What is a gluten-free diet? Our nutrition expert Jo Lewin explains what it means for your health, what to watch out for and where you can find support.
What is gluten?
Gluten is the protein component found in wheat, rye and barley. People often think oats contain gluten but they actually contain avenin, which is a protein similar to gluten. Research has shown many people who avoid gluten can safely eat avenin, however, problems can arise if oats are handled in the same place as wheat, barley or rye, as the oats can become contaminated by these other grains.
Gluten gives elasticity, strength and the ability to 'hold' food products together. The most obvious sources of gluten in most diets are bread, pasta, breakfast cereals, flour, pastry, pizza bases, cakes and biscuits. Gluten can also be found in processed foods, such as soups, sauces, ready meals and sausages.
Modern diets have become increasingly high in refined wheat products, which has led to the consumption of significant amounts of gluten. It is thought that some individuals are more sensitive to gluten than others. For the gluten sensitive individual, over consumption may lead to digestive symptoms such as bloating, pain and stomach cramps. For this reason, growing numbers of people choose to follow a gluten-free diet. Gluten intolerance is different from a condition called coeliac disease - this is an auto-immune disease caused by a reaction to gluten, which must be avoided for life.
A note about coeliac disease
Coeliac disease is a lifelong, autoimmune disease caused by the body reacting to gluten and is estimated to affect approximately 1 in 100 people. In people with coeliac disease, consuming gluten causes an immune reaction to the lining of the small intestine resulting in a range of symptoms including bloating, diarrhoea, nausea, wind, constipation, tiredness, headaches, sudden or unexpected weight loss (but not in all cases), hair loss and anaemia.
The myriad of symptoms and varying degrees of severity associated with coeliac disease make it hard to diagnose. Once diagnosed, it is treated by following a gluten-free diet for life. If you suspect you have coeliac disease, you are advised to go to your GP for further information before you make any changes to your diet.
A strict gluten-free diet involves the avoidance of any product made from wheat, barley or rye - check labels carefully.
Avoiding gluten can be hard as wheat is so widely used in commercially manufactured, ready-made foods. But eating gluten-free doesn't have to mean brick-like-bread, dry flaky pastries or gritty gluten-free crackers, nor does it mean sacrificing good nutrition and tasty food. Fortunately there are now a wide range of gluten-free products and resources available. Becoming informed and able to read labels and ingredient lists to recognise gluten in its many guises will certainly be an advantage. The Coeliac UK website has a trusted food and drink directory for members along with other useful advice on living gluten-free. They also have a mobile app complete with barcode scanner, label guide and eating out tips.
If you are following a gluten-free diet, try to ensure it is nutrient dense and full of whole foods. Although there are a wide range of gluten-free products now available, they may not be as high in fibre, iron, folic acid and B vitamins as gluten containing counterparts. If you have any queries concerning your nutritional intake you should speak to your GP.
To ensure you are getting enough fibre and B-vitamins, eat a wide variety of gluten-free grains, fruit and vegetables. Alternative grains such as corn (maize, polenta), soya, potato, quinoa, cornflour, millet, arrowroot, buckwheat, amaranth and rice flours can increase the nutrient profile of the gluten-free diet. Opt for whole grain gluten-free flour mixes which contain more fibre than the highly refined tapioca, white rice and corn starch flours.
The best sources of iron are from meat such as beef, poultry and fish or plant based sources such as beans, legumes and leafy green vegetables, which are all naturally gluten-free. To enhance the absorption of iron, consume iron rich foods with sources of vitamin C.
Folic acid has particular importance for pregnant women and women in their child-bearing years. Some of the best sources are yeast, green leafy vegetables, asparagus, broccoli, cauliflower, beans and lentils.
Things to watch out for
'Hidden' gluten may be in processed meats, dry roasted nuts, marinades, soy sauce, condiments, malt, spice mixes and more. It is advisable to read the labels on everything you plan to eat and create a 'safe' foods list
Oats: Some people with coeliac disease can eat oats but they are often produced in the same place as wheat, barley and rye and may be at risk of cross contamination. If you do eat oats, choose those labelled ‘gluten-free’.
Labelling: 'Gluten Free' food labels = There is now a law covering the use of ‘gluten-free’. When you see this label it must contain no more than 20 parts per million of gluten.
Cost: Gluten-free diets can be quite expensive. In some parts of the UK, people with coeliac disease are eligible for foods on prescription – check with your GP.
Gluten-free flours are not as easy to bake with as they lack the elastic properties of gluten. As a result breads may rise (due to yeast or raising agents) but fall again to leave rather dense loaves. Xanthan gum is a natural powder, which if added in small quantities to flour for bread and pastry making, makes a reasonable substitute for the elastic characteristics of gluten.
Combination flours work best for cakes, biscuits and pastry: 60% stronger flours (such as gram or maize) to 40% finer, lighter flours (such as white rice, potato or tapioca). Corn bread made from ground corn or maize meal (NOT cornflour) is a delicious gluten-free bread substitute.
Coeliac UK is a trusted source for gluten-free advice and has a comprehensive food and drink directory for members.
Be inspired and try more of our favourite gluten-free recipes.
Jo Lewin works as a Community Nutritionist and private consultant. She is a Registered Nutritionist (Public Health) registered with the UKVRN. Visit her website at www.nutrijo.co.uk or follow her on Twitter @nutri_jo.
This article was last reviewed on 26th September 2017 by nutritional therapist Kerry Torrens.
Kerry Torrens is a qualified Nutritionist (MBANT) with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Applied Nutrition and Nutritional Therapy (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food.
All health content on bbcgoodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider. See our website terms and conditions for more information.