Questions About Food Allergies? We’ve Got Answer

When you have a serious food allergy, you must pay close attention to everything you eat. From reading labels to making substitutions for ingredients, having a food allergy can sometimes feel like it takes over your life.

Food allergies affect about 2% of adults and up to 8% of children in the United States (1). What exactly causes someone to have an allergy to a food or ingredient? What’s the difference between a food allergy and food intolerance? How can you tell if a potential allergen is present in your food? We outlined science and laws surrounding allergens to get the answers you need.

What Are Food Allergies?

A food allergy occurs when the body’s immune system overreacts to a harmless protein found in a food. Having a food allergy means the immune system has become sensitized to a protein component of a certain food, triggering an abnormal immune response any time a person is exposed to that food (2, 3). A few common symptoms of food allergy include hives; swelling of the face, tongue, and lips; constricted airways; difficulty breathing; and sometimes gastrointestinal symptoms (4). An extreme allergic reaction, known as anaphylaxis, can be a medical emergency.

Although there are more than 160 foods that can cause a reaction in sensitive people, there are eight common foods that account for approximately 90% of all food allergy reactions (1). These foods include milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, and soybeans (2). The “big eight” as they are sometimes called, and any ingredient that contains protein derived from them, are designated as major food allergens.

If you suspect you might have a food allergy, it’s important to work with your doctor to find the cause of your symptoms and make sure you have the right treatment plan in place.

Food Allergens and Food Intolerance

Food allergy awareness has become more common among consumers; however, the difference between a food allergy and food sensitivity can be a confusing subject. Having a food allergy can be a scary and potentially life-threatening medical condition.  While a food intolerance can leave you feeling miserable, its symptoms are generally limited to the digestive tract and are not as dangerous as a food allergy (2).

A few common food intolerances include gluten and lactose. One potential cause of gluten intolerance is celiac disease, which affects approximately 1% of the population globally (5). Celiac disease is an autoimmune disorder that damages the lining of the small intestine and prevents the body from properly absorbing nutrients that is triggered by consuming foods that contain gluten (6). Although the immune system is involved in both celiac disease and a wheat allergy, the two conditions are very different.

Lactose intolerance is the inability to digest lactose, the sugar found in many milk products, due to reduced production of enzyme lactase after infancy. Although lactose intolerance is rare in some populations, such as those with Northern European heritage, it’s estimated that 65% of the adults around the world are lactose intolerant (7). Lactose intolerance can cause bloating, gas, and diarrhea after eating dairy foods that contain lactose. While it’s uncomfortable, it’s not a life-threatening condition (8).

Food Allergen Labeling

Knowing if your food has one of the big eight food allergens couldn’t be easier. The FDA enforces the Food Allergen Labeling and Consumer Protection Act that helps consumers identify if a food or ingredient contains one of the major food allergens. This labeling could either be in parenthesis following the name of the ingredient, such as flour (wheat) or near the list of ingredients in a statement, such as Contains Wheat, Milk, and Soy (9). Every potential allergen identified by the law must be disclosed on the label.

Although food allergies can be dangerous, understanding what an allergen is and how to avoid them may help you or someone you know. By understanding how to check for allergens on a label, you can safely avoid any foods or ingredients if allergens are a risk to you.


  1. USDA Food Safety and Inspection Service. Allergies and Food Safety. Updated December 01, 2016. Accessed May 07, 2020.
  2. National Institute of Allergy and Infectious Diseases. Food allergy, an overview. Updated October 29, 2018. Accessed May 05, 2020.
  3. Kagan, R. Food allergy: an overview. Environ Health Perspect. 2003; 111(2)223-225.
  4. Food and Drug Administration. What you need to know about food allergies. Updated September 26, 2018. Accessed May 05, 2020.
  5. Prashant S Global prevalence of celiac disease: Systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2018; 16:823-836.
  6. Rubio-Tapia A, Ludvigsson JF, Brantner TL, Murray JA, Everhart JE. The prevalence of celiac disease in the United States. Amer J Gastro. 2012;107(10):1538–1544.
  7. Bayless TM, Brown E, Paige DM. Lactase Non-persistence and Lactose Intolerance. Curr Gastroentrerol Rep. 2017;19(5):23.
  8. Lomer MC, Parkes GC, Sanderson JD. Review article: lactose intolerance in clinical practice–myths and realities. Aliment Pharmacol Ther. 2008 Jan 15;27(2):93-103.
  9. Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA). Pub. L. 108-282. Title II. Sec. 203.

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