In my last post I outlined how gluten triggered an immune reaction and damaged the gut cells in genetically predisposed people.
In this post I will look at studies that show gluten grains are not the only food to cause problems for those with celiac:
- Casein and dairy products can inflame the gut
- Non gluten grains and pseudo-grains have been confirmed to trigger the same anti-bodies as gluten grains
- Refractory Celiac disease type 1 (Severe celiac disease, that does not resolve with a gluten free diet) goes into remission with a paleo type diet.
Up to 30% of people with celiac disease do not go into remission on a gluten free diet, that is they continue to show anti bodies to gliadin and transglutaminase, and / or have on-going gut inflammation.
One study showed after a gluten free diet for 6 months only 8% of individuals showed complete normalisation of villous architecture (the gut cells, and all the folds).
A subset of those with celiac disease continues to suffer severe gut inflammation and on-going deterioration of the villous architecture. This is called refractory celiac disease, type 1 (mild), and type 2 (severe)
There are two theories as to why a standard gluten free diet does not stop all celiac disease:
- Many foods, particularly processed food and other grains may be contaminated with tiny amounts of gluten and the gut is continually reacting to this
- Some foods cause a similar anti-body triggering response to gluten, or inflame the gut cells, and increase gut permeability (leaky gut)
It appears both of these happen.
Contamination of ‘gluten free’ foods by gluten
A study that measured contamination by gluten tested 22 single-ingredient inherently gluten-free grains, seeds and flours, and found 32% of these products contained >20 ppm gluten and one product contained 2,925 ppm of gluten. The products tested that were positive for gluten included soy, millet, buckwheat, rice and sorghum flour. This is sufficient gluten to cause on-going symptoms in many celiac disease individuals.
Other foods cause an immune or inflammatory reaction just like gluten
A number of studies have shown that those with celiac cross-react to other grains (i.e. react to other foods in the same way as gluten)
As well other foods besides gluten grains inflame the gut cells of those with gluten intolerance
Casein – inflames the gut just like gluten
In this study 20 people with CD who had been on a gluten free diet for more than 2 years were tested to see if they reacted to cow’s milk. Half of these were only in partial remission and still showed abnormal bowel biopsies, but negative gliadin and TG antibodies. Fifteen controls (15 people without CD) were also tested. A rectal (i.e. up the back passage) tube was inserted with a balloon and patches of cow’s milk and casein which touched the mucosal wall. They were left for an hour. Fifteen hours later inflammatory responses were tested for. In 10 of the 20 CD patients the inflammatory response to casein or milk was similar to their reaction to a gluten rectal challenge. There was no or slight reaction in the controls. Casein has similarities to gliadin, high in proline and resistant to digestion, and has some similar amino acid sequences .
Maize and some types of Quinoa and Oats have proteins similar to gliadin and cause an auto-immune reaction
Maize has similar proteins to gluten and has been shown to act just like gliadin peptides in some people with CD. Maize prolamins (zeins) also contain proline rich amino acid sequences similar to immunodominant gluten peptides that like gluten are not able to be broken down by human digestive enzymes. When tested, IgA from some celiac patients with HLA-DQ2 or 8 recognised two alpha-zeins peptides after they had been digested by gut enzymes. Several zein peptides have been isolated that can be bound to HLA molecules involved in CD pathogenesis. This means that these peptides can be picked up and presented as foreign proteins in a similar way that gliadin is in those with CD. 
Most would think of quinoa as being a safe grain to eat in place of wheat. However some cultivars have peptides which elicit a reaction similar to gluten in cell tests.
Some cultivars of oats also have specific peptides from their prolamine avenin that are immunotoxic for those with CD. 
Alpha gliadin antibodies (celiac disease antibodies) react to a number of non-gluten foods
One of the tests for celiac disease is a blood test to check the levels of a-gliadin antibodies. This is the antibodies that your body makes in reaction to gliadin, in effect treating it as a pathogen or dangerous invader that it has to kill.
In this study the immune reactivity of these antibodies was tested against a range of different food proteins and antigens and the response was measured. Here is a chart of those reactions. You can see the control protein has virtually no reaction and a-gliadin (the protein from gluten) as expected the largest reaction. You will also note the two different oat cultivars were tested ; one reacted and one didn’t. Milk, casein and whey proteins all reacted (although whey was far less).
Instant coffee caused a reaction, but notably for those who love their espresso, several types showed no reaction (yay!), and neither did cocoa or dark chocolate. 
A paleo type diet puts people with unresponsive celiac disease into remission
In this study patients were chosen who had persistent villous atrophy despite following a strict gluten free diet. (Dietician checked) Of these, 5 patients had refractor celiac disease (RCD) This is a severe inflammatory form of celiac, which is particularly non responsive to a gluten free diet and can lead to cancer and early death.
Seventeen patients participated, eating a strict Gluten Contamination Elimination Diet (GCED) for 3 – 6 months.
Here is the diet:
As you see both brown and white rice were allowed as were dried beans and dairy. The diet contained whole unprocessed food, so that there was no chance of cross-contamination.
What were the results of eating a paleo type diet for those with hard to treat celiac?
Of the 17 patients who adhered to this diet, 14 responded to the diet, and 4 of 5 of those diagnosed with RCD. That is they stopped having clinical symptoms of celiac disease.
Interestingly of these 14, 11 were able to revert to a standard gluten free diet without recurrence of celiac symptoms. (They were followed for 20 months after the GCED trial). The other 3 needed to stay on the GCED diet to stop symptoms returning. 
All these studies bring up some interesting points and room for further research:
Given the cross-reactivity tests – should a diet free of all dairy and all grains including rice, be trialled for those with RCD? I think so.
Did this diet fail a small number of people because it contained rice (which has been shown to be contaminated with gluten), and dairy which is inflammatory of 50% of those with CD?
Does a paleo diet heal the gut enough for some people to resume eating foods they previously reacted to? It appears so.
Do you have celiac disease that is unresponsive to a standard gluten free diet? If so I highly recommend you try this GCED diet, a paleo diet or an auto-immune paleo diet.
1. Thompson, T., A.R. Lee, and T. Grace, Gluten Contamination of Grains, Seeds, and Flours in the United States: A Pilot Study. Journal of the American Dietetic Association, 2010. 110(6): p. 937-940.
2. Kristjansson, G., P. Venge, and R. Hallgren, Mucosal reactivity to cow’s milk protein in coeliac disease. Clinical and Experimental Immunology, 2007. 147(3): p. 449-455.
3. Cabrera-Chavez, F., et al., Maize Prolamins Resistant to Peptic-tryptic Digestion Maintain Immune-recognition by IgA from Some Celiac Disease Patients. Plant Foods for Human Nutrition, 2012. 67(1): p. 24-30.
4. Zevallos, V.F., et al., Variable activation of immune response by quinoa (Chenopodium quinoa Willd.) prolamins in celiac disease. American Journal of Clinical Nutrition, 2012. 96(2): p. 337-344.
5. Real, A., et al., Molecular and Immunological Characterization of Gluten Proteins Isolated from Oat Cultivars That Differ in Toxicity for Celiac Disease. PLoS ONE, 2012. 7(12).
6. Vojdani, A., Cross-Reaction between Gliadin and Different Food and Tissue Antigens. 2013. 4(1): p. 20-32.
7. Hollon, J., Trace gluten contamination may play a role in mucosal and clinical recovery in a subgroup of diet-adherent non-responsive celiac disease patients. BMC Gastroenterology. 13.