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Houston Department of Health and Human Services > Food Inspection and Safety (Consumer Health) > Food Safety Tips > Food Allergy

Food Allergy

We’ve heard about “allergies” in our routine daily lives, but have you heard about the “food allergies”? 

What are food allergens?

As one philosopher said, “The food of one may be poison for another” is very true. Food allergies are an immunological based affliction. When one consumes “innocent” dietary proteins, selective and specific antibodies (lgE) are produced in the body. The body reacts to the proteins like an invader and makes lgE against them. These lgE antibodies cause a release of cellular chemicals, which in turn cause the symptoms of allergic reactions. This is a similar mechanism as for dust, pets, bee stings and medicine allergies. 


The symptoms for food allergies can be:

  • Gastrointestinal (such as nausea, vomiting, abdominal pain, diarrhea, etc.)
  • Systemic (such as anaphylactic shock – severe loss of blood pressure and cardiac arythmia)
  • Cutaneous (such as urticaria – hives, angioedema – swelling, atopic dermatitis – eczema or itching and scratching)
  • Respiratory (such as rhinitis – runny nose, laryngeal edema – closing of throat, asthma)

As in many illnesses, not all symptoms occur in every case. For some people, a repeat exposure to an allergen can be fatal because the antibodies are already present in their body.


Four to six percent of infants have true food allergies. One to two percent of young children are allergic to specific foods while less than one percent of the adult population has true allergies of foods. According to the Journal of Allergy Clinical Immunology, approximately six to seven million Americans have food allergy. Researchers estimate that 29,000 emergency room visits and 150 to 200 deaths occur yearly due to food-induced anaphylaxis in the US.

Foods involved

The “Big Eight” food products are: peanut, tree nuts (cashew, pecans, almonds, brazil nut, pistachio, macadamia, walnut, pine nut, hazelnut, etc.), soybean, crustacea (lobster, shrimp, crawfish, crab, etc), milk, fish, eggs and wheat. There are 160 or more other foods that can cause allergic reactions but are rare in occurrence.

What causes food allergies?

The proteins are naturally occurring and are heat resistant. Some proteins are resistant to the digestive enzymes in the body and the acidity of food consumed. One food item can have more than one allergen in them. Errors and oversights in the processing of specific foods (such as inadequate cleaning of shared equipment, equipment design, contaminated raw ingredients, switching of ingredients, formulation mistakes, using re-work, wrong labels, labeling terms, wrong packaging, etc.) can cause processed foods to be allergic in some cases.

Few documented cases

A non-peanut cereal product caused allergic reactions for a consumer. Investigation revealed that the equipment was shared for production of cereal that contained peanuts. Due to inadequate sanitation of the equipment, traces of peanut were detected in the next processed batch.

A customer complained about allergic reactions from ingesting pesto. Investigation indicated that there were moderate amount of peanut in the product. The manufacturer used peanuts instead of pine nuts to save a few dollars. Adulteration can be dangerous to the consumers.

How to avoid food allergies

Ask your physician about your specific food allergies if you experience the symptoms described above. Avoid offending foods. Learn and understand the labels on the product/container.

Laws and regulation

Recent legislation would require food manufacturers to use familiar words in the labels rather than obscure words, e.g. milk instead of casein. Manufacturers will be prevented from collective listing of spices and flavors containing allergens on the ingredient listing. Food and Drug Administration (FDA) has made the food allergen a priority issue for the year 2003. A FDA compliance guide will be published in the near future.

For this, or any food-safety-related information, please contact Bureau of Consumer Health Services at 713/794-9200. More food safety tips can be found at: www.ci.houston.tx.us/hlt/foodpage.html

Contact the HDHHS Bureau of Consumer Health Services