Most people who have a food allergy depend on food labels to determine what is and isn't safe to eat. However, according to the Food and Drug Administration (FDA), food labels aren’t always as reliable as they should be.

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Undeclared Allergens

By law, major food allergens (substances that commonly cause allergic reactions)—such as milk, eggs, fish, shellfish, tree nuts, wheat, peanuts, and soybeans—must be identified in foods regulated by the FDA and marketed in the United States. But the FDA reports that "undeclared allergens"—ingredients that can cause an allergic reaction and are not listed on the food label—are the leading cause for food recalls.

It's important to reduce the numbers of undeclared food allergens to help prevent serious, potentially life-threatening, reactions. To help eliminate undeclared allergens in food, the FDA is:

  • Working to determine the cause for labeling/ingredient errors
  • Working with food industries to develop best practice plans
  • Working to develop new ways to detect the presence of food allergens

About 33 percent of foods reported as a serious health risk to the FDA from September 2009 to September 2012 involved undeclared allergens. Foods most often involved included:

  • Baked goods
  • Snack foods
  • Candy
  • Dairy products
  • Dressings, sauces, and gravies

Over this same time period, the most common allergens not listed on food labels were milk, wheat, and soy. Unidentified milk products—for example, in snacks that contain dark chocolate and are labeled "vegan" or "dairy-free"—can pose a significant health risk in people with milk allergies.

According to the Food and Drug Administration, food packaging errors often involve using the wrong label. Mistakes can occur as a result of look-alike packaging, newer cost-saving technologies—such as the ability to print labels directly on packages, etc. To help reduce undeclared allergens, the FDA is working with food manufacturers to improve industry awareness and change the way ingredients, labels, and packaging are tracked and handled at production facilities.

Testing for Allergens

The FDA also is working to develop more effective ways to test for allergens in food. Currently, the enzyme-linked immunosorbent assay (ELISA) is used most often throughout the world. This test is easy to use and inexpensive, but it can sometimes produce false-positive results.

Researchers are developing additional methods of detecting food allergens—including a technology called mass spectrometry. Using this method, it's possible to analyze the allergen content of a complex mix of proteins, fats, sugars, chemicals, and other substances in a particular food.

According to the FDA, mass spectrometry can differentiate among the 11 individual proteins in a peanut that can cause an allergic reaction in people with a peanut allergy. DNA-based methods (to evaluate deoxyribonucleic acid—the chemical basis of heredity and carrier of genetic information) are also being developed to help detect fish and shellfish allergens.

Source: U.S. Food and Drug Administration (FDA)

Publication Review By: the Editorial Staff at

Published: 18 Nov 2014

Last Modified: 18 Nov 2014