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  • Writer's picturefranceswalker@thefoodinto


Updated: Apr 8

Many people feel that avoiding bread makes them feel better, but are unsure why. What it is in bread that can affect some people?

The truth is that different people may be reacting to different things in bread such as the carbohydrate (FODMAPs) or the protein (gluten) or even preservatives that may be added.


Wheat has consistently been shown to be one of the most common factors causing gut symptoms (1). WHEAT ALLERGY (immune disorder)

True allergy to wheat is rare- only 0.4% people around the world have a wheat allergy and most of these are children who tend to outgrow their wheat allergy by the time they are 6 years old.

Symptoms come on minutes or hours after eating wheat and typically causes itching & swelling, skin rash and can even lead to life-threatening anaphylaxis.

Flour may not be eaten but accidentally inhaled which may result in baker's asthma and rhinitis (irritates inside of the nose), or contact with the skin may cause dermatitis (itchy inflamed skin) or hives (reddened, circular skin rash).

Chances are, if you are an adult- you probably do not have a wheat allergy. If you do, avoiding even small amounts of wheat is recommended. GLUTEN ALLERGY: COELIAC DISEASE (auto immune disorder)

Wheat containing bread is one of our biggest sources of gluten (each slice of bread contains approximately 4 g of gluten).

It is the gluten in wheat that gives wheat dough its characteristic elastic and spongy qualities.

Wheat gluten is a complex mixture of proteins including a protein called gliadin.

Several hundred gluten proteins are thought to trigger the immune response you see in Coeliac Disease, but the most dominant are these gliadin proteins.

Similar proteins to gliadin are also found in other grains such as rye, barley and oats.

Those who have an allergic reaction (in fact it is a semi allergic response) to gluten are said to have Coeliac Disease.

In people with Coeliac Disease, gluten triggers an immune response causing mucosal inflammation, a flattening of the villi in the gut (important for absorption of nutrients), and increased gut permeability.

The damage in the small intestine can cause common gut symptoms such as bloating and changing bowel habits (1).

The impacts of Coeliac Disease are not restricted to the gut. It can extend to many different parts of the body and cause inflammation, including the brain- where sufferers get the characteristic ' brain fog' (2).

  • 1 in 70 Australians have Coeliac Disease and 80% of these remain undiagnosed!

  • Half of the people with Coeliac Disease have no symptoms whatsoever

If you suspect you may have Coeliac Disease then get yourself checked out by your GP.

If you have a close relative with Coeliac Disease, there is a 10-20 chance that you also may have Coeliac Disease.

It is best NOT to go on a gluten free diet as you need to eat gluten (at least 2 slices of bread or equivalent) for 6 weeks prior to being tested otherwise the blood results will be meaningless and a waste of time.

If you are considering eliminating gluten or wheat foods, please check yourself out for Coeliac Disease before you do this, as untreated Coeliac Disease can significantly affect your health putting you at greater risk of gut cancers, osteoporosis, liver disease, heart disease and neurological effects.

The only existing treatment is a gluten free diet for the rest of your life. Doing this is actually quite tricky as gluten hides in foods such as sauces, as food additives, and can cling to commonly used kitchen items such as chopping boards and toasters.

Don't compromise your health- get yourself tested for Coeliac Disease. GLUTEN SENSITIVITY (Non-Coeliac Gluten Sensitivity- NCGS)

There is little doubt that wheat or gluten can induce symptoms in people who do not have Coeliac Disease (3).

Of all the wheat foods- bread tends to be the least tolerated as it has a double whammy of wheat flour as well as extra gluten added as an ingredient. This does not tend to happen with other wheat foods such as wheat flour and wheat biscuits. It is thought that NCGS does not have the long term health consequences that you see with Coeliac Disease (3).

This is a definitely a 'watch this space' kind of thing. Research is sorely needed to determine how it can be diagnosed, its mechanism, how common it is, and best management.

For now- best dietary management is to reduce gluten in foods (but not completely eliminate it) for 2-3 months to see if there is an improvement in symptoms:

  • Remove wheat, rye or barley flours from the diet such as found in bread (least well tolerated), pizza crust, biscuits and cake

  • No need to remove the tiny amounts of gluten from these flours that have been heavily processed to starches, thickeners and glucose. This is different from Coeliac Disease where even these tiny amounts of highly processed gluten flours do need to be avoided.

If your symptoms have improved after 2-3 months then you can reintroduce gluten to see what you can tolerate:

  • Oat can be trialled as many people (although not all) find they can tolerate oats

  • SPELT can often be tolerated although SPELT is a wheat grain.

  • Wheat foods such as wraps can also be trialled as can be a useful substitute for bread.

Some people thought to have NCGS do NOT get significant improvement in their symptoms when going on a gluten free diet (3).

This indicates that there may be other intolerances which may benefit from being investigated.


Bread is usually made from wheat which is high in the FODMAP FRUCTAN.

Fructans are an indigestible carbohydrate resistant to enzymes in the gut so pass intact through to the large intestines where it provides a fantastic source of food for all the microbes colonies in the gut (our gut biome).

Fermentation of the wheat fructans by our gut bacteria results in the production of gases.

This is very normal and good for us but if your have FODMAP intolerance then the gases produced will cause an exaggerated expansion of your gut in your stomach which your gut brain (yes- our guts have so many nerves in the wall that it is literally like a 2nd brain) sends a message to your head brain saying: OUCH.

So you get the bloat, the gut pain and either diarrhoea or constipation (or alternating).

A low FODMAP elimination diet can diagnose FODMAP intolerance and manage your symptoms, especially if you suffer from BLOATING.

Medically directed hypnotherapy and cognitive behavioural therapy has been shown to be equally effective for people with IBS (4).

PROPIONATES (Food chemical & additive intolerance)

Propionates are a type of food preservative that are commonly found in bread.

Often people switch to gluten free bread to see if they can reduce their symptoms but little do they know that gluten free bread is very likely to contain propionates.

As with all food chemical sensitivities, well designed scientific evidence is lacking, so reports of propionate sensitivity is based on reported symptoms which range from irritability, being anxious, moody, having poor concentration, itchy skin, bed wetting (children) to extreme fatigue, migraine and many more too numerous to list.

You can identify the propionates in bread by reading the ingredient list and watch out for the numbers 280 - 283.

In addition, avoiding cultured or fermented: whey, wheat, rice or dextrose may be worthwhile as these may be used in the bread making process to produce propionates as part of a fermentation process.

Foods like bread crumbs, dressings, mayonnaises, fruit juices, vegetable juices, drinks, jams and chutneys may also contain propionates, so you can see it is widespread throughout many foods and drinks we buy and consume.

JOIN THE COMMUNITY: BRAND NEW Dietitian led Facebook group: Amines, Salicylates and Glutamates: The Food Intolerance Dietitian for great information and community support.


  • Wheat allergy in adults is rare, where it does exist, even minute amounts of wheat need to be avoided

  • Gluten can provoke serious symptoms in people with Coeliac Disease

  • If you decide to go gluten free, useful to check for Coeliac disease first as blood tests and biopsy require a certain amount of gluten to be in the diet 6 weeks preceding the tests for meaningful results.

  • Gluten sensitivity does not require avoidance as strictly as in Coeliac Disease

  • Additives such as propionates can cause issues for people sensitive to food additives, and naturally occurring chemicals: salicylates, amines and glutamates

  • Not to mention the things that may be added as a topping! If you are sensitive to dairy proteins then you may react to the butter you add; if you are sensitive to various food additives then the preservative or natural chemicals in some margarines such as olive oil margarine may be an issue. If you are sensitive to glutamates and MSG then vegemite may be a problem for you. The list goes on.... If your symptoms are a bother to you- getting to the root of the problem can help you better manage your symptoms.


REFERENCES 1. Biesiekierski, J. R. (2017) What is gluten? Journal of Gastroenterology and Hepatology, 32: 78–81. doi: 10.1111/jgh.13703. 2. Yelland, G. W. (2017) Gluten-induced cognitive impairment (“brain fog”) in coeliac disease. Journal of Gastroenterology and Hepatology, 32: 90–93. doi: 10.1111/jgh.13706. 3. Gibson, P. R., Skodje, G. I., and Lundin, K. E. A. (2017) Non-coeliac gluten sensitivity. Journal of Gastroenterology and Hepatology, 32: 86–89. doi: 10.1111/jgh.13705. 4. Peters SL, Muir JG, Gibson PR. Review article: gut-directed hypnotherapy in the management of irritable bowel syndrome and inflammatory bowel disease. Aliment. Pharmacol. Ther. 2015; 41: 1104–1115. 5. Loblay R, Soutter V, Swain A. RPAH Food Intolerance Handbook Volime II: Challenges, liberalising & management. Allergy Unit, Royal Prince Alfred Hospital, 2016.


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