The gluten in wheat and other grain products is recognised to be one of the most prevalent food intolerances. In its extreme form, as coeliac disease it affects approximately 1% of the population and 20% of people with digestive disorders also test positive to gluten sensitivity using recognised medical tests.
Gluten is also very hard to avoid and many sufferers may find that they can tolerate some foods whilst not being able to tolerate other similar foods made by a different manufacturer (for example) and that they may be able to tolerate a food one day and not the next. So, what is going on?
Well, it’s complicated ...
What is gluten?
Gluten comprises 80% of the protein found in grains of wheat and it contains two different proteins: glaidin and glutenin. Both these proteins have different properties and potentially bring different problems as listed below.
The glutenin in gluten
Glutenin is insoluble which means that it is left behind when starch is washed away from wheat flours. Glutenin in a product forms a network of cross-links and it is this that gives wheat flour its elasticity and chewiness and also allows products to rise and hold their shape. The glutenin content of foods can vary considerably as outlined below:
As a rule, the chewier the product, the higher the glutenin content. So that the flours used for pizza and bagels are higher in glutenin than those used for baking cakes, for example.
The amount the product is worked increases the glutenin content. So that, the more a product - such as bread - has been kneaded the higher the gluten content and the less the product has been worked - such as pastry - the lower the gluten.
The amount of moisture in the dough. Greater water content promotes gluten development.
The amount of extra gluten which may have been added
And, finally, the molecular weight of the glutenin!
The gliadin content of gluten
Gliadin is classified as a prolamine, and the prolamines in rye (secalin), barley (hordein) and oats (avenin) are all slightly different, but tend to be classed together as gluten.
Gliadin is also found on the surface of the Adenovirus and creates holes between cell walls in the lungs thus promoting lung infections. Some people carry the genes required to bind the antibodies that bind to gliadin and rapidly stop any Adenovirus infection and this has probably had some survival value in previous times. Gliadin is also unique in that it contains polyglutamine and the degree to which it may cause intolerances is also related to the length of this molecule.
Gliadin is not very water soluble, but processes like fine grinding, baking, fermenting and chemical treatments can make it more water soluble. In its water soluble form it can bind to cells and can trigger an immune reaction. If it binds to the intestines (especially if the lining is inflamed or damaged) then significant amounts of gliadin can cross the intestine and enter the blood stream. Unlike glutenin, gliadin does not form cross-links.
Symptoms of gluten-intolerance
When the immune system attacks the proteins in gluten, it can cause considerable damage to the lining of the small intestine. This damaged lining can then be permeated by large proteins leading to the development of further food intolerances. This also allows gluten into the blood stream where it can attach to any cell, be attacked by the immune system and thus cause damage. This means that the symptoms of gluten-intolerance can be wide ranging and in far flung body parts. This includes symptoms such as allergies, anaemia, digestive problems, headaches and fatigue. A cardinal sign of gluten sensitivity is an uncontrollable craving for gluten-containing products and an inability to stop eating grains once you have started.
Whilst the proteins in rye and barley are quite similar to those found in wheat, the proteins in oats are slightly different and may or may not be harmful to people with coeliac disease and gluten-intolerance. Some sufferers appear able to tolerate small amounts on an occasional basis and the purity or contamination of the oats by other grains may also be an issue.
Also, whilst corn (maize) and rice contain gluten, it lacks gliadin and buckwheat too (a member of the rhubarb family) contains a gluten that is considered chemically different enough not to be an issue for most gluten-intolerance sufferers.
The gluten-free grains include:
Coeliac disease and gluten
Coeliac disease is considered to be the most serious gluten sensitive-related illness. It is classed as an autoimmune disease and the standards used to diagnose coeliac disease are now extremely – some might say impossibly – rigorous.
The test usually used is the ELISA (Enzyme Linked Immuno-Sorbent Assay) to detect anti-gliadin antibodies and no blood test is 100% accurate and false positive and false negative results can and do occur. The accuracy of any blood test also depends upon whether the individual has been eating gluten-containing foods and for how long and in what quantities. One or more biopsies of the intestinal lining may also be required.
The only conventional treatment for the condition is to eat a gluten-free diet for the rest of life avoiding breads, biscuits, pastas, cereals, powdered gravy and sauce mixes, yeasts and alcohol products made from grains and less obvious products such as ice cream and tomato ketchup which may have flour added.
Good books on the topic include Dangerous Grains and The Gluten Effect listed under Fatigue Syndromes and Toxicity in Recommended Reading.
For a step-by-step approach to recovering from chronic illness including addressing food intolerances please refer to The Natural Recovery Plan book