What is the Difference Between Food Intolerance and Food Allergy?

DIFFERENCES BETWEEN FOOD INTOLERANCE AND FOOD ALLERGY

What is food allergy and food intolerance?

Food allergy
The immune system’s reaction (defence of the body) against something (allergen) that seems strange, usually proteins that, can be derived from food, dust mites, pollens and animal hair.
Food intolerance
The difficulty of the body to digest a specific food is usually due to a lack of any relevant substance, such as digestive enzymes. It can be due to metabolic diseases, intoxications and other disorders.

Body response:

Food allergy
Immediate, exaggerated, abnormal
Food intolerance
Reactions are delayed and occur several hours or days after ingestion

Quantity of substance to cause adverse reaction

Food allergy
Minimum quantity is needed and the body will react every time you eat the food.
Food intolerance
It may depend on the amount of food you eat and level of intolerance to cause any symptoms.

Symptoms

Food allergy
In general: cramps, vomiting, diarrhoea, stool bleeding, skin rash (urticaria), respiratory system (wheezing), and even more severe such as glottic oedema and anaphylactic shock (pressure drop with loss of consciousness), as well as general symptoms such as difficulty in gaining weight and growth.
Food intolerance
In general: gas, diarrhoea, bloating, heartburn, constipation, migraine, eczema, joint pain

Tests to detect

Food allergy
Blood test or skin test
Food intolerance
Guided elimination diet (IgG testing may be used as a supportive tool alongside dietitian assessment)

Antibodies involved

Food allergy
IgE (Immunoglobulin E)
Food intolerance
IgG (Immunoglobulin G)

Treatment

Food allergy
Exclusion of the food or substance in combination with mediterranean diet.
Recommendations: a diet with minimally processed foods and rich in foods that support natural detox (prefer organic and nutrient-rich diet – avocado and pomegranate are sources of glutathione, a natural detoxifier). Peppermint to reduce histamine, ginger to improve GI symptoms, and turmeric to improve digestion and intestinal permeability. Label reading. Completion of a food diary correlated with symptoms.
If symptoms disappear, progress to a gradual reintroduction diet with medical supervision.
Food intolerance
The elimination diet is recommended for 4 to 12 weeks. If the patient has not undergone food sensitivity testing – the standard exclusion diet for sensitivity-causing foods (more restrictive) can be used. The nutritionist will guide you on how to eliminate and re-introduce the foods you are intolerant. In some cases, depending on the degree of the intolerance, it’s enough just to reduce the frequency and quantity consumed. If gastrointestinal symptoms are present the nutritionist may suggest a Low FODMAP Diet.
Recommendations: a diet with minimally processed foods and rich in foods that support natural detox (prefer organic and nutrient-rich diet – avocado and pomegranate are sources of glutathione, a natural detoxifier). Peppermint to reduce histamine, ginger to improve GI symptoms, and turmeric to improve digestion and intestinal permeability. Label reading. Completion of a food diary correlated with symptoms.
Frequently asked question: if I am intolerant to cow’s milk, should avoid all dairy?
Some individuals might be intolerant to cow’s milk but they can tolerate milk products like yoghurt and cheese as they contain less concentration of the proteins that cause intolerance.

Types of food that cause allergy or intolerances

Allergy

Food components that cause allergy the most are cow’s milk, eggs, soy, wheat, crustaceans, citrus fruits, peanuts and nuts.

Intolerance

Food components that cause intolerance the most are cow’s milk, gluten, yeast, eggs, and nuts.

At the Raquel Britzke Clinic in London, we offer food allergy and food intolerance assessments to help identify potential food reactions using a small blood sample as one of several supportive tools. Understanding the differences between allergy and intolerance can be an important first step in supporting your health and quality of life.

In our food intolerance assessment, we analyse 200 types of food. Our allergy test panel includes the most common foods and environmental substances like dust, mites, pollen, etc.

Please note: IgG food intolerance testing is used by our clinic as one of several supportive tools to guide dietary assessment alongside a qualified dietitian. It is not a standalone diagnostic test and is not currently recommended as such by the NHS or the British Dietetic Association (BDA). If you have concerns about food allergies or digestive symptoms, we recommend speaking with your GP or a registered healthcare professional.

Click here to order your food intolerance test or contact us on WhatsApp to find out more information.