Around one in 20 people will develop a food allergy in their lives. So how do you recognise the signs, and what can you do about it? Paulette Crowley shares the answers.
If you don’t have a food allergy, then you probably know someone who does. Perhaps it’s an allergy to shellfish which means they can’t share in the joys of prawns and lobster; or maybe it’s an allergy to peanuts which means not just avoiding nuts, but also not eating the many chocolate products made with nuts.
Developing a food allergy can be a bewildering experience, firstly trying to work out what is causing all those unpleasant symptoms, then learning to avoid the offending foods. But the good news is that over time, as you learn how to avoid the foods you’re allergic to and you come to discover new and tasty substitutes, managing a food allergy becomes easier.
In Australia, the most common food allergies are to milk, soy, eggs, peanuts and fish. Commonly, food allergies are diagnosed in the first year of a person’s life and, happily, many of us grow out of these food allergies during childhood. If a member of your family has a food allergy, your risk of developing a food allergy increases by up to 40 per cent.
A food allergy occurs when your immune system reacts to the food you eat as if it is a foreign body, and attacks it by releasing histamine.
If you’re allergic to a food, the symptoms will usually appear within 30 minutes of having eaten just a small amount of the food you’re allergic to. These may include:
- Hives, welts and/or a rash on the skin that can be itchy and sore.
- Nausea, vomiting or diarrhoea.
- Swelling – particularly around the eyes and lips.
- Anaphylaxis – swelling of the tongue and throat, which can potentially constrict breathing. This is the most serious reaction of all, and requires urgent medical attention.
The most important thing to remember about the symptoms of food allergies is that they will occur every time the suspected food is eaten, says clinical immunologist and allergist Dr Marianne Empson.
“Every time the person eats the food they are allergic to they will react. If they don’t eat the food they won’t react.”
If the symptoms occur irregularly after eating the suspected food, they are probably not related to food allergy and it may be a food intolerance, (see Food allergy vs food intolerance, below) and should be investigated by your doctor for other causes.
Suspect you have a food allergy?
Dr Empson says it is important that if you suspect you or your child have a food allergy that you have it investigated by a doctor.
Your GP may recommend you see a specialist for an allergy test. This is done by what is known as a skin prick or RAST test. This usually involves your arm being gently pricked with a number of allergens to test for allergic reactions. Sometimes up to 20 foods are tested at once. If you respond with a raised, red lump, it may indicate that you have an allergy to that particular food.
There is no cure for food allergy and the best treatment is complete avoidance of the allergen, says Dr Empson. This is often a little harder than it seems as the offending food can be an ingredient in a whole variety of processed foods.
At this point, it is useful to seek advice from a dietitian who specialises in allergies. “Education is phenomenally important and will help to prevent a lot of recurrences”, says Dr Empson.
The severity of your allergic reaction will determine the type of medication that is recommended for you. Antihistamine is a good treatment for people who have mild allergic reactions to food. For people who have life-threatening, anaphylactic reactions your doctor may prescribe you an EpiPen or Anapen, which is an injectable dose of adrenalin to keep for emergencies. Dr Empson suggests some of her patients wear MedicAlert bracelets so they can get appropriate medical help quickly in the event of anaphylaxis. The Australian Society of Clinical Immunology and Allergy also recommends you develop an action plan for anaphylaxis to ensure a swift response in such an event.
Are allergies becoming more common?
Food allergy vs food intolerance
Food allergy involves the immune system, whereas food intolerance usually affects the digestive system. While a food intolerance may produce similar symptoms to a food allergy, the cause is quite different. Reasons for food intolerance include:
- Lacking an enzyme to properly digest the food (such as a lactose intolerance).
- Sensitivity to stress.
- Sensitivity to certain preservatives, sugars (eg. lactose in dairy) or food chemicals (eg. salicylates or amines) found in foods.
The frequency of allergies has approximately doubled in the past few decades. The following theories are being studied extensively:
- We’re too clean: our obsession with cleanliness reduces exposure to bacteria that helps build our immune systems. Vaccinations mean we are no longer exposed to the range of illnesses we once were.
- Our diets have changed dramatically over the past century: we’re eating a greater variety of foods than we used to, and more processed and packaged foods too, meaning there are more potential allergens in our diets.
- Protecting infants from eating potentially allergenic foods might actually be inhibiting their bodies’ ability to tolerate these foods.
- Pollution: we all have more exposure to chemicals in our day-to-day lives.
Dos and don’ts
- Eliminate a food you think you may be allergic to without having a diagnosis – you could be wrong and miss out on essential nutrients.
- Be fooled – the only scientifically-proven test for diagnosing food allergy is a skin-prick test that should be done by a medical professional experienced with diagnosing and treating allergies. Other tests, such as kinesiology and Vega testing have no scientific evidence to prove they work.
- Eat a food (especially if it’s packaged or you’re eating out) unless you’re absolutley sure it is allergen free.
- Panic – millions of people around the world enjoy happy and healthy lives living with a food allergy.
- Lose heart – there is a life after food allergy. You can still enjoy an interesting diet!
- Visit a dietitian if you have a diagnosed food allergy. A dietitian can help you plan your diet so you don’t miss out on vital nutrients.
- Talk to your doctor about re-testing if your child has an allergy or intolerance – it is possible to grow out of them.
- Get organised and plan your diet once diagnosed. Prepare your own food where possible. Or, make sure you check ahead with friends or cafés and restaurants to see if they can cater for your diet.
- Tell your family, friends, schools and workmates that you have an allergy, and let them know what help you need in the event of a severe reaction.
- Carry antihistamine in case of an allergic reaction and get a MedicAlert bracelet and an EpiPen or Anapen if you’ve ever had an anaphylactic reaction.
Reading labels for allergies
If you need to avoid a certain food, always read the label, even if you wouldn’t think a particular product would contain the allergen – for example, cow’s milk in bread. By law, most packaged foods must contain an ingredients list and have any allergens clearly labelled. This includes peanuts, tree nuts, shellfish, fish, cow’s milk, soy, egg, gluten and sesame. Carefully read the labels of foods in supermarkets for words indicating the presence of allergen. ‘May contain’ statements are not compulsory, so if you’re worried contact the manufacturer. Allergy and Anaphylaxis Australia recommend you:
- Read all product labels every time you buy. Food labels, ingredient listings and allergen warning statements can change.
- While imported goods must comply with Australian food labelling legislation, mistakes can occur in translation. So, use extra care. Labelling requirements in some other countries are less stringent than Australian standards so there’s a greater risk of incorrect labelling of imported products.
- Check labelling on both outer and inner packages as discrepancies have been found.
- Check labels of products that come in different sized packages, as they may differ.
- Don’t rely on products labelled as ‘Free from….’ Always read the ingredient list and allergen warning statement.
Allergy alert – don’t miss out on vital nutrients!
If you have a food allergy and are avoiding certain foods, you may be missing out on essential nutrients so it’s important to make sure you are getting them elsewhere. This will help to prevent any deficiencies and ensure that children in particular are getting what they need to grow and develop properly.
Peanuts and tree nuts
Avoid: All foods containing the nut you are allergic to (eg. peanuts, almonds, Brazil nuts) which may include biscuits, cakes, chocolate, cereals, mueslis, muesli bars and sauces among other things. If you’re allergic to peanuts, you may also have to avoid legumes such as peas, beans and lentils – as peanuts are technically a legume, not a nut.
What you could miss out on: Protein, ‘heart-healthy’ monounsaturated fats, B vitamins and vitamin E.
Stock up on: Seeds – swap peanut butter for tahini or sunflower seed spread. You could also try olive oil and avocados to get your monounsaturated fats.
Shellfish and fish
Avoid: The fish or seafood that causes the problem, plus foods that contain them. This may be prawns, lobster, crab, oysters or even fish sauce, oyster sauce, fish stock and dips.
What you could miss out on: Omega-3 fats which are important for heart health.
Stock up on: Any seafood or oily fish like salmon, herring, mackerel, tuna or sardines that don’t affect you. Otherwise go for linseeds/flaxseeds (ground, whole or oil), walnuts, pecans, soy or canola oil.
Avoid: All cow’s milk and related products such as yoghurt, cheese, margarine, butter, cream, milk-based sauces and processed products such as biscuits, cakes or pastries which may contain milk powder or milk solids.
What you could miss out on: Protein and calcium, important for healthy bones.
Did you know? One in 10 babies has an allergy to eggs or peanuts.
Stock up on: Dairy substitutes such as calcium-fortified soy milk, yoghurt and cheese. Other foods including calcium-fortified tofu, sardines and salmon (with bones), broccoli, nuts and seeds. It’s important not to substitute with other dairy alternatives such as rice, almond or oat milk, especially with children under two years old, until you have received advice from an APD.
Avoid: All eggs and dishes made with eggs. Also watch out for products such as pasta, cakes, biscuits, pastry, ice-cream and some sauces.
What you could miss out on: B vitamins which are vital for a healthy nervous system, blood, skin and energy release, plus vitamins A, E, D and protein.
Stock up on: Other sources of B vitamins – meat, fish, whole grains, dairy, leafy greens, vegemite, nuts and seeds.
Avoid: Soy beans, tofu, soy sauce, meat-substitutes like vegie burgers and soy ‘dairy’ (milk, yoghurt and cheese). Also look out for soy on labels of processed foods such as pizza, bread mixes, flavoured milks, cakes and biscuits.
What you could miss out on: Protein – especially important if you are vegetarian or vegan.
Stock up on: Chickpeas and lentils are good sources of protein. But they are closely related to soy, so if you’re allergic, you may have problems with these too. Be sure to check with your doctor or dietitian. Choose other sources of protein such as meat, fish, eggs, cow’s dairy, nuts, seeds and peas.
Adults and allergy
Adults with food allergy are far less common than children, but this is expected to rise as more children than ever are being affected. “Large numbers of allergic children haven’t reached adulthood, so we’re dealing with a different adult population to what we will be in 10 years,” says Dr Empson. Seafood is the most common food adults are allergic to and is usually permanent once it happens. It can develop at any time, even to people who have always eaten seafood without a problem. No one knows why this happens, or what triggers the immune system to launch into ‘attack’ mode for something it has previously recognised as harmless.
Allergies and children
A recent Australian study found that one in 10 babies had allergies to eggs or peanuts. But the good news is that most children will grow out of their allergy by around the age of five.
The most common foods children are allergic to are peanuts, eggs and cow’s milk. Peanut allergies tend to be more permanent – only around 20 per cent of children will outgrow them, although they are at risk of re-developing the allergy at some stage.
Studies are beginning to show that introducing allergenic food much earlier in a child’s life may reduce the incidence of food allergy. One study looked at Jewish children living in the UK and Israel. The group in the UK, who did not eat peanuts, were 10 times more likely to have a peanut allergy than those in Israel, where the children ate large quantities of peanuts from very early in their life.
Dr Empson says doctors are now questioning whether previous advice of delaying the introduction of allergenic foods to children was the right thing to do.
Dietitian Anna Richards says current advice is now moving towards mothers continuing breastfeeding their babies for as long as possible but to introduce solids, including eggs, dairy, peanuts and soy, between 17–24 weeks.
I wrote this article when I was the editor of Allergy Today magazine and it first was published in Healthy Food Guide in Oct 2012.