.  Wow!


  • […] “Anti-Nutritionism, L-Canavanine, And The Limitations of N=1 Self-Experimentation” from Gnolls.org This entry was posted in Workout of the Day by Todd. Bookmark the permalink. […]

  • Ihor Basko, DVM

    Great and thought provoking website.

    Being a veterinarian, I have similar beliefs about pet food.

  • Dr. Basko:

    It seems to my untutored eye that pet food is generally made to be cheap, not healthy: I see no evidence that corn and wheat are part of the ancestral diet of anything in order Carnivora.

    Feel free to share your thoughts here, or on the forums.


  • […] I’ve cautioned about extrapolating based on personal experience (“N=1″) before, so I’ll preface this with “correlation is not causation, etc.” However, my warning applies primarily to proving the negative: just because something doesn’t make us feel bad or kill us within a few months doesn’t mean it’s either harmless or good for us! […]

  • Whitefox

    On the antinutrient topic, what about sweet potatoes and “cyanogenetic glycosides? They block cell breathing, cause gastrointestinal symptoms, influence carbohydrates and calcium transport and cause iodine deficiency deficiency at high doses” (from Adel at SuppVersity)

    The L-canavanine thing is interesting, but studies on primates and in-vitro cells is still not humans (though the one case study is interesting). It seems like the same thing with MSG – lots of scary rat studies and organ cells and excitotoxicity… but doesn’t necessarily pan out in humans (as discussed above).

    Also, I know that rice miRNA affects the LDL receptor in humans, but we haven’t seen to what extent (if any) this has on long-term health. Cultures who eat rice+beans and sweet potatoes aren’t dying in droves from autoimmunity or other ailments. I understand (and agree with) not eating certain things as a precaution (I don’t eat gluten), but with less well-defined antinutrient effects I don’t see legumes/milk/certain veggies being shunned anytime soon.

    Examples: http://www.ncbi.nlm.nih.gov/pubmed/21206508

  • Whitefox:

    That's a good point about sweet potatoes.  It's also important to note that there are many different “sweet potatoes”, which vary greatly in nutrient and antinutrient content.  (White potatoes are the same.)

    All plants contain antinutrients.  The important question is “Did our ancestors eat them frequently enough, and for enough generations, that an ability to metabolize or eliminate the antinutrient has arisen and been universally selected for?”  For instance, aspirin is toxic to cats, who have been purely carnivorous for so long that they've lost the ability to metabolize that class of plant toxins.

    That is why I'm more suspicious of antinutrients in Neolithic foods: based on what we know of issues like gluten intolerance, celiac, Hashimoto's, etc., we know that the process of adaptation to Neolithic toxins is incomplete at best.  Thus my point: just because we eat something for a few months and “feel fine” doesn't mean it's healthy to eat. 

    (There was a lot of that going around the paleo community when I wrote this article, e.g. “I ate corn for a few months and I feel fine, therefore corn is healthy to eat.”  Fortunately, most of the people involved concluded paleo was “too limiting” for them and have explicitly abandoned the term…though a few of them refuse to go away, because they know the paleo community is where the action is.)

    And yes, the jury is still out on most of these issues.  Whether and how often you “cheat” is a personal decision that I can't possibly make for anyone.


  • J. Stanton said

    All plants contain antinutrients.  The important question is “Did our ancestors eat them frequently enough, and for enough generations, that an ability to metabolize or eliminate the antinutrient has arisen and been universally selected for?”  For instance, aspirin is toxic to cats, who have been purely carnivorous for so long that they’ve lost the ability to metabolize that class of plant toxins.

    … Thus my point: just because we eat something for a few months and “feel fine” doesn’t mean it’s healthy to eat.


    … and THAT is exactly why seasonality and localism is so important.

    You’ve said it again and again, “the dose makes the poison”; something that is entirely wrong with the paleo formula. Let nature decide your plate (your intelligence is required here in a modern world of ‘Food365’ to understand what is in in season, your inner hunter/gatherer to seek out foods ACTUALLY grown in season, not just seasonal) and let fate decide the little things (whether something is in stock at the supermarket, or simply clearing out the reduced section). Not only seasonal, but what’s available; what can be “hunted and gathered” in the modern world.

    Ha! You and thought I was going to flower into an “everything in moderation” statement. What rot!

  • […] such as Alfalfa contain L-Cavanine that might lead to fall in the Red Blood Cells […]

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