Diabetes and Coeliac Disease


Coeliac disease is becoming increasingly common, affecting around one in 100 people in the UK and Australia, and one in 133 Americans. For reasons that we do not yet completely understand, people with type 1 diabetes are at up to 10 times greater risk of developing the coeliac disease than people who do not have type 1 diabetes.

Like type 1 diabetes, coeliac disease is thought to be an autoimmune disease that is ‘triggered’ in genetically susceptible people. Unfortunately, coeliac disease can make the management of blood glucose levels even harder than usual in people with type 1 diabetes, with an increased risk of both hyperglycemia and hypoglycemia. People with type 2 diabetes or pre-diabetes are believed to have the same chance of having the coeliac disease as the rest of the population.

The immune system of those with coeliac disease reacts abnormally to the protein gluten that is found in wheat, rye and barley (and is a common contaminant in oats), causing damage to the small bowel (intestine). The tiny, finger-like projections known as villi that line the small intestine becomes inflamed and flattened, a condition that is known as villous atrophy. As a consequence, the surface area of the intestine available for the absorption of nutrients is reduced, which can lead to various gastrointestinal and malabsorptive symptoms like diarrhea; constipation; large, bulky, foul stools; unwanted weight loss or poor growth in children; flatulence; abdominal bloating, distension or pain; and anaemia. Long-term complications can be very serious and include infertility, miscarriage, depression, and dental enamel defects. There is also an increased risk of developing certain forms of cancer, such as lymphoma of the small bowel.

If you have a family history of coeliac disease, some or even all of these symptoms, it’s important that you don’t simply self-diagnose coeliac disease and commence a gluten-free diet. A diagnosis of coeliac disease can only be made by demonstrating the typical villous atrophy of coeliac disease in a small bowel biopsy. This involves a gastroscopy in which several tiny samples of the small bowel are taken and examined under a microscope. It is important that you are still eating gluten regularly before the procedure is performed, or you may get a false negative result.


Some people believe that they are sensitive to gluten, even though small bowel biopsy results show that they don’t have coeliac disease. When people with gluten intolerance avoid gluten, their gastrointestinal symptoms generally improve. However, a recent Australian study suggests that people with so-called gluten intolerance may not, in fact, be sensitive to gluten as such. Indeed, their gut symptoms may be due to other dietary factors, in particular, fermentable, poorly absorbed short-chain carbohydrates, that is fermentable, oligo-, di-, monosaccharides and polyols (FODMAPs) that are found in a wide range of foods. Rather than simply avoiding gluten, people with these symptoms may instead benefit from a low FODMAPs diet.

Because the symptoms of non-coeliac gluten sensitivity can be very similar to coeliac disease, or other conditions, it is important that you don’t self-diagnose and go on a gluten-free diet — see your doctor first.

Gluten-free foods

Following a gluten-free diet is currently the only known treatment for coeliac disease. Unfortunately, the diet needs to be followed for life because those with coeliac disease remain sensitive to gluten their whole lives. At this point in time, the condition can’t be cured as such. However, by removing the cause of the disease, a gluten-free diet allows the small bowel lining to heal and symptoms to resolve. As long as the gluten-free diet is strictly adhered to, the problems arising from the coeliac disease should not return.

In the not-too-distant past, having to consume a gluten-free diet was a culinary disaster. Thankfully, there are now gluten-free alternatives available for most foods. Many gluten-free core foods like milk, yogurt, some starchy vegetables, legumes, and most fruits also have a low GI (glycaemic index.). However, many gluten-free grain alternatives aren’t low GI, so finding suitable gluten-free bread, pasta, and breakfast cereals can still be a challenge for those diagnosed with both coeliac disease and diabetes.