How to spot a food allergy, sensitivity or intolerance Nutrition The UK has some of the highest prevalence rates of allergic conditions in the world, with over 20% of the population affected by one or more allergic disorder.1 When it comes to food, some of the most common allergies include shellfish, milk, peanut, tree nuts, egg, wheat and soy. But there are a number of different ways that your body can react to food, and it may not be an actual allergy that is causing your distress. What is a food allergy? A food allergy is usually identified by explicit and pronounced symptoms such as hives, swelling and anaphylaxis. When you have an allergic reaction to a food, an immune cell called IgE is produced very quickly. This antibody produces big reactions in the body and thus very quickly produces symptoms. The reason the IgE antibody is produced in the first place is due to a haphazard in your immune system that’s created a memory to a certain food. This memory is usually very long and so it’s likely that your allergy will be lifelong. If you suspect you have a food allergy, you should consult a doctor. What is a food sensitivity? You may have been tested for a food allergy and the result came back negative, yet when you eat a particular food, you still don’t feel well afterwards. This may be because have a sensitivity instead. This is when immune cells are still created in response to the food you’re eating, but they’re not IgE immune cells – they’re IgG. We all create IgG cells as they’re an important part of the immune system. For some people, however, there’s something further going on with their immune system and these IgG cells. We don’t just produce one type of IgG antibody – we produce around four different types. Some work very closely with IgE to educate and protect against having an IgE reaction. What’s more, sometimes when we consume particular foods, we create an IgG response, but then a further inflammatory response happens; activation of a protein called compliment. Therefore, it might be that your symptoms are a result of an inflammatory response further down the chain, rather than the IgG antibody. What is a food intolerance? A food intolerance can be easily confused with a sensitivity due to overlapping symptoms; bloating, brain fog, extreme tiredness etc. However, a food intolerance is actually caused by lower levels of a particular digestive enzyme, making it harder to digest the food and creating symptoms as a result –a good example is lactose intolerance. Moreover, bacteria that reside in our gut, when exposed to the diet we consume, can release gases. These gases are similar in their presentation of how they make us feel to a food sensitivity. Therefore, it might be the microbes in your gut that are causing your symptoms, rather than a further inflammatory response that’s more related to the immune system. How to identify an allergy, sensitivity or intolerance 1) Keep a food diary for a period of time to keep an eye on what you’re eating and how you’re feeling. Note down any symptoms to identify patterns (e.g. abdominal pain, bloating, changes in bowel movement, low energy, head fog). 2) Include a wide range of foods in your diet to diversify your gut. Mix up grains, vegetables, nuts etc. This will help to reduce the effects of food sensitivities over time. 3) You can always consult a registered nutritional therapist at our Optimum Nutrition Clinic if you have concerns. They will be able to carry out a full assessment of your diet, including any necessary tests. Enjoyed reading? Subscribe to our free digital Optimum Nutrition for more articles.