The incidence of food allergies has doubled in Western countries in the past decade. These are the special focus this month for national charity Allergy NZ.
“Around one in 10 children is likely to have a food allergy by their first birthday,” says Allergy NZ allergy adviser Penny Jorgensen.
“Many factors are being investigated to explain the increase but, at this stage, it is agreed it is due to a complex interaction between our genetics and our changing environment and lifestyle.”
Food allergies are also an emerging condition in developing countries.
However, with the rise of selective lifestyle choices, like gluten free diets, the lines are increasingly blurred about what’s a choice, what’s an intolerance and what is a life-threatening illness. Penny explains below.
How to tell whether you have a food allergy or an intolerance
The key difference between a food allergy and an intolerance is that a food allergy is an immune system over-response to protein in a particular food that is otherwise harmless. Reactions tend to happen within minutes, rarely beyond a couple of hours, and will happen every time the person ingests even a small amount.
Food intolerances, on the other hand, are usually to do with the digestive system not coping with a food substance. This may be because of an enzyme deficiency. For example, people lacking in the lactase enzyme have difficulty breaking down lactose, which is the sugar in milk.
Some naturally occurring chemicals in food and beverages (e.g. caffeine in coffee and tea; salicylates in fruit and vegetables) cause some people to have problems. In many cases, a small amount occasionally won’t cause a problem but a large amount will.
What symptoms could suggest either?
Food allergic reactions happen quite quickly and range from mild to severe. Mild to moderate reactions include hives or welts on the skin; swelling — often on the face, lips and/or eyes — and abdominal pain and vomiting.
Severe reactions are referred to as anaphylaxis because the symptoms are life-threatening. This is where the airways and/or cardiovascular system are affected. Signs include difficulty in breathing or talking, swelling of the tongue or in the throat, persistent cough, dizziness and/or collapse. Young children may just go pale and floppy.
Symptoms of food intolerance vary considerably. Timing can be within hours or even days, and are often doseresponsive. Symptoms can include headaches, mouth ulcers, skin rashes, stomach upset, nausea and bloating.
Common trigger foods
There are eight foods known to cause about 90 per cent of all food allergies, globally. These are milk (dairy), eggs, peanuts, tree nuts, soy, wheat, fish and shellfish. However, there are also regional variations, often to do with food common in local diets. Sesame allergy is common in Australia, and kiwifruit allergy seems to be increasing in New Zealand.
People with coeliac disease have an immune-related condition where gluten inflames the gut and prevents the absorption of nutrients. This is different from gluten intolerance which causes digestive problems but is not immune-mediated.
Food intolerances are often caused by natural substances in foods, which can also include food additives, e.g. food high in salicylates include citrus fruit, strawberries, kiwifruit and avocados, and also dried fruits; and processed foods such as tomato sauce.
Diagnosis
Food allergies can be diagnosed through a patient’s clinical history, followed by a skin prick or blood test. Patients should consult their general practitioner in the first instance; young children with, or suspected as having, food allergies should be referred to a paediatric clinic.
Food intolerances are more complex to diagnose as there are few recognised tests. Symptoms are variable and often delayed. An elimination diet may help determine the cause of the problem and you should seek advice from a dietitian for this.
Gluten and dairy-free banana cake with dark chocolate ganache
Victoria from Love Cake offers this allergy friendly cake that is guaranteed to find favour with all. It can be doubled to make a layered cake. Simply cut both cakes in half horizontally and sandwich together with whipped coconut cream or coconut yoghurt and caramelised bananas, if you wish. Top with chocolate ganache. To make it easier to work with, make the cakes the day before, wrap in plastic wrap and store in the fridge overnight. Assemble and decorate the next day.
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More gluten-free recipes
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