Dr. John’s Wheat Belly Rebuttal

In This Article

Gluten and Wheat

In a recent New York Times article, entitled “The Myth of Big Bad Gluten,” (1) journalist Moises Velasquez-Manoff set out to debunk the premise of best-selling anti-gluten books, The Grain Brain and Wheat Belly. Dr. William Davis, the author of Wheat Belly, wrote a rebuttal on his website, calling the New York Times article “silly” and a “big bad mistake.” (2)

Clearly, the Times article was far from silly and made many excellent points that challenge the premise that gluten is a poison. In fact, there are volumes of science suggesting that whole grains and whole wheat can actually reverse the negative health conditions attributed to gluten in both The Grain Brain and Wheat Belly.

In my new book, Eat Wheat, I cite over 600 of these studies that I feel need to be heard before grains are removed from our diets – a now widespread belief based on an incomplete interpretation of the science.

That said, a growing number of people do feel bad when they eat wheat and it makes sense to take it out when that happens. But, in doing so, are we addressing the underlying cause of food intolerance? Perhaps there is a bigger, untreated problem that is lurking behind our digestive, brain fog and fatigue woes that is actually unrelated to wheat. Before we pass judgment, let’s look at some of the science the 16-billion-dollar gluten-free industry does not want you to hear.

In Dr. Davis’s rebuttal, he asked to have a real evidence-based debate, to determine whether gluten is just a hard-to-digest protein or a poison. My book, Eat Wheatoffers solid evidence for such a debate and, in this article, I will go point by point, citing the opposing science that Dr. Davis used in his rebuttal to the New York Times article.

We DO Have the Genetics to Eat Wheat

dna in hands image

In the original New York Times article, Velasquez-Manoff makes the case that eating wheat for the past 10-12,000 years is plenty of time to genetically adapt to eating wheat or other cereal grains. He used the example of lactase persistence, a concrete example of modern humans genetically adapting to digesting milk-sugar lactase into adulthood – suggesting that humans have adapted to eating hard-to-digest foods in much less than 10,000 years.

Davis suggests that one adaptation we have made for the digestion of cereal grains was that in less than 10% of the population, humans combated the iron-blocking effects of phytic acids found in wheat and grains with gene variations to hold onto more iron. This adaption seems to have back-fired, as holding onto excess iron can be dangerous, putting these folks at risk for a condition known as hemochromatosis.

Generally, humans do not create genetic adaptations to external stimuli that cause serious or even lethal consequences, as in the case of hemochromatosis. What Dr. Davis failed to mention are studies that have shown that people who eat a high-grain, rich, phytic acid diet actually have 41% better absorption of iron than folks who eat a low-phytic acid diet. (4) This suggests that the body is well-adapted to handle phytic acids.

In addition, phytic acid is a calcium-blocker and it, along with wheat and grains, has been blamed for osteoporosis. However, when studies compare groups on high- versus low-phytic acid diets, they find that the group who ate the high-phytic acid diet had significantly greater bone density. (5)

Dr. Davis also did not mention that the phytic acids that are not digested in the small intestine are powerful nutrients in the colon. The colon is where phytic acids boost the production of beneficial short-chain fatty acids, such as butyric acid, which plays a major role in about 80% of our immunity, the health of the gut microbiome, healthy cholesterol levels, and reduced risk of kidney stones and colon cancer. (6)

When we take any food apart, constituent by constituent, almost every food is likely to have some chemicals that are challenging to digest. Then, when you look at the plant as a whole, like in the case of phytic acids, there are also numerous benefits that offset the so-called risks. Humans have been consuming naturally-occurring food toxins for millions of years, and only recently have we hybridized many of these toxins out of our foods. The tomatine in tomatoes and the solanine in potatoes and tomatoes were lethal as recent as the 1800s, but have been hybridized out of these foods.

The Science They Don’t Want You to Know About

Dr. Davis goes on to say that the gliadins in wheat/gluten are linked to autism, ADHD, Alzheimer’s, and a host of other neurological disorders. As scary as this sounds, there are plenty of studies that I cite in my book, Eat Wheat, that show that a diet rich in unrefined whole grains and whole wheat actually reduces the risk of autism, depression anxiety, schizophrenia, Alzheimer’s, diabetes, obesity, inflammation and cancers. (7) The science here is clear. Sugar increases the risk of these conditions, and whole grains and whole wheat have been shown in study after study to lower blood sugar and reduce the risk of diabetes. (7)

When we look at the science objectively, we find that there are studies on both sides, so who do we believe? Logic tells us to be careful when we blame a food group that we have been eating for 3-4 million years. Numerous studies have found proof of gluten in the teeth plaque of early humans dating back some 4 million years, and that cereal grains made up about 40 percent of their diets on average. (3) Since we have only been hunting our own meat for some 500,000 years, we are more genetically adapted to eat wheat than we are meat – by a couple of million years! (3)

Refined wheat and processed foods, in general, raise blood sugar and are antagonistic to good health. Wheat, in its refined, processed form, has been overeaten for nearly 60 years by many Americans.

Could a Gluten-Free Diet Actually Be Harmful?

Wheat, and in fact all grains, are meant to be eaten seasonally – not every day of the year. Overeating wheat in its super-processed form has severely compromised our ability to digest it. Interestingly, the harder-to-digest components of grains, like lectins and phytic acids, have been shown to have numerous health benefits, particularly in the prevention of colon cancer. (3,8)

New theories are suggesting that if we keep removing harder-to-digest foods from our diet, we may be taking the immune-boosting stimulation that the body needs to protect itself from an ever-changing environment.

For example, in one recent study, mercury levels were compared in three groups of people:

  1. Non-celiac patients
  2. Celiac patients who have not yet started a gluten-free diet
  3. Celiac patients who have been on a gluten-free diet

The group of celiac patients that had been on a gluten-free diet had 4-times the amount of toxic mercury in their blood compared to the other two groups. (9)

The concept that our overall health and immunity is determined and boosted by irritants and certain low-grade toxins is called “The Hygiene Hypothesis.” Since the discovery of the microbiome, this theory is gaining much traction. (10)

Before we sterilize our digestive tracts and remove all of the foods that are a challenge to digest, we should realize what compromised our digestion in the first place: processed foods and pesticides.

In one study, a diet of processed foods increased the likelihood of belly fat, high blood sugar, high blood pressure and high cholesterol by a whopping 141 percent. (11) These are all factors that decrease digestive strength and increase the risk of metabolic syndrome. Metabolic syndrome includes:

  • Abdominal obesity
  • High triglycerides
  • Low HDLs
  • High blood pressure
  • High blood sugar

In the same study, those who ate a whole food, a non-processed diet that included whole grains and whole wheat reduced their risk of metabolic syndrome by 38 percent. Bottom line: Eat organic, whole, non-processed foods!

Our Wheat-Eating Genetics

Dr. Davis makes the claim that the wheat we eat is much different than the wheat we ate thousands of years ago which, therefore, is responsible for the growing number of gluten sensitivity cases. The first hexaploid wheat strains were hybridized from the more ancient, simpler genetic forms, diploid and tetraploid, some 8-10,000 years ago. (12) The hexaploid wheat, which is considered a harmful strain, was naturally hybridized in the farm fields and has been eaten for thousands of years longer than the dairy that we have adapted the ability to digest.

In addition, ancient grains like Kamut, for example, were found to have two times the amount of hard-to-digest gliadins compared to modern wheat, suggesting that ancient wheat would be more difficult to digest.

As soon as we start chewing a slice of bread, there are numerous microbes in the mouth that produce enzymes to start working on breaking down the hard-to-digest gluten gliadins. (20,21) These microbes are also found in the esophagus and stomach, suggesting that we have evolved a sophisticated process to be gluten-ready in the upper digestive tract as well as in the mouth.

In the small intestine, a gluten (gliadin)-digesting enzyme called dipeptidyl peptidase IV (DPP-IV) is produced to assist in the complete breakdown of allergenic proteins such as gluten (wheat, rye, barley) and casein (milk and dairy products). (22) DPP-IV is one of the few enzymes able to facilitate the digestion of the hard-to-digest gliadins or proline-rich proteins and polypeptides. (22)

Gluten-digesting bacteria were also found in the large intestine, where they release enzymes called glutinases that also completely break down the hard-to-digest gliadins of gluten. The broken-down gluten proteins are used to feed the intestinal bacteria that produce gut-healthy short-chain fatty acids (SCFA). These microbes are also able to provide the fuel supply for other important bacteria in the gut. Any extra gluten is eliminated in the stool. (21,23)

If we have not evolved to digest wheat, it seems the body has developed a very elaborate system that makes use of wheat in every aspect of our digestive systems for some other unknown reason. That said, organic whole wheat is critical. Pesticides can kill the microbes responsible for digesting wheat, gluten and gliadins.

Ancient vs. Modern Wheat

In the study that Dr. Davis used to suggest that modern wheat was linked to the rise of celiac disease, researchers compared 36 modern wheat varieties to 50 ancient wheat strains. The study set out to find new wheat strains that could be bred and fed to celiac patients.

In that study, only one of the 36 modern wheat strains had a low-level immune reaction, while 9 of the ancient strains had low-level immune reactions. Interestingly, both ancient and modern wheat had the same number of high-level immune reactions. (13)

For future wheat breeding, specifically choosing wheat strains that have more low-level immune reactions and less high-level immune reactions would make sense. To say that ancient wheat is better when they had the same number of high-level immune reactions is not evidence that ancient grains are less irritating to celiac patients. They are both equally irritating to celiac patients.

This study was also only measuring celiac immune reactions and not the reactions in non-celiac patients. While less than 1% (.71 %) of the population is celiac and perhaps another 2% of the population may be undiagnosed, we are only talking about a maximum of 3% of the population. (14)

The bottom line: The study found high immune reactivity in both the modern and ancient wheat, suggesting that neither is OK for patients with celiac. Neither ancient nor modern wheat has been found to be reactive in non-celiac patients, which make up more than 99% of the population.

Wheat is No More Addictive than Mother’s Milk

Dr. Davis makes the case that naturally-occurring wheat opioids cause cravings, foods addictions, overeating and weight gain. However, there are many foods that have natural opiates or trigger an opiate response, such as mother’s milk, soy, spinach, rice, meat, fish, wheat, dairy, fruit, coffee and chocolate. Are we to stop eating all of these foods?

Wheat Belly cites studies that show a significant reduction in wheat consumption when wheat opiates are blocked by an opioid-blocking drug. But when you dig just a little deeper, you find that the consumption of meat was also blocked by up to 50 percent when meat-eaters were given the same opioid-blocker. (15)

In fact, there are numerous studies that found that the same opioid-blockers reduce people’s total consumption of all food by 22 percent in one study (16) and 28 percent in another, suggesting that perhaps all foods trigger some sort of pleasure, opioid-like response that is linked to our survival and that we are hard-wired to eat. (17)

In another study, the wheat opioids passed through the intestines in mice, but are too large to enter the bloodstream in humans. We cannot assume that a mice study will have the same effect on humans!

The reality is that there are toxins in a lot of the foods we eat, but we have been eating them and adapting to them for millions of years. The exorphins in wheat, if not completely digested, can cause some intestinal irritation, but it is also clear that we have the digestive power, microbes and enzymes to fully digest wheat – opioids and all!

For example, the enzyme DPP-IV mentioned above is a naturally-occurring enzyme that is found in the mouth saliva, small intestines and intestinal lymph. This enzyme can completely break down gluten and its opioid exorphins. (18,19).


Yes, wheat is hard to digest.

Yes, we have overeaten wheat.

Yes, we have rendered wheat and many other foods more difficult to digest by processing and refining them.

Yes, we can re-boot and strengthen our digestive systems and, once again, eat wheat!

Explore more on this topic in my new book, Eat Wheat.

Eat Wheat


  1. http://www.nytimes.com/2015/07/05/opinion/sunday/the-myth-of-big-bad-gluten.html?_r=2
  2. http://www.wheatbellyblog.com/2015/07/the-new-york-times-makes-a-big-bad-mistake/
  3. http://archive.unews.utah.edu/news_releases/a-grassy-trend-in-human-ancestors-diets/
  4. https://www.ncbi.nlm.nih.gov/pubmed/26041677
  5. https://www.ncbi.nlm.nih.gov/pubmed/25351648
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3507301/
  7. Douillard, J. Eat Wheat. pgs. 19-28. Morgan James. New York
  8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3507301/
  9. https://www.ncbi.nlm.nih.gov/pubmed/25802516
  10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448690/
  11. http://www.ncbi.nlm.nih.gov/pubmed/14747241
  12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3573730/
  13. https://www.ncbi.nlm.nih.gov/pubmed/20664999
  14. https://www.ncbi.nlm.nih.gov/pubmed/22850429
  15. http://www.ncbi.nlm.nih.gov/pubmed/2315439
  16. http://www.ncbi.nlm.nih.gov/pubmed/2315439
  17. http://www.ncbi.nlm.nih.gov/pubmed/4048359
  18. https://jhpn.biomedcentral.com/articles/10.1186/s41043-015-0032-y
  19. http://www.ncbi.nlm.nih.gov/pubmed/19020287
  20. http://www.ncbi.nlm.nih.gov/pubmed/20948997
  21. http://www.ncbi.nlm.nih.gov/pubmed/25519429
  22. http://pubmedcentralcanada.ca/pmcc/articles/PMC3179774/
  23. http://www.ncbi.nlm.nih.gov/pubmed/21671042

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