NUTRITION MANAGEMENT
GLUTEN-FREE DIET - FACT OR FAD? Rebecca Gasche Registered Dietitian, Countess of Chester Hospital NHS Trust Rebecca has a keen interest and specialises in gastroenterology dietetics. She currently works in the community setting in the Chester area, running clinics and group sessions to manage a wide range of gastroenterology conditions.
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This article will take it back to basics and discuss what a gluten-free diet is and when it may be used. Gluten is the name for the proteins which are found in wheat, barley and rye. Gluten itself can be broken down into two main protein groups: glutenin and gliadin. Its purpose is to help food to maintain its shape, add stretchiness and texture to bakes such as bread and pizza dough, and can be used to thicken sauces and soups.1 It is only in the past 10,000 years that humankind has begun consuming gluten and, as a result, it remains a relatively new introduction to the human diet (considering the estimation that we have been here for 2.5 million years!).2 Gluten-free diets have risen in popularity over the years, partly due to better diagnosis of diseases such as coeliac disease and recognition of conditions such as non-coeliac gluten sensitivity. However, with glutenfree diets becoming better known and products more easily available, a ‘trend’ in restricting gluten in the modern day diet seems to have taken off. FOODS THAT ARE GLUTEN FREE AND NOT GLUTEN FREE
Naturally gluten-free foods are those which are not derivatives from, or contain, wheat, barley or rye. Some foods such a breads, pastas, cakes and biscuits can be specially manufactured and have gluten removed from them, making them gluten free (see Table 1). The most common foods that are not gluten free include bread, pasta and some cereals. Other foods/drinks that are not so obvious sources of gluten are some alcoholic drinks such as beer/ale, and sauces such a soy sauce. (See Table 2).
For people with coeliac disease, there are a number of foods that they need to check to ensure they are gluten free, such as sauces, gravy, ready meals and other items that are not obviously gluten free. Confusingly, some gluten-free products contain an ingredient called gluten-free (Codex) wheat starch, a specially manufactured wheat starch where the gluten has been reduced to a trace level so that it is suitable for people with coeliac disease.13 Gluten-free (Codex) wheat starch is often found in products such as gluten-free flour and bread to improve texture. There may be a small number of people with coeliac disease who also have a wheat intolerance, who cannot tolerate wheat starch. These patients will need to follow a gluten-free and wheat-free diet - this can be trialled if a patient has ongoing symptoms despite following a gluten-free diet.3 Oats are naturally gluten free, but, nevertheless, are available to buy specifically termed ‘gluten free’ to show that they have not been contaminated with other gluten-containing products during production. This is more important for those with coeliac disease who need to avoid cross-contamination. However, oats do contain a similar protein to gluten - avenin - which a small number of people with coeliac disease can’t tolerate. This is due to the body reacting to avenin in the same way it does to gluten. This group of patients may choose to follow a glutenand oat-free diet.3 FOOD LABELLING AND A GLUTEN-FREE DIET
All foods labelled as gluten free must meet the Codex standard which is to contain less than 20ppm (parts per million) of gluten.3 www.NHDmag.com July 2018 - Issue 136
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Gluten-Free Starter Pack Service To ease the transition onto a gluten-free diet, Juvela offer newly diagnosed coeliac patients a complimentary starter pack.
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Table 1: Main gluten-free foods
Table 2: Main gluten-containing foods
Rice
Millet
Bread
Pasta
Potatoes
Polenta
Cakes
Quinoa
Flaxseeds
Wheat-based cereals, e.g. Weetabix
Buckwheat
Meat (not in breadcrumbs)
Biscuits
Pastries
Maize
Fish (not in breadcrumbs)
Noodles
Bulgur wheat
Couscous
Pearl barley
Beer/Ale
Some sauces, e.g. soy sauce, gravy
Flour
Rye based products
Corn
Eggs
Oats
Dairy
Fruit
Vegetables
Gluten-free products (bread/pasta/cereal/flour)
Rice/oat/corn-based cereals, e.g. Rice Krispies
All packaged foods in the UK are covered by a law on allergen labelling, which means that you can identify from an ingredients list if a product contains gluten. If a cereal containing gluten is used as an ingredient, it must be listed on the ingredients list, no matter how little is used. It will also be emphasised in bold, italic, underlined or highlighted and the specific grain will be named (e.g. wheat, rye, barley, spelt, kamut) so that the consumer can clearly see what is included in a product. Manufacturers may (legally) use labelling such as: • ‘may contain traces of gluten’ • ‘made on a line handling wheat’ • ‘made in factory also handling wheat’ These terms mean that there is a risk the product could be contaminated with gluten (even if the risk is very small). Coeliac UK, the registered charity for coeliac disease, provides a comprehensive list in their Foods and Drink directory, available to those diagnosed with coeliac disease: www.coeliac. org.uk/gluten-free-diet-and-lifestyle/foodshopping/food-and-drink-directory/ WHEN IS A GLUTEN-FREE DIET NEEDED?
Coeliac disease Coeliac disease is a lifelong autoimmune disease which affects one in 100 people in the UK.2 It is caused when the body has an abnormal response to gluten, a protein found in wheat, barley and rye. This response causes damage to the microvilli found within the small intestine, which can lead to gastrointestinal symptoms and the
malabsorption of nutrients. The only treatment which reverses the damage done to the microvilli - is to follow a strict gluten-free diet. Dermatitis herpetiformis (DH) DH is a skin condition linked to coeliac disease. DH affects fewer people than typical coeliac disease, at around one in 3300 people. DH can appear at any age, but is most commonly diagnosed in those aged between 50 and 69 years. The treatment for this is to follow a glutenfree diet, sometimes in addition to medication such as Dapsone.3 Irritable bowel syndrome (IBS) IBS is long-term condition affecting the digestive tract, thought to affect one in five people in the UK.4 It can most commonly cause symptoms such as abdominal discomfort, an altered bowel habit and bloating, and can have a huge impact on a patient’s quality of life. Part of the difficulty in managing IBS is the wide variety and severity of symptoms that patients may have and how these symptoms are often triggered by different things. However, it is known that diet and lifestyle factors play a huge role in managing symptoms.2 The low FODMAP (fermentable oligo-saccharides disaccharides monosaccharides and polyols) diet may be used as second-line treatment for people with IBS. This involves an elimination phase of high FODMAP foods, which includes restricting wheat, barley and rye products as they contain high levels of the FODMAP fructans. Patients following a low FODMAP diet therefore choose gluten-free products to avoid wheat in their diet. www.NHDmag.com July 2018 - Issue 136
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WEIGHT MANAGEMENT Non-coeliac gluten sensitivity (NCGS) This can be described as when symptoms similar to coeliac disease are experienced, but there are no associated antibodies and no damage to the lining of the gut that you would find in coeliac disease.5 These symptoms may occur several hours or days following gluten ingestion. Wheat allergy This is potentially a serious condition, but estimated to be rare, and is caused by a reaction to the proteins found in wheat, which is triggered by the immune system.5 It differs from coeliac disease as it is an immunoglobulin E (IgE) mediated response.6 A reaction to wheat in someone with a wheat allergy usually occurs within seconds or minutes of consuming wheat, and can range from a rash or an itchy sensation in the mouth, to throat swelling, difficulty breathing and, in rare cases, anaphylactic shock.7 Patients with a wheat allergy will, of course, avoid foods containing wheat and will, therefore, follow a mostly gluten-free diet. However, they can include gluten-containing foods from barley and rye products. WHAT’S THE PROBLEM?
In recent years, there has been a trend for people to follow a gluten-free diet when it isn’t necessarily needed. Gluten has had a bit of a bad press, with people being misinformed that it is bad for you. The assumption is that gluten is poorly digested and linked to weight gain. Don’t get me wrong, following a gluten-free diet is not detrimental if it is clinically indicated, however, restricting any foods unnecessarily is not recommended, as you could miss out on vital fibre, vitamins and minerals. I often see influencers on social media platforms promoting health products, recipes and snacks as gluten free and I am dubious about whether there is any medical reason for this. David Sanders, a Professor of Gastroenterology at Sheffield University, was quoted speaking to The Guardian about the growing numbers of people who are cutting gluten out simply because they believe it is unhealthy: “What you might call the ‘lifestylers’,” he says. “The truth is, there really isn’t any clear evidence base… Even if people believe they have symptoms related to gluten, do not put yourself on a gluten-free diet.” 34
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Rather, he advises people to go to their GP and have coeliac disease ruled out.8 Another misconception around gluten is that following a gluten-free diet will help you lose weight. A recent study proves this theory wrong and actually demonstrated that glutenfree products can be higher in sugar, fat and salt.9 A 2007 study10 also demonstrated that gluten-free foods have poor availability and are more expensive than their gluten-containing counterparts. It also commented on how, as the rate of diagnosis of coeliac disease is increasing, there are growing demands for gluten-free products. This study indicates that gluten-free products are difficult to obtain and are more expensive, placing great burden on the patients who are trying to address the therapy of their disease.10 Walking down the aisle at your local supermarket, you will see a growing number of gluten-free products appearing in the ‘free from’ sections. Look a little closer and you’ll notice some products being advocated as gluten free when they traditionally contain zero gluten in the first place! For me, this is a clear example of manufacturers taking advantage of the glutenfree trend and high price tags on these products. Further studies have identified other difficulties in the gluten-free diet, such as a lack of vitamins and fibre, resulting in the need for supplementation.11,12 In saying this, the more people aware of and following a glutenfree diet does come with its benefits. More people following a gluten-free diet means more knowledge in restaurants and more gluten-free food being available, which particularly helps in the localities that have stopped gluten-free food on prescription. There are also hopes that it will eventually bring the price of gluten-free alternatives down. One study has also commented that a gluten-free diet tends to include more fruits, vegetables and meats, as these products are naturally gluten free and more readily available than some gluten-free products.10 Overall, I think the evidence is clear: unless a diagnosis of a recognised condition has been made, suggesting that a gluten-free diet should be followed, then gluten is a friend! Those who are unsure should be advised to discuss this with their GP in order to be referred onto the appropriate healthcare professional.