Nearly 32 million Americans suffer from food allergies — that’s about one in every 10 adults and one in every 13 children. According to the Centers for Disease Control and Prevention, food allergies in children increased 50 percent from 1997 to 2011, and from 1997 to 2008 the number of children with a peanut or tree nut allergy tripled. Children with eczema or asthma are more likely to develop food allergies.
While the U.S. Food and Drug Administration’s approval of Palforzia, the first-ever drug for reducing the severity of allergic reactions to peanuts, has many excited about the future of food allergy treatments, there is no cure or definite way to prevent food allergies. However, methods such as the early introduction of certain potentially allergenic foods (with the approval of a pediatrician) between 4 and 6 months of age may be effective at reducing the risk of developing food allergies.
Defining Food Allergies
Food allergies occur when there is a negative immune response to an ingested protein. When an allergen is eaten by someone who is allergic to it, the body responds by attacking the protein. This attack can result in mild symptoms such as itchy throat and hives or more severe symptoms including throat swelling, difficulty breathing or anaphylaxis, which can cause death. An allergic reaction occurs every time an allergen is eaten, and symptoms usually occur immediately, but they can happen within a couple of hours.
In the United States, the eight major food allergens are milk, eggs, peanuts, tree nuts, fish, crustacean shellfish, wheat and soy. These foods represent 90 percent of food allergies in the U.S. and must be clearly labeled on food packaging according to the FDA Food Allergen Labeling and Consumer Protection Act of 2004. Although sesame is not currently recognized as a major allergen in the U.S., a significant increase in people allergic to sesame has created a push to make it required on labels.
Making a Diagnosis
The best way to diagnose a food allergy is through an oral food challenge, which involves someone eating the allergen in order to monitor the response. This is done under close supervision with gradually increasing doses. Even though it is the most reliable method for diagnosing a food allergy, it is not regularly used because it can be costly, time-consuming and dangerous.
Other methods of diagnosis that are more frequently used include skin prick tests and serum IgE tests. Immunoglobulin E, or IgE, are the antibodies produced by the immune system when an allergy occurs. Collecting a diet history is crucial in the diagnosis of a food allergy and, along with a medical history, will aid in developing the nutrition intervention.
Preventing Food Allergies?
There have been great strides in research regarding the reduction of peanut allergies. A 2015 landmark study, Learning Early about Peanut Allergy (LEAP), found that early introduction of peanut-containing foods to babies at high risk of developing a peanut allergy helped prevent peanut allergy later in life.
During the LEAP study, researchers randomly divided 640 infants with severe eczema or egg allergy (or both) into two groups. Following a skin-prick test, 542 infants with negative test results were assigned to either a group who ate peanut-containing foods starting at 4 to 11 months old or a group who avoided peanut-containing foods entirely. The intention-to-treat analysis of 530 infants who originally tested negative revealed an 86-percent relative reduction of peanut allergies in the peanut product-eating group at 5 years old compared to children who avoided peanut-containing foods.
These findings led the American Academy of Pediatrics to endorse a consensus report developed by several organizations supporting the early introduction of age-appropriate peanut-containing foods (in forms that are not choking hazards) for preventing the development of peanut allergy in high-risk infants. In 2017, addendum guidelines in support of the early introduction of peanut-containing foods based on the infant’s allergy risk level were developed by an expert panel, sponsored by the National Institute of Allergy and Infectious Diseases and supported by the Academy of Nutrition and Dietetics.