Health and Wellness Blog

One in three people believe they suffer from food allergies. However – according to Health Canada — only about three to four percent of adults and six percent of young children experience true food allergies. In reality, far more people suffer the unpleasant symptoms associated with food intolerance. So what's the difference?

What is food allergy?

A food allergy is an immune system reponse. When your immune system mistakenly identifies a specific food as harmful — usually a protein – it releases antibodies called immunoglobulin E (IgE) and histamines. Allergy symptoms develop when these antibodies fight the mistaken "invaders". (source)

What is food intolerance?

A food intolerance does not involve the immune system. It occurs most often when your body is unable to properly digest certain types of food due to a lack of digestive enzymes. Unlike food allergies, where even a miniscule amount of the offending food can'trigger a serious reaction, it usually takes normal sized portions to cause symptoms. While symptoms vary, they tend to originate in the gastrointestinal system. (source)

What are the symptoms of food allergy?

Symptoms of food allergy can range from mild to severe. Anaphylaxis is the most severe type of allergic reaction and can be fatal. Symptoms typically appear within minutes to two hours after you have eaten the offending food. Symptoms may include: (source)

• tingling sensation in the mouth
• swelling of the tonge and throat  
• difficulty breathing  
• rashes and hives
• vomiting
• abdominal cramps
• diarrhea
• drop in blood pressure
• loss of consciousness and death

 What are the symptoms of food intolerance?

Because food intolerance may produce symptoms similar to food allergies, people often confuse the two. They include: (source)

• nausea
• stomach pain
• gas, cramps, bloating
• vomiting
• heartburn
• diarrhea
• headaches
• irratibility, nervousness

 What are the most common food allergens?(source)

• peanuts
• tree nuts (walnuts, almonds, hazelnuts etc.,)
• milk
• eggs
• fish/shellfish
• soy
• sesame seeds
• wheat

What are the causes of food intolerance?

Often it is not the actual food that causes the food intolerance, but substances used in the preparation of food. For example, sulfites used as a preservative may trigger asthmatic reactions. Other substances include artifical colours, nitrates and nitrites; salicylates; preservatives BHA & BHT; MSG and artifical flavourings.

Another major cause of food intolerance is the absence of enzymes needed for proper digestion. A prime example is lactose intolerance. If you lack the enzyme lactase, you won't be able to digest lactose, the main sugar in milk products. (source)

Can you outgrow a food allergy? (source)

Babies and toddlers may outgrow allergies to foods like milk, egg, wheat and soy. Allergies acquired after age three are less likely to be outgrown. Allergies to peanuts, treenuts and seafood may persist throughout a person's life. But there is hope, even for the most severe cases. An exciting new study   describes how people with anaphylactic food allergy can be desensitized and may be able to eat peanuts again. (source)

What should you do if you suspect a food allergy or food intolerance? (source)

First of all, it is important to get a proper diagnosis. Talk to your health care practitioner who can refer you to an allergy specialist for tests. If you have been diagnosed with food allergy or food intolerance, you may have to avoid certain foods alltogether or supplement the missing enzymes. Reading food labels, checking with manufacturers and restaurant owners about ingredients is also very important. And if you are at high risk for anaphylaxis, you have carry an Epipen with you at all times!

Prepared by marietta forster-haberer — Consumer Health Information Service — Toronto Reference Library.

Further Reading:

National Agricultural Library USDA. Food and Nutrition Information Center. Resource List on Food Allergies and Intolerances. (February 2008)

http://www.nal.usda.gov/fnic/pubs/bibs/gen/allergy.pdf     

U.S. Department of Health and Human Services. National Institute of Allergy and Infectious Diseases. Food Allergy: an overview. (July 2007)

http://www.allergywatch.org/basic/food_allergy.pdf     

U.S. Food and Drug Administration. Food Allergies: when food becomes the enemy. (April 2004)

http://www.fda.gov/FDAC/features/2001/401_food.html

Mayo Clinic. Food Allergy. (February 2007)

http:// www.mayoclinic.com/health/food-allergy/DS00082