Understanding food intolerances and allergies
Navigating food-related health issues can be challenging, especially when it comes to distinguishing between food intolerances and food allergies. These conditions can significantly affect quality of life, making it essential to understand their differences, symptoms, and management. Whether you're dealing with an unexplained reaction or seeking clarity on your dietary triggers, this article will help you understand the basics and take informed steps.
Food intolerances vs. Food allergies:
While both a food intolerance and a food allergy can cause adverse reactions, they differ significantly in their mechanisms. An allergic reaction involves the immune system, while an intolerance does not.
Food intolerances: These are much more common than food allergies, however they are much harder to identify. Unlike allergies, intolerances do not always involve the immune system and can take hours or days to appear. Common food intolerances include: Lactose, glutamate, amines, histamines, salicylates. For instance, lactose intolerance results from a temporary deficiency of the lactase enzyme, while other intolerances may stem from chemical irritation of nerve endings. Usually, people can tolerate some or small amount of the food so depending on how much is eaten, a reaction isn’t always seen. Everyone has their own individual “threshold” or limit of how much they can tolerate before symptoms develop.
Food allergies: Only about 5% of people have a food allergy and most are seen in childhood. This occurs when the immune system overreacts to a harmless substance (allergen). The body produces antibodies, triggering a reaction that often appears in a matter of minutes but can take as long as a few hours. Common food allergens include dairy, eggs, soy, peanuts, tree nuts, shellfish, fish, sesame, and wheat. Allergies can also stem from non-food sources like dust mites, pet dander, pollens, insect bites, or medications.
It’s worth noting that coeliac disease, though often labelled as an intolerance to gluten, is an autoimmune condition (neither allergy or intolerance) requiring lifelong avoidance of gluten (found in wheat, rye, and barley).
Common symptoms of food intolerances and allergies:
Recognising the symptoms is crucial for distinguishing between an allergy and an intolerance.
Allergy symptoms:
- Immediate reactions: These can include hives, facial swelling, wheezing, rashes, and in severe cases, anaphylaxis. Such reactions are typically detectable through blood tests (IgE) or skin prick tests.
- Delayed reactions: Symptoms may include eczema, gastrointestinal issues (diarrhea, constipation, vomiting, colic, or blood and mucus in stoold). These reactions are not detectable through standard allergy tests but can be diagnosed with a food and symptom diary and guided elimination diets and challenges.
Food intolerance symptoms:
- Bloating, gas, or diarrhea (e.g. lactose intolerance)
- Migraines, headaches
- Skin irritation
- Fatigue
- Low mood
- Flushed skin
- Eczema
- Asthmatic reactions
- Nasal congestion
Testing and diagnosing food intolerances and allergies:
Diagnosing these conditions often requires specific testing methods:
- Food intolerances: These are typically diagnosed through guided elimination diets followed by gradual reintroduction of foods to determine tolerance levels. These are best done with the help of a dietitian with specialist training and experience in this area.
- Food allergies: Blood tests (IgE levels) or skin prick tests
Consulting an allergist or dietitian can streamline the diagnosis process and help create a tailored management plan.
Managing symptoms and knowing when to seek help
Addressing food intolerances and allergies requires a strategic approach:
- For allergies: Avoiding the allergen is crucial. In cases of severe allergies, always carry an epinephrine auto-injector and educate yourself and your family on managing anaphylaxis.
- For intolerances: Follow an elimination diet under the guidance of a dietitian to identify triggers and determine safe levels of consumption. Reintroducing foods gradually helps establish tolerance levels.
- General tips: Read food labels carefully, maintain a symptom diary, and consult a specialist when symptoms affect your daily life. Food intolerances, although not life-threatening, can still impact quality of life and benefit from professional guidance. For further information you can visit the Australian Society of Clinical Immunology and Allergy website which has lots of fact sheets and useful information.
Understanding the distinction between food intolerance and food allergy is essential for effective management. While allergies involve the immune system and can be life-threatening, intolerances are more about individual thresholds and chemical responses. If you suspect a reaction to food, seeking specialist advice can provide clarity and a personalised plan to improve your health and well-being. Taking proactive steps toward diagnosis and management can make a world of difference for you and your family.
