Mayo Clinic Health Library

Food allergies: Understanding food labels

Updated: 01-04-2011

In the United States, the Food and Drug Administration (FDA) requires food manufacturers to list the eight most common ingredients that trigger food allergies. Most other countries have similar rules. In the United States, information about food allergies has to be written in simple terms adults and older children can understand. The eight foods included in food allergy labeling account for an estimated 90 percent of allergic reactions. These eight foods are:

  • Milk
  • Eggs
  • Peanuts
  • Tree nuts (such as almonds, cashews, walnuts)
  • Fish (such as bass, cod, flounder)
  • Shellfish (such as crab, lobster, shrimp)
  • Soy
  • Wheat

Understanding food labels

U.S. food labels take some of the guesswork out of label reading, helping you more easily identify foods that could cause an allergic reaction. Here are answers to a few common questions about food label requirements.

  • What foods are labeled? Domestic or imported packaged food is required to have a label that lists whether the product contains one of the top eight allergens.
  • What allergy information is included on the label? The label lists the type of allergen — for example, the type of tree nut (almond, walnut) or the type of crustacean shellfish (crab, shrimp) — as well as any ingredient that contains a protein from the eight major food allergens. The labels also include any allergens found in flavorings, colorings or other additives.
  • What foods aren't labeled? Fresh produce, fresh meat and certain highly refined oils don't require listing on labels.

Unintended ingredients

Food labeling laws require food allergens to be identified even in very small amounts — but only when they're contained as an ingredient. Manufacturers aren't required to include warnings about food allergens accidentally introduced during manufacturing or packaging (cross contamination). This common occurrence can cause trouble if you're very sensitive to food allergens.

Many manufacturers voluntarily include warnings, but these advisory labels aren't always clear. And, manufacturers have different ways of saying a food allergen may be present. For example, labels may say "manufactured in a factory that also processes wheat" or "may contain soy." The FDA is working to make the format of these advisory labels more consistent so that it's easier to identify which products contain allergens. When in doubt about whether a product contains something you're allergic to, it's best to avoid it.

Gluten-free labels

Although gluten intolerance is different than a food allergy, it can cause serious reactions. Gluten causes serious health problems in people who have celiac disease, a chronic digestive disorder. Gluten is a protein that occurs in grains such as wheat, barley and rye. It's found in many foods and food ingredients.

The FDA has established initial guidelines for use of the term "gluten-free" on food labels. Currently, the "gluten-free" label is voluntary — it's up to the manufacturer whether to include it. Many foods are naturally gluten-free and may or may not be labeled as such. The FDA is in the process of refining guidelines for gluten-free labeling.

The bottom line: Be cautious

Always double-check labels to be sure you know what you're eating and drinking. Even though a food product may have been safe the last time you purchased or consumed it, it's possible that the ingredients have changed or the label has been updated. If you have any doubt about food ingredients, contact the manufacturer about whether the food could possibly contain a food allergen.