Auckland Allergy & Eczema Clinic

Food Allergy: Hidden Allergens & Food Labelling

Food Allergy:
Hidden Allergens &
Food Labelling

It is important to remember that the only proven therapy is avoidance and the only life saving drug is adrenaline.

Elimination Diets

Elimination diets may lead to malnutrition and/or eating disorders especially if they involve more than one food and/or are used for extended periods of time. It is therefore very important to work very closely with a registered dietician.

Clinical reactivity to food allergens is usually very specific, and patients rarely react to members of more than one botanical family.

Clinical cross-reactivity among members of plant & animal species

Clinical cross-reactivity among members.png

It should be noted that patients frequently have positive skin prick test or RAST results to other members of a plant family or animal species (>80%), but this does not correlate with clinical reactivity. Clinical reactivity is typically very food-allergen specific. Therefore, foods should not be eliminated from the diet based solely on a skin or blood test.

Hidden Food Allergies

Sources of unlabelled Allergenic Foods in the Packaged Food Industry:

  • Use of shared processing equipment and failure to clean it adequately

Documented Episodes:

  • Milk contamination from shared ice cream equipment
  • Peanut contamination of sunflower butter from shared equipment

Commonly shared equipment:

  • Ice Cream — milk, soy, egg, peanut, tree nut
  • Chocolate — milk, peanut, tree nut
  • Pasta — egg
  • Baked Goods — peanut, tree nut, egg, etc
  • Breakfast cereal — peanut, tree nut

Use of Re-work

Re-work is the food industry leftovers. Most large food processing companies have a like-into-like policy to avoid problems from the use of rework.

Known episodes:

  • Peanut in ice-cream
  • Peanuts in chocolate bars
  • Peanut in ginger bread cookies

Switching ingredients

Documented Episode: Oscar Myers switched the source of its natural flavouring in its hot dogs from autolyzed yeast to hydrolysed casein, received numerous complaints of adverse reactions from parents of milk-allergic children, switched back to autolyzed yeast.

Misformulation of Foods

Known Episode:

Milk ingredient mistakenly added to snack crackers.

Use of wrong Packaging Material

Known Episodes:

  • Peanut butter granola bars in wrong boxes
  • Use of old packaging for nutritional beverage that failed to list presence of eggs
  • Wrong label on soup can

Economic Adulteration

Documented Episode: Soybean adulteration of hamburger meat.

Confusing Labelling Terms

  • Hydrolysed vegetable protein 
  • Edible oils (peanut, soy, sunflower are safe if highly refined)
  • Natural Flavouring
  • Artificial Flavouring
  • Lecithin (egg or soybean)

The 25% rule still exist in NZ & Europe: If a component of a food makes up <25% of the product there is no requirement to label the ingredients of that component, e.g., wheat and eggs in case of pasta (the label would simply say "noodles")

Sources of Unlabeled Allergenic Foods in Restaurant/Foodservice Industry:

  • Shared cooking utensils, Containers & servers
  • Same Frying oil and Fryers for All Deep-Fat Fried Foods
  • Same grill for All Grilled Foods
  • Creative Recipes eg Peanut butter in chilli (documented death)

Uninformed Wait/Cook Staff

  • Pine nuts in pesto sauce
  • Peanuts in Vietnamese entrée (documented death)

Tableside cooking

  • Sizzling shrimp platters

Frustrations of Ingredient Labelling

For the food allergic individual food labelling is the only means of identifying and hence avoiding their allergen.

The Australia New Zealand Food Authority (ANZFA) (the equivalent of the US Food and Drug Administration) is currently in its final stages of approving a new Food Standards Code. ANZFA was established in 1991 in order to get rid of discrepancies in food standards between Australia and New Zealand as well as to review the impact of these standards on the consumers, the food industry, and our governments.

As a result of the review, manufacturers will have to make some important changes in the way foods are labelled. The proposed changes are outlined below.

Mandatory declaration of certain substances in foods

Currently, a component food (an ingredient that itself the product of 2 or more ingredients, such as sausage on a frozen pizza) must be itemized only if it constitutes more than 25% of the final product (10% if it is a component additive).

ANZFA has identified a list of foods that have the "potential to cause severe adverse reactions in susceptible individuals" In view of the need of allergy sufferers to identify & avoid certain foods, the new standards specify that ingredient lists must include the following at all times:

  • Cereals containing gluten (wheat, rye, barley, and oats and their hybridised strains)
  • Crustacea (shellfish) and their products
  • Eggs and egg products
  • Fish and fish products
  • Milk and milk products
  • Nut and sesame seeds and their products
  • Peanut and soybean and their products
  • Sulfite in concentration of 10mg/kg or more

All these ingredients must be declared when present in any amounts.

The naming of ingredients

In order to improve the consumer’s ability to identify allergens in foods, and to limit unnecessary avoidance of foods, ANZFA has restricted the use of generic class names.

The "may contain" labels

To protect the allergic consumer, responsible food companies use statements such as "may contain" or another variation as "processed on the same equipment" when they know that the allergens could be carried over from one product to the next made on that production line. 

Unfortunately that statement "may contain" is now being used irresponsibly on products where it is obvious that the manufacturer is merely trying to avoid liability for sloppy manufacturing and cleanup practices. 

In some cases the statement is used because there is an actual risk of allergens getting into the wrong product from another line. In other cases it is a response to questions from consumers. As a result, food allergic patients are now experiencing a more narrow range of products from which to choose.

The "may contain" label was meant to be used only when proper cleaning and operating procedures cannot assure that there will be no carryover of allergens between products.

At present there are no specific guidelines as to how statements should be worded and when the statements can be used.

  • In the class of "fats or oils", the specific source must be declared when it is peanut, soy or sesame
  • Under the class name "fish", the specific name must be declared when it’s a crustacean
  • If the class "starch" is a gluten the specific name of the grain must be declared
  • The generic name "milk solids" can be used to replace less recognizable terms "whey" and "caseinate", but this is not mandatory.