Food allergies, intolerances and sensitivities

Understanding food reactions

Our digestive and immune systems are constantly scanning for potential harmful substances that enter the body. Whatever we eat, the immune system is assessing for safety, and symptoms of allergies, intolerances and sensitivities reflect the immune system detecting a food as a threat. The way the immune system reacts to a substance can be as individual as we are, changing over time and becoming less or more sensitive to foods.

middle aged woman with food sensitivity sitting on couch arms wrapped around painful stomach
melbourne functional medicine practitioner rebecca hughes discussion food sensitivity test results with health coach

Food sensitivity testing and treatment

State of the art testing alongside symptoms and a food diary can help determine the foods a person is reacting to. Comprehensive assessment involves looking at the types of food reactions to determine if a food reaction is an allergy, intolerance or sensitivity.

Our digestive specialists can help determine how to treat any underlying factors that might be causing the food reactions, with the aim of increasing the ability to tolerate more foods over time, where possible.


What is the difference between food allergies, intolerances and sensitivities?

Food allergy reactions can be divided into two main groups:

1. Immediate hypersensitivity reactions (allergies)

This is a true food allergy which involves an immune reaction by IgE antibodies. These reactions develop within minutes to an hour or so from ingestion. The immune system (via IgE) responds by triggering mast cells to break open and release histamine, which then triggers more mast cells to break open, creating a chain reaction that causes symptoms like hives, coughing, sneezing, and watery eyes or anaphylaxis, a life threatening reaction requiring adrenaline (via an EpiPen) and emergency medical treatment. Susceptibility to allergies often runs in families.

Symptoms can appear anywhere on the body and can be very mild to severe and even life threatening. Anaphylaxis is a type of allergic reaction where the throat swells, restricting breathing, rapid loss of blood pressure occurs and the person goes into shock and can die.

Almost any molecule can be an allergen however, the most common food allergies include:

  • Peanuts
  • Tree nuts
  • Dairy
  • Fish, shellfish and sea foods
  • Soy
  • Egg

2. Delayed hypersensitivity reactions (food sensitivities)

These food reactions are also called non-IgE mediated food sensitivities, and can have a delay of 1.5 - 72 hours from the time of consumption to the time a symptom first appears, making these food allergens hard to identify. This type of food reaction involves the production of IgG antibodies and sometimes pro-inflammatory compounds, yet these reactions are not life threatening unlike allergies. An example of this is non-celiac gluten sensitivity (NCGS).

Food intolerances

A food intolerance is where uncomfortable digestive symptoms are a reaction to an ingested food or substance. This type of food reaction does not involve the immune system - it is often due to lack of an enzyme or chemical required to break it down. An example of this is lactose intolerance.

Food intolerance symptoms are much more common than allergies, are predominantly gastrointestinal and are often a delayed reaction.

Symptoms of food allergies, intolerances and sensitivities

Allergy symptoms

Food allergy symptoms can change throughout a person’s life, from no reaction to severe reaction. Some people never grow out of childhood allergies and some gather allergies as they age. Two people with the same allergy can have very different reactions, in both the symptoms and the severity.

Symptoms of allergic reactions may include:

Skin symptoms:

  • Hives/urticaria - a rash, usually itchy that is raised, red and can form tiny blisters
  • Angioedema - redness and swelling, often around the face, eyes, lips and mouth/throat
  • Eczema/atopic dermatitis
  • Psoriasis

Respiratory symptoms:

  • Sneezing
  • Difficulty breathing
  • Asthma

Digestive symptoms:

Other symptoms:

  • Runny nose
  • Rhinitis
  • Sinusitis
  • Fatigue
  • Watery/itchy eyes
  • Conjunctivitis
  • Headaches
  • Swelling of the larynx and throat
  • Anaphylactic shock/anaphylaxis
  • Low blood pressure
  • Loss of consciousness
  • Cardiac symptoms - rapid, or reduced heart rate
  • Mood and behavioural changes

Food allergy symptoms tend to appear either immediately or within a few hours of exposure.

Food sensitivity symptoms

Symptoms of food sensitivities can be similar to allergies, and include:

  • Skin rashes like hives and eczema
  • Fatigue
  • Brain fog and mood symptoms
  • Digestive symptoms
  • Achy joints
  • Pain
  • General weakness

Symptoms typically are delayed, generally occurring within a 72 hour period post exposure to a food.

Whilst they are not immediately life threatening, food sensitivity symptoms can be severe and lead to complications such as nutritional deficiencies, dysbiosis of the gut flora. They have been linked to the development of autoimmune conditions when not detected and treated. They can have a significant effect on quality of life and enjoyment of food.

Food intolerance symptoms

Food intolerance symptoms can include all of the above allergy symptoms, but are most commonly:

Digestive symptoms:

  • Diarrhoea, can be loose stool right through to explosive watery diarrhoea, which can be smelly, frothy, or contain mucus
  • Constipation
  • Nausea
  • Vomiting
  • Flatulence
  • Colic
  • Abdominal pain

Other symptoms:

  • Difficulty breathing, wheezing, shortness of breath
  • Asthma
  • Headaches/migraine
  • Brain fog
  • Eczema and hives
  • Joint pain
  • Vertigo

What causes food allergies, intolerances and sensitivities?

Many triggers, or sometimes combinations of triggers cause the development of food sensitivities, food allergies and food intolerances. These can include:

  • Genetic predisposition to (any) allergy - strongly associated with, but not limited to food allergy
  • Asthma or eczema conditions in the family
  • Seasonal hay fever
  • Gut flora disruption, reduced number of species, or proliferation of damaging species
  • Intestinal hyperpermeability (sometimes referred to as leaky gut)
  • Medications
  • Impaired gastric or pancreatic digestive secretions
  • Slow motility (the transit time of food through the digestive system)
  • Reduced or increased mucous secretion
  • IgA antibody deficiency
  • Tick bite - which can trigger the alpha-gal protein allergy from red meat and animal products, such as gelatin
  • Frequently eaten foods
  • Skin exposure - particularly broken/damaged skin to a repeated substance
  • Workplace repeat exposure to a substance, e.g. latex, which often occurs with banana allergy

Food intolerances can also include any molecules as triggers, however, common intolerances are:

  • Dairy - both lactose (a milk sugar) and casein (milk protein) can be allergens
  • Wheat
  • Yeast
  • Egg
  • Beans (Red Kidney)
  • Corn
  • Barley
  • Pistachio
  • Tomatoes
  • Eggplant
  • Bananas
  • FODMAPs (fructose, oligosaccharides, polyols)
  • Caffeine
  • MSG - monosodium glutamate
  • Salicylates and amines (molecules found commonly in foods)
  • Sulphites and benzoates (often used as preservatives and in drinks)

Food intolerances can be related to the deficiency of particular enzymes and other molecules required for breakdown, such as:

  • Lactose - lacking the enzyme lactase (dairy)
  • Sucrose, galactose, fructose and pentose (all very rare)
  • Trehalose - lacking trehalase enzyme (mushrooms)
  • Amino acids - results in protein malnutrition (very rare)
  • Fat - bile insufficiency

When left untreated, food intolerances have been linked with development of autoimmune diseases, rheumatic diseases and neurological conditions such as rheumatoid arthritis, lupus, multiple sclerosis, type 1 diabetes and cerebral ataxia. Therefore, identifying food reactions and addressing them can be essential for maintenance of long term health.

What causes eczema?


Research has found people with the ‘atopic triad’ have a defective barrier of the skin and upper and lower respiratory tracts.

These genetic alterations cause a loss of function of filaggrin (filament aggregating protein), which is a protein in the skin that normally breaks down to create natural moisturisation and protect the skin from penetration by pathogens and allergens.

Filaggrin mutations are found in approximately 30 percent of people with atopic dermatitis, and also predispose people to asthma, allergic rhinitis (hayfever), keratosis pilaris (dry rough patches and bumps on the skin), and ichthyosis vulgaris (a chronic condition which causes thick, dry, scaly skin.)If one parent carries this genetic alteration, there is a 50 percent chance their child will develop atopic symptoms. And that risk increases to 80 percent if both parents are affected. 

Food allergy and sensitivity

Food hypersensitivity has been found to cause or exacerbate atopic dermatitis in 10-30% of cases, and 90% of these are caused by eggs, milk, peanuts, soy and wheat.

Compromised gut health

The connection between the gut microbiome and skin health is complex, however, research has found the microbiota contributes to the development, persistence, and severity of atopic dermatitis through immunologic, metabolic and neuroendocrine pathways.

Nutritional deficiencies

Deficiency of Omega-6 essential fatty acids (EFA) has been linked with the increased incidence of atopic dermatitis, along with the inability for the body to efficiently metabolise EFA’s to gamma linoleic acids (GLA) and arachidonic acids (AA).

Weather and environment

Changing weather conditions can certainly aggravate eczema symptoms, but the triggers are subject to change among individuals.


Hormones also play a role in the course of atopic dermatitis, including the stress hormone cortisol which triggers an inflammatory immune response affecting all organs of the body, including the skin.

Mould exposure

Mould exposure and susceptibility to mould can cause Chronic Inflammatory Response Syndrome (CIRS), of which dermatitis is a manifestation.

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Conventional treatment for food allergies, intolerance and sensitivity

Mostly, your GP will be concerned with an IgE mediated allergy, or may need to differentiate from an autoimmune condition such as coeliac disease. Depending on the severity and type of food sensitivity, your GP may refer you for food sensitivity testing to identify your food triggers.

Food sensitivity testing used in Australia includes:

  • Skin prick testing - to determine an IgE antibody reaction
  • Blood tests
  • Oral allergen challenge tests
  • Patch tests

Permanent avoidance of the food allergen is likely to be the first recommendation, in addition to medications, which include:

  • Antihistamines may be prescribed for less severe allergies,
  • Intranasal corticosteroid sprays (INCS)
  • Combined INCS and antihistamine sprays
  • Salt water nasal sprays and rinses
  • Adrenaline autoinjector(EpiPen) may be prescribed if there is any chance of anaphylaxis. In an emergency, adrenaline rapidly reverses the effects of anaphylaxis by reducing swelling of the throat, opening airways and maintaining blood pressure and heart function.

Immunotherapy - a process of desensitisation by administering small, gradually increasing doses of allergens over 3 to 5 years, may be administered.

If a non-IgE food intolerance is identified, your GP will recommend lifetime avoidance of that food.

Due to the inaccuracy of some food intolerance tests, conventional doctors can be over-cautious in the assessment of good quality naturopath food sensitivity testing and evidence-based functional food sensitivity testing.

This is why it is important to seek help from experienced food allergy and food intolerance functional medicine practitioners. Functional testing for food allergy and intolerance from state of the art pathology labs, and experienced interpretation of those tests are important to effective treatment.

Food allergy, intolerance and sensitivity testing Melbourne

Food sensitivity testing and treatment by functional medicine specialist practitioners may include a range of different tests to identify allergies, nutrient deficiencies, intolerances and digestive function including: microbiome species make up and diversity, inflammation, parasites, motility dysfunction (speed of transit of food), barrier integrity of the digestive lining, sugar intolerance testing. The results of these tests can inform practitioners on which other body systems may be involved and the best course of treatment.

At Melbourne Functional Medicine, our specialist food intolerance practitioners use state of the art pathology labs, for the highest quality testing. Food sensitivity testing may include:

  • Precision Point P88 Dietary Antigen Test - a comprehensive food test for IgG, and IgE reactions
  • GI Map or, GI 360 - state of the art microbiome testing to understand the microbiome environment and digestive function
  • Other tests as required for your specific symptoms
  • Food allergy testing is available for residents Melbourne and Australia wide.

How to reverse food reactions naturally - the functional medicine approach

Functional medicine food sensitivity testing and treatment is holistic and personalised. Once testing has identified any food allergens, food intolerances or sensitivities then treatment strategies will include:

  • Elimination of food triggers (at least in the short term)
  • Specific dietary inclusions
  • Restoration of mucosal linings of the digestive tract
  • Improvement of barrier function where intestinal hyperpermeability is detected
  • Reducing inflammation
  • Reducing overactive histamine response and stabilising mast cells
  • Modulating the immune reaction
  • Improving gut flora species make up and diversity
  • Improving gut motility
  • Ensuring healthy amounts of acid and gastric secretions for proper digestion
  • Ensuring healthy micronutrient levels are achieved and maintained

Functional medicine is perfectly placed to treat food sensitivities, allergy and intolerances. All treatments use evidence based methods to reduce reactivity, improve digestion and immune function and it is delivered within a holistic, and patient centred framework. Treatment may include:

  • Vitamin, mineral or other micronutrient supplementation, such as magnesium, Vitamin C, B vitamins, Vitamins A and D, Zinc, or N-acetyl cysteine
  • Herbs for modulating and regulating immune function, such as Echinacea, Albizia lebbeck, Baical skullcap or Poke Root
  • Herbs to improve digestive function such as Slippery Elm powder, Meadowsweet, Ginger, and Gentian
  • Herbs to reduce inflammation such as Turmeric, Boswellia, Garlic, Fenugreek, Licorice and Calendula

In our supportive, personalised 6 month program, you’ll have the guidance of your practitioner and the support of your health coach to help you implement your treatment plan with ease and get the results you’re seeking. Find out more below.

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Are food allergies autoimmune?

Food allergies are an IgE antibody reaction, and this is part of the immune system, but not an autoimmune condition.

The body mistakenly produces antibodies in response to a food that it has identified as being dangerous, and it is the food that causes the reaction. In an autoimmune condition the body is reacting to another part of itself, due to misidentification.

There is some emerging evidence of a link of untreated food reactions triggering autoimmune conditions in individuals that are susceptible or have a genetic predisposition.

Can food allergies cause behaviour problems?

Yes, food allergies can cause many types of reactions, including ones that disrupt neurotransmitter production.

These chemicals are the body’s mood chemicals, and when out of balance, can cause depression, anger, anxiety, hyperactivity and withdrawal.

This is particularly noticeable in children, but not limited to children.

Food allergy testing by functional medicine specialists is available in Melbourne to help identify foods and improve these symptoms.

Can food intolerances be reversed?

Food intolerances, depending on the underlying cause and severity can sometimes be reversed, or at least reduced.

If a person is lactose intolerant to dairy because their body doesn’t produce the enzyme lactase required to break it down, then it is possible to take a lactase supplement - although this does not reverse the intolerance.

If another person is sensitive to a food due to gut flora imbalances, intestinal hyperpermeability, or other digestive condition, then repairing these issues may result in the complete reversal of food sensitivities.

Seeing a specialist functional medicine food intolerance practitioner can help clarify what the root cause of your food intolerance is, access food intolerance testing, and create a plan to treat it naturally and effectively.

Can food sensitivities cause weight gain?

Yes, any type of food sensitivity can result in maldigestion, and disruption of the gut flora and/or metabolism which can result in weight gain or weight loss.

Figuring out if you have a food intolerance, sensitivity or allergy, and the underlying cause, can help to reverse how it impacts on your body weight.

The food intolerance specialist practitioners at Melbourne Functional Medicine can help isolate what the issue is and how to treat it effectively.

Can menopause cause food intolerance?

Yes. Peri-menopause is the stage before the last period and this can last for 7-10 years. In that time, oestrogen is fluctuating wildly, and progesterone is dropping.

Oestrogen stimulates histamine, the chemical messenger that is released by immune mast cells, and histamine can influence food reactions.

Both oestrogen and progesterone are generally protective and provide a calming presence to inflammation, but when they are depleted, we lose this protection. In menopause (12 months after the last period) there is very little oestrogen, and no progesterone, so it is common to develop food sensitivities.

It is also a time of change in a woman’s life, where kids, parents and jobs are often in transition, and this can have an impact on stress levels. Stress can affect every part of the body, but in particular the digestive system, and so this too can contribute to food intolerances.

What component of food is responsible for an allergic reaction?

It is possible to have an allergic reaction to any kind of molecule, there are even people in the world who are allergic to water, or sunshine - though these are uncommon.

Often, common allergies are to proteins in food, however they are not limited only to proteins, so any food can provoke an allergic reaction.

Are food intolerances hereditary?

There is a strong correlation in the research that shows that allergies, including food allergies, run in families.

This is also true of food sensitivities, however by a different mechanism, generally by disrupting digestive function.

The susceptibility to digestive disorders that can contribute to food sensitivities can be inherited, such as IBS, or autoimmune conditions such as IBD. With regards to food intolerances, genetically inherited is the likelihood of not producing sufficient enzymes for breaking down a particular molecule like the lactase enzyme, required for breaking down lactose in milk.

Is there food allergy testing near me?

We offer food intolerance testing in Melbourne and across Australia. We offer food tests such as food sensitivity testing, food intolerance testing, and food allergy testing using a range of labs and at home tests.

Can’t find what you’re looking for? Reach out to the team directly – we’ll be happy to assist.