Canadian Health Network

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Defining the problem

• Allergic reactions occur when the immune system develops an overly sensitive response to normally harmless substances. The immune system then produces antibodies that trigger unpleasant and sometimes dangerous reactions.
• Food intolerances are more likely to originate in the gastrointestinal system and usually reflect an inability to digest or absorb certain foods, or components of those foods.

Food allergies:

• Symptoms of food allergies may include digestive problems, rashes or hives, breathing problems, wide spread swelling of the skin and mucous membranes. In severe reactions the blood pressure can drop and unconsciousness and death can occur.
• Reactions can occur extremely quickly and can be life threatening.
• It often takes only a trace amount of the offending food to cause a problem. eg. a knife with traces of peanut butter could contaminate butter or jam and that is enough protein to cause a severe reaction.

• Unlabelled allergens can be a particular problem, eg. trace amounts of milk in flavourings or seasonings that don't have to be declared.
Eggs, for example, can be found in some of the least expected places, including processed meats, breakfast cereals, marshmallows, noodles and some cosmetics.
• Some of the most common allergensinclude:
  • peanuts
  • tree nuts (almonds, Brazil nuts, cashews, hazelnuts (filberts), macadamia nuts, pecans, pinenuts, pistachios, walnuts)
  • sesame seeds
  • milk
  • eggs
  • fish
  • crustaceans (e.g. crab, crayfish, lobster, shrimp) and shellfish (e.g. clams, mussels, oysters, scallops)
  • soy
  • wheat
  • sulphites

Allergies are best diagnosed by an allergist who is a member of the Canadian Society of Allergy and Clinical Immunology. If at risk of a severe reaction (anaphylaxis), an epinephrine auto injector should be carried at all times and a medic alert bracelet worn.

Food intolerance

• Symptoms of food intolerance usually take longer to appear than similar symptoms caused by food allergies.
• The offending food is often one that is quite common and is eaten frequently.
• As opposed to allergies where a small amount of food can cause a reaction, it generally takes a more normal sized portion to produce symptoms of food intolerance.

• One of most common intolerances is to dairy products.
• Many people lack an enzyme called lactase which is needed to digest lactose (a sugar in milk.)
• Symptoms of lactase deficiency may include abdominal pain and bloating, diarrhea and flatulence.

• The best way to prevent allergic reactions or intolerance is to avoid the offending foods.
• In some cases, substitutes can be found to replace "problem" foods.
• In the case of lactose intolerance, people can eat dairy products depending on their individual tolerance to lactose. Studies have shown that people who eat milk and other lactose-containing foods may improve their tolerance to lactose.
• Lactase capsules or pills will help some people with an intolerance to lactose, but will not help people with an allergy to milk protein.
• A range of dairy free products including rice and soya milk, tofu based cream cheese spread, ice cream and cheese substitutes can replace dairy products.
• Carob powder or chips can replace chocolate in baking.
• While substitutes may not taste quite like the traditional foods they are replacing, they can be very tasty in their own right.

• Read product labels carefully and watch for offending ingredients.
• In restaurants, don't hesitate to ask your server about the ingredients in the dishes you may want to order.
• Cookbooks that focus on food allergies and intolerances are available through your local public library.

• Food Recalls and Allergy Alerts (Canadian Food Inspection Agency)