You may have read anecdotes about the carnivore diet reversing a wide range of autoimmune diseases. For the most part, there is little research on the carnivore diet so there is much that we don’t know. However, there is some science that would explain why some people see dramatic improvements on a carnivore diet. Here’s what we do know:

The scientific literature suggests that intestinal permeability is the common link between most autoimmune conditions. The carnivore diet may work by restoring intestinal permeability, thus stopping foreign proteins from entering the body and triggering the immune system.

is the common link between most autoimmune conditions. The carnivore diet may work by restoring intestinal permeability, thus stopping foreign proteins from entering the body and triggering the immune system. Elimination diets are effective in treating rheumatoid arthritis (for some patients). Mikhaila Peterson’s rheumatoid arthritis story is not that surprising if you read about 2 studies on elimination diets from the 1980s.

Gluten-induced conditions such as celiac disease, gluten ataxia, and some forms of epilepsy are often undiagnosed. Any gluten-free diet, carnivore or not, can resolve such conditions. Dermatitis herpetiformis is another condition that responds to a gluten-free diet.

Intestinal permeability (“leaky gut”)

For decades, scientists have noted that people with autoimmune conditions also tend to have highly elevated intestinal permeability. This dysfunctional intestinal permeability allows large molecules such as foreign proteins to enter the body. The theory is that these foreign proteins trigger an immune response. In people with genes that make them vulnerable to autoimmune disease, the immune reaction malfunctions and erroneously attacks the body’s own tissues while going after the foreign proteins.

There is fairly good evidence that intestinal permeability leads to the development of type 1 diabetes (diabetes caused by the body attacking insulin-producing cells) in diabetes-prone rats.

Alessio Fasano and his colleagues have discovered that the giladin in gluten binds to the CXCR3 receptor and causes the body to produce zonulin, which leads to an increase in intestinal permeability. See “Zonulin and Intestinal Barrier Function” for a review of the research on the subject. In BioBreeding diabetic-prone (BBDP) rats, elevated levels of zonulin and increased intestinal permeability precede the development of type 1 diabetes. (See the discussion of T1D on page 14 of the paper mentioned earlier for more details.) When these rats are given a zonulin inhibitor, Larazotide Acetate (also known as FZI/0 or AT-1001), the intestinal permeability is restored and the rats develop T1D at a much lower rate. The relevant study found that: Without the inhibitor, 11 out of 15 rats developed type 1 diabetes (73%). With the inhibitor, 3 out of 15 rats developed type 1 diabetes (20%). Despite Fasano’s enthusiasm, these results could not be replicated in humans as that particular zonulin inhibitor doesn’t affect intestinal permeability in humans (see here and here for the results of 2 different trials reported in 2012).

Fortunately, there is evidence that intestinal permeability can be restored in human beings. According to Paleomedicina, their version of a carnivore diet (the PKD or paleo ketogenic diet) is highly effective in restoring intestinal permeability in humans.

Zsofia Clemens’ presentation (available on Youtube) goes over the diet and why they believe it works. At the 6:15 mark, she explains that pathological intestinal permeability (and that of other membranes) is the suspected cause of autoimmune diseases and cancer.

Pages 13-15 from the presentation slides contain examples of intestinal permeability measurements before and after placing patients on their treatment diet (lower is better).



So far, Paleomedicina has published case studies on treating diseases such as type 1 diabetes. Surprisingly, they have found that some of their type 1 diabetes patients can live an insulin-free life as long as they still have enough insulin-producing cells (!). Their T1D case studies are published here and here. (Unfortunately, some of their patients seem to go off their diet and permanently lose their remaining insulin-producing cells.)

To fully prove the link between intestinal permeability and autoimmune disease, randomized controlled trials would be nice to have. Sadly, such trials do not currently exist. Right now, we only have case studies (and anecdotes) showing that many autoimmune diseases can be reversed in some patients. Paleomedicina has published their case studies on various health conditions:

Other (weak) evidence in favour of the intestinal permeability theory

Many scientific papers note that autoimmune diseases are more common if somebody already has one autoimmune disease. Here’s a sample:

A cross-sectional study of rheumatoid arthritis patients found that 24.3% of RA patients had at least one non-RA autoimmune disease versus 10.5% in the osteoarthritis cohort used as a control.

of RA patients had at least one non-RA autoimmune disease versus in the osteoarthritis cohort used as a control. A multi-center study by Fasano and his colleagues found that roughly 1 in 23 celiac patients also have type 1 diabetes. A different study estimates the prevalence of T1D in the general United States population to be 1 in 300.

Intestinal permeability would neatly explain why such a vast range of autoimmune diseases are correlated with one another. To be fair, these correlations may also be due to pre-disposing genetics, environmental factors, microbiome factors (e.g. dysbiosis / unhealthy composition of gut bacteria), and/or other causes.

A 2011 paper by Fasano cites 3 studies on multiple sclerosis which looked at autoimmune brain inflammation (autoimmune encephalomyelitis) in rats:

Ochoa-Repáraz J, Mielcarz DW, Ditrio LE, Burroughs AR, Foureau DM, Haque-Begum S, Kasper LH. Role of gut commensal microflora in the development of experimental autoimmune encephalomyelitis. J Immunol 183: 6041– 6050, 2009. (Full paper.)

C57BL/6 mice were treated orally with a broad spectrum of antibiotics to reduce gut microflora. The authors concluded that “long-term control of bacterial populations with oral treatment with antibiotics confers complete protection against EAE”. Westall FC. Abnormal hormonal control of gut hydrolytic enzymes causes autoimmune attack on the CNS by production of immune-mimic and adjuvant molecules: a comprehensive explanation for the induction of multiple sclerosis. Med Hypotheses 68: 364 –369, 2007. (Abstract.)

This paper argues that abnormal hormonal control of gut proteolytic enzymes leads to those enzymes digesting gut bacteria and creating problematic protein fragments. Yokote H, Miyake S, Croxford JL, Oki S, Mizusawa H, Yamamura T. NKT cell-dependent amelioration of a mouse model of multiple sclerosis by altering gut flora. Am J Pathol 173: 1714 – 1723, 2008. (Full paper.)

This study used antibiotics to alter the gut flora, leading to a much lower level of EAE (which is thought to be analogous to multiple sclerosis in humans).

All 3 studies put the blame on proteins (or protein fragments) that originate from gut bacteria. When the problematic bacteria were eliminated with antibiotics in two of the studies, there were lower levels of brain inflammation. While the papers do not focus on intestinal permeability, Fasano is implying that the problematic proteins are getting into the body through defects in intestinal permeability. If intestinal permeability is restored, these proteins would not be able to enter the body and trigger the autoimmune process.

Undiagnosed celiac disease

It is generally known that a gluten-free diet resolves celiac disease (and wheat allergies). However, what most people don’t know is that celiac disease is often undiagnosed. The symptoms of celiac disease can be vague and have many other causes. Typical symptoms (see page 3 of this paper) are:

Chronic diarrhea.

Iron-deficient anemia.

Growth faltering (in children) and weight loss (in adults).

Other symptoms of celiac disease include:

Bloating

Gas

Fatigue

Constipation

Depression

Itchy rash and/or dermatitis herpetiformis

Most celiacs do not exhibit diarrhea and other GI symptoms ‘typical’ of celiac disease, leading to under-diagnosis. A multi-center study on the prevalence of celiac disease (by Alessio Fasano and his colleagues) found that only 35% of newly-diagnosed patients exhibited chronic constipation, which was the most frequent symptom. Among first and second-degree relatives of those with celiac disease (CD), the rate of CD was almost identical between those exhibiting symptoms and those not exhibiting symptoms. 4.32% of symptomatic relatives had CD while 3.91% of relatives without symptoms had CD.

Furthermore, common practices in diagnosing celiac disease can lead to under-diagnosis. While antibody tests are not fool-proof, many doctors will not order a biopsy if the antibody tests come back negative. And while biopsies are often considered to be the gold standard in terms of diagnosis, they may miss borderline cases. Of the patients in multi-center study mentioned previously, 350 tested positive for EMA antibodies. Out of those 344, 116 had biopsies performed (71 of the 350 had their biopsy request denied by their physician or insurance company). Of those 116, only 34% showed classic signs of celiac disease in their biopsy results (Marsh stage 3b marked villous atrophy or Marsh stage 3c flat mucosa). The remaining 66% were borderline cases that exhibited hyperplastic changes or mild villous flattening.

A 2010 paper by Alessio Fasano and Carlo Catassi argues that celiac disease should be diagnosed based on a “4 out of 5” rule, which would broaden the definition of celiac disease and reduce the amount of undiagnosed celiac disease.

Benefits of treating celiac disease

In symptomatic patients, a gluten-free diet can relieve symptoms such as chronic diarrhea, nutrient malabsorption, iron-deficient anemia, etc.

In patients without obvious symptoms (“silent” celiac), there may be general improvements in well-being and/or depression.

While most people do not have celiac disease (most sources estimate the prevalence at roughly 1% in the general population), it seems likely that a small portion of the benefits of the carnivore diet can be attributed to the avoidance of gluten.

A carnivore diet has a much lower risk of accidental gluten

Celiacs often unintentionally ingest gluten due to cross-contamination. An Australian study found that 2.7% of “gluten-free” foods tested were not compliant with the Australian standard of no detectable gluten. A similar study by some of the same researchers also found that 9% of Melbourne restaurant food contained measurable levels of gluten.

To avoid this type of accidental ingestion, Alessio Fasano and his colleagues did a study on their Gluten Contamination Elimination Diet (GCED), which is described in Table 1 of their paper. The GCED is a highly-restrictive diet that eliminates various potential sources of contamination such as oats and grains. The carnivore diet can be thought of as a more restrictive version of the GCED. Because of this, it naturally avoids various sources of potential cross-contamination; see my post on how to eat gluten-free as it details various ways in which somebody can accidentally eat gluten.

Non-celiac conditions caused by gluten/wheat

A group of Baltimore researchers (which, yet again, includes Alessio Fasano) have compiled an overview of the neurologic and psychiatric manifestations of celiac disease and gluten sensitivity (Psychiatr Q. 2012 Mar; 83(1): 91–102.):

Epilepsy : In a very small segment of epilepsy patients, there is a triad of specific symptoms: occipital calcifications, seizures originating from a number of brain locations, and celiac disease or gluten sensitivity. See “Epilepsy and Seizure Disorders” in the paper for more information.

: In a very small segment of epilepsy patients, there is a triad of specific symptoms: occipital calcifications, seizures originating from a number of brain locations, and celiac disease or gluten sensitivity. See “Epilepsy and Seizure Disorders” in the paper for more information. Gluten ataxia , or ataxia caused by gluten sensitivity. Gluten ataxia is an autoimmune disorder where brain damage causes problems in balance, speech, posture, walking, and running.

, or ataxia caused by gluten sensitivity. Gluten ataxia is an autoimmune disorder where brain damage causes problems in balance, speech, posture, walking, and running. From the paper: “Other neurological manifestations of gluten sensitivity and celiac disease include peripheral neuropathy [26], inflammatory myopathies [27], myelopathies [3], headache [28], and gluten encephalopathy [29]. White matter abnormalities associated with gluten sensitivity have also been reported [30].”

Since the publication of that paper in 2012, there have been 2 small studies in 2014 and 2015 that drew a link between non-celiac gluten sensitivity and mild depression. A small randomized placebo-controlled trial by Simone Peters, Peter Gibson, and their colleagues found that a minority of test subjects with self-reported non-coeliac gluten sensitivity (NCGS) saw their depression increase when they ingested gluten (see Figure 2 in the paper for a visualization of the data). Another randomized placebo-controlled trial found that small amounts of gluten induced depression and ‘brain fog’ in subjects with self-reported NCGS (see Figure 3). The effect of gluten in both studies was fairly mild and most of the test subjects did not exhibit NCGS.

Gluten-related conditions may be underdiagnosed for various reasons:

There is controversy over whether or not non-celiac gluten/wheat sensitivity and (to a lesser extent) gluten ataxia are real conditions. Medical professionals may be unfamiliar with gluten ataxia as it isn’t well-known.

In epilepsy, many doctors simply don’t tell patients about dietary treatments. While the ketogenic diet has been around since the 1920s, many doctors in the past didn’t tell their patients about it and never learned how to treat patients with it. Many doctors are also unaware of the various scientific papers on gluten-free diets being effective for some forms of epilepsy. When it comes to epilepsy, there is a mixture of ignorance, indoctrination, and indifference among the medical community.

Known dietary causes of autoimmune diseases

Gluten is implicated in:

Celiac disease

Type 1 diabetes in mice

in mice Some forms of epilepsy (*may not be an autoimmune condition)

(*may not be an autoimmune condition) Gluten ataxia

Dermatitis herpetiformis. For more information on the skin condition, see this Indian review on diet in dermatology.

Rheumatoid arthritis has a long list of dietary triggers, with wheat and corn being the most common. See “dietary causes of rheumatoid arthritis” for an in-depth discussion.

Dairy is implicated in type 1 diabetes in mice. However, a large randomized controlled trial was not able to replicate the results in humans. The TRIGR study gave its intervention group hydrolyzed infant formula; the theory was that the broken-down (hydrolyzed) proteins would not cause the emergence of type 1 diabetes later on in life. Nonetheless, both the intervention and control (normal cow-milk-based infant formula) groups developed type 1 diabetes at similar rates.

Not all carnivore diets will work

If you are looking to see if diet can affect your autoimmune condition, you may wish to avoid unnecessary variables that may cause problems. Some foods in less restrictive versions of the carnivore diet may impair intestinal permeability, e.g. some cheeses and processed meats contain gluten. Some foods like dairy are a known trigger of rheumatoid arthritis.

Details on Paleomedicina’s PKD diet is described in my post on all-meat diets; also see Paleomedicina’s protocol paper. Dairy, processed meats, supplement pills, and seasonings/sauces may potentially worsen intestinal permeability and are not allowed on Paleomedicina’s PKD diet. (Paleomedicina may make an exception for vitamin D supplementation.) These issues are discussed in Zsofia Clemens’ presentation which was mentioned earlier.

Mainstream medicine’s relationship with scientific evidence

Those defending mainstream medicine may rightfully point out that it would be good to have randomized clinical trials (RCTs) on the carnivore diet as a treatment for autoimmune diseases. I would agree. Unfortunately, it is unlikely that the mainstream medical establishment wants such trials to occur. While there have been RCTs on elimination diets as a treatment for rheumatoid arthritis, mainstream medicine continues to ignore that science (see my post on the dietary causes of rheumatoid arthritis). Despite examples of various autoimmune diseases being reversed, mainstream medicine continues to spin the myth that the respective autoimmune diseases are ‘chronic’ conditions that require lifelong treatment as there ‘is no cure’. When scientific evidence threatens vested interests (such as the money to be made from a lifetime of expensive treatment), mainstream medicine is quick to ignore or discredit that evidence.

Regrettably, this leads to a situation where those suffering from autoimmune conditions don’t benefit from the best that science can offer. More research would help us better understand the benefits, risks, and limitations of dietary interventions such as the carnivore diet. The anecdotes indicate that it works in some people. However, we don’t have good research as to what the success rate should be and how to increase the chances of success.

What to do if you have a serious health condition

If you are interested in the carnivore diet, I would strongly encourage you to do your research on its risks and limitations. As far as the risks go, please be aware that some people faint during the fat adaptation phase of a ketogenic diet like the carnivore diet (see the “what you need to know” section in my meat-only diet post). Fainting is dangerous if you are driving. So, carry some carbs with you and don’t drive if you feel like you are about to faint.

You can dig up negative and neutral anecdotes about the carnivore diet. For example, you can search the Reddit community r/zerocarb for posts mentioning the word ‘thyroiditis’. You may find that many people don’t see a reversal of autoimmune (Hashimoto’s) thyroiditis and continue to take thyroid medication. There is a list of social media communities at the bottom of this post.

Some things to watch out for:

Bias . For example, the website Meat Heals is a useful collection of anecdotes. However, it is clearly one-sided as it doesn’t publish any negative anecdotes.

. For example, the website Meat Heals is a useful collection of anecdotes. However, it is clearly one-sided as it doesn’t publish any negative anecdotes. “Keto flu”: Some people in the carnivore and zerocarb communities may claim that many problems are due to the “keto flu” and can be treated by consuming some unspecified combination of electrolytes. As discussed in my post on meat-only diets, the scientific literature describes a low blood sugar phenomenon (which electrolytes won’t fix) but does not describe a “keto flu” phenomenon.

Lastly, I’d like to wish you the best of luck in your health journey regardless of what route you decide to take.

Links and resources

Reddit communities: r/zerocarb and r/carnivore

To search Reddit, use the search bar at the top of the Reddit website.

Facebook communities: World Carnivore Tribe, Zeroing in on Health, Principia Carnivora

To search Facebook groups, use the search box near the bottom of the left sidebar.

Anecdotes: The Meat Heals website is a collection of anecdotes that you can brows; simply search through the category list on the right. Note that this website is biased to only include positive anecdotes.

My primer on meat-only carnivore diets.

Read the scientific literature for yourself: You can use Google Scholar and Pubmed to find papers on the carnivore and “paleo ketogenic” diets. You may find a few papers that cite Paleomedicina’s papers; however, there isn’t much that’s interesting. One review on epilepsy by a naturopathic doctor favourably mentions the PKD for epilepsy (though the author would prefer the Modified Atkins Diet over it). A review on ketogenic diets for the treatment of cancer briefly mentions the paleo ketogenic diet.

Some negative anecdotes

Fainting: While the popular version of the keto diet is not the same as the carnivore diet, both are ketogenic diets and therefore the initial fat adaptation phase should be similar between the two diets. If you search the Reddit community r/keto, you will find that fainting is a side effect. Somewhat similar stories can be found on Youtube- see the experiences of Gabbie Hanna (one of Youtube’s most popular stars with 6.4 million subscribers) and Scott Ste Marie / Depression to Expression. My post on meat-only diets goes over some of the relevant scientific literature.

UK newspaper article: My carnivore diet: what I learned from eating only beef, salt and water – This journalist tried the diet for 7 days and found the adaptation period to be “truly, punishingly awful”.

The Carnivore Diet Is the Latest Fad to Ignore That Food Does More Than Just Feed Us – This author lost 7 pounds but is quite opposed to the lifestyle of restrictive eating.