Could it be gluten? Coeliac disease and beyond...

Over the last decade, there has been a rise in the popularity and use of the gluten-free diet (GFD) which is disproportionate to the prevalence of medical conditions recognised to benefit from it. This article looks at the gluten-related conditions for which a GFD can offer a solution.

Rise of the GFD

A Google search of the term ‘gluten-free diet’ brings back over 9 million results highlighting the level of interest in this as a dietary option¹. For some, it might be due to lifestyle or general health reasons for which there is no evidence base to support its use². For others, their interest may be as a means of managing their symptoms or due to a medical condition.

Which conditions require a GFD?

There has been an increase in coeliac disease (CD), the most established gluten-related condition, over the last 50 years³. CD, an autoimmune condition triggered by an intolerance to gluten, a protein found in wheat, rye and barley, is now estimated to affect 1 in 100 people in the UK⁴.

The rise in prevalence can be partly attributed to a greater recognition of how this condition presents, combined with advances in diagnostic testing. However, only 36% of people with the condition are currently diagnosed⁴.

The table below shows the wide range of symptoms which can be associated with CD⁴:

Due to a number of CD symptoms being associated with other conditions, such as irritable bowel syndrome (IBS), misdiagnosis can be common. The condition also has a genetic component meaning close family relatives of those with CD have a higher risk of developing the condition (1 in 10) than the general population⁴.

I think I have coeliac disease, what should I do?

It is important to seek medical advice and obtain a diagnosis as there are associated long-term health complications if the condition remains undiagnosed and untreated.

The first step in this process would be to visit your GP and discuss your symptoms. A simple blood test can be undertaken to detect if coeliac antibodies are present. If the test is positive or there is suspicion of CD, a referral will be made to a gut specialist for further tests which may include a gut biopsy.

It is essential that anyone suspected of having CD continues to eat gluten throughout the diagnosis process, until otherwise advised, to ensure test results are accurate.

The only known treatment for CD is a strict, lifelong gluten-free diet (GFD). For more information on CD, click here.

A GFD: Beyond Coeliac Disease

Many people obtain a negative coeliac blood test result but still feel they have symptoms when they eat gluten. It may be that CD will develop in later life in this instance. For some people with ongoing symptoms related to gluten, it may be they have a condition known as ‘non-coeliac gluten sensitivity’ (NCGS). The symptoms are very similar to CD, however, there is no test to diagnose NCGS at present. In a UK study, 13% of a general population sample reported symptoms attributed to gluten, a far greater number than with coeliac disease⁵. For those with NCGS, eating gluten does not appear to cause any damage to the lining of the gut and eating small amounts of gluten in the diet may be tolerated by some, whilst others have to avoid it altogether.

IBS

IBS affects between 10-20% of the population and 80% report experiencing food intolerances or food-related symptoms⁶. As such, dietary changes are fundamental in treatment. Currently, the first-line dietary advice for IBS involves a number of healthy eating strategies – e.g. eating regular meals, taking time to eat, avoiding gut irritants such as spicy, fatty foods, alcohol and caffeine. Second-line advice (as part of the BDA IBS guidelines) is a low FODMAP diet. This is a complicated approach requiring multiple food avoidance and careful reintroduction to tolerance. This also involves the removal of wheat-based (and therefore gluten-containing) foods.

Gluten-Free & IBS

A recent study found that 68% of patients who continued to follow a personalised low FODMAP diet in the long term were purchasing specialist gluten and wheat-free products to help control symptoms⁷. This, as part of a growing body of evidence indicating that a GFD is effective in managing symptoms in people with non-constipated IBS^8,9, has led researchers to suggest a GFD may offer a solution for a percentage of this group. 

In conclusion, if you suspect that you have symptoms related to gluten, consult with a health professional to ensure you have a proper diagnosis and for advice on dietary options to help manage your symptoms.

References

1. Google. Accessed April 2023
2. Croall I, Aziz I, Trott N et al. Gluten does not induce gastrointestinal symptoms in healthy volunteers: A double-blind, randomised placebo trial. Gastro 2019; 57 (3): 881-883
3. Al Toma A, Volta U, Aurrcchio R et al. European Society for the Study of Coeliac Disease (ESsCD) guideline for for Coeliac Disease & other Gluten-Related Disorders. United Eur Gastro J 2019; 7 (5): 583-613
4. www.coeliac.org.uk. Accessed April 2023
5. Aziz I et al. A UK study assessing the population prevalence of self-reported gluten sensitivity and referral characteristics to secondary care. Eur J Gastro Hepatol 2014;26:33-39
6. NICE Clinical Guideline 61. Irritable Bowel Syndrome in adults: diagnosis and management. Updated 2017.
7. Rej A, Shaw C, Buckle R et al. The low FODMAP diet for IBS; A multicentre UK study assessing long-term follow up. Dig Liver Dis 2021; 53(11): 1404-1411
8. Aziz I, Trott N, Briggs R et al. Efficacy of a gluten-free diet in subjects with IBS-diarrhoea unaware of their HLA-DQ2/8 genotype. Clin Gastroenterol Hepatol 2016;14(5): 696-703
9. Rej A, Sanders DS, Shaw CC et al. Efficacy and acceptability of dietary therapies in non-constipated irritable bowel syndrome: A randomised trial of traditional dietary advice, the low FODMAP diet and the gluten-free diet. Clinical Gastro & Hepatol 2022;20:2876-2887