Regular readers of this blog will know that I’m no lover of commercial bread. It is generally a food that is very disruptive to blood sugar levels, and its prime component is wheat, which in practice appears to elicit adverse symptoms in quite a significant percentage of people. Some people have wheat sensitivity because they are sufferers of coeliac disease – sensitivity to the protein gluten which can cause a flattening out of the gut wall and cause a variety of symptoms including fatigue, neurological symptoms and digestive discomfort and bloating.
Standard tests for coeliac disease include gut biopsy (looking for characteristic flattening of the gut wall) and blood tests looking for specific antibodies (known as endomysial and tissue transglutaminase). However, many people who claim to react adversely to wheat who come to be tested for coeliac disease turn out to have normal test results for coeliac disease as well normal test results for wheat allergy (immune reaction to wheat caused by what are known as IgE antibodies). So, individuals complain of, say, digestive discomfort and bloating when they eat wheat, but ‘all the tests are negative’. This phenomenon has often been used to paint those who believe they are wheat-sensitive as neurotic and gullible (perhaps imagining they have a problem because they read about it in a woman’s magazine).
Today, the British Medical Journal published an interesting article which asks if gluten sensitivity in the absence of coeliac actually exists . In other words, can some be sensitive wheat (or other gluten-containing food such as barley or rye) but not have coeliac disease (or wheat allergy)?
The authors of the piece refer to a study (due to be published) in which 920 patients with symptoms of irritable bowel syndrome (e.g. abdominal discomfort and bloating) have wheat (as well as other foods including cow’s milk) removed from the diet . On blind challenging with food (participants did not know what food they were being challenged with), a full third of patients responded adversely to wheat and not with placebo. As the authors say:
The evidence therefore suggests that, even in the absence of coeliac disease, gluten based products can induce abdominal symptoms which may present as irritable bowel syndrome.
As a result of this and other evidence, non-coeliac gluten sensitivity was recognised earlier this year by a group of 15 international experts . Common symptoms that are attributed to this condition include “intestinal symptoms such as abdominal discomfort, bloating, pain, and diarrhoea (also consistent with irritable bowel syndrome) or with a variety of extra-intestinal symptoms such as headaches, “foggy mind,” depression, fatigue, musculoskeletal pains, and skin rash.”
The authors conclude:
For patients who report wheat intolerance or gluten sensitivity, exclude coeliac disease… and wheat allergy…. Those patients with negative results should be diagnosed with non-coeliac gluten sensitivity. These patients benefit symptomatically from a gluten-free diet. They should be told that non-coeliac gluten sensitivity is a newly recognised clinical entity for which we do not yet fully understand the natural course or pathophysiology.
I am almost speechless at the balanced and honest nature of this account of gluten sensitivity: it recognises the limitations of medical testing and admits there’s things we simply don’t know or understand. I have a feeling there’s going to be plenty of people reading this who will feel inclined to shove these findings in the face of a practitioner who told them their tests were negative and that their wheat sensitivity is imagined and ‘all in their mind’.
1. Aziz I, et al. Does gluten sensitivity in the absence of coeliac disease exist? BMJ published 30 November 2012
2. Carroccio A, et al. Non-celiac wheat sensitivity diagnosed by double-blind placebo-controlled challenge: exploring a new clinical entity. Am J Gastroenterol (forthcoming).
3. Sapone A, et al. Spectrum of gluten-related disorders: consensus on new nomenclature and classification. BMC Med2012;10:13