Coeliac FAQ

Diagnosis requires two steps: a positive blood test (tTG-IgA, and sometimes EMA-IgA) while eating gluten, followed by a small-bowel biopsy via endoscopy showing villous atrophy. Both are needed for a confirmed diagnosis. Never go gluten-free before testing — it will invalidate the results.

Home tTG-IgA finger-prick tests are available and can be a useful first screen, but a positive home test must be confirmed by a GP blood test and biopsy before a formal diagnosis is made. A negative home test doesn't completely rule out coeliac disease.

Going gluten-free before testing causes a false negative — antibody levels drop without gluten in the diet. To get an accurate result, you need to eat at least 2 slices of wheat bread daily for 6 weeks before retesting. This is called a 'gluten challenge'. Speak to your gastroenterologist first.

This is called 'potential coeliac disease'. Antibodies are elevated but the gut isn't yet damaged. Most gastroenterologists recommend a strict GF diet anyway, as damage often follows. Some patients have patchy damage — a negative biopsy doesn't always mean no coeliac. Discuss with your specialist.

Yes. First-degree relatives (parents, siblings, children) of coeliacs have a 1 in 10 chance of also having coeliac disease — 10× higher than the general population. Current guidelines recommend testing all first-degree relatives, even without symptoms.

The 20ppm threshold is based on multiple intervention studies showing that the vast majority of coeliacs can tolerate up to 10–50mg of gluten per day without measurable gut damage. 20ppm means 20mg per kg of food — at typical serving sizes, this is well below the damage threshold for most people. Some sensitive individuals may react to lower levels.

Pure, certified gluten-free oats are safe for the majority of coeliacs. The problem is contamination — conventional oats are grown and processed near wheat and contain significant gluten. Use only oats labelled 'gluten-free'. About 5% of coeliacs also react to avenin (the oat protein itself) — introduce GF oats slowly and monitor for symptoms.

No. Malt vinegar is made from barley and contains gluten. Use wine vinegar, cider vinegar, or rice vinegar instead. Distilled vinegar (sometimes labelled 'spirit vinegar') is generally considered GF as distillation removes gluten proteins, but coeliac organisations differ on whether to recommend it.

No. Barley malt extract contains gluten and must be avoided. It appears in many cereals, malted drinks (Ovaltine, Horlicks), and some chocolates. It's a common hidden gluten source.

Yes, but you need to manage cross-contact risk. Ask to speak to the manager or chef — not just the waiter. Key questions: Does the kitchen have a dedicated GF prep area? Are fryers shared? Are GF dishes prepared on shared surfaces? A good restaurant will take you seriously. If they seem dismissive, don't risk it.

'Wheat-free' means no wheat but may still contain barley, rye, or contaminated oats — all of which contain gluten. 'Gluten-free' (<20ppm) is the standard you need as a coeliac. Never assume wheat-free = gluten-free.

Traditional soy sauce contains wheat. Use tamari (check label — some tamari also contains wheat). Coconut aminos is a naturally GF alternative. Most GF-labelled soy sauces are tamari-based.

Yes. Neurological and psychiatric symptoms are well-documented in coeliac disease, including anxiety, depression, brain fog, and peripheral neuropathy. The mechanisms include nutrient deficiencies (B12, folate, iron, zinc), gut-brain axis disruption, and direct neurological effects of anti-gliadin antibodies. A strict GF diet often improves these symptoms significantly.

The most common cause is inadvertent gluten ingestion — often from hidden sources (sauces, seasonings, cross-contact). Other causes include secondary lactose intolerance, SIBO, IBS, microscopic colitis, or refractory coeliac disease. If symptoms persist after 12 months of strict GF diet, see your gastroenterologist for investigation.

Symptom improvement typically begins within 2–6 weeks. Antibody normalisation takes 6–12 months. Full villous healing takes 1–2 years in adults and up to 2 years in children. Some adults, particularly those diagnosed later in life, may have incomplete healing even after several years.

Untreated coeliac disease is associated with increased risk of miscarriage, preterm birth, low birth weight, and infertility in both men and women. A strict GF diet before and during pregnancy significantly reduces these risks. All women with unexplained infertility or recurrent miscarriage should be tested for coeliac.

At diagnosis, the most common deficiencies are: iron (especially in menstruating women), calcium, vitamin D, folate, vitamin B12, zinc, and magnesium. Ask your GP to test for these at diagnosis and annually. Most resolve with a strict GF diet and targeted supplementation.

The Crossed Grain trademark (a wheat stalk with a line through it) is a licensed symbol indicating the product meets the <20ppm gluten standard. It's used by Coeliac UK licensees and some international equivalents. It's a useful additional confirmation, but products don't need it to be GF — any product labelled 'gluten-free' in the EU/UK must legally meet the <20ppm standard.

Yes. Glucose syrup derived from wheat (also called wheat dextrose) is highly processed and contains no detectable gluten protein — confirmed GF by coeliac organisations in Europe, UK, and Australia. EU allergen labelling still requires 'wheat' to be declared, but this is an allergen declaration, not a gluten risk.

Maltodextrin derived from wheat is considered safe for most coeliacs as the processing removes gluten protein to well below 20ppm. However, if you're very sensitive, opt for maltodextrin from corn or tapioca (most common in North America).

Plain salted potato crisps are usually GF, but flavoured varieties frequently contain wheat-based flavourings or maltodextrin. Always check labels. Crisps cooked in shared fryers at restaurants or takeaways are not GF.

Most spirits (whisky, vodka, gin, rum) are GF regardless of the grain source — distillation removes gluten proteins. Wine, cider, and certified GF beers are safe. Standard beer, lager, and ales are made from barley malt and are NOT GF. Some coeliacs react to even distilled spirits from gluten grains — if in doubt, choose potato vodka or grape-based spirits.

Research before you go. Use apps like FindMeGlutenFree or The HTGF travel translation card. Learn the key phrase 'I have coeliac disease and cannot eat gluten' in the local language. Countries with high wheat-free awareness include the UK, Australia, Italy, and Scandinavia. High-risk destinations include France, China, and many Southeast Asian countries where wheat is ubiquitous.

Italy has excellent GF awareness — the AIC (Associazione Italiana Celiachia) certifies restaurants with the 'Spiga Barrata' symbol. However, traditional pasta, pizza, and bread use wheat. Always ask for dedicated GF menus and confirm that GF pasta is cooked in separate water with separate utensils.

Pre-order a gluten-free meal when booking your flight — most airlines offer this. Carry GF snacks as backup — airline GF meals can be unreliable. For long-haul flights, download offline maps of GF restaurants at your destination. Airport lounges often have GF options but always check labels.