Common Questions

1.What is a food intolerance, what is a food allergy and what are the differences between these?

  • Food intolerances and food allergies are often confused by the public even though the severity of symptoms produced by each condition varies significantly.  Food intolerances do not involve the immune system and reactions compared to food allergies are less severe.
  • Food allergies are immune-mediated responses, also known as anaphylaxis and can exhibit be life-threatening symptoms.  Food intolerances are believed to affect up to 25% of the population whereas food allergies are far less common although Australia has one of the highest prevalence rates in the world.


2.What are the symptoms of food allergies and intolerance?

  • Given that a food intolerance is really just an inability to digest a food, common symptoms are related to the gastrointestinal tract and include; bloating, irregular bowel habits, constipation/diarrhoea, nausea and stomach pains.  Some people may also experience other symptoms such as migraines/headaches, hives/itchiness and wheezing or a runny nose.  These symptoms do not involve the immune system and are generally not life threatening.  Symptoms can onset either immediately or many hours, even up to many days after consuming particular foods.
  • Severe symptoms of a food allergy cause a life-threatening, whole body reaction known as anaphylaxis.   Anaphylactic attacks produce symptoms such as hives, swelling of the face, tongue and throat, plus difficulty breathing, vomiting and loss of consciousness.

3.What causes a food allergy and food intolerance?

The increasing incidence of food allergies and intolerance is concerning and currently there is no cure for food allergies and the only successful method to manage a food allergy or intolerance is to avoid the foods containing that allergen or food component.  The actual causes are unknown and speculation goes back as far as to the environment in utero during pregnancy including the mothers diet and exposure to allergens. 

There is even lots of research now around the benefits of breast feeding for preventing food allergies/intolerances as well as the timing of food/solids introduction to babies, especially the timing of introductions of common food allergens.

4.The most common food allergens include;

  • crustaceans
  • eggs
  • fish
  • milk
  • peanuts
  • soybeans
  • tree nuts
  • sesame seeds
  • gluten/wheat

5.The most common food intolerances include;

  • Lactose - Commonly found in milk and dairy products.  The incidence of Lactose intolerance in Australia is thought to be around 10%.  Lactose intolerance results from a lack of the enzyme lactase needed to digest lactose.
  • Fructose - In fructose malabsorption, the small bowel has difficulty in absorbing fructose, and as a result, the fructose moves through to the large intestine unabsorbed.  Fructose is found in various fruits/vegetables, wheat and honey.
  • FODMAPs - Along with Fructose, many people suffer from malabsorption of other carbohydrates grouped together by the term FODMAPs. FODMAPs include Fructose, Fructans, Galactans (Raffinose), Polyols (Sorbitol) and Lactose. Only fructose and lactose can be tested, the remaining FODMAPs will be identified as triggers during a dietary challenge conducted in consultation with a dietitian.
  • Food additives - such as colours, preservatives and additives
  • Sulphites, Salicylates and Amines - these are natural food chemicals found in a huge variety of foods including herbs and spices, fruits and vegetables as well as wine and meat.

6.What foods/ingredients do I need to avoid if I have an intolerance to:

  • Gluten - People with Coeliac disease are Gluten intolerant but many other people often report symptoms upon ingestion of Gluten.  Gluten is a protein found in foods such as wheat, rye, barley and oats.  Food labels must list if Gluten is an ingredient in a product so spend some time label reading as Gluten is often hidden in many food products.
  • Lactose - choose lactose-free dairy products, hard cheeses and Calcium-fortified milk-alternatives such as soy products instead.
  • Fructose and Fructans - There is a very extensive list of foods which contain Fructose, and its longer chain companion, fructans.  People with Fructose intolerance may also be intolerant to a variety of carbohydrate based foods known as FODMAPs.  Some high fructose foods include Honey, Apples, Pears, dried fruit and high fructose corn syrup. A few common foods high in Fructans include wheat, onions and garlic.
  • Wheat - This is commonly found in most baked goods and packaged foods so like gluten, reading labels and ingredients lists is recommended.

7.What should you do if you think you have a food intolerance?

Seek a referral from your GP to an Accredited Practicing Dietitian (APD) or go to the Dietitians Association of Australia website for a listing of all APD’s -

8.How are food intolerances diagnosed?

  • The gold-standard test for diagnosing lactose and fructose intolerance is a Hydrogen Breath Test.  This test involves the ingestion of the substrate in a liquid form, then performing several breath tests over 2-3 hours to assess the production of hydrogen from bacteria in the bowels.  Humans don’t naturally produce Hydrogen, therefore if levels increase significantly above baseline levels, then it can be assumed that food is being undigested and then fermented back bacteria in the gut.
  • Other food intolerances can be diagnosed with the help of an experienced Accredited Practising Dietitian (APD) by using an elimination diet and then the re-introduction of foods over a period of 6-8 weeks as symptoms resolve.

9.Many people tend to self-diagnose their food intolerances or use unorthodox testing methods. What are the problems associated with cutting out certain types of foods/food groups without being professionally diagnosed with an intolerance?

  • Self-diagnosed and use of unorthodox tests for diagnosing food allergies and intolerances can produce misleading results.  Unorthodox testing methods (ie; Vega testing, iridology and pulse testing) have been shown to be inaccurate and poorly reproducible when subjected to careful study.  Treatment based on inaccurate results is not only misleading but can result in ineffective and sometimes harmful treatments.  I would recommend seeking more information on these methods on the ASCIA website:
  • Unnecessarily restricting foods from your diet without professional advice from a dietitian can lead to nutritional deficiencies and further medical problems given the complex nature of food intolerances.

10.Why do some people who experience the symptoms of a food intolerance not seek medical advice?

Many Doctors and other health professionals are misinformed about food intolerances and often don’t know how to treat these conditions therefore they can be overlooked.  Advice from an experience Accredited Practicing Dietitian is recommended.
If you know that something is not quite right, then find out for your test today

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Do any of these products make you feel sick?

  • Chewing Gum
  • Orange Juice
  • Sports Drinks
  • Honey
  • Muffin
  • Apple
  • Nicorette Gum
  • Milk
  • Pasta
  • Bread
  • Jelly Beans
  • Garlic & Onion
  • Ice Cream
  • Pear

No Referral is Required in our clinic

Do you think you suffer from a food intolerance such as Lactose or Fructose or perhaps Small-intestinal bacterial overgrowth syndrome (SIBOS)?
There is a simple, accurate, pain free way to find out. It’s called Hydrogen Breath testing... and there are no blood tests!

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