Researchers Identify Factors Linked to the Development of Food Allergies

Diet, genetics, and infection may play a role in childhood food allergies and whether new reactions to foods develop in adulthood.

Estimates indicate that one in 10 adults and one in 13 children in the United States have food allergies. Reactions to food can be mild, characterized by an itchy mouth and hives, to severe, which can cause symptoms such as throat tightness and breathing difficulties. Food allergies can also cause anaphylaxis, which is a serious, potentially fatal reaction.

However, despite the negative impact of food allergies, scientists are unsure why some people develop them during childhood or later in life as adults.

A new study published in the November issue of the Annals of Allergy, Asthma & Immunology may have identified factors that lead to the development of food allergies.

To conduct the study, researchers surveyed 40,443 adults and the parents or caregivers of 38,408 children in the U.S. with documented food allergies and asked them what factors they observed before developing reactions to food.

After analyzing the data, the scientists found that among adult participants, nearly 19% felt their food allergy resulted from eating too much of the allergenic food. Moreover, 16% thought their food allergies were related to genetics and family history, and 12% noticed food allergies after antibiotic use.

In addition, around 10% thought eating too little of the allergenic food caused their allergy.

Among young people ages zero to 10 and 11 to 17 years old, about 25% of parents and caregivers linked the child's food allergy development to a viral infection.

"Allergists and other health care professionals can help get the word out to parents of infants and others that it's preventative to introduce certain allergenic foods early in life," said Ruchi Gupta, M.D., senior study author and member of the American College of Allergy, Asthma, and Immunology (ACAAI). "For new-onset adult allergies, understanding potential triggers that may be involved with the development of an allergy is critical."

According to Gupta, these triggers may include infections, changes in the environment, and hormonal changes.

Though the participants self-reported their observations and perceived reasons for the development of food allergies, the scientists say the results of this study warrant further research examining each of these potential factors.

Which foods are most allergenic?

According to the Food Allergy Research & Education (FARE), over 170 different types of food are known to cause allergic reactions. Of those, egg, milk, peanut, tree nuts, wheat, soy, fish, shellfish, and sesame are responsible for most of the severe food allergy reactions in the U.S.

The organization also says food allergies are on the rise, as the prevalence of the condition among American children has increased by 50% and tree nut allergies have more than tripled since 1997.