Never Quit Gluten Before You Get Tested. Here Is Why.

It also changes the standard. Someone avoiding gluten by preference can accept a little cross contamination. Someone with coeliac disease cannot, and needs to know that with certainty rather than as a guess.

The condition that is not coeliac disease

Many people who feel better without gluten do not have coeliac disease. The usual term is non coeliac gluten sensitivity, and it is real, poorly understood and difficult to pin down.

The central difficulty is that there is no biomarker. As a review in the paper setting out the Salerno experts' criteria states, no clinical biomarker is available to diagnose the condition and its true prevalence is unknown. Diagnosis rests on excluding coeliac disease and wheat allergy, then testing symptoms against a placebo controlled rechallenge, which is a research procedure rather than something a GP can run in a clinic.

The mechanisms differ too. Coeliac disease is autoimmune and wheat allergy is allergen mediated, while non coeliac gluten sensitivity is thought to involve an innate immune response, according to a review in Mayo Clinic Proceedings.

It may not be the gluten at all

Here is the complication that changes a lot of people's conclusions. Wheat contains fermentable carbohydrates known as FODMAPs alongside its gluten, and these have been implicated as the trigger in people who believe they react to gluten.

Cutting out bread and pasta removes both at once. Feeling better afterwards tells you something was causing symptoms; it does not tell you which thing. That distinction is the difference between avoiding one protein and managing a much broader group of carbohydrates found across many foods, as the Cleveland Clinic overview discusses.

This is reporting, not medical advice

This article describes how testing works and what published guidance says. It is journalism and not clinical advice, and it cannot account for your history. Decisions about testing, about a gluten challenge, and about any restrictive diet belong with a clinician who knows your case. If you have symptoms that concern you, particularly unexplained weight loss, persistent diarrhoea or anaemia, that conversation should happen sooner rather than later.

What to do with all this

The practical instruction is short. If you suspect gluten is a problem, get tested before you change your diet, not after. If you have already changed it, say so plainly to your doctor rather than quietly resuming bread the week before a blood test.

A gluten free diet is manageable and, for people with coeliac disease, necessary for life. It is worth knowing which of those two situations you are actually in.