Allergens in Food
Allergens in Food
Anyone with true food allergy or coeliac disease needs to be very careful about avoiding certain foods. The information given here is aimed mainly at such people, rather than those with food intolerance (see p. 74), who can usually tolerate small amounts of their offending foods. However, some of the basic information given here is relevant to those with food intolerance as well.
There are different levels of sensitivity even among those with true food allergy. The ‘exquisitely sensitive’ can react to unbelievably minute traces of the food, and for them life is especially difficult. The same is true of some coelicacs, who can be affected by the tiniest quantity of gluten.
These people are a small minority. The level of vigilance required of such people will not be necessary for most people reading this book, so don’t get things out of proportion. While it is vital to be sensible about avoiding your problem food, it is also important not to become over-anxious.
Buying basic ingredients
Cooking for yourself is the safest way to eat for those with true food allergy and coeliac disease. There are relatively few hazards, but do beware of well-meaning assistants in health-food shops who try to sell you some exotic package of grain or flour – spelt or kamut or triticale, for example – reassuring
you that it is ‘definitely not wheat’. Be well informed about the different forms of your problem food and the names under which it is sold (see pp. 172-5).
Oils made from foods such as corn or peanut sometimes cause concern. Ordinary refined oils have been so thoroughly processed that they actually contain no allergenic proteins, so you can safely use these. Bottles of gourmet walnut oil and almond oil are a different story however, and should be avoided if you have nut allergies. Sesame oil is not purified either and can provoke serious reactions. With any oil, if you are unsure how safe it might be, go by the smell. Oils that smell or taste like the food from which they are made could well contain allergens.
Those with allergy to tuna can usually eat tinned tuna because the processing makes it safe. The allergens in fresh fruit and vegetables are generally inactivated by cooking too, so jams and tinned fruits tend to be safe – but test very cautiously. Cooking does not have much effect on other food allergens, apart from eggs. In rare cases, cooking can create allergens (see box on p. 186).
If you share your kitchen with others, and are highly sensitive, check that all cooking utensils are truly clean before use. Coeliac should watch out for breadcrumbs in the butter dish, jam or toaster. Where small children are allergic to a food, it may be best to keep the culprit out of the house entirely.
Genetic engineering and food allergy
Many people with food allergies are very concerned about the possibility that genetic engineering could introduce allergens from one plant species into another. This concern seems to be shared by government officials and those in the food industry, who are being extremely vigilant and cautious at present. As long as this attitude continues, there should be little danger to food allergy sufferers.
Finding food in funny places
If you are suffering some inexplicable reactions to non-food items, it might, just possibly, be a food reaction. Some latex gloves contain the milk protein casein, for example, added as a manufacturing aid.
Buying packaged foods
There are several different issues here:
• the need to read labels carefully for allergenic ingredients described by unfamiliar names (see p. 172)
• errors in the packaging used (see pp. 174-5)
• contamination by minute traces of a food substance due to processing machinery not being cleaned adequately. Cartons of fruit drink have occasionally been contaminated with traces of milk because the same production lines were used for packaging milk drinks. Tofu desserts made in ice-cream factories can also become contaminated with milk. These tiny traces of a food will only affect the most highly sensitive individuals, but contamination by nuts can involve large pieces and affect anyone with nut allergy (see p. 174).
• foodstuffs which are used as part of the production process
and leave a tiny residue in the finished item (see p. 174).
Be very cautious indeed about ready-made food that is unlabelled, such as that from bakeries and home-made stalls. Egg is frequently used as a glaze on baked products, nuts may lurk within, and milk or wheat can turn up in the most unlikely places.
Restaurants, cafes and takeaways
The majority of fatal and near-fatal incidents involving people with true food allergy are due to restaurants, cafeterias and canteens. Takeaways can also be a problem except in the case of the large chains such as McDonald’s, where ingredients are standardised. It is alarming that highly allergenic foods (e.g. peanut) are sometimes used – yet far from obvious – in recipes and sandwich fillings where they would simply not be expected. Anyone with peanut or shellfish allergy should be ultra-cautious about Chinese, Thai or Malaysian cooking – but those with milk allergy should find a haven here, because milk is not part of these culinary traditions.
The simplest solution is to eat very plainly when you go out –steak and salad, for example. Steer clear of casseroles and thick soups, where you can’t see what’s in it (the occasional chef throws in peanut butter to thicken the mix…). Food wrapped in pastry is best avoided for the same reason. Desserts and cakes are risky for anyone with nut, egg or milk allergy.
You must insist on accurate information about the food before you taste it. If the counter staff, the waiter or the waitress
is unsure of the ingredients, ask them to check with the chef, or with the label on pre-packaged food. Be persistent and never eat anything unless you are sure. Make eye contact with the person concerned, and learn to be a good judge of character. Your life could depend on telling the difference between the waiter who knows the facts about the food and the waiter who is being blandly reassuring for the sake of a quiet life.
It is a great mistake to pick out the pieces of offending food – kiwi fruit from a fruit salad for example – and eat the rest. There is often enough allergen left behind to cause anaphylaxis in the highly allergic individual.
Those who are extremely sensitive to the offending food must also consider the problem of contamination in the kitchen. Grills and fryers in restaurants and canteens can become contaminated with fish allergens or nut allergens (e.g. from nut cutlets) and these can be transferred to fried potatoes or other foods, provoking anaphylaxis in the highly allergic individual. One person with fish allergy died in this way. Sesame seeds can also contaminate equipment, work-surfaces or bakery counters.
Parties and buffets
Milk, egg, shellfish or nut allergies can make it especially hazardous to eat buffet or party food. Regard everything with suspicion. Cocktail snacks with nuts or peanut paste hidden inside are a particular problem.
When fish allergy isn’t fish allergy
Anisakis is a parasitic worm that infests fish and can sometimes survive the
cooking process to infect humans. The worms are easily thrown off by the human immune system, but the body is primed to make IgE antibodies should
it ever encounter Anisakis again. Another meal of parasitised fish – even if the Anisakis worms are all dead this time, and only the allergens remain
will provoke a massive IgE-mediated reaction, leading to anaphylactic shock. This problem is usually misdiagnosed as allergy to fish itself.
Other inconsistent reactions to food can be due to contaminants such as antibiotics, preservatives, other food additives or (especially in the case of shellfish) naturally occuring toxins.