Kurt G. Harris MD

PāNu means paleonutrition. The "paleo" here signifies "old" and not necessarily paleolithic. The PāNu approach to nutrition is grounded on clinical medicine and basic sciences disciplined by knowledge of evolutionary biology and paleoanthropology. The best evidence from multiple disciplines supports eating a pastoral (animal-based) diet rather than a grain-based agricultural one, while avoiding what I call the neolithic agents of disease - wheat, excess fructose and excess linoleic acid.

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« 1) Eliminate sugar and refined carbohydrates like white flour. | Main | Fats and Oils »

The Argument Against Cereal Grains

What is a cereal grain?

Cereal grains are seeds of monocot grasses that have been artificially selected by humans to serve as food. The ones that cause the most trouble, and constitute the biggest part of European and North American diets, are the gluten grains Wheat, Barley and Rye. I use the term gluten grains to signify primarily wheat barley and rye, but spelt, triticale and other less common grains, and some argue, oats are also gluten containing. One factor complicating gluten grain avoidance is the fact that non- gluten grains can often be contaminated by being processed on the same equipment as gluten grains.

How about other grains? Corn, rice and other non-gluten grains are carbohydrate heavy have antinutrients that interfere with mineral absorption and offer no nutritional advantages over animal products and non-seed vegetables in a food-abundant (non-subsistence) environment. As these non-gluten grains were also not consumed in important amounts in the Paleolithic period, the healthiest strategy is just complete grain avoidance.

That’s what I do generally. I have a little corn or white rice now and then, but no wheat, barley or rye if I can help it.

Here is the argument against gluten grains.

In a paleolithic non-food-abundant environment, omnivorous humans would at least occasionally eat anything that had caloric value that would not kill them. Natural selection favors propagation of the gene, even if the organism is not made "healthy" or does not live as long. It does not follow that any particular thing eaten was or is healthy, particularly if it were a type of plant that uses poisons in its seeds to discourage consumption by wild animals.

We need to apply the PaNu methodology to see if there evolutionary discordance. This has two parts. First, we look at evidence from modern medical sciences like biochemistry and epidemiology. Then, we look to the past with paleoanthropology to see if that supports our argument.

All plants tend to be in a contest with predators who might consume them. When we contemplate the chief difference between plants and animals, it makes sense that animal sources in general may be healthier for us.  Animals are mobile, and can avoid predation by running away from us. Plants use a variety of strategies to avoid predation, but one of them is to discourage consumption by elaborating toxic substances. Hence there is a contest of co-evolution over generations between plants “trying” to avoid consumption and animals evolving adaptations (or not) to the plant’s defenses.

Nuts are seeds that have a physical hard shell to discourage consumption. Relying more on this physical barrier than poisons, nuts like walnuts or pecans are seeds but safer to eat than grass seeds.

Gluten grains are grasses that use wind to disperse their seeds. The seeds contain carbohydrate and protein meant to help the seed germinate and grow. The seed has lectins and physical structure designed to discourage consumption by predators, whether single cell, fungus, insects or vertebrates. Some creatures, like birds, are clearly adapted to overcome the defenses of gluten cereal grains and use them as a primary food source. Most animals, including most mammals and our closest relatives the omnivorous fruit and insect-eating chimpanzees, are not adapted to grains and don’t eat them in substantial quantities. The question is, are humans adapted?

The answer is no.

First, see 6s and 3s and the logic of grain avoidance, for what happens when bovines that are adapted to eating grasses, eat too many grass seeds (grains) to which they are not adapted.

Now consider humans:

1) Fully 1% of the population has celiac disease, with 97% of these currently undiagnosed. 30% of the population has the genetic HLA haplotype that is susceptible to celiac disease -we can only know which of these 30% have it by testing. Celiac disease is caused by gluten grain consumption, with the offending gliadin proteins heat stable and not destroyed by cooking. Nearly every common autoimmune disease described is associated with at least an order of magnitude increased risk of celiac disease. Conversely, celiac patients have increased cancer, osteoporosis, and autoimmune diseases like DM I, autoimmune thyroid disease, Multiple Sclerosis, Sjogren disease, Rheumatoid arthritis, neuropathies, and even neurological disorders like schizophrenia. We don't know how big the iceberg is with these diseases, but the tip seems very large. 

2) Gluten grains are grass seeds that are employing a biologic strategy to avoid consumption, including elaborating the heat stable lectin WGA, which is known to damage the human gut. The nutritive value of gluten grains is inferior to the vast majority of non-gluten plant sources of carbohydrate and protein that have lesser adverse biological effects, and there is no evidence they provide anything uniquely essential. In addition to wheat germ agglutinin and gliadin proteins, there are a variety of other antinutrients in cereal grains, including phytates that bind essential minerals, and enzyme inhibitors that inhibit digestion. These are known to have their own dose-related adverse effects when included in the human diet. Inclusion of gluten grains and the oils extracted from grains in the diet also skews the ratio of n-6 to n-3 fatty acids in an unhealthy direction that adversely affects immune function.

3) The paleoanthropological record shows that humans and their hominid progenitors would eat nearly anything that had calories that would not immediately kill them, including occasional grass seeds. Nevertheless, the evidence also tells us that monocot grass seeds in general and gluten cereal grains in particular were inconsistent and trivial food sources prior to agriculture. The evidence is that cereal grains and legumes have antinutrients with clinically significant effects, and the evidence that these are an evolutionarily recent food source supports our observation that we are poorly adapted to them.

Note that the PaNu method does not ask solely if a food was or could have been eaten in Paleolithic times.  A history of being a paleolithic food source is neither necessary nor sufficient to establish it as concordant or discordant. There must be evidence that it is discordant both in the present and in the past under the PaNu method.

Dairy products are evolutionarily novel, but I believe in the context of a modern food abundant environment, and given what we really know about their health effects in the present, they are healthy for most people if your gut is not made leaky by grain consumption. Although dairy products are historically neolithic food, there is evidence of traditional cultures doing very well with them.

So when I call something a neolithic agent of disease, that really has two parts: 1) We have current evidence that is is noxious and 2) It is somehow outside of our evolutionary experience

Conversely, wild honey is a preferred food source for its caloric value among modern hunter gatherers and has probably been a hominid food source for millions of years. Wild honey is just fructose and glucose with dirt and pollen in it. Would there be negative health effects with 100% elimination of sucrose (a disaccharide of glucose and fructose) from your diet ? Honey can keep you from starving if food is scarce, but is there some magic ingredient in there with the sugar? I have convinced you, I hope, that in a food abundant environment, excess sucrose or its chemical equivalent is not healthy, as anything you eat is necessarily displacing something else you could be eating. Clearly the argument in favor of a food must rest on more than simply whether it was ever exploited.

I am now making the same elimination argument for gluten grains we have made for refined sugar and white flour, even though the specific biological argument is different. In a food abundant environment where anything you eat displaces something else in a roughly isocaloric diet, eating gluten grains is not optimal for your health. What is in wheat that you cannot better get from a green salad with egg on it - without the lectins and the gliadin proteins?

I have never had anyone able to tell me exactly what evil would befall a person without wheat, barley or rye in their diet. I have scores of non-celiacs that say that it made a huge change for the better, and some say it did much more than the sugar elimination.

Our cultural veneration of grains literally amounts to making a virtue of necessity, as 55% of world calories consumed is from grains. A paradigm shift is possible, though, if you are willing to read some more and adopt a radical skepticism of current government, mainstream media and industry supported nutritional dogma. I was initially as skeptical as you might be, and only came to my conclusions through investigation. 

Again I ask, rhetorically, possible negative health consequence could there be to eliminating wheat, barley and rye from your diet? 

Ditch the grains. Don't be a wheat-eater.

Read Part II Here.

References (28)

References allow you to track sources for this article, as well as articles that were written in response to this article.

Reader Comments (20)

Amen! With the reduction of insulin and elimination of gluten grains, there would be no health care debate. It wouldn't be an issue since the vast majority of disease in this country would be greatly reduced or eliminated altogether. Yet, trying to get people to do just that is nearly impossible. Whole grains are the sacred cow. People keep ingesting and glorifying the very thing that is killing them. On the other hand, it means more meat and fat for me.

June 23, 2009 | Unregistered Commenterjason

Thanks Jason

I appreciate your comments. My own non-scientific estimate is that we could reduce the overall spending on "health care" by 60% or more with no other changes required but zero gluten grains and LC eating all around. We could then focus more medical attention on trauma and the few leftover diseases that are not diseases of civilization.


June 23, 2009 | Registered CommenterKurt G. Harris MD

Kurt, LOVE your blog. I am an engineer so I love your analytical dissection of issues and logical thinking. Over the past 6 months I have all but eliminated wheat and grains from my diet and have noticed the following profound benefits:

1. Weight Loss: I am 42 and consider myself fairly fit and not overweight, yet I lost what was starting to be the "middle age spread". Tummy - gone. Love handles - gone.

2. Loss of addiction to carbs: Yes, carbs are addictive, particularly for me, bread and pasta. I could polish off a huge amount of pasta in one sitting and pay for it later with very uncomfortable bloating. I also no longer have the mid-afternoon sugar cravings.

3. Gastro-intestinal issues: Bloating and heartburn - gone with elimination of grains, especially the wheat.

4. Headaches: I used to get these really heavy headaches which I thought was an allergy condition. Now completely gone since eliminating wheat.

5. Better sleep: I was never a bad sleep, but I now feel I get a much better *quality* of sleep without grains in my diet.

6. More alert and more energy: It is a common myth that you need carbs for energy - what garbage! I can keep up with my young kids much better now than on my low fat hight carb diet.

All in all - I feel like I'm in my 20's again!

June 25, 2009 | Unregistered CommenterShmaltzy

The Argument For Cereal Grains: I like them. All plants are good. Eat cereal grains, and eat them often, if you can, and when you do, really enjoy them.

June 25, 2009 | Unregistered CommenterMatt

Hi Matt.

"All plants are good"

I like a salad made of tree bark, nightshade and grass. Yum.

June 25, 2009 | Registered CommenterKurt G. Harris MD

Thank you schmalzy.

I too used to think it was normal to have to loosen my belt at the end of a meal. Tonight I had a 12 oz ribeye with blue cheese on top, 2 glasses of bordeaux, a pile of green beans sauteed in butter and a pinch of garlic. Full but not bloated!


June 25, 2009 | Registered CommenterKurt G. Harris MD


Thanks for this blog. I think it is a truely inspirational and nuanced site of information!

I was wondering if there is a 'dose-response' relationship when you're eating grains: the more you eat of them, the worse?

Or can even the slightest amount of grain/gluten/gliadin cause bad effects?

Why do I want to know? Normally I don't eat grains and grain deriven product, but on some occasions (family visit, restaurant, ... you know) it is hard not to eat some.

Thanks for your thoughts,


June 27, 2009 | Unregistered CommenterPieter D

Yeah this is a great site, found it through conditioningresearch.blogspot.com, and love the attention to detail you give. I have the same question as Pieter, since so far its been easy to not eat grains/gluten derived foods when I'm by myself, but going to family dinners or to a friend's gathering, it's hard and pretty strange to reject such foods, and maybe I haven't been off those foods long enough because I definitely still enjoy cakes and pastas a lot. I found the above site from some intermittent fasting site, which led me to Brad Pilon...from what I've read by him and from you, I'm under the impression that most if not all negative effects from the intake of such foods in moderation(no more than a couple times week, just an arbitrary number I'm putting) would be nullified by an intermittent fasting lifestyle.

Thanks for the site and your input


June 27, 2009 | Unregistered CommenterDavid P

Cereal grains are the great democratizer. With cereal grain cultivation, we could, finally, depend on food to be there, instead of randomly stumbling upon it. Once we grew grains, we began to stop and observe the cosmos around us, and percieve recurrent order, rather than wandering aimlesly, chaotically; led by a 3% minority of tyrants. Then followed development of tools, science, art, culture - all thanks to cereal grains. And we didn't have a paleolithic internet connection either - it was the end of the self-appointed, migrant, arcane priesthood.

June 27, 2009 | Unregistered CommenterProtoman

Pieter and David

I plan a post addressing gluten avoidance in the next few days.

The "social freak" part is real and much harder than just low carb eating. Get used to it!

June 28, 2009 | Unregistered CommenterKurt G. Harris MD

Hi, Lots of your reference have a wrong link like this one


July 2, 2009 | Unregistered CommenterMiguel Angel

Hello Miguel

Something happened to the links

I'll see if I can fix it

Meantime, try typing the titles into pubmed


July 2, 2009 | Registered CommenterKurt G. Harris MD

Excellent treatment of the subject! I've been grain-free for 6 weeks now and have never felt better. I've also lost almost 15 pounds. Surprisingly, I feel I eat the same amount of food, minus the grains and I never want to snack. Does the insulin rush from the grains prompt us to eat more? Or may the snacking behaviour be from not fully absorbing nutrients from meals?

September 4, 2009 | Unregistered CommenterDeb

Hi Kurt,
I'm really enjoying the exploration of your site and its a real pleasure to read someone who has looked at the data, and some real-life applications of it, to inform their opinions. I was also thrilled to read your position on cereal grains.

BUT your position on dairy may be questionable. 2/3 of the world's adult population is lactose intolerant. While gluten contains 5 opioid peptides (along with other psychoactive peptides) dairy proteins contain 8 opioid sequences. Immune responses to dairy proteins can cause villous atrophy indistinguishable, under a microscope, from that caused by gluten in the context of celiac disease. Excessive quantities of highly bioavailable calcium may overwhelm transport mechanisms leading to deficiencies of competing minerals.

I am watching the U. Maryland research very closely. From zonulin to haptoglobulin 2, I believe they are unlocking some of the secrets of leaky gut. Dairy protein may well incite increased zonulin production but that notion is purely speculative.

Thanks for all the work you do on this site. I hope you have dropped an email to Gary Taubes. I think he would be thrilled by both your selfless efforts and the impressive, thoughtful results.

Best Wishes,

September 12, 2009 | Unregistered CommenterRon Hoggan


I've read your book. Thanks for your thoughts.

"Immune responses to dairy proteins can cause villous atrophy indistinguishable, under a microscope, from that caused by gluten in the context of celiac disease."

Do you have a reference for this? Villous atrophy is a common end point of many different pathologic processes, so that it could occur with an immune response to any particular protein would not be surprising.I would be very surprised if this has any analogy with gluten.

Dairy proteins can be antigenic, but so can beef and seafood proteins.

My audience is europe and north america. where lactose intolerance is nowhere near that common.

Lactase is an inducible enzyme - adults make less lactase when they stop drinking lactose. Lactose intolerance, if you are dumb enough to keep drinking milk when you have it, is just due to failure to cleave the sugar with consequent malabsorption.

"Excessive quantities of highly bioavailable calcium may overwhelm transport mechanisms leading to deficiencies of competing minerals."

That is why I don't think calcium supplements are a great idea. Not convinced that it's a real concern with dairy in general.

Not ready to make a blanket indictment of dairy until I see more convincing evidence.

Wheat, fructose and linoleic acid.

September 13, 2009 | Unregistered CommenterKurt G. Harris MD

but what is a vegetarian to do? i'm not talking vegetarian due to an -ism, but having grown up in a vegetraian culture (india) and cannot stand the taste/smell/texture of meat. i must be doomed...

October 8, 2009 | Unregistered Commentersonia

I have eliminated sugar and flour, but I have one ounce of oatmeal everyday. Do you think this is okay?

October 18, 2009 | Unregistered CommenterGary

Hi Kurt.

You're conclusion is absolutly right. I can't think of an argument someone could tell you (nutritionnaly speaking) as for why grain should be a part of our diet. I'd really like to see a nutritionist trying it tho.

High quality meat and bunch of non starchy vegetable give us absolutly everything we need to be optimaly healthful.

It's sooooo cool to see many MD adopting that point of view. I'm quite young, and i'm really hoping to see the day when the gouvernement will loose it's face on this issue. Actually they'll probably find a way to make it seems like they were not wrong, but oh well. We all will know they were.

Thanks for making this world a better place to think freely!

November 21, 2009 | Unregistered CommenterFrank

I just love your site. You offer us a lot of precious information! I'm thankful for that.

So far, I have one question. I didn't see an article about number 8 (Eliminate legumes). So I was wondering why. I know they are full of carbs and this suppose to be a low carb diet. But this is the only reason? Or legumes have other bad properties like grains have?

Have a beautiful day!
And once again, thank you for this marvelous blog and for taking your time to write it!


Thank You

Carbs, lectins, PUFAs and in the case of soy, molecules that can have endocrine effects. Legumes are not higher on the list simply because they are not as ubiquitous or nasty as gluten grains.

Many articles left to write.

December 4, 2009 | Unregistered CommenterLivia

I was wondering how you feel about Chia seeds.


Discussed somewhere in the comments I think but what is the point? - they are seeds

Eat fish or fish oil for DHA/EPA - plant sources are inadequate

January 6, 2010 | Unregistered CommenterMichael
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