This page was reviewed or revised on Thursday, November 12, 2015 9:41 AM
A food allergy is an abnormal immune system response to a protein found in a specific food. Once a person develops a food allergy, an allergic reaction happens each time the food is eaten.
Many foods can cause allergic reactions. The most common are eggs, fish, milk, mustard, peanuts, sesame seeds, soy, sulfates, tree nuts and wheat.
For some people, eating even a tiny amount of the offending food can cause a reaction. While these reactions are often minor, in some cases they can cause serious illness or death.
For more information on the ten most common food allergens, visit the Health Canada website or call 1-800-465-7735.
Food allergy reactions vary from person-to-person and can affect one or many body systems. Common symptoms include:
Anaphylactic (ana-fil-ac-tic) shock is the most severe food allergy reaction. It can happen within minutes after eating a specific food. Without immediate medical help, it can cause death. For more information about anaphylaxis visit Food Allergy Canada.
Food intolerance is more common than food allergy. The immune system does not cause the symptoms of food intolerance; however, the symptoms may feel like those of a food allergy.
Example: people with lactose intolerance are unable to digest the sugar in milk, while someone with a milk allergy reacts to cow's milk protein.
People with food intolerance can sometimes eat small amounts of the offending food, while a person with a food allergy must never eat it.
Example: someone with lactose intolerance may be able to eat some cheese, yogurt, and cow's milk, but a person with a milk allergy must avoid all sources of milk protein.
Many babies develop food allergies in the first year of life. No one is sure if it is possible to prevent babies from getting food allergies. Studies say:
Enjoy a variety of healthy foods. There is no strong research that suggests avoiding certain foods during pregnancy or breastfeeding will decrease your baby's risk of food allergies.
Breastfeed for the first 6 months of life. Breast milk is the best food for babies and may lower their risk of food allergies. Breast milk is all the food babies need until they are 6 months old. Breastfeeding should continue until babies are 2 years or older.
Wait until baby is 6 months of age to introduce solid food. Research does not show that delaying foods like peanut butter, fish and eggs past 6 months prevents food allergies.
Talk with your doctor or health care provider who can send you for tests. Do not diagnose it yourself. Symptoms of a food allergy and food intolerance can be so similar that one can be confused for the other. If you assume you have a food allergy, you may cut foods from your diet without need.
Allergic reactions to food can be avoided, but the only treatment is totally removing the specific food from your diet.
Here are a few tips to get you started:
It is a good idea to wear a Medic Alert identification which has information about your allergies in case of emergency.
Food allergies are most common in young children and are often outgrown by 7 years of age. It is common for infants and toddlers to outgrow allergies to milk, egg, wheat and soy. However, allergies to peanuts, nuts, shellfish and fish are less likely to be outgrown. In some cases, symptoms become more severe every time the person is exposed to the allergen. Food allergies developed after age 3 years are less likely to be outgrown. Adult allergies are permanent. About 3.5% of adults around the world have food allergies, and 30% of these adults developed the allergy as children.
For more information on food allergies call the Registered Dietitians at 519-383-8331 or toll free at 1-800-667-1839.