A gluten-free diet is essential for people who have coeliac disease or dermatitis herpetiformis (a gluten induced skin sensitivity). However, according to recent research, there are many pre-coeliacs or gluten-intolerant/sensitive individuals that benefit from a gluten-free diet.
What is gluten?
Gluten is a mixture of proteins found in wheat, rye and barley (and to a lesser extent, oats). A gluten-free diet is the complete avoidance of foods containing these grains.
It is important to note, that a gluten-free diet is not the same as a wheat-free diet, and some gluten-free foods are not wheat free.
What is coeliac disease?
A severe intolerance to gluten is known as coeliac disease. This condition can affect around 1 in 100 people and whilst it can occur in anyone at any age, the risks are higher if the condition runs in the family.
Symptoms include severe pain, diarrhoea, constipation, tiredness, abdominal discomfort, anaemia, mouth ulcers, often accompanied by weight loss and malnutrition.
This condition, however, can be completely reversed by following a gluten-free diet.
How is coeliac disease tested?
Testing is simple and involves screening the patient’s blood for anti-tissue Transglutaminase IgA antibodies, with a follow up intestinal biopsy in positive cases, to confirm the presence of damaged villi.
Once coeliac disease has been diagnosed, it is recommended that a gluten-free diet is followed for life. It is also essential to ensure a nutritionally adequate diet, to compensate for the malabsorption of nutrients that may have occurred. The Coeliac Society publishes a list of gluten-free manufactured products in a booklet which is updated every year.
Often many coeliac sufferers are found to be anaemic. This is usually due to iron deficiency due to malabsorption. Folic acid or vitamin B12 may also be deficient. An iron supplement maybe prescribed until the digestive system recovers and can absorb iron again. To ensure a good intake of iron, pulses, lentils, nuts and green vegetables should be included in the daily diet . Tea should be avoided with meals as it inhibits iron absorption, but fruit juice will aid absorption (due to vitamin C content). For further details see www.coeliac.co.uk
Is it possible to be gluten intolerant without coeliac disease?
Many people find that they have a sensitivity to gluten, but do not test positive for coeliac disease. A food intolerance IgG test will confirm the presence of antibodies to gluten, and hence the likelihood of intolerance. If intolerant to gluten, then a gluten-free diet needs to be followed as for coeliac disease, although some people find that they may tolerate oats if they have not been contaminated with wheat. With an intolerance, gluten maybe introduced successfully back in to the diet after a few months of elimination, whereas this is not the case with coeliac disease.
How does a gluten-free diet affect vegetarians or vegans?
Vegetarians and vegans should be aware that some gluten-free flours are low in protein, due to the removal of gluten, however, specially manufactured, prescribed gluten-free flours often have milk protein added. Please check ingredients labels carefully.
Other proteins suitable for vegetarians/ vegans can be obtained from nuts & seeds, pulses, non-gluten containing cereals, soya products, milk, cheese and free range eggs.
The Vegetarian Society can provide further information. See www.vegsoc.org
Where can gluten-free foods be bought?
A wide range of specially manufactured gluten-free foods such as, bread, bread mix, pasta, biscuits, cakes, crisp bread and flour can be found in most supermarkets (such as Tesco, Sainsburys, Waitrose and Asda), chemists (Boots, Lloyds) and health food shops (such as Holland and Barratt). Some manufacturers use the gluten-free symbol on their label.
If I've been avoiding gluten will this affect the test?
The NICE guidelines from May 2009 state that gluten should be included in the diet in at least one meal daily for a minimum of 6 weeks before testing, which is what we also advise. However, we also recommend that if you start having severe symptoms when reintroducing gluten to stop. However it is possible that symptoms may be due to being intolerant to other proteins in wheat in which case you may like to experiment with foods including rye or barley in your diet. If symptoms subside this will ensure that you are still eating gluten and so are able to perform the test.