Coeliac Disease and the Gluten Free Diet

Written by a CORU Registered Dietitian.

Coeliac disease

Coeliac disease is an autoimmune disease that is triggered by gluten. It causes damage to the lining of the gut, making it harder to digest and absorb food. It can also affect many other parts of the body, including the brain, nervous system, bones and skin. It is a genetic condition and is lifelong and irreversible. Around one in 50 people in Ireland have coeliac disease, but many are undiagnosed. Up to 75 percent of people with coeliac disease do not know that they have it.

Coeliac disease can cause many symptoms. People often think of diarrhoea, stomach pain and nausea, but coeliac disease can present in many other ways. It is worth remembering that up to 40 percent of people with coeliac disease do not have any gut symptoms at all.

Who should be tested for coeliac disease?

Anyone with symptoms of coeliac disease should be tested, even if the symptoms are mild. People who have recurrent headaches or migraines, osteoporosis, low iron, infertility, low folate or low vitamin B12 should also be tested. People with a family history of coeliac disease are at higher risk of developing the condition and should also be tested. Around one in 50 people in the general population have coeliac disease, but this increases to one in ten for first-degree relatives, including parents, siblings and children.

People with Down’s syndrome, Turner syndrome, an underactive thyroid or type 1 diabetes are also at higher risk of developing coeliac disease and should be tested.

Coeliac disease and the gluten free diet

The diet for coeliac disease is often described as a strict gluten free diet. This is because people with coeliac disease must avoid all gluten at all times. There are no days off, no exceptions and no crumbs. Even a very small amount of gluten can cause damage, even if symptoms do not appear straight away.

What foods contain gluten?

Gluten is found in wheat, rye, barley and standard oats. Some people with coeliac disease also react to gluten free oats. Remember that spelt, semolina and couscous are all forms of wheat and contain gluten.

Foods such as bread, pasta, cakes, noodles and breakfast cereals commonly contain gluten.

Gluten can also be found in many other foods where flour or barley malt is used as an ingredient. This includes stock cubes, sauces, soups and sausages. The Coeliac Society produces an up-to-date list of safe gluten free foods each year. Visit www.coeliac.ie.

Gluten and cross contamination

Cross contamination occurs when gluten free food comes into contact with food containing gluten. This alone is enough to cause damage. Examples include a crumb in butter, sandwiches placed on a shared plate, stirring gluten free sauce with the same spoon as regular sauce, or cooking chips in oil that has previously been used for foods such as chicken nuggets. These are common ways people with coeliac disease can accidentally consume gluten.

Avoiding cross contamination

Use a separate toaster or toaster bags if sharing a toaster.
Keep separate butter, jam, marmalade and similar items. Anything that has a knife dipped into it can contain crumbs.
If frying food, use fresh, clean oil. Deep fat fryers used for foods such as chicken nuggets or onion rings will contain gluten and the oil must be replaced before cooking gluten free foods.
Use separate chopping boards and store gluten free food away from gluten-containing foods, especially bread.
Do not allow gluten free food to touch foods containing gluten.

Cross contamination in foods you buy

If a product states that it may contain gluten, or may contain wheat, barley, oats or rye, people with coeliac disease must avoid it. This warning is only used when there is a genuine risk of gluten contamination.

There is no such thing as slightly coeliac

Some people become unwell after consuming even a tiny amount of gluten, while others may eat small amounts for some time before feeling unwell. This does not mean that one person has a milder form of coeliac disease. The internal damage is the same, regardless of symptoms. Continuing to eat gluten increases the risk of osteoporosis, fertility problems and other health conditions. This is why everyone with coeliac disease must avoid all gluten at all times.

Coeliac disease and nutrition

Vitamin D

People with coeliac disease are at increased risk of osteoporosis. This may be due to poor absorption of vitamin D or calcium, but gluten can also directly damage bone health. People with coeliac disease should take vitamin D during the winter months, and some health professionals recommend supplementation throughout the year.

Calcium

Calcium is essential for bone health alongside vitamin D. Dairy foods such as milk, yoghurt and cheese are good sources. Calcium-fortified plant-based milks are also suitable. Always check labels, as not all plant-based milks contain added calcium.

Fibre

Getting enough fibre on a gluten free diet can be challenging. Many people move from diarrhoea to constipation after starting a strict gluten free diet. Fibre-rich gluten free foods include:

Fruit and vegetables
Nuts and seeds
Beans and lentils
Brown rice, potatoes with skins and quinoa

Have you seen your dietitian?

The only treatment for coeliac disease is a strict gluten free diet. People who do not see a dietitian at diagnosis are often still consuming gluten and experiencing symptoms years later. Make sure you see a CORU-registered dietitian at diagnosis, after six months and after one year. After this, aim for regular reviews, ideally once a year. Remember to have your coeliac blood tests checked annually and ask your doctor to monitor iron, vitamin B12 and folate levels.