The 13-20th of March marks Coeliac Awareness Week (CAW) for 2021. CAW aims to raise awareness for Coeliac Disease and the need for it to be treated seriously. Today we’ll explain what Coeliac Disease is, the difference between being this disease and gluten intolerance and how the low FODMAP diet interacts with this type of gluten sensitivity.
What is Coeliac Disease?
355,000 Australians have Coeliac Disease. That’s approximately 1 in 70! Even if you don’t have Coeliac Disease, you may know someone who does. Coeliac Disease is an autoimmune condition – a person’s own immune cells, specifically T cells in their gut, attack themselves upon eating gluten. This reaction induces an inflammatory immune response. What is gluten, you ask? Gluten is a family of proteins found in grains, including wheat, barley, rye and oats. You can think of gluten as the ‘glue’ that holds grains together – such as bread, cakes, biscuits and breakfast cereals. Gluten is not to be confused with fructans, which are the oligosaccharides and polysaccharides that are found in wheat products and are considered FODMAPs.
Since Coeliac Disease is a serious medical condition with lifelong implications, receiving a definitive diagnosis is essential. A blood test called a coeliac serology is used to screen for Coeliac Disease. This test measures the levels of an antibody called transglutaminase. A positive blood test must be coupled with a small bowel biopsy, which looks for the bowel damage associated with undiagnosed Coeliac Disease. This bowel damage is known as villous atrophy (damage to the villi – the finger like projections found in our small intestine that help us absorb nutrients). It is important to note that these tests can only be undertaken while the person is still eating gluten – without gluten in our system, the results can be unreliable. At this stage, Coeliac Disease cannot be treated, but can be managed by following a lifelong strictly gluten-free diet.
Coeliac Disease vs gluten intolerance – what is the difference?
Only 1 in 70 Australians have Coeliac Disease, but more than 1 in 70 Australians follow a gluten free diet. Why is this the case?
For those with Coeliac Disease, gluten can cause gastrointestinal problems for multiple reasons. When a person diagnosed with Coeliac Disease eats gluten, their body overreacts to the protein and damages their villi. Even the smallest particle gluten (such as remnants in the toaster) can cause a serious reaction, painful symptoms and intestinal damage that takes months to heal. When the villi is continuously damaged over the long term, people with Coeliac Disease struggle to absorb nutrients and may develop symptoms such as fatigue, joint or bone pain, anaemia, depression or anxiety. This is why there should be zero traces of gluten for someone with Coeliac Disease. Separate toasters, separate food preparation areas and respect of avoiding cross-contamination of gluten are very important.
Whereas, gluten intolerance, also known as non-coeliac gluten sensitivity (NCGS), describes when people without Coeliac Disease experience uncomfortable gut symptoms after eating gluten. The symptoms are non-specific but can include abdominal pain, diarrhoea and bloating. Do these symptoms sound familiar to you? That may be because they overlap with IBS. When a person with NCGS eats gluten-containing foods, they experience gut symptoms but not long-term intestinal damage. This is not to say that NCGS isn’t ‘real’ or any less painful, but it means that it is a functional sensitivity. For those with NCGS, eating gluten will not have the serious consequences associated with Coeliac Disease. Thus no need to be as strict with cross-contamination nor have separate toasters.
Why do people with gluten sensitivity feel better following a gluten free diet?
Emerging evidence suggests that non-coeliac gluten sensitivity could be due to the FODMAP component of wheat, fructans, rather than the protein component – gluten. You can think of gluten and fructans as friends – although they’re from different families, they’re often found together in foods. This is why the gluten free and low FODMAP diets overlap. You can read more about this concept here.
Upon receiving a diagnosis for IBS, a doctor will sometimes recommend following a gluten free diet. Why so? Gluten free foods are not necessarily low FODMAP, just as low FODMAP foods are not necessarily gluten free. However, if you imagine a Venn diagram, there is a large ‘grey area’ in the middle of foods that are both low FODMAP and gluten free. Hence, gluten free diets are a good ‘rule of thumb’ recommendation for those with IBS. You may feel better on a gluten free diet as some of the FODMAP content can be removed with the gluten during removal of the gluten protein.
When searching for gluten free foods, there is only one variable to be concerned about – gluten. However, when it comes to FODMAP-containing foods, there are a few more variables to think about. For example, onions may be gluten free, but they contain high amounts of fructans (a type of oligosaccharide) and may induce discomfort in those with IBS. This is why it is very important to understand the foods that are gluten free, but high FODMAP in specific quantities.
To follow or not to follow a gluten free diet?
Following the gluten free diet if you do not have Coeliac Disease can be quite restrictive and unnecessary. For those with IBS, following a strict low FODMAP diet does not have the lifelong requirements associated with Coeliac Disease. This is why it is worth seeing a qualified gut health Dietitian who can talk you through the low FODMAP diet and help you find your FODMAP triggers. This process will help you expand your diet and enhance nutrient intake in the longer term.
There is a large ‘grey’ area between a low FODMAP and gluten free diets. However, IBS and Coeliac Disease are very different conditions and need to be treated as such. Coeliac Disease is a serious autoimmune condition that must be treated with a lifelong, strict gluten free diet. Whereas NCGS is likely due to the FODMAPs in wheat rather than gluten. A low FODMAP diet protocol may be a better plan of action rather than following a strict gluten free diet. In both conditions, it is important to consult a Doctor and Dietitian who will be able to support you in either coeliac testing or following the low FODMAP diet.
Written by: Charlotte Barber (Student Nutritionist)
Reviewed by: Kiarra Martindale (Accredited Practising Dietitian)