If certain foods are leaving you tired, bloated, or unwell, you might be wondering whether you have a food allergy or a food intolerance. While both can affect your quality of life, they are very different — and knowing which one you’re dealing with is key to feeling better.
In this guide, we’ll explain the difference between food allergy and food intolerance, outline common symptoms, and share how testing with Swan Science can help.
A food allergy is a reaction by your immune system. Your body mistakenly identifies a food as a threat and releases chemicals like histamine. This can cause immediate and often severe symptoms.
Common allergy symptoms include:
Food allergies usually occur quickly — often within minutes — and are triggered by even tiny amounts of a food. Common allergens include nuts, milk, eggs, shellfish, and wheat.
Learn more about our Food Allergy Test
(Safe, ISO-accredited IgE testing available through Swan Science.)
A food intolerance is not caused by the immune system. It occurs when your body struggles to digest or process certain foods. This can lead to chronic, delayed symptoms that affect daily wellbeing.
Common intolerance symptoms include:
Unlike allergies, intolerances don’t cause life-threatening reactions — but they can make you feel miserable for weeks or even years. Symptoms may appear hours (or even days) after eating.
Our ISO-accredited food intolerance test checks your body’s IgG antibody response to over 200 foods — helping to identify low-grade reactions that may be behind your symptoms.
Whether you suspect dairy, gluten, yeast, or something else entirely, our test gives you personalised results within 7 days — allowing you to start a targeted elimination diet or seek support from a nutritionist.
Take a Food Intolerance Test – £149 or find exclusive offers here
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