Coeliac disease, also called gluten sensitive enteropathy or celiac sprue is an autoimmune disorder. Autoimmune disorders affect about 1 in every 6 people(1) and represent a major part of the disease burden in modern first world countries. Coeliac disease is quite a common example, being found in between 1-2 people in every 100 (2), which is roughly the prevalence I've found with my clients. Like many autoimmune diseases, the incidence of coeliac disease appears to be increasing rapidly(3).
The symptoms of coeliac disease vary for different people. The most common symptoms are:
- Abdominal pain.
- Fatigue, which can be caused by anemia due to lack of absorption of iron.
- Weight loss, experienced by about half of all coeliacs.
Other symptoms include:
- Diarrhoea, which is a symptom in about 1/3rd of cases.
- Constipation, which affects about 1/5th of coeliacs.
- Itchy skin rashes (dermatitis herpetiformis), which again affects about 1/5 of cases.
- Neuropathy - tingling hands and feet.
The lists above are by no means exhaustive. Some people suffer no symptoms at all and yet are still damaged by the disease. Others get headaches or depression.
How can I be sure I've got it
Normally you get your blood tested for certain enzymes such as tissue transgutaminase, endomysial antibody and anti-gliadin. For further proof a biopsy is sometimes taken from your small intestine. The anti-emdomysial antibody (EMA) test is the cheapest and most accurate test that is used(4). Your doctor should offer you this if there is good reason to believe you may have coeliac disease.
Sometimes nothing is found, but this does not mean that you have no problems with wheat products.
At DrDobbin nutrition we can do a coeliac screen that tests for the enzymes in blood for £108 (2014 prices). A cheaper option is to test for just one of the enzymes and we can do a tissue transglutaminase test for £31.
What's going on
A normal gut
The outer layer of your small intestines is made up of epithelial cells. This outer layer is folded into multiple villi, which appear like projecting fingers from the interior layers of the gut. Between the villi are shallow crypts which contain cells that enhance digestion by secreting various substances and also contain young cells which are produced to replace the older cells that are shed from the villi as they age. The villi are responsible for our ability to absorb nutrients from the foods we eat. Without properly functioning villi we absorb less and may develop deficiencies in certain vitamins and minerals.
How coeliac guts are affected by gluten
With coeliac disease your immune system attacks the lining of your small intestines. It does this when a protein called gluten, found primarily in grains such as wheat, passes through the stomach without being broken down.
Gluten being a protein contains continuous strings of amino acids called peptides. One such peptide, called 33mer is found in gliadin, the soluble protein found in gluten. 33 mer reacts strongly with antibodies found in the body of coeliacs, which amplify the immune response, ultimately leading to damage to the villi lining the small intestine. The villi typically become flattened and as a consequence many nutrients are not properly absorbed from our food. In particular iron may be in short supply and this can lead to anaemia and fatigue.
Coeliac disease is getting more common
Of course most people don't react to the peptides in gluten. Why is that? Well 3 factors need to come together to cause coeliac disease. Firstly coeliacs, like roughly 1/3rd of the population have genes called DQ2 and DQ8. Their genes make the antibodies that react with gluten peptides such as 33mer. Secondly, most if not all coeliacs will have leaky guts, that is to say that the tight junctions between the cells that line their guts are open for longer than non-coeliacs. This is due to a protein called zonulin that is produced in larger amounts by coeliacs. Finally gluten exposure is required to allow coeliac disease to establish itself. The gaps between the cells that line the gut (enterocytes) allow large molecules through that include gluten, which then stimulates the immune system to produce an inflammatory response.
Coeliac disease has become more common recently(3), despite the fact that the prevalence of people carrying genes that make them susceptable to coeliac disease has not increased. It is thought that decreased exposure to infectious disease, increased use of antibiotics and reduced breast-feeding rates(5) may be partly to blame. All these factors can lead to a less effective population of bacteria in the intestines.
Having good bacteria in the gut
Certain types of bacteria such as enterococci, bifidobacter and lactobacilli are associated with absence of coeliac disease. This does not mean that they confer resistance to someone who has them. as it is quite likely that having coeliac disease makes life harder for these creatures. However, it explains why infectious disease and antibiotics are associated with increased incidence of coeliac disease.
The key dietary apporach with coelic disease is to stop consuming gluten, which can be quite difficult for some people. This is because there are many hidden sources of gluten in processed foods.
Here are some foods that usually contain gluten:
- Bread, pastries, pasta and noodles.
- Crackers, cakes and cookies.
- Breakfast cereals, waffles, pancakes.
- Croutons, gravy, soy sauce.
Here are some foods that should always be checked for gluten:
- Energy bars (remember some oats are not gluten free).
- Soups - often thick soups have been thickened with a gluten based thickener.
- Starch on a food label could come from wheat.
- Salad dressings.
I'm not a fan of "free from" foods. Most contain ingredients that one would also prefer to be free from if living a healthy lifestyle. The price is often not good for the pocket also. There is no nutritional reason to consume the types of foods that contain gluten.
Going beyond gluten-free
Does gluten free always work?
There is some evidence that despite a gluten free diet, many coeliacs still have evidence of damage in their gut(6). They may also find they experience problems after eating certain types of food that should cause them no problem. There are at least three reasons for this continued ill health. Firstly many coeliacs on a gluten free diet still do not absorb as much from their intestines as they should and are therefore at risk of vitamin and mineral deficiencies. Secondly they may have leaky guts which allow a degree of autoimmune responses to persist. Finally, inflammation often remains in the gut even after many years on a gluten free diet.
Restoring gut health by going beyond gluten free.
To restore health when there is some evidence that the gut is still damaged it is worth trying a beefed up version of a gluten free diet(7). One diet that is worth trying is the SCD diet(6). In this diet you are encouraged to eat natural foods. Contrast this with what many coeliacs are doing, which is eating the standard western diet with many additional processed foods labelled as gluten free. Gluten free labelled foods are rarely natural and the "gluten free" market is now worth more than 10billion dollars worldwide.
To beef up your gluten free diet you are encouraged to:
- Drop other cereal grains such as corn, rice and oats. Note that oats can contain small amounts of gluten anyway.
- Cut out all soya derived products including tofu and soya milk. This is identified as a problem due to its purported effect on your thyroid and sex hormones.
- Remove so called industrialised seed oils. These are generally bad for health. The theory in the SCD diet is that they contribute to inflammation in the gut. Toxic oils included here are sunflower, safflower, canola and rape seed oil. I'd also add anything labelled as vegetable oil or fat to this list.
- Eliminate sugar from the diet. This is identified as a concern because of the types of bacteria it encourages to thrive in your intestines.
4) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1379574/ anti-endomysial test is the best