Coeliac Disease (CD) is an autoimmune disease, affecting approximately 1 percent of the global population. In Australia 1 in 100 people have CD with about 80 % (200,000) being undiagnosed. It is believed that there are three factors that underlie the development of CD. These include an environmental trigger (gluten), a genetic susceptibility (genes for HLA DQ-2 and HLA DQ-8 proteins) and an unusually permeable gut.
The environmental trigger of CD is gluten, which is the major protein in wheat, or of related proteins found in other grains, including rye, oats, barley and triticale. Gluten is the composite of two proteins, gliadin and gluten in and makes up 80% of the protein in wheat. Gluten has the physical properties of elasticity and extensibility which provide the qualities we see in wheat based breads and cakes.
In people with CD, 95% have a genetic susceptibility possessing the gene for either HLA-DQ2 or for HLA-DQ8, or both, whereas 30 40 % of the general population have one of those versions. It is these genes doctors test for when exploring an individual’s risk of developing CD. Only one in 30 people who carry the gene will develop CD.
The common symptoms of CD are abdominal pain, bloating, constipation, diarrhoea, weight loss, nausea and vomiting. However the presentation of the disease may be less dramatic or atypical. The disease may produce symptoms such as osteoporosis, joint pain, chronic fatigue, short stature, skin lesions, epilepsy, dementia, schizophrenia and seizure.
WHAT HAPPENS IN THE GUT
In digestion, partly processed food from the stomach enters the small intestine, which is lined with finger like projections called villi. Enzymes from the pancreas and on the surface of the villi break down most of the partly digested food into its smallest components which are then absorbed into the blood stream and travel to the tissues throughout the body. Glutens structure and properties make it difficult for the gut to break down all parts of this protein, resulting in small indigestible protein fragments being left in the gut which are then excreted. Normally any gluten that may cross the gut lining is too minimal to excite a significant immune response in a normally functioning immune system. However in individuals with CD, they have a heightened sensitivity to gluten. In this case the gluten fragment induces the release of a protein called Zonulin, which causes a leaky gut. The gluten then leaks through the lining of the gut and arouses immune system cells which trigger the release of the enzyme Tissue Transglutaminase (TTG). The TTG attempts to heal the damaged cells. The TTG enzyme modifies the gluten which then binds to a HLA molecule, resulting in the production of other immune cells which result in damage to the cells of the villi of the small intestine. Hence, it is the repeated exposure of gluten to the small intestine which causes damage to its architecture, resulting in the chronic inflammation and damage of the villi, the finger like projection in the small intestine. The repeated damage results in an increase in TTG antibody levels in the blood stream. It is these antibodies which are measured via a blood test to determine whether you have Coeliac Disease. The diagnosis is then confirmed with a small bowel biopsy.
Diagnosis requires a blood test and a gastroscopy of the small intestine. The blood test measures the TTG
Antibodies. The gastroscopy (passing a tube from the mouth into the gut) is a microscopic examination where five biopsies of the wall of the small intestine are taken to determine whether the villi are damaged. It is important to have the biopsy before commencing a gluten free diet to ensure a definite diagnosis. To confirm a diagnosis, the biopsy should be repeated after 6-12 months of commencing a gluten free diet, to demonstrate improvement to the villi.
The only treatment for Coeliac Disease is the lifelong adherence to a gluten-free diet. When gluten is removed from the diet, the villi in the small intestine will start to heal and overall health improves. Even small amounts of gluten can cause some damage to the lining of the small intestine without any obvious symptoms. There is no agreement amongst doctors, scientists and dieticians as to what (if any) is a safe level of gluten in the diet for someone with Coeliac Disease, The Coeliac Society of Australia Inc. believes that gluten should be entirely removed, but individual should consult their dietician or doctor.
LONG TERM RISKS
The long term risks of undiagnosed Coeliac Disease or non-adherence to the gluten-free diet include:-
- chronic poor health
- osteoporosis due to calcium malabsorption
- dental enamel defects
- risk of gastrointestinal & oesophageal carcinoma
It is sensible to have your blood checked annually for iron and folic acid levels, and to have a bone mineral density test performed.
Coeliac Disease can also be associated with other autoimmune conditions such as type 1 diabetes, autoimmune thyroid disease, pernicious anaemia, rheumatoid arthritis, inflammatory bowel disease and lupus. It has not been shown that there is a causative link, but having one genetic autoimmune disease increases your risk of having another.
FOLLOWING A GLUTEN-FREE DIET
It is important to avoid wheat, spelt, rye, oats, barley and triticale and foods manufactured using these ingredients.
- The Australian Food Standards Code requires that food labelled as gluten free must not contain any detectable gluten and no oats or malt
- New food labelling laws state that any ingredient derived from wheat, rye, barley or oats must be declared on the label
Modified Starches (thickeners 1400-1450)
- If these are made from wheat they are contain residual starch and therefore are not gluten-free. If the starch is from wheat, it will be specified as such. For example wheat starch, modified starch (wheat)? or thickener 14xx (wheat)
- If these thickeners are modified maize starch, modified potato starch or modified tapioca starch, they do not contain any gluten
- Maltodextrin is made from wheat or from maize (corn).
- If Maltodextrin is sourced from wheat it is not gluten free. It will be listed as wheat Maltodextrin or Maltodextrin from wheat
- If Maltodextrin is sourced from maize or potato it is gluten free. It will be listed as Maltodextrin
Medications and Vitamin Supplements
- Pharmaceutical manufacturers and producers of vitamin and mineral supplements sometimes use wheat starch or gluten as a filler within capsules and tablets.
- However, unlike food labelling requirements, drug labelling requirements do not require for gluten or gluten derivatives to be declared on the label.
- You should check with your doctor or pharmacist about whether a drug or supplement contains gluten. If either the doctor or pharmacist is in doubt about whether a product contains gluten, it is best to contact the manufacturer directly.
Avoiding Hidden Gluten
It is possible to inadvertently eat gluten unless you are particularly careful. Because even small amounts of gluten can cause intestinal damage, it is important to consider the following tips with preparation:
- Making gluten-free meals for the whole family, where practical.
- Clearly label all foods in your pantry/refrigerator/freezer.
- Use different utensils when preparing gluten-free and gluten-containing foods at the same time.
- Prepare gluten-free foods first.
- Use separate working areas for gluten-free and gluten containing foods.
- Have your own margarine spread to avoid contamination with breadcrumbs.
- Wash utensils thoroughly to remove all traces of gluten.
- Utensils with small crevices i.e. chopping boards/sifters may contain trace amounts of gluten containing particles. You may want to consider having separate utensils.
- Ensure sandwich makers, toaster are thoroughly cleaned before using them for gluten-free foods.
Other possible sources of hidden gluten
- BBQ chicken (seasoning/spices, stuffing)
- Salted hot chips may have been fried in same oil as battered and crumbed foods. Chicken salt may be added, this is not gluten free
- Potato wedges breadcrumbs, chicken salt
- Soy Sauce
- Flavoured potato/corn chips
- Unspecified cornflour
- Manufactured deli meats
- Confectionary lollies, chocolates
- Processing aids wheat starch on boiled lollies etc.
- Gluten-free bread from baker via ordinary breadcrumbs being on the bread slicer
- Gluten free sausages from the butcher, unless all sausages made on the premises are gluten free.
- Icing sugar mixture instead of pure icing sugar
- Communion wafers maize wafers are available.
- This should still be enjoyable. Waiting staff and chefs/cooks are usually happy to tell you how they prepared the foods and what ingredients were used once you explain the importance of gluten-free diet.
- Remember to check each time you go to a restaurant, even if you are ordering the same meal as staff and recipes can change.
- When ordering a meal, pay particular attention to sauces, dressings and soups. Check menu items for:
– Flour even grilled foods such as fish can be coated with flour.
– Stock powder/booster. Can be used in items such as risotto.
– Soy sauce
– Cornflour a lot of Chinese restaurants use wheaten cornflour to thicken sauces, custards and other desserts.
– Malt vinegar dressings, marinades.
– Mayonnaise may contain thickeners, malt vinegar.
– Icing sugar check whether it’s pure.
Gluten- Free Baking
It is important to realise that gluten-free flours do not behave the same as gluten-containing flours. Be prepared to experiment with your recipes. Directly swapping gluten-free flours for wheat flours works well for biscuit recipes, however some cake recipes work better than others!
Here are some tips for you:
- Measure ingredients carefully.
- Ensure your oven temperature is correct- over baking will dry the cake/bread out.
- Grease all baking tins even non-stick ones- or line, to prevent sticking
- Plain flour substitute: equal parts soy flour, rice flour and potato/maize flour.
- Gluten-free baking powder two parts cream of tartar with one part of bicarbonate soda. Use 2 teaspoons of this mixture with every cup of gluten free flour.
- Extra egg, xanthan gum can aid rising and results in a better texture. 1 teaspoon of xanthan gum should be added to biscuits/slices; 1-2 teaspoons to cakes/pastries; and, 1 tablespoon to breads. Commercial bread mixes already contain a gum.
- Roll gluten-free pastry onto non-stick baking paper it’s easier to lift.
- Cake and bread batters will always be thinner than the wheat counterparts.
- Cakes will cook better in a ring tin.
- Cornflakes and rolled rice flakes are good alternatives to rolled oats.
- Freeze bread immediately and use from the freezer.
- Set the timer for gluten-free pasta as it can become quickly over-cooked.
- Packaged gluten-free breadcrumbs or crushed gluten-free cornflakes are useful for crumbing foods.
COELIAC DISEASE WEBSITES
- Australian Coeliac Society. www.coeliac.org.au
o Queensland branch. www.qld.coeliac.org.au
o Victorian Branch http://www.vic.coeliac.org.au/ (This site has better general information than previous sites)
- http://www.allergyassist.com/ online shop for many gluten free products, specialising in products for people with multiple food allergies or intolerances. (Website to be launched September October 2009)
- http://www.glutenfreeshop.com.au/ online shop for many gluten free products however many products are available in supermarkets as well. Good site for getting an idea of what products are available to Coeliacs.
- http://www.orgran.com/ another site giving examples of available gluten free products.
- http://www.celiac.com/ U.S. site. Very comprehensive and informative about Coeliac Disease, gluten free foods and recipes. Click on site index for website contents. Also contains link to message board where you can post questions and read other’s experiences. http://www.glutenfreeforum.com/
- http://www.coeliac.org/ ? UK site. Another very informative site and very easy to navigate as well.