The Lowdown on Gluten

Gluten has become an increasingly popular buzzword in the health industry with many claiming that going on a gluten-free diet has ‘cured’ their gut issues. But what is gluten, what is the evidence behind these claims, and is gluten harmful for us?


Gluten is actually the protein in grains such as wheat, barley, rye and triticale (a wheat-rye hybrid). It is quite a ‘sticky’ substance, helping the food to hold its shape. It is a perfectly natural component of food and has been consumed for thousands of years as part of the human diet. So why do people avoid gluten?

Those who have coeliac disease are the only people that really should avoid gluten completely as eating gluten is physically detrimental to their digestive tract. People who have coeliac disease have impaired villi function. Villi are small, finger-like projections that line the inside of our small intestine and function to absorb nutrients from our food, as it is being digested. When coeliacs eats gluten, these villi physically flatten in response to the presence of gluten, reducing the body’s ability to absorb nutrients properly. This can lead to nutrient deficiencies an array of uncomfortable symptoms, including vomiting, diarrhoea, abdominal pain, bloating, constipation, fatigue, pale, foul-smelling or fatty stool, among others. Coeliac disease is an auto-immune condition, meaning that this response is produced by the body’s own immune system. If you suspect you might have coeliac disease, it would be worth going to visit your GP to get tested.


Where does that leave the rest of us who are not coeliac? Everyone without coeliac disease (including those with gluten intolerance or sensitivity) do not experience this flattening of the villi, upon gluten consumption. (NOTE: if you suspect they might have a gluten sensitivity or intolerance, ensure you read the bottom paragraph!) Therefore, it is important to understand that your nutrient intake may change if strictly cutting gluten out from your diet. A variety of nutrients may be at risk for those following a gluten-free diet include fibre, iron, calcium, thiamin, riboflavin, niacin and folate. Gluten-free varieties and products are also often more heavily processed and higher in sugar and fat than regular varieties! This makes it even more important to read food labels and be aware that the label of ‘gluten-free’ does not equate to ‘healthier’ when it comes to food choices.


But what about all the claims for restricting gluten for the general population? Let’s take a deeper dive into the hard evidence to find out! A recent paper reviewed this exact question and demonstrated that there is some evidence on the benefits of a gluten free diet to assist with specific conditions such as gluten-sensitive irritable bowel syndrome (IBS), schizophrenia, atopy, fibromyalgia and endometriosis. Although at this stage, this evidence is not sufficiently conclusive for a gluten free diet to be recommended as a main treatment option (NOTE: consult your GP or dietitian before trialling a gluten free diet for any condition you may have). When looking at a gluten free diet in relation to the general population, it was concluded that “it appears that most individuals who participate in a GFD (gluten-free diet) do not have a physiologic requirement for the diet and likely do not derive substantial benefit. Existing evidence for potential harms of a GFD include possible nutritional deficiencies, financial costs, and negative psychosocial implications. As with other dietary interventions, a GFD is a rapidly evolving topic, and additional insight is needed to guide a complete discussion between patients considering a GFD and their health care providers.” All in all, at this point in time, it seems the risks may outweigh the benefits in terms of strictly restricting gluten in the healthy population!


IMPORTANT: if you suspect you have a sensitivity to gluten but are not coeliac, it is recommended to see your GP first to rule out other possible conditions causing your symptoms. You may then wish to enlist the help of a dietitian who can assist with determining the particular food intolerance or sensitivity. By eating a strict gluten free diet to manage symptoms, you are likely to be doing more harm than good to your gut health by cutting out a wide variety of foods and nutrients, that you may actually be able to tolerate! It may just be that you need a smaller portion of gluten and it also may turn out that the cause of your symptoms is not gluten at all, but actually another component or chemical in food.


Dietitian and Exercise Scientist



Niland, B., & Cash, B. D. (2018). Health Benefits and Adverse Effects of a Gluten-Free Diet in Non-Celiac Disease Patients. Gastroenterology & hepatology, 14(2), 82–91.



Call 02 8188 9730