Author: Jacqueline Newson, BSc (Hons) Nutritional Therapy

What’s The Difference Between A Food Allergy And An Intolerance?

What’s The Difference Between A Food Allergy And An Intolerance?

The incidences of food allergies in the UK are some of the highest in the world with as many as 20% of the population affected with one or multiple allergies. (1)

In Europe food allergies are a common condition. 

Food intolerances are also problematic and are believed to affect 5-20% of the general population. (2)

Interestingly, food intolerances are significantly more common in women than men.

We always take an evidence-based approach and aim to provide you with actionable tips to help you on your journey to optimal health. 

In this article we will outline the differences between food allergies and intolerances, identify the potential causes and explain how to determine whether you may have an allergy or an intolerance.

Nutritional choices and supplements that may help are also discussed.

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For most people eating is one of life’s ultimate pleasures, something to plan, look forward to and indulge in.

But for those with food allergies or intolerances, food can be a minefield of potential threats which can take the enjoyment and spontaneity out of eating.

Food allergies and intolerances seem to be increasingly commonplace these days, so much so that major supermarkets and health food stores have expanded their product ranges to include ‘free from’ foods.

Cafés and restaurants are also embracing this, with menus that cater to sufferers and an abundance of gluten-free and dairy-free options.

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What are Food Allergies?

A food allergy occurs when your immune system generates an inappropriate reaction to specific proteins that are found in everyday foods. (3)

Symptoms can be severe and sudden. For example, a rash may develop immediately after eating an apple or an individual could be violently sick after eating shellfish.

In more serious but relatively rare cases an allergy may cause anaphylactic shock.

This causes the airways to close due to swelling and if not treated immediately can, in extreme cases, lead to death. (3)

Generally, a reaction to a food develops within the first hour after consumption and sometimes within minutes.

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What Causes the Allergic Reaction?

Regardless of whether the allergic reaction is mild or severe, the immune system is always involved.

Your immune system produces specialised cells called antibodies and their role is to identify potential invaders that may harm your body, usually harmful bacteria or viruses, but in certain cases it reacts to specific foods.

Antibodies signal to your immune system to release chemicals that round up and kill the threat - to prevent an infection from spreading.

Where there is a food allergy, the immune system doesn’t recognise the food eaten and releases a type of antibody called immunoglobulin E (IgE).

The IgE is instructed to falsely target a food that contains a specific protein it sees as a hazard to your health. (2)

Common allergens are nuts, eggs and seafood, which may provoke symptoms such as swelling, itchy eyes, a rash and (rarely) anaphylactic shock.

Each time you eat the offending food, the IgE antibodies trigger the release of a range of chemicals, in particular histamine, which causes inflammation. (4)

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How to Identify if You Have a Classic Food Allergy

Skin tests and/or blood tests are often used to test for food allergy.

Your doctor will be looking for the presence of IgE antibodies.

IgE antibodies have a long-term memory, which means if you have an IgE immune response to a substance, you will almost always have this type of reaction.

Once a classic food allergy is diagnosed, the only proven method of managing the allergy is to strictly avoid the specific food or foods.

However, following recent developments, medical experts are now investigating the possibility of introducing the raw allergen gradually in a clinical environment to desensitise and potentially induce tolerance in individuals with allergies. (5)

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Distinguishing Between a Food Allergy and an Intolerance

Food intolerance reactions are much slower in onset than allergic reactions.

Symptoms or reactions rarely occur immediately after consuming the offending food and may manifest after a few hours or even up to 10 days later.

Some people have various intolerances, which makes it very difficult to pinpoint which foods are the culprit.

Food intolerances are not usually life threatening, but may significantly undermine a person’s wellbeing, causing several uncomfortable symptoms including:

  • Nausea
  • Bloating
  • Abdominal pain
  • Diarrhoea
  • Migraine
  • Headaches
  • Fatigue
  • Depression/anxiety
  • Dark circles under the eyes
  • Asthma
  • Eczema
  • Muscular aches
  • IBS
  • Constipation
  • Joint pain
  • Water retention
  • Arthritis

You can have an intolerance to virtually any type of food although foods eaten most regularly are often the chief culprits.

Common offenders include wheat, dairy, eggs, yeast, alcohol, chocolate, coffee, citrus fruits and grains containing gluten.

Some intolerances are due to a lack of specific chemicals or enzymes needed to digest food e.g. lactose intolerance is due to a lack of the lactase enzyme, so the body is unable to absorb lactose (a milk sugar) into the digestive system.

However, most food intolerances are the result of an immune response to foods, which involves IgG antibodies.

IgG antibodies, unlike the IgE antibodies present in allergic reactions, have shorter memories.

Eliminating the offending foods completely from the diet for a period of time and then reintroducing them gradually will usually clear up the intolerance.

Care should be taken to only consume these foods in moderation.

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Contributing Factors

Although the most common reason for developing a food intolerance is over consumption of a particular food or food family, there may be other factors such as:

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How to Identify if You Have a Food Intolerance

The simplest way to determine if you have a food intolerance is to remove the suspected food from your diet, see if the symptoms improve and then try reintroducing the food.

It is best to avoid the suspected food for at least one to three months.

Once you have reintroduced the food, if the symptoms then reappear it is likely you have an intolerance to that specific food.

In some people there may be intolerances to more than one food, or an intolerance may have developed to a food family such as the nightshade family which includes potatoes, aubergines, peppers, tobacco and paprika.

Although some symptoms may improve, they might not clear up completely so your results could be confusing.

It can be beneficial to enlist the help of a nutritional therapist or naturopath when investigating food intolerances as it can be challenging and confusing without expert guidance.

Blood tests are a quicker and easier way to identify if you have a food intolerance and need to be arranged through a nutritionist or naturopath.

The tests look for the presence of IgG antibodies.

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Nutrition Advice

  • Identify any potential food intolerances, either through an elimination diet or by taking a simple pin-prick blood test.
  • Once you have identified the offending foods, remove the foods for a minimum of a month, taking care to replace these foods with a nutritious alternative.
  • Start to reintroduce the offending foods - preferably under the guidance of a qualified nutritionist.
  • Increase fresh and whole foods into your eating plan and aim for as much variety as possible, taking care not to eat too much of any one food especially those that were previously problematic.
  • Avoid artificial colours, flavouring and preservatives.
  • Avoid highly processed preserved meats such as salami, bacon, sausages and hot dogs
  • Drink more water
  • Support your immune system and digestion to limit the likelihood of intolerances returning

  • Some useful supplements include:
    • Digestive enzymes - to aid the breakdown and absorption of food
    • Vitamin C - to support immune function
    • Probiotic bacteria - to help repopulate the gut with good bacteria
    • Glutamine - to help heal the gut lining in cases of ‘leaky gut’
    • Gamma oryzanol - has anti-inflammatory effects which benefit gut health
    • Omega-3 essential fats - help to reduce inflammation
    • A multivitamin & mineral formula - to enhance inflammatory and antioxidative barrier, and promote immunological tolerance

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Classic food allergies must always be treated by a medical professional. 

However, improving overall nutrition and including the above mentioned supplements may help to influence the nature of an immune response and are important in ensuring appropriate functioning of the immune system.

If you suspect you have a food intolerance and would like further guidance on testing and how to navigate a successful elimination diet, why not take advantage of a complimentary consultation with one of Amchara’s qualified nutritionists or naturopaths.

Free 360 Health Consultation

Do you have experience of food allergies or intolerances? 

What did you do? 

We’d love to hear your experiences, please get in touch. 


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