Updated: Oct 1, 2020
Coeliac disease is very different to gluten sensitivity. In coeliac disease it is imperative that gluten is avoided because it causes the villi (tiny profusions on the gut wall) to lie flat, making digestion of certain protein molecules and also some minerals very difficult. Therefore there is damage to the gut.
In NCGS (non coeliac gluten sensitivity) abdominal pain, bloating and nausea may be experienced after eating gluten, but no damage to the gut occurs. In some people who have self diagnosed as being gluten intolerant, it may in fact be the small carbohydrates which are causing them discomfort, not the protein gluten. In which case, they would do well to consult a nutritionist or dietitian to try to identify which carbohydrates they can tolerate and at what portion size.
Gluten is found in wheat- all kinds including triticale, rye, barley and possibly oats. Corn gluten (sometimes seen on food labels) is OK for coeliacs. Gluten is made up of two proteins - gliadin and glutenin.
To be labelled as gluten free, a food must have the amount of gluten (or less) that is thought to do no harm. In Australia the amount is set at 3mg of gluten per 100g of food, which means that oats are not considered to be gluten free. In some other countries the threshold is set higher. Therefore, if you travel, you cannot necessarily trust GF labelling.
The latest research suggests that regular ingestion of 0.15mg/day can cause symptoms and 50mg/day will cause villi damage. However, everyone is different and there is a high degree of variability insensitivity in coeliac disease.
In one slice of bread (which in itself is highly variable in weight, size and ingredients) there is typically about 2.5mg gluten. So, one fiftieth of a slice of bread is enough to do harm. This makes cross contamination an important issue. Just a few breadcrumbs left on the board, or crumbs in the butter pot can be enough to affect someone who is coeliac. Add to this the cumulative effect over the day of similar small contaminants and the problem grows.
Research suggests that 30-50% of patients following a gluten free diet will still have ongoing villi damage. This suggests that gluten is creeping into their diet, maybe because they are ‘cheating’ or maybe because they are inadvertently ingesting small amounts here and there. 4-15% of people have still not recovered (ie are symptom free and villi are repaired) five years later. Generally, children have the best outcomes, perhaps because they are habituated to the diet and its exclusions from an early age? Or, perhaps their bodies are better at repairing damage then older bodies?
Background contamination of gluten free foods is often the problem. Typically, background gluten contamination occurs at about 200-400mg/day. How sensitive you are is thought to be linked to the make-up of your gut microbiome. There are now some ‘at home’ tests to detect how much gluten you have ingested. However, these can cause hypervigilance and food anxiety.
Where can background gluten appear?
Gluten is sometimes used as a food additive and labelled as number of different things (eg thickener). If a food is labelled as gluten free, it should be. However studies in Australia found that 96% were truly gluten free. Unlucky people who ate the other 4%! Other foods which are known to contain no gluten (eg rice or lentils) but have no labelling can also be contaminated by other foods or in processing.
Restaurant meals are another minefield - one Melbourne study found that of meals which claimed to be gluten free, only 91% truly were.
Non-compliance by people to a gluten free diet is completely understandable. It requires constant vigilance and often limited choice. Social gatherings become difficult and mistakes are often made. Quality of life can be affected by this.
There are currently no drugs which can ‘cure’ coeliac disease. The gluten free diet is the only way to repair villi damage. One way to make eating out a little easier however, is to take an enzyme just before eating which will help to digest small amounts of gluten. This can create confidence when eating out. Gluten free options should still be chosen, but small amounts of gluten will be ‘mopped up’ by the enzyme.
One on the Australian market at the moment is called Gluteguard. It is made from natural latex in the skin of paw paw fruit and contains the enzyme Caricain. In tests, coeliac people ate 1g gluten per day for 42 weeks and took Gluteguard too. There were no noted side effects and significantly less nausea, fatigue, vomiting and no increase in villi damage, compared to a control group who ate the 1g gluten per day but did not take gluteguard. On their website, 58.4% of users of Gluteguard report that it is very helpful and 24.3% said ‘life changing’. It is of most use when gluten ingestion remains at or below 1g/day. So it is definitely not an invitation to eat pizza! The future may bring similar products to the fore.
Coeliac Australia has a good list of gluten free foods and many helpful resources.
What is clear is that navigating a truly gluten free diet is problematic, and needs to done with care and attention.